WO2013069785A1 - Light guide body, solar cell module, and photovoltaic power generation device - Google Patents
Light guide body, solar cell module, and photovoltaic power generation device Download PDFInfo
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- WO2013069785A1 WO2013069785A1 PCT/JP2012/079171 JP2012079171W WO2013069785A1 WO 2013069785 A1 WO2013069785 A1 WO 2013069785A1 JP 2012079171 W JP2012079171 W JP 2012079171W WO 2013069785 A1 WO2013069785 A1 WO 2013069785A1
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- WIPO (PCT)
- Prior art keywords
- light guide
- light
- solar cell
- optical functional
- functional material
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Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
- H01L31/054—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
- H01L31/055—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means where light is absorbed and re-emitted at a different wavelength by the optical element directly associated or integrated with the PV cell, e.g. by using luminescent material, fluorescent concentrators or up-conversion arrangements
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
- H01L31/054—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
- H01L31/0547—Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means comprising light concentrating means of the reflecting type, e.g. parabolic mirrors, concentrators using total internal reflection
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0003—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being doped with fluorescent agents
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/0035—Means for improving the coupling-out of light from the light guide provided on the surface of the light guide or in the bulk of it
- G02B6/0038—Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/52—PV systems with concentrators
Definitions
- the present invention relates to a light guide, a solar cell module, and a solar power generation device.
- This application claims priority based on Japanese Patent Application No. 2011-247470 filed in Japan on November 11, 2011 and Japanese Patent Application No. 2011-281502 filed in Japan on December 22, 2011. The contents are incorporated herein.
- a solar power generation apparatus in which a solar cell element is installed on the end face of a light guide, and light that has propagated through the light guide is incident on the solar cell element to generate power.
- patent document 1 it has the structure which propagates a part of sunlight which injected from one main surface of the light guide to the inside of a light guide, and guides it to a solar cell element.
- a phosphor is applied to the surface of the light guide, and the phosphor is excited by sunlight incident on the light guide.
- Light (fluorescence) emitted from the phosphor propagates through the light guide and enters the solar cell element to generate power.
- patent document 2 it has the structure which propagates a part of sunlight which injected from one main surface of the light guide to the inside of a light guide, and guides it to a photoelectric conversion part.
- the finger s-directional luminescent particles are dispersed inside the light guide. Sunlight incident on the light guide is converted by the directional luminescent particles so as to have directivity in the direction of the photoelectric conversion unit.
- patent document 1 the sunlight used for excitation of a fluorescent substance is very little of the sunlight which injects into a light guide. Most of the sunlight incident on the light guide is transmitted through the light guide and does not contribute to power generation.
- patent document 2 it is the structure by which the sunlight which injected into the light guide is converted with one kind of directional light-emitting particle. Therefore, the wavelength range that can be used for power generation is limited.
- Patent Document 2 the directivity (anisotropy) of emitted light is used. However, this configuration has an effect of absorption directivity, and incident light having an angle close to vertical is transmitted. Therefore, in these patent documents 1 and 2, a solar power generation device with high power generation efficiency cannot be provided.
- the objective in the aspect of this invention is providing the light guide with high extraction efficiency of light, the solar cell module with high power generation efficiency, and a solar power generation device using the same.
- Another object of the present invention is to provide a solar cell module having high light extraction efficiency and high power generation efficiency, and a solar power generation apparatus using the solar cell module.
- the light guide in one aspect of the present invention has a first main surface and a first end surface, includes at least one optical functional material, and the at least one optical functional material emits light anisotropically.
- a first optical functional material configured to propagate at least light emitted from the first optical functional material and emit the light from the end face, and the first optical functional material is emitted from the first optical functional material.
- the orientation is such that the angle formed between the direction of maximum light emission intensity and the normal line of the first main surface is greater than or equal to the critical angle.
- the first optical functional material may absorb a part of external light incident from the first main surface.
- the light guide in one embodiment of the present invention may further include a second optical functional material that isotropically absorbs part of incident external light.
- the second optical functional material has a property of absorbing light isotropically or has a property of absorbing light anisotropically. Any of the optical functional materials in a random state that is difficult to be oriented with respect to the contained material may be used.
- the light guide in one aspect of the present invention may include a plurality of the optical functional materials, and the first optical functional material may include an optical functional material having a maximum emission spectrum peak wavelength among the plurality of optical functional materials. .
- the first optical functional material has a direction in which the emission intensity of the light emitted from the first optical functional material is the largest when viewed from the normal direction of the first main surface. You may orientate so that it may face the said end surface.
- the first optical functional material may include an optical functional material made of a dichroic fluorescent dye.
- the dichroic fluorescent dye may include a positive dichroic fluorescent dye in which the direction orthogonal to the molecular long axis is the direction with the highest emission intensity.
- the light guide in one embodiment of the present invention may further include a diffusion plate that is provided on the first main surface side and diffuses external light incident from the outside of the light guide.
- the light guide in one embodiment of the present invention causes energy transfer by a Forster mechanism between the plurality of optical functional materials, and emits light emitted from the optical functional material having the largest peak wavelength of the emission spectrum. You may inject from one end surface.
- one or a plurality of optical functional materials other than the optical functional material having the largest peak wavelength of the emission spectrum has a fluorescence quantum yield of 80. % Or less of optical functional material may be included.
- the fluorescence quantum yield of the optical functional material having the largest peak wavelength of the emission spectrum is greater than the fluorescence quantum yield of any other optical functional material included in the light guide. May be higher.
- the optical functional material may include an optical functional material made of an inorganic material.
- the optical functional material made of the inorganic material may include an optical functional material made of quantum dots.
- the optical functional material may include an optical functional material made of an organic-inorganic hybrid phosphor.
- the light guide in one embodiment of the present invention may further include a reflective layer that reflects light propagating through the light guide.
- the reflection layer may be a scattering reflection layer that scatters and reflects incident light.
- the light guide in one embodiment of the present invention may further include a retardation plate between the light guide and the reflective layer.
- the retardation plate may be a 1 / 4 ⁇ plate.
- the light guide in one embodiment of the present invention may include a transparent light guide and the plurality of optical functional materials dispersed inside the transparent light guide.
- the light guide in one aspect of the present invention is provided on the third main surface of the transparent light guide and the transparent light guide, and the optical functional material layer in which the plurality of optical functional materials are dispersed, May be included.
- the light guide in one embodiment of the present invention may further include a peelable adhesive layer, and the transparent light guide and the optical functional material layer may be bonded by the adhesive layer.
- a solar cell module includes a light guide and a first solar cell element that receives the light emitted from the first end face of the light guide.
- the spectral sensitivity of the first solar cell element at the peak wavelength of the emission spectrum of the optical functional material having the largest emission spectrum peak wavelength among the optical functional materials is the light guide. It may be larger than the spectral sensitivity of the first solar cell element at the peak wavelength of the emission spectrum of any other optical functional material provided in the body.
- the solar cell module according to another aspect of the present invention further includes a third main surface and a second end surface, is disposed on the second main surface side, and transmits light transmitted from the second main surface to the third main surface.
- the second light guide has a fourth main surface facing the third main surface, and the second light guide propagates and is emitted from the end surface. Are reflected from the third main surface and emitted from the end surface, reflected from the fourth main surface and emitted from the end surface, and emitted from the end surface while being reflected between the third main surface and the fourth main surface. Or may be emitted from an end face without being incident on any of the third main surface and the fourth main surface.
- the anisotropic light functional material has a direction in which the light emission intensity of light emitted from the anisotropic light functional material is the largest when viewed from the normal direction of the first main surface. It may be oriented to face the first end face.
- the second light guide reflects and propagates light at an inclined surface provided on the fourth main surface, and is emitted from the second end surface. It may be a body.
- a reflective layer that reflects light transmitted from the fourth main surface side of the second light guide on the fourth main surface side of the second light guide. May be provided.
- the first solar cell element and the second solar cell element may be constituted by a common solar cell element.
- a solar power generation device includes the solar cell module.
- the light guide in still another aspect of the present invention has a first main surface and an end surface, includes a plurality of optical functional materials, and the plurality of optical functional materials emit at least light anisotropically.
- the light emitted from one optical functional material is propagated and emitted from the end face, and the first optical functional material has a direction in which the emission intensity of light emitted from the first optical functional material is highest and the It is oriented so that the angle formed with the normal line of the first main surface is not less than the critical angle.
- the light guide in still another aspect of the present invention has a second main surface facing the first main surface, and the propagation and emission from the end surface means that the light is reflected from the first main surface and is reflected from the end surface. Injecting, reflecting from the second main surface opposite to the first main surface and emitting from the end surface, emitting from the end surface while reflecting between the first main surface and the second main surface, or the Either of the first main surface and the second main surface may be emitted from the end surface without being incident.
- the second optical functional material is a material having the property of absorbing light isotropically or having the property of absorbing light anisotropically. Any of the optical functional materials in a random state that is difficult to be oriented with respect to the material included in the light body may be used.
- the first optical functional material may include an optical functional material having a peak wavelength of an emission spectrum that is the largest among the plurality of optical functional materials.
- the first optical functional material has the highest light emission intensity of light emitted from the first optical functional material when viewed from the normal direction of the first main surface. You may orientate so that a direction may face the said end surface.
- the first optical functional material may include an optical functional material made of a dichroic fluorescent dye.
- the dichroic fluorescent dye may include a positive dichroic fluorescent dye in which the direction perpendicular to the molecular long axis is the direction with the highest emission intensity.
- the light guide in still another aspect of the present invention may further include a diffusion plate that is provided on the first main surface side and diffuses external light incident from the outside of the light guide.
- energy is transferred by the Forster mechanism between the plurality of optical functional materials, and the light emitted from the optical functional material having the largest peak wavelength of the emission spectrum is obtained. You may inject from the said end surface.
- one or a plurality of optical functional materials other than the optical functional material having the largest peak wavelength of the emission spectrum has a fluorescence quantum yield. 80% or less of the optical functional material may be included.
- the fluorescence quantum yield of the optical functional material having the largest peak wavelength of the emission spectrum is the fluorescence quantum yield of any other optical functional material included in the light guide. It may be higher than the rate.
- the optical functional material may include an optical functional material made of an inorganic material.
- the optical functional material may include an optical functional material made of an organic-inorganic hybrid phosphor.
- the optical functional material made of the inorganic material may include an optical functional material made of quantum dots.
- the light guide in still another aspect of the present invention may further include a reflective layer that reflects light propagating through the light guide.
- the reflection layer may be a scattering reflection layer that scatters and reflects incident light.
- the light guide in still another aspect of the present invention may further include a retardation plate between the light guide and the reflective layer.
- the retardation plate may be a 1 / 4 ⁇ plate.
- the light guide in still another aspect of the present invention may include a transparent light guide and the plurality of optical functional materials dispersed inside the transparent light guide.
- the light guide in still another aspect of the present invention is provided with a transparent light guide and a third main surface of the transparent light guide, and an optical functional material layer in which the plurality of optical functional materials are dispersed. And may be included.
- the light guide in still another aspect of the present invention may further include a peelable adhesive layer, and the transparent light guide and the optical functional material layer may be bonded together by the adhesive layer.
- a solar cell module includes the light guide and a solar cell element that receives the light emitted from an end surface of the light guide.
- the spectral sensitivity of the solar cell element at the peak wavelength of the emission spectrum of the optical functional material having the largest emission spectrum peak wavelength among the plurality of optical functional materials is calculated as It may be larger than the spectral sensitivity of the solar cell element at the peak wavelength of the emission spectrum of any other optical functional material provided in the light body.
- a solar power generation device includes the solar cell module.
- a solar cell module includes a first main surface, a second main surface, and a first end surface, includes an optical functional material, and includes one of external light incident from the first main surface.
- a first light guide that absorbs a portion by the optical functional material, propagates light emitted from the optical functional material, and exits from the first end surface; a third main surface; and a second end surface The light transmitted from the second main surface is incident on the third main surface, propagates, and is emitted from the second end surface, disposed on the second main surface side opposite to the first main surface.
- a second light guide body a first solar cell element provided on the first end face for receiving light emitted from the first end face, and provided on the second end face and emitted from the second end face.
- a second solar cell element that receives the received light.
- the optical functional material includes an anisotropic optical functional material that emits light anisotropically. In the anisotropic light functional material, an angle formed by a direction in which the emission intensity of light emitted from the anisotropic light functional material is maximum and a normal line of the first main surface of the first light guide is equal to or greater than a critical angle. Is oriented.
- the propagating and emitting from the end surface means reflecting the first main surface and emitting from the end surface. Reflecting and exiting from the end face, reflecting from between the first main face and the second main face, and exiting from the end face, or entering neither the first main face nor the second main face Either from the end face
- the second light guide has a fourth main surface facing the third main surface
- the propagating and emitting from the end surface means reflecting from the third main surface and emitting from the end surface, reflecting from the fourth main surface and emitting from the end surface, and the third main surface Either the light is emitted from the end surface while being reflected from the fourth main surface, or the light is emitted from the end surface without being incident on either the third main surface or the fourth main surface.
- the anisotropic light functional material has the highest light emission intensity of light emitted from the anisotropic light functional material when viewed from the normal direction of the first main surface.
- the direction may be oriented so as to face the first end face.
- the anisotropic light functional material may include a light functional material made of a dichroic fluorescent dye.
- the dichroic fluorescent dye includes a positive dichroic fluorescent dye in which the direction orthogonal to the molecular long axis is the direction with the highest emission intensity. May be.
- the optical functional material includes a plurality of optical functional materials, and at least one of the optical functional materials includes the dichroic fluorescent dye. Good.
- the dichroic fluorescent dye may be an optical functional material having the largest emission spectrum peak wavelength among the plurality of optical functional materials.
- the optical functional material may include an optical functional material composed of the dichroic fluorescent dye and an isotropic optical functional material that absorbs light isotropically. Good.
- the isotropic light functional material is a material having absorption isotropic property to absorb light isotropically, or an absorption anisotropic material to absorb light anisotropically.
- it may be an optical functional material that is not easily oriented with respect to the material included in the first light guide and is arranged in a random state.
- the optical functional material may include a plurality of optical functional materials made of the dichroic fluorescent dye.
- the first light guide causes energy transfer by the Forster mechanism between the plurality of optical functional materials, and has the largest peak wavelength of the emission spectrum.
- the light emitted from the optical functional material may be emitted from the first end face.
- the solar cell module according to still another aspect of the present invention may further include a diffusion plate that diffuses external light incident from the outside of the first light guide on the first main surface side.
- the second light guide body reflects and propagates light between the third main surface and the inclined surface provided on the fourth main surface,
- emitted from the said 2nd end surface may be sufficient.
- the solar cell module according to still another aspect of the present invention may further include a reflective layer on the fourth main surface side, which reflects light transmitted from the fourth main surface side.
- the first solar cell element and the second solar cell element may be configured by a common solar cell element.
- a solar power generation device includes the solar cell module.
- the present invention it is possible to provide a light guide with high light extraction efficiency, a solar cell module with high power generation efficiency, and a solar power generation device using the same.
- the second light guide is arranged behind the first light guide, the light having a deep incident angle is condensed by the first light guide and vertically Near-angle incident light can be condensed by the second light guide. Therefore, it is possible to provide a solar cell module with high light extraction efficiency and high power generation efficiency, and a solar power generation apparatus using the solar cell module.
- FIG. 1st Embodiment It is a schematic perspective view of the solar cell module of 1st Embodiment. It is sectional drawing of a solar cell module. It is a figure which shows the characteristic of a dichroic fluorescent dye. It is a figure which shows the characteristic of a dichroic fluorescent dye. It is a figure which shows the orientation state of a dichroic fluorescent dye. It is a figure for demonstrating the effect
- FIG. 1 is a schematic perspective view of the solar cell module 11 of the first embodiment.
- the solar cell module 11 includes a light guide 14 (fluorescent light guide), a solar cell element 16, and a frame 110.
- the solar cell element 16 is a solar cell element 16 that receives light emitted from the end face 14 c of the light guide 14.
- the frame 110 is a frame 110 that integrally holds the light guide 14 and the solar cell element 16.
- the light guide 14 includes a first main surface 14a, a second main surface 14b, and an end surface 14c.
- the first main surface 14a is a first main surface 14a that is a light incident surface on which external light L is incident.
- the second main surface 14b faces the first main surface 14a.
- the end surface 14c of the second main surface 14b is an end surface 14c that is a light emission surface.
- the direction parallel to the first main surface 14a of the light guide 14 is the x-axis direction
- the direction orthogonal to the x-axis direction is the y-axis direction
- the direction orthogonal to the first main surface 14a is defined as the z-axis direction.
- the light guide 14 is a substantially rectangular plate-like member having a first main surface 14a and a second main surface 14b.
- the first main surface 14a and the second main surface 14b of the light guide 14 are flat surfaces.
- the light guide 14 is obtained by dispersing a plurality of optical functional materials in a base material (transparent substrate) made of a liquid crystalline polymer. At least one of the plurality of optical functional materials is a phosphor. The light emitted from the phosphor propagates through the light guide 14 and is emitted from the end face 14 c, and is used for power generation by the solar cell element 16.
- the solar cell element 16 is disposed with the light receiving surface facing the four end surfaces 14 c of the light guide 14.
- the solar cell element 16 is preferably optically bonded to the end face 14c.
- a known solar cell such as a silicon solar cell, a compound solar cell, or an organic solar cell can be used.
- a compound solar cell using a compound semiconductor is suitable as the solar cell element 16 because it can generate power with high efficiency.
- compound solar cells include InGaP, GaAs, InGaAs, AlGaAs, Cu (In, Ga) Se 2 , Cu (In, Ga) (Se, S) 2 , CuInS 2 , CdTe, CdS, and the like.
- the quantum dot solar cell include Si and InGaAs.
- the solar cell element 16 is installed on the four end surfaces of the light guide 14 in FIG. 1, an example in which the solar cell element 16 is installed on the four end surfaces of the light guide 14 is shown, but the solar cell element 16 may be installed on a part of the four end surfaces of the light guide 14. Good. In the case where the solar cell element 16 is installed on a part of the end face (one side, two sides, or three sides) of the light guide body 14, the end face where the solar cell element is not installed is provided from the inside of the light guide body 14. It is preferable to install a reflective layer that reflects light traveling toward the outside of the light guide 14 toward the inside of the light guide 14.
- the frame body 110 includes a transmission surface 110 a that transmits the light L on a surface facing the first main surface 14 a of the light guide body 14.
- the transmission surface 110a may be an opening of the frame 110, or may be a transparent member such as glass fitted into the opening of the frame 110.
- the first main surface 14a of the light guide 14 is a light incident surface. A portion of the first main surface 14a that overlaps the transmission surface 110a of the frame 110 when viewed from the Z direction is a light incident region.
- the four end faces 14 c of the light guide body 14 are the light exit faces of the light guide body 14.
- FIG. 2 is a cross-sectional view of the solar cell module 11.
- the light guide body 14 includes a plurality of optical functional materials.
- the plurality of optical functional materials include a first optical functional material 12 and a second optical functional material 18.
- the second optical functional material 18 is a material having a property of absorbing light isotropically (absorption isotropic property).
- the optical functional material has a property of absorbing light anisotropically (absorption anisotropy) but is difficult to be oriented with respect to the light guide forming material and is in a random state.
- the first optical functional material 12 is a material having a property of emitting light anisotropically (light emission anisotropy).
- a phosphor having a predetermined absorption wavelength region is used as the second optical functional material 18.
- the phosphor 18 absorbs external light and emits fluorescence.
- the phosphor 18 is mixed when the light guide 14 is molded.
- an optical functional material made of a dichroic fluorescent dye is used as the first optical functional material 12.
- the “dichroic fluorescent dye” is a dye having a property of absorbing light anisotropically (absorption anisotropy) and a property of emitting light anisotropically (light emission anisotropy).
- a positive dichroic fluorescent dye having a direction with the highest emission intensity is used as the first optical functional material made of the dichroic fluorescent dye.
- the dichroic fluorescent dye is not limited to a positive dichroic fluorescent dye, and various dichroic fluorescent dyes can be used.
- a negative dichroic fluorescent dye in which the direction of the molecular long axis is the direction in which the emission intensity is the highest can also be used.
- FIGS. 3A and 3B are diagrams showing the characteristics of the dichroic fluorescent dye.
- FIG. 3A is a diagram showing the absorption characteristics of a dichroic fluorescent dye.
- FIG. 3B is a diagram showing the light emission characteristics of the dichroic fluorescent dye.
- the symbol V1 is the molecular long axis of the dichroic fluorescent dye 12
- the symbol V2 is an axis orthogonal to the molecular long axis V1.
- the dichroic fluorescent dye 12 of this embodiment has absorption anisotropy.
- the absorption characteristics of light incident on the dichroic fluorescent dye 12 from below in the direction along the molecular long axis V1 are viewed, before entering the dichroic fluorescent dye 12 and via the dichroic fluorescent dye 12
- the height of the curve showing the absorption characteristics hardly changes after and after.
- the dichroic fluorescent dye 12 hardly absorbs light incident in the direction along the molecular long axis V1 from below.
- the dichroic fluorescent dye 12 absorbs most of the light incident in the direction along the axis V2 orthogonal to the molecular long axis from the left side.
- the dichroic fluorescent dye 12 of the present embodiment has relatively small absorption characteristics in the direction along the molecular long axis V1, and relatively absorbs in the direction along the axis V2 orthogonal to the molecular long axis. Great characteristics.
- the dichroic fluorescent dye 12 of the present embodiment has emission anisotropy as shown in FIG. 3B.
- the direction along the molecular long axis V1 is the direction with the smallest emission intensity.
- the direction along the axis V2 orthogonal to the molecular long axis is the direction with the highest emission intensity.
- the dichroic fluorescent dye 12 of the present embodiment has a relatively small emission intensity in the direction along the molecular long axis V1, and relatively emits light in the direction along the axis V2 orthogonal to the molecular long axis. High strength.
- FIG. 4 is a diagram showing the orientation state of the dichroic fluorescent dye.
- the symbol V1 is the molecular long axis of the dichroic fluorescent dye 12
- the symbol V2 is an axis orthogonal to the molecular long axis V1.
- the dichroic fluorescent dye 12 of this embodiment is oriented so that the axis V2 orthogonal to the molecular long axis and the first main surface 14a of the light guide 14 are parallel to each other. That is, the dichroic fluorescent dye 12 of this embodiment is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 14a of the light guide 14. Has been.
- the light guide 14 of this embodiment is a substantially rectangular plate-like member having a first main surface 14a and a second main surface 14b that are perpendicular to the Z axis (parallel to the XY plane). Therefore, the dichroic fluorescent dye 12 of this embodiment is oriented so that the axis V2 orthogonal to the molecular long axis and the second main surface 14b of the light guide 14 are parallel to each other. That is, the dichroic fluorescent dye 12 of this embodiment is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the second main surface 14b of the light guide 14. Has been.
- a method for orienting the dichroic fluorescent dye 12 will be described with an example.
- a liquid crystal polymer or the like is used as a light guide forming material.
- a liquid crystal polymer (UCL018) manufactured by DIC is used.
- UCL018 polymer liquid crystal manufactured by DIC
- Coumarin 6 dichroic fluorescent dye
- FC-4430 surfactant
- toluene are mixed.
- the mixing ratio of each material is UCL018 (40%), Coumarin 6 (0.40%), FC-4430 (0.40%), and toluene (59.2%).
- the produced mixed solution is applied onto the substrate using a spin cast manufacturing method.
- the coating conditions are 20 sec and film formation at 500 rpm to form a film having a thickness of 1 ⁇ m.
- the film forming conditions are not limited to this, and the rotation time and the rotation speed are appropriately changed, and the film thickness is also changed in accordance with the light absorption amount of the fluorescent dye.
- the manufacturing method is not limited to this, and a manufacturing method such as slit coating, dip coating, roll coating, or bar coating may be used.
- the substrate on which the mixed solution is applied is placed on a hot plate and heat-treated under the conditions of a processing temperature of 50 ° C. and a processing time of 1 min to evaporate the solvent in the mixed solution.
- the processing temperature is lowered to room temperature.
- i-line (365 nm) is irradiated using a UV lamp, and exposure is performed for a processing time of 2 min.
- the dichroic fluorescent dye 12 can be oriented.
- FIG. 1 For example, an example is given and demonstrated about the method for verifying the orientation state of the dichroic fluorescent dye 12.
- FIG. 1 light of a predetermined wavelength band is incident on the light guide body 14 including the dichroic fluorescent dye 12 from each direction, and it is verified whether or not there is a place where the amount of light absorption differs depending on the light incident direction. If there is a difference in the amount of light absorption, the wavelength of the light is examined. The wavelength of this light becomes the absorption wavelength of the dichroic fluorescent dye 12.
- light corresponding to the absorption wavelength of the dichroic fluorescent dye 12 is incident on the light guide body 14, and confinement efficiency (light absorption efficiency of the dichroic fluorescent dye 12) is isotropically emitted. It is confirmed that the value is higher than that assumed.
- the confinement efficiency is 75% when the refractive index of the light guide is 1.5.
- light having a wavelength other than the absorption wavelength of the dichroic fluorescent dye 12 is incident on the light guide 14, and the light emitted from the end face of the light guide 14 is the emission wavelength of the dichroic fluorescent dye 12. make sure that there is. With the above flow, the orientation state of the dichroic fluorescent dye 12 can be verified.
- FIG. 5A to 5C are diagrams for explaining the action of the dichroic fluorescent dye.
- FIG. 5A is a diagram illustrating how energy transfer occurs between the phosphor 18 (second optical functional material) and the dichroic fluorescent dye 12 (first optical functional material).
- FIG. 5B and FIG. 5C are diagrams showing how the light emitted from the dichroic fluorescent dye 12 propagates inside the light guide 14.
- the symbol ⁇ is an angle formed by the traveling direction of a part of the light L1 emitted from the dichroic fluorescent dye 12 and the normal line of the second main surface 14b of the light guide 14, and the symbol ⁇ m is Is the critical angle.
- a part of the external light incident on the first main surface 14 a of the light guide 14 is absorbed by the phosphor 18.
- the phosphor 18 absorbs part of the external light, the excitation energy moves from the phosphor 18 toward the dichroic fluorescent dye 12.
- the dichroic fluorescent dye 12 emits light anisotropically by excitation energy from the phosphor 18.
- the dichroic fluorescent dye 12 of this embodiment is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 14a of the light guide 14. Yes. Therefore, light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the solar cell element 16. The mechanism by which the dichroic fluorescent dye 12 emits light anisotropically by excitation energy from the phosphor 18 will be described later.
- most of the light emitted from the dichroic fluorescent dye 12 has a large incident angle ⁇ on the first main surface 14 a or the second main surface 14 b of the light guide 14.
- the critical angle ⁇ m in the second main surface 14b of the light guide 14 is about 42 ° from Snell's law.
- the incident angle of the light L1 on the second main surface 14b is larger than 42 ° which is a critical angle. Since the total reflection condition is satisfied, the light L is totally reflected by the second main surface 14b. Thereafter, the light L is repeatedly reflected between the first main surface 14 a and the second main surface 14 b and guided to the solar cell element 16.
- the direction in which the emission intensity of light emitted from the dichroic fluorescent dye 12 is the smallest is orthogonal to the first main surface 14 a of the light guide 14.
- the incident angle of the light L2 on the second main surface 14b is a critical angle 42. Since it becomes smaller than ° and does not satisfy the total reflection condition, the light L2 is emitted to the external space.
- the light emitted from the dichroic fluorescent dye 12 is confined inside the light guide 14 when the angle of incidence on the first main surface 14a or the second main surface 14b is larger than the critical angle, and the first main surface When the incident angle to 14a or the second main surface 14b is smaller than the critical angle, the light is emitted to the outside.
- the dichroic fluorescent dye 12 is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 14 a of the light guide 14. ing.
- the dichroic fluorescent dye 12 has a large incident angle ⁇ on the first main surface 14a or the second main surface 14b of the light guide 14 and satisfies the total reflection condition. It will be. Therefore, most of the light emitted from the dichroic fluorescent dye 12 is confined inside the light guide 14 and guided to the solar cell element 16 without being emitted outside.
- the dichroic fluorescent dye 12 is included in the light guide 14, and the light emission intensity of the light emitted from the dichroic fluorescent dye 12 is increased. It is oriented so that the largest direction faces the end surface of the light guide 14 on which the solar cell element 16 is disposed.
- the direction in which the emission intensity is the largest among the light emitted from the dichroic fluorescent dye 12 is parallel to the first main surface 14a of the light guide 14, so that the sunlight incident on the light guide 14 is Most of them are directly led to the solar cell element 16. Thereby, it is suppressed that most of the sunlight incident on the light guide body 14 is transmitted through the light guide body 14 before reaching the solar cell element 16. Therefore, most of the sunlight incident on the light guide 14 can be contributed to power generation. Therefore, a solar cell module with high power generation efficiency can be provided.
- the configuration in which the axis V2 orthogonal to the molecular long axis and the first main surface 14a of the light guide 14 are aligned in parallel has been described as an example. Not exclusively.
- FIG. 6 is a diagram showing another example of the orientation state of the dichroic fluorescent dye.
- symbol V1 is a molecular long axis of the dichroic fluorescent dye 12
- symbol V2 is an axis orthogonal to the molecular long axis V1.
- the angle ⁇ formed by the axis V2 orthogonal to the molecular long axis and the normal line of the second main surface 14b of the light guide 14 is critical. It may be oriented so that it has an angle ⁇ m or more.
- the dichroic fluorescent dye 12 of the present embodiment has an angle ⁇ formed by the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is highest and the normal line of the second main surface 14b of the light guide 14. May be oriented so as to be not less than the critical angle ⁇ m.
- the light guide 14 of the present embodiment is a substantially rectangular plate-like member having a first main surface 14a and a second main surface 14b. Therefore, in the dichroic fluorescent dye 12 of the present embodiment, the angle ⁇ formed by the axis V2 orthogonal to the molecular long axis and the normal line of the first main surface 14a of the light guide 14 is not less than the critical angle ⁇ m. It may be oriented. That is, the dichroic fluorescent dye 12 of the present embodiment has an angle ⁇ formed by the direction in which the light emission intensity of the light emitted from the dichroic fluorescent dye 12 is highest and the normal line of the first main surface 14a of the light guide 14. May be oriented so as to be not less than the critical angle ⁇ m.
- the solar cell module 11 when the solar cell module 11 is installed on a roof or the like and arranged with the first main surface 14a facing upward, the axis V2 orthogonal to the molecular long axis and the first main surface 14a of the light guide 14 are parallel to each other. It becomes possible to set it as the structure which absorbs sunlight compared with the structure orientated so that it may become. That is, as shown in FIG. 39, the elevation angle ⁇ s of the sun S changes from about 30 ° to about 80 ° depending on the season in Japan, but the axis V2 shown in FIG. By arranging so as to face the sun, it is possible to easily absorb sunlight.
- the solar cell module 11 including the light guide 14 and the solar cell element 16 has been described.
- the present invention is not limited to this.
- the present embodiment can be applied to a configuration that does not include the solar cell element 16, that is, a configuration that includes only the light guide 14. According to this configuration, it is possible to provide the light guide 14 having high light extraction efficiency from the end face.
- FIG. 7 is a cross-sectional view of the solar cell module 11A of the second embodiment.
- the basic configuration of the solar cell module 11A of the present embodiment is the same as that of the first embodiment, and two types of phosphors (first phosphor 18a and second phosphor 18b) are provided inside the light guide body 14. This is different from the first embodiment.
- first phosphor 18a and second phosphor 18b two types of phosphors
- a plurality of types of phosphors having different absorption wavelength ranges are used as the second optical functional material 18.
- the first phosphor 18a for example, Lumogen F Violet 570 (trade name) manufactured by BASF can be used.
- the second phosphor 18b for example, Lumogen F Yellow 083 (trade name) manufactured by BASF can be used.
- FIG. 8 is a diagram showing an emission spectrum of the second optical functional material (first phosphor 18a, second phosphor 18b) used in the solar cell module 11A of the second embodiment.
- FIG. 9 is a diagram showing an absorption spectrum of the second optical functional material (first phosphor 18a, second phosphor 18b) used in the solar cell module 11A of the second embodiment.
- the emission spectrum 1101 of the first phosphor 18a has a peak wavelength at 430 nm
- the emission spectrum 1102 of the second phosphor 18b has a peak wavelength at 500 nm
- the absorption spectrum 1111 of the first phosphor 18a has a peak wavelength at 380 nm
- the absorption spectrum 1112 of the second phosphor 18b has a peak wavelength at 480 nm.
- the dichroic fluorescent dye 12 of the present embodiment emits light anisotropically by energy transfer from the first phosphor 18a and the second phosphor 18b.
- the dichroic fluorescent dye 12 for example, a material represented by the following chemical formula (1) can be used.
- the material represented by the chemical formula (2) is It is chemically reacted with 5-fromylthiophene-2-ylboronic acid, Pd (PPh 3 ) 2 Cl 2 , 2 M Na 2 CO 3 , benzene / EtOH. Thereby, the material shown in the following chemical formula (3) is generated.
- the material represented by the chemical formula (3) is Chemical reaction with arylmethyltriphenylphosphonium bromide, KOH, DMSO.
- the dichroic fluorescent dye 12 shown to Chemical formula (1) in this embodiment can be produced
- FIG. 10 is a diagram showing an emission spectrum and an absorption spectrum of the first optical functional material (dichroic fluorescent dye 12) used in the solar cell module 11A of the second embodiment.
- the symbol F // is a light emission characteristic in a direction parallel to the molecular long axis of the dichroic fluorescent dye 12.
- the symbol F ⁇ is a light emission characteristic in a direction orthogonal to the molecular long axis of the dichroic fluorescent dye 12.
- Symbol N F is the ratio of F // and F ⁇ (F // / F ⁇ ).
- the symbol A // is an absorption characteristic in a direction parallel to the molecular long axis of the dichroic fluorescent dye 12.
- the symbol A ⁇ is an absorption characteristic in a direction orthogonal to the molecular long axis of the dichroic fluorescent dye 12.
- Symbol N A is the ratio of A // and A ⁇ (A // / A ⁇ ).
- the emission spectrum of the dichroic fluorescent dye 12 has a peak wavelength at 640 nm in a direction parallel to the molecular long axis (F // ). Moreover, it has a peak wavelength at 630 nm in the direction orthogonal to the molecular long axis (F ⁇ ).
- the absorption spectrum of the dichroic fluorescent dye 12 has a peak wavelength at 530 nm (A // ) in the direction parallel to the molecular long axis. Moreover, it has a peak wavelength at 520 nm (A ⁇ ) in the direction orthogonal to the molecular long axis.
- the solar cell module 11A of the present embodiment most of the sunlight incident on the light guide 14 can be contributed to power generation. Further, in the present embodiment, a plurality of types (two types) of second optical functional materials (first phosphor 18 a and second phosphor 18 b) are included in the light guide 14. Thereby, the sunlight which injected into the light guide 14 can be utilized for electric power generation in a wide wavelength range. Therefore, a solar cell module with high power generation efficiency can be provided.
- FIG. 11 is a cross-sectional view of the solar cell module 11B of the third embodiment.
- the basic configuration of the solar cell module 11B of this embodiment is the same as that of the first embodiment, and there are three types of phosphors (first phosphor 18a, second phosphor 18b, and third phosphor) inside the light guide body 14. 18c) is different from the first embodiment.
- first phosphor 18a, second phosphor 18b, and third phosphor inside the light guide body 14.
- 18c is different from the first embodiment.
- symbol is attached
- a plurality of types of phosphors having different absorption wavelength ranges (for example, the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c in FIG. 11) are dispersed.
- the first phosphor 18a absorbs ultraviolet light and emits blue fluorescence.
- the second phosphor 18b absorbs blue light and emits green fluorescence.
- the third phosphor 18c absorbs green light and emits red fluorescence.
- the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c are mixed when the light guide is molded.
- the mixing ratio of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c is as follows.
- the mixing ratio of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c is shown as a volume ratio with respect to the light guide.
- First phosphor 18a BASF Lumogen F Violet 570 (trade name) 0.02%
- second phosphor 18b BASF Lumogen F Yellow 083 (trade name) 0.02%
- third phosphor 18c BASF Lumogen F Red 305 (trade name) 0.02%.
- the dichroic fluorescent dye 12 of this embodiment emits light anisotropically by energy transfer from the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c.
- a mechanism in which the dichroic fluorescent dye 12 emits light anisotropically by excitation energy from the phosphors 18a, 18b, and 18c will be described.
- FIGS. 12 to 15 are diagrams showing the emission characteristics and absorption characteristics of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c.
- a curve 1121 shows the spectrum of sunlight after the ultraviolet light is absorbed by the first phosphor 18a.
- a curve 1122 shows the spectrum of sunlight after the blue light is absorbed by the second phosphor 18b.
- a curve 1123 indicates the spectrum of sunlight after the green light is absorbed by the third phosphor 18c.
- a curve 1124 shows the spectrum of sunlight.
- FIG. 13 a curve 1125 shows the spectrum of sunlight after ultraviolet light, blue light, and green light are absorbed by the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c.
- a curve 1124 shows the spectrum of sunlight.
- a curve 1126 is an emission spectrum of the first phosphor 18a.
- a curve 1127 is an emission spectrum of the second phosphor 18b.
- a curve 1128 is an emission spectrum of the third phosphor 18c.
- a curve 1129 is a spectrum of light emitted from the end face of the light guide including the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c.
- the first phosphor 18a absorbs light having a wavelength of approximately 420 nm or less.
- the second phosphor 18b absorbs light having a wavelength of approximately 420 nm or more and 520 nm or less.
- the third phosphor 18c absorbs light having a wavelength of approximately 520 nm or more and 620 nm or less.
- the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c absorb almost all light having a wavelength of 620 nm or less in the sunlight incident on the light guide.
- the proportion of light having a wavelength of 620 nm or less is about 48%. Therefore, 48% of the light incident on the light incident surface of the light guide is absorbed by the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c included in the light guide.
- the emission spectrum of the first phosphor 18a has a peak wavelength at 430 nm.
- the emission spectrum of the second phosphor 18b has a peak wavelength at 520 nm.
- the emission spectrum of the third phosphor 18c has a peak wavelength at 630 nm.
- the spectrum of light emitted from the end face of the light guide including the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c is the emission spectrum of the third phosphor 18c.
- the peak wavelength has only a wavelength corresponding to the peak wavelength (630 nm) of the first phosphor 18a, and corresponds to the peak wavelength (430 nm) of the emission spectrum of the first phosphor 18a and the peak wavelength (520 nm) of the emission spectrum of the second phosphor 18b.
- the wavelength does not have a peak wavelength. Accordingly, excitation energy is transferred between the three types of phosphors used here by the Forster mechanism, and fluorescence emitted from the third phosphor having the largest peak wavelength of the fluorescence spectrum is obtained.
- the cause of the disappearance of the peak of the emission spectrum corresponding to the first phosphor 18a and the peak of the emission spectrum corresponding to the second phosphor 18b is the energy transfer between the phosphors due to photoluminescence (PL) and the Forster mechanism.
- Examples thereof include energy transfer between phosphors by (fluorescence resonance energy transfer). Energy transfer by photoluminescence occurs when fluorescence emitted from one phosphor is used as excitation energy for another phosphor. In the Förster mechanism, excitation energy directly moves between two adjacent phosphors by electron resonance without going through such light emission and absorption processes.
- the dichroic fluorescent dye 12 of this embodiment emits light anisotropically by energy transfer from the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c.
- the energy transfer from the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c to the dichroic fluorescent dye 12 includes energy transfer by photoluminescence, energy transfer by Forster mechanism. Either can be adopted.
- the energy transfer between the phosphors by the Förster mechanism is performed without going through the process of light emission and absorption, so that the energy loss is small under the optimum conditions. Therefore, it contributes to the improvement of the power generation efficiency of the solar cell module.
- the density of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c is increased, and the Forster mechanism is used between the phosphors. Energy transfer is performed.
- FIG. 16A is a diagram illustrating energy transfer by photoluminescence (color conversion by photoluminescence).
- FIG. 16B is a diagram illustrating energy transfer (color conversion by energy transfer) by the Forster mechanism.
- FIG. 17A is a diagram for explaining a generation mechanism of energy transfer by the Forster mechanism.
- FIG. 17B is a diagram showing energy transfer by the Forster mechanism.
- energy transfer may occur from a molecule A in an excited state to a molecule B in a ground state by a Forster mechanism.
- the molecule A when the molecule A is excited and undergoes energy transfer to the molecule B, the molecule B emits light. This energy transfer depends on the distance between molecules, the emission spectrum of molecule A, and the absorption spectrum of molecule B.
- the rate constant k H ⁇ G moving probability
- ⁇ is the frequency
- f ′ H ( ⁇ ) is the emission spectrum of the host molecule A
- ⁇ ( ⁇ ) is the absorption spectrum of the guest molecule B
- N is the Avogadro constant
- n is the refractive index
- ⁇ 0 is the fluorescence lifetime of the host molecule A
- R is the intermolecular distance
- K 2 is the transition dipole moment (2/3 at random).
- [1] represents the ease of resonance between two adjacent phosphors.
- FIG. 17A when the peak wavelength of the emission spectrum of the host molecule A is close to the peak wavelength of the absorption spectrum of the guest molecule B, energy transfer due to the Forster mechanism is likely to occur.
- FIG. 17B when the guest molecule B in the ground state exists near the host molecule A in the excited state, the wave function of the guest molecule A changes due to the resonance property, and the host molecule A in the ground state and the excited state in the excited state. Guest molecule B is formed. Thereby, energy transfer occurs between the host molecule A and the guest molecule B, and the guest molecule B emits light.
- the intermolecular distance at which energy transfer by the Forster mechanism occurs is usually about 10 nm. If the conditions are met, energy transfer occurs even when the intermolecular distance is about 20 nm. If the mixing ratio of the first phosphor, the second phosphor, and the third phosphor described above is used, the distance between the phosphors is shorter than 20 nm. Therefore, energy transfer by the Forster mechanism can occur sufficiently. Moreover, the emission spectrum and absorption spectrum of the first phosphor, the second phosphor, and the third phosphor shown in FIGS. 13 and 15 sufficiently satisfy the condition [1].
- the light guide although the phosphors having the three different emission spectra (the first phosphor, the second phosphor, and the third phosphor) are mixed, the light guide is substantially affected by the energy transfer by the Förster mechanism. In this case, only the emission of the third phosphor occurs.
- the emission quantum efficiency of the third phosphor is, for example, 92%. Therefore, by mixing the first phosphor, the second phosphor, and the third phosphor in the light guide, light in the wavelength region up to 620 nm is absorbed, and red light emission with a peak wavelength of 630 nm is achieved with an efficiency of 92%. Can be generated.
- This type of energy transfer phenomenon is unique to organic phosphors and is generally considered not to occur in inorganic phosphors, but in some inorganic nanoparticle phosphors such as quantum dots, Those that cause energy transfer between inorganic materials or between inorganic materials and organic materials by a star mechanism are known.
- energy transfer occurs between two types of quantum dots having different sizes of ZnO / MgZnO core / shell structure. Since a quantum dot having a dimensional ratio of 1: ⁇ 2 has a resonating exciton level, for example, 2 having a radius of 3 nm (peak wavelength of emission spectrum: 350 nm) and a radius of 4.5 nm (peak wavelength of emission spectrum: 357 nm). Between types of quantum dots, energy transfer occurs from small to large quantum dots. Energy transfer also occurs between two different sized quantum dots of the CdSe / ZnS core-shell structure.
- Mn2 + doped ZnSe quantum dots having a diameter of 8 nm to 9 nm have emission peaks at 450 nm and 580 nm, and are dye molecules 1 ′, 3′-dihydro-1 ′, 3 ′, 3′-trimethyl-6-nitrospiro [ 2H-1-benzopyran-'2,2 '-(2H] -indole] is in good agreement with the light absorption spectrum of the ring-opened Spiropyran molecule (SPO open; Merocynanine form) obtained by irradiating ultraviolet rays to the quantum dot
- SPO open Merocynanine form
- the phosphor A first emits light with a certain efficiency, enters the phosphor B, and the phosphor B absorbs and emits light. As a result, light is emitted from the phosphor B. In such energy transfer by photoluminescence, energy loss occurs in the light emission process in the phosphor A and the light absorption process in the phosphor B, and the energy transfer efficiency is small.
- energy transfer by the Forster mechanism occurs not only in a luminescent material such as a phosphor, but also in a non-luminescent material that is excited by external light but deactivates without generating light.
- the final power generation amount depends on the fluorescence quantum yield of the guest molecule and does not depend on the fluorescence quantum yield of the host molecule. Therefore, even if only the guest molecule is composed of a phosphor having a high fluorescence quantum yield and the host molecule is composed of a phosphor having a low fluorescence quantum yield or a non-light emitting material that does not emit fluorescence, the same amount of power generation can be obtained. Therefore, as compared with the case where a high fluorescence quantum yield is required for all phosphors, such as when energy transfer is performed by photoluminescence, the range of material selection for the host molecule is widened.
- FIG. 18 shows a spectral sensitivity curve 1134 of an amorphous silicon solar cell which is an example of the solar cell element 16 together with an emission spectrum 1131 of the first phosphor, an emission spectrum 1132 of the second phosphor, and an emission spectrum 1133 of the third phosphor.
- FIG. 18 shows a spectral sensitivity curve 1134 of an amorphous silicon solar cell which is an example of the solar cell element 16 together with an emission spectrum 1131 of the first phosphor, an emission spectrum 1132 of the second phosphor, and an emission spectrum 1133 of the third phosphor.
- the spectrum of the light L1 emitted from the end face 14c of the light guide body 14 substantially matches the emission spectrum 1133 of the third phosphor 18c. Therefore, the solar cell element 16 should just have a high sensitivity in the peak wavelength (630 nm) of the emission spectrum 1133 of the 3rd fluorescent substance 18c.
- the amorphous silicon solar cell has the highest spectral sensitivity with respect to light having a wavelength near 600 nm.
- the spectral sensitivity 1134 of the amorphous silicon solar cell at the peak wavelength of the emission spectrum 1131 of the first phosphor, the peak wavelength of the emission spectrum 1132 of the second phosphor, and the peak wavelength of the emission spectrum 1133 of the third phosphor is compared, the light emission is highest.
- the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of the third phosphor having a large spectrum peak wavelength is any other phosphor (first phosphor or second phosphor) provided in the light guide. It is larger than the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum. Therefore, if an amorphous silicon solar cell is used as the solar cell element 16, power generation can be performed with high efficiency.
- the type of solar cell applied to the solar cell element 16 is determined according to the wavelength of light incident on the solar cell element.
- an amorphous silicon solar cell is used as the solar cell element 16, but the solar cell element 16 is not limited to this.
- FIG. 19 is a diagram showing spectral sensitivity curves of various solar cells that can be used as the solar cell element 16.
- FIG. 20 is a diagram showing the energy conversion efficiency ⁇ ⁇ of these solar cells.
- reference numeral 1141 indicates a spectral sensitivity curve of the single crystal silicon solar cell.
- Reference numeral 1142 indicates a spectral sensitivity curve of the amorphous silicon solar cell (single junction).
- Reference numeral 1143 indicates a spectral sensitivity curve of the gallium arsenide solar cell (single junction).
- Reference numeral 1144 denotes a spectral sensitivity curve of the cadmium tellurium solar cell.
- Reference numeral 1145 indicates a spectral sensitivity curve of the Cu (In, Ga) (Se, S) 2 solar cell.
- reference numeral 1151 indicates the energy conversion efficiency ⁇ ⁇ of the single crystal silicon solar cell.
- Reference numeral 1152 indicates the energy conversion efficiency ⁇ ⁇ of the amorphous silicon solar cell (single junction).
- Reference numeral 1153 indicates the energy conversion efficiency ⁇ ⁇ of the gallium arsenide solar cell (single junction).
- Reference numeral 1154 indicates the energy conversion efficiency ⁇ ⁇ of the cadmium tellurium solar cell.
- Reference numeral 1155 indicates the energy conversion efficiency ⁇ ⁇ of the Cu (In, Ga) (Se, S) 2 solar cell.
- the spectral sensitivity and energy conversion efficiency of the solar cell at the peak wavelength (630 nm) of the emission spectrum of the third phosphor 18c having the largest emission spectrum peak wavelength are as follows. Is larger than the spectral sensitivity and energy conversion efficiency of the solar cell at the peak wavelength of the emission spectrum of any of the other phosphors (first phosphor 18a, second phosphor 18b). Therefore, if these solar cells are used as the solar cell element 16, power generation can be performed with high efficiency.
- the solar cell element 16 cannot have high spectral sensitivity with respect to the entire wavelength region of sunlight, such as a dye-sensitized solar cell or an organic solar cell, but with respect to light in a specific narrow wavelength region. It is also possible to actively use solar cells having very high spectral sensitivity.
- the solar cell module 11B of this embodiment most of the sunlight incident on the light guide 14 can be contributed to power generation.
- a plurality of types (three types) of second optical functional materials (first phosphor 18a, second phosphor 18b, and third phosphor 18c) are included in the light guide body 14. ing.
- the sunlight which injected into the light guide 14 can be utilized for electric power generation in a wide wavelength range. Therefore, a solar cell module with high power generation efficiency can be provided.
- a part of the external light L incident on the first main surface 14a is converted into a plurality of optical functional materials (first phosphor 18a, second phosphor 18b, and third phosphor 18c. )
- first phosphor 18a, second phosphor 18b, and third phosphor 18c To cause energy transfer by a Forster mechanism among a plurality of optical functional materials, and light emitted from the optical functional material (third phosphor 18c) having the largest peak wavelength of the emission spectrum is dichroic.
- the directivity is enhanced by the fluorescent dye 12, the light is condensed on the end surface 14 c of the light guide 14, and is incident on the solar cell element 16. Therefore, as the solar cell element 16, a solar cell having very high spectral sensitivity in a limited narrow wavelength range can be used.
- the light guide body 14 includes three types of second optical functional materials (first phosphor 18a, second phosphor 18b, and third phosphor 18c). Although it gave an example, it is not restricted to this. For example, the present embodiment can also be applied to a configuration in which four or more types of second optical functional materials are included in the light guide 14.
- FIG. 21 is a cross-sectional view of the solar cell module 11C of the fourth embodiment.
- the basic configuration of the solar cell module 11C of the present embodiment is the same as that of the third embodiment, and is different from the first embodiment in that a diffusion plate 13 is provided on the first main surface 14a side of the light guide 14.
- the same reference numerals are given to the configurations common to the solar cell module 11 ⁇ / b> B of the third embodiment, and detailed description thereof is omitted.
- a diffusion plate 13 is provided on the first main surface 14a side of the light guide 14 via an air layer.
- the presence of an air layer between the light guide 14 and the diffusion plate 13 makes it easy for light emitted from the dichroic fluorescent dye 12 to satisfy the total reflection condition at the interface between the light guide 14 and the air layer.
- the diffusion plate 13 is provided on the first main surface 14a side of the light guide 14 via the air layer, but the present invention is not limited to this.
- the diffusion plate 13 may be provided in direct contact with the first main surface 14a of the light guide body 14 without using an air layer.
- the diffusion plate 13 is configured by dispersing a large number of light scatterers such as acrylic beads in a binder resin such as an acrylic resin.
- the thickness of the diffusion plate 13 is about 20 ⁇ m, and the spherical diameter of the spherical light scatterer is about 0.5 ⁇ m to 20 ⁇ m.
- the diffuser plate 13 diffuses external light isotropically from the outside of the light guide 14 toward the inside of the light guide 14.
- the light scatterer is not limited to this, and is made of an acrylic polymer, an olefin polymer, a vinyl polymer, a cellulose polymer, an amide polymer, a fluorine polymer, a urethane polymer, a silicone polymer, an imide polymer, or the like. You may be comprised with appropriate transparent substances, such as a resin piece and a glass bead. In addition to these transparent substances, scatterers and reflectors that do not absorb light can be used.
- the shape of each light scatterer can be formed in various shapes such as a spherical shape, an elliptical spherical shape, a flat plate shape, and a polygonal cube. It is only necessary that the size of the light scatterer is uniform or nonuniform.
- FIG. 22 is a diagram for explaining the operation of the diffusion plate.
- the phosphor is not shown for convenience.
- the diffusion plate 13 is disposed on the first main surface 14 a side of the light guide 14.
- the light incident perpendicularly to the solar cell module 11 ⁇ / b> C (the diffusion plate 13) is diffused by the diffusion plate 13 and then enters the light guide body 14.
- light of various angles enters the dichroic fluorescent dye 12.
- the proportion of light in the direction in which the dichroic fluorescent dye 12 is easy to absorb is larger than when there is no diffuser.
- the dichroic fluorescent dye 12 has an absorption characteristic that is relatively small in the direction along the molecular long axis V1 and relatively large in the direction along the axis V2 orthogonal to the molecular long axis. Even if it exists, it becomes possible to absorb a part of light which enters perpendicularly with respect to solar cell module 11A (diffusion plate 13).
- the diffusion plate 13 since the diffusion plate 13 is provided, a part of the external light incident on the first main surface 14a of the light guide 14 is two compared to the configuration of the third embodiment.
- the proportion absorbed by the chromatic fluorescent dye 12 increases.
- the dichroic fluorescent dye 12 absorbs part of external light, it emits light anisotropically.
- the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is oriented so as to be parallel to the first main surface 14a of the light guide 14. Therefore, light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the solar cell element 16. Therefore, most of the sunlight incident on the light guide 14 can be contributed to power generation.
- FIG. 23 is a cross-sectional view of the solar cell module 11D of the fifth embodiment.
- the basic configuration of the solar cell module 11D of the present embodiment is the same as that of the fourth embodiment, and is different from the fourth embodiment in that the reflective layer 15 is provided on the second main surface 14b side of the light guide 14.
- symbol is attached
- the reflective layer 15 is provided on the second main surface 14b side of the light guide 14 via an air layer.
- the presence of an air layer between the light guide 14 and the reflective layer 15 makes it easier for light emitted from the dichroic fluorescent dye 12 to satisfy the total reflection condition at the interface between the light guide 14 and the air layer.
- the reflective layer 15 is provided on the second main surface 14b side of the light guide 14 via an air layer, but the present invention is not limited to this.
- the reflective layer 15 may be provided in direct contact with the second main surface 14b of the light guide 14 without an air layer.
- the reflective layer 15 reflects light propagating through the light guide 14. In addition, light that is incident from the first main surface 14 a but is not absorbed by the optical functional material and is emitted from the second main surface 14 b is also reflected toward the inside of the light guide 14.
- the reflective layer 15 a reflective layer made of a metal film such as silver or aluminum, or a reflective layer made of a dielectric multilayer film such as an ESR (Enhanced Specular Reflector) reflective film (manufactured by 3M) can be used.
- the reflection layer 15 may be a specular reflection layer that specularly reflects incident light, or may be a scattering reflection layer that scatters and reflects incident light.
- a scattering reflection layer is used for the reflection layer 15, the amount of light that goes directly in the direction of the solar cell element 16 increases, so that the light collection efficiency to the solar cell element 16 increases and the amount of power generation increases. In addition, since the reflected light is scattered, changes in the amount of power generation with time and season are averaged.
- microfoamed PET polyethylene terephthalate
- Furukawa Electric can be used as the scattering reflection layer.
- the dichroic fluorescent dye 12 absorbs a part of the external light, the dichroic fluorescent dye 12 emits light anisotropically, and the light having the highest light emission intensity emitted from the dichroic fluorescent dye 12 is directly guided to the solar cell element 16. It is burned. Therefore, most of the sunlight incident on the light guide 14 can be contributed to power generation.
- FIG. 24 is a cross-sectional view of the solar cell module 11E of the sixth embodiment.
- the basic configuration of the solar cell module 11E of the present embodiment is the same as that of the fifth embodiment, and is different from the fifth embodiment in that a diffusion plate 13 is provided on the second main surface 14b side of the light guide 14.
- a diffusion plate 13 is provided on the second main surface 14b side of the light guide 14.
- symbol is attached
- the reflective layer 15 is provided on the second main surface 14b side of the light guide 14 via an air layer. That is, the solar cell module 11E of the present embodiment has a configuration in which the diffusion plate 13 is provided on the first main surface 14a side of the light guide body 14 according to the fourth embodiment in the configuration of the third embodiment. The configuration is a combination of the configuration in which the reflective layer 15 is provided on the second main surface 14b side of the light guide body 14 according to the embodiment.
- the same effects as those of the fourth embodiment and the fifth embodiment can be achieved, such that most of the sunlight incident on the light guide 14 can be contributed to power generation.
- the diffusing plate 13 and the reflective layer 15 are provided, the above effect is remarkable.
- FIG. 34 is a cross-sectional view of the solar cell module 11H of the seventh embodiment.
- the basic configuration of the solar cell module 11H of the present embodiment is the same as that of the fifth embodiment, and a quarter ⁇ plate 19 is provided between the second main surface 14b of the light guide 14 and the reflective layer 15. Is different from the fifth embodiment.
- symbol is attached
- the quarter ⁇ plate 19 is provided between the second main surface 14b of the light guide 14 and the reflective layer 15 via an air layer. It has been. That is, the 1 ⁇ 4 ⁇ plate 19 is adjacent to the second main surface 14b of the light guide 14 through the air layer. The quarter ⁇ plate 19 is adjacent to the reflective layer 15 through an air layer.
- the light guide 14 does not function as a polarizing plate for light incident in parallel to the Z axis, but does not function as light incident obliquely to the Z axis. On the other hand, it functions as a polarizing plate. Therefore, as shown in FIGS. 35A and 35B, when the non-polarized sunlight L passes through the light guide body 14, it becomes linearly polarized light L11. As shown in FIG. 35C, the linearly polarized light L11 passes through the 1 ⁇ 4 ⁇ plate 19 to become circularly polarized light L12. As shown in FIG.
- the circularly polarized light L12 is reflected by the reflective layer 15, and becomes circularly polarized light L13 having a different optical rotation direction from the circularly polarized light 12.
- the circularly polarized light L13 is incident on the 1 ⁇ 4 ⁇ plate 19 again to become the linearly polarized light L14.
- the linearly polarized light L14 has a deflection direction different from that of the linearly polarized light L11 (ideally 90 °). Different). Therefore, the linearly polarized light L14 is easily absorbed by the dichroic fluorescent dye 12 as compared with the light emitted from the light guide 14 and reflected by the reflective layer 15 without passing through the 1 ⁇ 4 ⁇ plate 19.
- the quarter ⁇ plate 19 is used.
- the present embodiment is not limited to this, and other phase difference plates may be used.
- a 1 / 8 ⁇ plate, a 5 / 8 ⁇ plate, a 3 / 4 ⁇ plate, or the like may be used instead of the 1 / 4 ⁇ plate 19, a 1 / 8 ⁇ plate, a 5 / 8 ⁇ plate, a 3 / 4 ⁇ plate, or the like.
- the reflection layer 15 may be a scattering reflection layer.
- the same effects as those of the fourth embodiment and the fifth embodiment can be achieved, such that most of the sunlight incident on the light guide 14 can be contributed to power generation.
- the reflection layer 15 and the 1 ⁇ 4 ⁇ plate 19 are provided, the above-described effect becomes remarkable.
- FIG. 25 is a cross-sectional view of the solar cell module 11F of the eighth embodiment.
- the basic configuration of the solar cell module 11F of the present embodiment is the same as that of the third embodiment, and two types of dichroic fluorescent dyes (first dichroic fluorescent dye 112a and second dichroic dye are provided inside the light guide body 14.
- the third embodiment is different from the third embodiment in that a fluorescent fluorescent dye 112b) is provided.
- a fluorescent fluorescent dye 112b is provided.
- symbol is attached
- a part of the external light L incident on the first main surface 14a is converted into a plurality of second optical functional materials (first phosphor 18a, second phosphor 18b, third phosphor). 18c), energy transfer was caused by the Forster mechanism between the plurality of second optical functional materials. Then, the light emitted from the second optical functional material (third phosphor 18c) having the largest peak wavelength of the emission spectrum is enhanced in directivity by the dichroic fluorescent dye 12 (first optical functional material), and the light guide 14 was condensed on the end face 14 c of the solar cell element 16 and made incident on the solar cell element 16.
- the solar cell module 11F of the present embodiment a part of the external light L incident on the first main surface 14a is converted into a plurality of second optical functional materials (first phosphor 18a, second phosphor 18b, first 3 phosphor 18c), and energy transfer is caused by the Förster mechanism between some second optical functional materials of the plurality of second optical functional materials. Then, the light emitted from the second optical functional material having the largest peak wavelength of the emission spectrum is enhanced in directivity by the first dichroic fluorescent dye 112a (first optical functional material) and applied to the end face 14c of the light guide body 14. The light is condensed and made incident on the solar cell element 16.
- energy transfer is caused by the photoluminescence mechanism between the remaining second optical functional materials of the plurality of second optical functional materials. Then, the light emitted from the second optical functional material having the largest peak wavelength of the emission spectrum is enhanced in directivity by the second dichroic fluorescent dye 112b (first optical functional material) and applied to the end face 14c of the light guide body 14. The light is condensed and made incident on the solar cell element 16. That is, in this embodiment, both energy transfer by the Forster mechanism and energy transfer by the photoluminescence mechanism are caused.
- FIG. 26 is a cross-sectional view of the solar cell module 11G of the ninth embodiment.
- FIG. 27 is a diagram illustrating an emission spectrum of an optical functional material used in the solar cell module 11G of the ninth embodiment and a spectral sensitivity of the solar cell element.
- the basic configuration of the solar cell module 11G of this embodiment is the same as that of the first embodiment, and two types of phosphors (first phosphor 18d and second phosphor 18e) are provided inside the light guide body 14. This is different from the first embodiment.
- first phosphor 18d and second phosphor 18e two types of phosphors
- each of the three phosphors (the first phosphor 18a and the second phosphor) having a high fluorescence quantum yield. 18b, the third phosphor 18c) was used.
- the first phosphor 18d having a low fluorescence quantum yield and the second having a high fluorescence quantum yield.
- a phosphor 18e is used as the plurality of second optical functional materials provided in the light guide.
- the first phosphor 18d is a host molecule
- the second phosphor 18e is a guest molecule
- energy transfer occurs due to the Forster mechanism between the first phosphor 18d and the second phosphor 18e, and substantially, Only the second phosphor 18e, which is a guest molecule, emits light.
- the light emitted from the second phosphor 18e is enhanced in directivity by the dichroic fluorescent dye 12 (first optical functional material) and condensed on the end surface 14c of the light guide 14 so as to be solar cells. The light is incident on the element 16.
- the first phosphor 18d is, for example, NPB (N, N-di (naphthalene-1-yl) -N, N-diphenyl-benzidene).
- the fluorescence quantum yield of the first phosphor 18d is 42%, and the peak wavelength 1161 of the emission spectrum of the first phosphor 18d is 430 nm.
- the second phosphor 18e is, for example, rubrene.
- the fluorescence quantum yield of the second phosphor 18e is a high fluorescence quantum yield close to 100%, and the peak wavelength of the emission spectrum 1162 of the second phosphor 18e is 560 nm.
- the content of the second phosphor 18e is 2% with respect to the first phosphor 18d.
- an optical functional material layer including a first phosphor 18d and a second phosphor 18e is formed on a first main surface of a transparent light guide made of a glass substrate having a thickness of 2 mm.
- the film is formed to a thickness of 5 ⁇ m, and parylene is formed to a thickness of 1 ⁇ m as a transparent protective film on the surface of the optical functional material layer.
- an amorphous silicon solar cell is used as the solar cell element 16. Comparing the spectral sensitivities 1163 of the amorphous silicon solar cells at the peak wavelengths of the emission spectra of the first phosphor 18d and the second phosphor 18e, at the peak wavelength of the emission spectrum of the second phosphor 18e having the largest peak wavelength of the emission spectrum.
- the spectral sensitivity of the amorphous silicon solar cell is larger than the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of the first phosphor 18d. Therefore, if an amorphous silicon solar cell is used as the solar cell element 16, power generation can be performed with high efficiency.
- the fluorescence quantum yield of the first phosphor 18d which is a host molecule
- the final power generation amount is the guest It depends on the fluorescence quantum yield of the molecule and does not depend on the fluorescence quantum yield of the host molecule. Therefore, if only the guest molecule is composed of a phosphor having a high fluorescence quantum yield, the same power generation amount can be obtained even if the host molecule is composed of a phosphor having a low fluorescence quantum yield.
- a phosphor with a low fluorescence quantum yield cannot be used, but when only energy is directly transferred without emitting light as in this embodiment. Even if the fluorescence quantum yield is low, the final power generation amount does not change, so it can be used.
- phosphors having a high fluorescence quantum yield are expensive, have low light resistance, and have a short lifetime, so that maintenance costs are high.
- phosphors with low fluorescence quantum yields are low in price, abundant in materials, high in light resistance, and long in life, so that maintenance costs can be reduced.
- the first phosphor 18d it is preferable to use a fluorescent quantum yield of less than 90%, more preferably a fluorescent quantum yield of 80% or less.
- the lifetime of a solar cell is the time until the conversion efficiency reaches 90% of the initial value, the time until the emission intensity of the phosphor decreases by 10% in the light guide can also be regarded as the lifetime. it can.
- phosphors are usually premised on use as light emitters, a high fluorescence quantum yield of 100% to 90% is required as a fluorescence quantum yield. Therefore, the lifetime of the phosphor can be regarded as the time until the fluorescence quantum yield drops by 10% from the initial value, that is, the time until the fluorescence quantum yield drops from 90% to 81%.
- a phosphor having a fluorescence quantum yield of 80% or less is not usually used, and even if such a phosphor exists, it can be obtained at a low cost as a phosphor with poor performance. Therefore, if such a phosphor with a low fluorescence quantum yield is used, a solar cell module with high power generation efficiency can be provided at low cost.
- NPB is used as an example of the first phosphor 18d, but the first phosphor 18d is not limited to this.
- Other materials include N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1'-biphenyl] -4,4'-diamine (TPD), 4,4'-bis -[N- (1-naphthyl) -N-phenylamino] -biphenyl) (a-NPD), 4,4'-bis- [N- (9-phenanthyl) -N-phenylamino] -biphenyl (PPD), N , N, N ', N'-tetra-tolyl-1,1'-cyclohexyl-4,4'-diamine (TPAC), 1,1,4,4-tetraphenyl-1,3-butadiene (TPB), TCAP , Poly (N-vinylcarbazole) (PVK), PVK
- the host molecule is composed of only one type of second optical functional material (first phosphor 18d), but two or more types of second optical functional material may be used as the host material.
- the final power generation amount is determined by the fluorescence quantum yield of the second optical functional material having the largest peak wavelength of the emission spectrum. Therefore, it is desirable that the fluorescence quantum yield of the second optical functional material having the largest peak wavelength of the emission spectrum is higher than the fluorescence quantum yield of any other second optical functional material provided in the light guide.
- FIG. 28 is a diagram illustrating an emission spectrum of an optical functional material used in the solar cell module of the tenth embodiment and a spectral sensitivity of the solar cell element.
- the first phosphor 18d having a fluorescence quantum yield of 42% was used as the host molecule.
- a first phosphor having a fluorescence quantum yield of 3% is used as a host molecule.
- the first phosphor can be regarded as a non-light emitter that has a very low fluorescence quantum yield and does not emit light substantially.
- the first phosphor is a host molecule
- the second phosphor is a guest molecule
- energy transfer occurs by the Forster mechanism between the first phosphor and the second phosphor, and is substantially a guest molecule. Only the second phosphor emits light.
- the first phosphor is, for example, TPDS (N, N, N ′, N′-tetra-tolyl-1,1′-diphenylsulphide-4,4′-diamine).
- the fluorescence quantum yield of the first phosphor is 3%, and the peak wavelength of the emission spectrum 1171 of the first phosphor is 420 nm.
- the second phosphor of the present embodiment is the same rubrene as the second phosphor of the eighth embodiment.
- Reference numeral 1172 indicates the emission spectrum of the second phosphor.
- the content of the second phosphor is 3% with respect to the first phosphor.
- an optical functional material layer including a first phosphor and a second phosphor is formed on a first main surface of a transparent light guide made of a glass substrate having a thickness of 2 mm.
- the film is formed with a thickness, and parylene is formed with a thickness of 1 ⁇ m as a transparent protective film on the surface of the optical functional material layer.
- An amorphous silicon solar cell is used as the solar cell element. Comparing the spectral sensitivity 1173 of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of the first phosphor and the second phosphor, the amorphous silicon at the peak wavelength of the emission spectrum 1172 of the second phosphor having the largest peak wavelength of the emission spectrum The spectral sensitivity 1173 of the solar cell is higher than the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of any of the other phosphors (first phosphors) provided in the light guide. Therefore, if an amorphous silicon solar cell is used as the solar cell element, power generation can be performed with high efficiency.
- a phosphor having a low fluorescence quantum yield such as the first phosphor (for example, TPDS) can be obtained at low cost and has high light resistance, so that a solar cell module with high power generation efficiency can be provided at low cost.
- FIG. 36 is a schematic perspective view of the solar cell module 21 of the eleventh embodiment.
- the same reference numerals are given to configurations common to the solar cell module 11 of the first embodiment, and detailed description thereof is omitted.
- the solar cell module 21 includes a first light guide (fluorescent light guide) 22, a second light guide (shape light guide) 23, a first solar cell element 16, a second solar cell element 25, And a frame body 26.
- the first solar cell element 16 receives light emitted from the first end face 22 c of the first light guide 22.
- the expression “exit” is also used in the same meaning as “injection”.
- the second solar cell element 25 receives light emitted from the second end surface 23 c of the second light guide 23.
- the frame 26 integrally holds the first light guide 22, the second light guide 23, the first solar cell element 16, and the second solar cell element 25.
- the direction parallel to the first main surface 22a of the first light guide 22 is the x-axis direction, the direction parallel to the first main surface 22a, and the x-axis direction.
- the direction orthogonal to the first axis is defined as the y-axis direction, and the direction orthogonal to the first main surface 22a (thickness direction of the first light guide 22) is defined as the z-axis direction.
- the first light guide 22 includes a first main surface 22a, a second main surface 22b, and a first end surface 22c.
- the first main surface 22a is a light incident surface on which external light L is incident.
- the second main surface 22b is located on the opposite side of the first main surface 23a.
- the first end surface 22c is a light exit surface.
- the second light guide 23 is disposed on the second main surface 22 b side of the first light guide 22.
- the second light guide 23 includes a first main surface 23a, a second main surface 23b, and a second end surface 23c.
- the first main surface 23a is a light incident surface on which light transmitted from the second main surface 22b is incident.
- the second main surface 23b is located on the opposite side of the first main surface 23a.
- the second end surface 23c is a light exit surface.
- the first light guide 22 and the second light guide 23 are arranged such that the second main surface 22b of the first light guide 22 and the first main surface 23a of the second light guide 23 face each other.
- the light guide 22 and the second light guide 23 are stacked in the Z direction via an air layer K (low refractive index layer) having a refractive index smaller than that of the second light guide 23.
- the first main surface 22a of the first light guide 22 and the first main surface 23a of the second light guide 23 are arranged to face each other in the same direction (light incident side: -Z direction).
- the 1st light guide 22 and the 2nd light guide 23 are laminated
- the light that could not be captured at 22 can be captured by the second light guide 23 on the rear stage side (the side far from the side where the light L is incident).
- first end face 22c of the first light guide 22 and the second end face 23c of the second light guide 23 are oriented in the same direction.
- the first end face 22c of the first light guide 22 and the second end face 23c of the second light guide 23 are arranged on the same plane parallel to the XZ plane. Accordingly, the first solar cell element 16 that receives the light emitted from the first end face 22c of the first light guide 22 and the second sun that receives the light emitted from the second end face 23c of the second light guide 23.
- the battery element 25 is arranged in one place. In addition, it is preferable that these solar cell elements 16 and 25 are optically bonded to the corresponding end face 22c (23c).
- the first light guide 22 is a substantially rectangular plate-like member having a first main surface 22a and a second main surface 22b perpendicular to the Z axis (parallel to the XY plane).
- the first main surface 22a and the second main surface 22b of the first light guide 22 are flat surfaces substantially parallel to the XY plane.
- the first light guide 22 is obtained by dispersing the anisotropic light functional material 12 inside a transparent substrate made of a liquid crystalline polymer as shown in FIG.
- the anisotropic optical functional material 12 can be the same as the first optical functional material 12 of the first embodiment. That is, the anisotropic light functional material 12 is a material having a property of emitting light anisotropically (light emission anisotropy), and a dichroic fluorescent dye is used in the present embodiment.
- the dichroic fluorescent dye is a dye having both the property of absorbing light anisotropically (absorption anisotropy) and the property of emitting light anisotropically (light emission anisotropy).
- the dichroic fluorescent dye anisotropic optical functional material 12
- a positive dichroic fluorescent dye in which the direction orthogonal to the molecular long axis is the direction with the highest emission intensity is used as the dichroic fluorescent dye (anisotropic optical functional material 12).
- the dichroic fluorescent dye is not limited to the positive dichroic fluorescent dye, and various dichroic fluorescent dyes can be used.
- a negative dichroic fluorescent dye in which the direction of the molecular long axis is the direction in which the emission intensity is the highest can also be used.
- Such a dichroic fluorescent dye absorbs, for example, ultraviolet light or visible light and emits visible light or infrared light.
- the light emitted from the dichroic fluorescent dye is a first light guide. It propagates through the inside of the body 22 and is emitted from the first end face 22 c and is used for power generation by the first solar cell element 16.
- the dichroic fluorescent dye used as the anisotropic light functional material 12 of the present embodiment has the characteristics shown in FIG. Also, the dichroic fluorescent dye of the present embodiment exhibits a light distribution state similar to that of the dichroic fluorescent dye of the first embodiment. Specifically, the dichroic fluorescent dye exhibits an orientation state as shown in FIG.
- the light guide 14, the first main surface 14a, and the second main surface 14b illustrated in FIG. 4 correspond to the first light guide 22, the first main surface 22a, and the second main surface 22b of the present embodiment, respectively. . As shown in FIG.
- the dichroic fluorescent dye 12 of the present embodiment is oriented so that the axis V2 orthogonal to the molecular long axis and the first main surface 22a of the first light guide 22 are parallel to each other. Yes. That is, in the dichroic fluorescent dye 12 of this embodiment, the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is largest is parallel to the first main surface 22a of the first light guide 22.
- the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is largest is parallel to the first main surface 22a of the first light guide 22.
- the 1st light guide 22 of this embodiment is a substantially rectangular plate-shaped member which has the 1st main surface 22a perpendicular
- the method for aligning the dichroic fluorescent dye 12 and the method for verifying the alignment state of the dichroic fluorescent dye 12 are the same as the method described in the first embodiment.
- the dichroic fluorescent dye 12 emits light anisotropically by the excitation energy of external light incident from the first main surface 22a.
- the dichroic fluorescent dye 12 of the present embodiment is oriented so that the direction in which the light emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 22a of the first light guide 22. Has been. Therefore, light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the first solar cell element 16.
- most of the light emitted from the dichroic fluorescent dye 12 has a large incident angle ⁇ on the first main surface 22a or the second main surface 22b of the first light guide 22.
- ⁇ m that is, the critical angle at the interface between the liquid crystalline polymer constituting the first light guide 22 and air is about 42 ° from Snell's law.
- the incident angle of the light L1 on the first main surface 22a is larger than 42 ° which is a critical angle. Since the total reflection condition is satisfied, the light L is totally reflected by the first main surface 22a. Thereafter, the light L1 is repeatedly reflected between the first main surface 22a and the second main surface 22b, and is guided to the first solar cell element 16.
- the direction in which the emission intensity of light emitted from the dichroic fluorescent dye 12 is the smallest is the first main surface 22a and the second main surface of the first light guide 22. 22b is orthogonal to each other.
- the incident angle of the light L2 on the second main surface 22b is a critical angle 42.
- the light L2 is emitted to the second light guide 23 side because it becomes smaller than ° and does not satisfy the total reflection condition.
- the light emitted from the dichroic fluorescent dye 12 is confined in the first light guide 22 when the incident angle to the first main surface 22a or the second main surface 22b is larger than the critical angle, and the first When the incident angle to the main surface 22a or the second main surface 22b is smaller than the critical angle, the light is emitted to the outside.
- the dichroic fluorescent dye 12 is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is maximum is parallel to the first main surface 22a of the first light guide 22. Has been.
- the dichroic fluorescent dye 12 has a large incident angle ⁇ on the first main surface 22a or the second main surface 22b of the first light guide 22, and the total reflection condition. Will be satisfied. Therefore, most of the light emitted from the dichroic fluorescent dye 12 is confined inside the first light guide 22 and propagates toward the first solar cell element 16 without being emitted outside. .
- propagating means that the first main surface 22a is reflected on the first end surface 22c, the second main surface 22b is reflected on the first end surface 22c, and the first main surface 22a is reflected on the first main surface 22a. It means either the case where the first end surface 22c is reached while being reflected by both of the second main surfaces 22b, or the case where the first end surface 22c is reached without hitting any of the main surfaces 14a, 14b.
- light (fluorescent light) emitted (emitted) from the anisotropic light functional material 12 is formed on the end surface of the first light guide 22 other than the first end surface 22c. ) Is provided.
- a reflective layer made of a metal film such as silver or aluminum, or a reflective layer made of a dielectric multilayer film such as an ESR (Enhanced Specular Reflector) reflective film (manufactured by 3M) can be used.
- the reflection layer 28 may be a specular reflection layer that specularly reflects incident light, or may be a scattering reflection layer that scatters and reflects incident light.
- the second light guide 23 is a substantially rectangular plate-like member having a first main surface 23a perpendicular to the Z-axis (parallel to the XY plane) and a second main surface 23b opposite to the first main surface 23a. It is.
- a highly transparent organic material or inorganic material such as acrylic resin, polycarbonate resin, or glass is used.
- the second main surface 23b of the second light guide 23 is provided with a plurality of grooves T extending in the X direction.
- the groove T is a V-shaped groove having an inclined surface T1 that is inclined with respect to a plane parallel to the XY plane and a surface T2 that intersects the inclined surface T1.
- FIG. 36 only a few grooves T are shown in order to simplify the drawing, but in practice, a large number of fine grooves T having a width of about 100 ⁇ m are formed.
- the groove T is formed, for example, by injection molding a resin (for example, polymethyl methacrylate resin: PMMA) using a mold.
- the inclined surface T1 totally reflects the light L2 incident from the first main surface 23a (the light L2 transmitted from the first light guide 22), and the traveling direction of the light is directed to the second end surface 23c. It is a reflective surface that changes in the direction it heads.
- the light L2 incident at an angle close to perpendicular to the first main surface 23a is reflected by the inclined surface T1 and propagates in the second light guide 23 in the Y direction.
- the second light guide 23 is a shape light guide that reflects and propagates light at the inclined surface T1 provided on the second main surface 23b and emits the light from the second end surface 23c. ing.
- a plurality of such grooves T are provided in the Y direction on the second main surface 23b of the second light guide 23 so that the inclined surfaces T1 and T2 are in contact with each other.
- the shapes and sizes of the plurality of grooves T provided on the second main surface 23b are all the same.
- the inclination angle ⁇ of the inclined surface T1 is 30 °
- the width w in the Y direction of one groove T is 100 ⁇ m
- the depth d in the Z direction of the groove T is 90 ⁇ m
- the refractive index of the second light guide 23 is 1.5.
- the inclination angle ⁇ , the width w of the groove T, the depth d of the groove T, and the refractive index of the second light guide 23 are of course not limited thereto.
- the groove T may have a symmetrical V-shape and the inclination angle ⁇ may be 40 °.
- a reflective layer may be provided instead of the second solar cell element 25.
- the second light guide is provided from the end face to the end face other than the second end face 23c (23d) of the second light guide 23, that is, the end face where the second solar cell element 25 is not disposed.
- a reflection layer is provided that reflects light leaking out of the body 23 to the inside of the second light guide 23.
- the same layers as those of the reflective layer 28 are used.
- the first light guide 22 and the second light guide 23 have an air layer K interposed between them as shown in FIG. 37, but they may be in contact with each other by adhesion or the like. .
- the air layer K is interposed between the first light guide 22 and the second light guide 23, the light emitted from the dichroic fluorescent dye (anisotropic light functional material 12) is transmitted to the first light guide.
- the total reflection condition is easily satisfied at the interface between the air layer 22 and the air layer, which is preferable.
- the 1st solar cell element 16 and the 2nd solar cell element 25 well-known solar cells, such as a silicon type solar cell, a compound type solar cell, a quantum dot solar cell, and an organic type solar cell, can be used.
- compound solar cells and quantum dot solar cells using compound semiconductors are suitable as these solar cell elements 4 and 5 because they can generate power with high efficiency.
- compound solar cells include InGaP, GaAs, InGaAs, AlGaAs, Cu (In, Ga) Se 2 , Cu (In, Ga) (Se, S) 2 , CuInS 2 , CdTe, CdS, and the like.
- the quantum dot solar cell include Si and InGaAs.
- first solar cell element 16 and the second solar cell element 25 are appropriately solar cell elements that can perform photoelectric conversion with higher efficiency corresponding to the wavelength range of light emitted from the light guides 14 and 23. It is preferable to select and use. However, it goes without saying that the same type of solar cell element may be used.
- the frame body 26 is made of a frame such as aluminum, and the first main surface 22a of the first light guide 22 is exposed to the outside, and the first light guide 22 and the second light guide are in that state. While holding the four circumferences of the body 23, the first solar cell element 16 and the second solar cell element 25 are also held together with the light guides 14 and 23.
- a transparent member such as glass may be fitted into the opening 26a that allows the first main surface 22a of the first light guide 22 to face the outside.
- the first light guide 22 has a first main surface 22a facing the outside from the frame 26 as a light incident surface. Further, the first end face 22c of the first light guide 22 and the second end face 23c of the second light guide 23 are light emission surfaces.
- the dichroic fluorescent dye (anisotropic light functional material 12) is included in the first light guide 22, and emitted from the dichroic fluorescent dye 12.
- the direction in which the emission intensity of the emitted light is the largest is oriented so as to face the first end face 22c of the first light guide 22 on which the first solar cell element 16 is disposed. That is, the direction in which the emission intensity is the largest among the light emitted from the dichroic fluorescent dye 12 is parallel to the first main surface 22a of the first light guide 22, and therefore the direction in which the emission intensity is the highest and the first light guide. 22 is oriented so that the angle formed with the normal line of the first major surface 22a at 22 is not less than the critical angle.
- the solar cell module 21 of the present embodiment most of the external light (sunlight) incident on the first light guide 22 at a relatively large (deep) incident angle propagates to the first end face 22c side. To the first solar cell element 16.
- light incident on the first light guide 22 at an angle close to perpendicular (small incident angle) cannot be absorbed due to the absorption anisotropy of the dichroic fluorescent dye 12, and is transmitted through the second main surface 22b.
- the light emitted from the second main surface 22 b can be condensed by the second light guide 23 and guided to the second solar cell element 25.
- the angle of light incident on the second light guide 23 is mainly vertical light
- the angle of the inclined surface T1 of the second light guide 23 which is a shape light guide is appropriately set.
- the light collection efficiency can be further increased. Therefore, according to the solar cell module 21 of the present embodiment, high power generation efficiency can be realized by increasing the light extraction efficiency.
- the first solar cell element 16 is installed only on one end face (first end face 22c) with respect to the first light guide 22;
- One solar cell element 16 may be installed on a plurality of (2 to 4) end faces among the four end faces of the first light guide 22.
- the second light guide 23 a shape light guide that reflects and propagates light at the inclined surface T1 provided on the second main surface 23b and emits from the second end surface 23c is used.
- a fluorescent light guide in which phosphors to be described later are dispersed may be used.
- the fluorescent light guide one using a dichroic fluorescent dye as the fluorescent material can be used.
- the dichroic fluorescent dye is not oriented in the same direction as the first light guide 22, that is, the direction with the highest emission intensity among the light emitted from the dichroic fluorescent dye is the second light guide.
- the body 23 is oriented so that the direction with the highest emission intensity is directed to the first main surface 23a side to some extent without being parallel to the first main surface 23a.
- FIG. 39 is a side sectional view showing a schematic configuration of a solar cell module 21A of the twelfth embodiment.
- the solar cell module 21A of the present embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc., in the solar cell module 21 of the eleventh embodiment of the first light guide body 22.
- the dichroic fluorescent dye anisotropic light functional material 12
- the dichroic fluorescent dye is arranged such that the direction in which the emission intensity is the largest among the light emitted from the dichroic fluorescent dye 12 is parallel to the first main surface 22a of the first light guide 22.
- the first light guide 22 is oriented so that the direction with the highest light emission intensity is not parallel to the first main surface 22a.
- the orientation of the dichroic fluorescent dye 12 is oriented in a predetermined direction by the action of the orientation material (liquid crystalline polymer) as described above.
- the orientation control by this orientation material is in a desired direction (the direction in which the emission intensity is the largest in the light emitted from the dichroic fluorescent dye 12 is parallel to the first main surface 22a of the first light guide 22).
- the direction in which the emission intensity is the largest among the light emitted from the dichroic fluorescent dye 12 is not parallel to the first main surface 22a of the first light guide 22 but is slightly inclined and oriented. It is a case.
- the dichroic fluorescent dye 12 may be light-distributed as shown in FIG. 6 as in the first embodiment.
- the light guide 14, the first main surface 14a, and the second main surface 14b of FIG. 6 correspond to the first light guide 22, the first main surface 22a, and the second main surface 22b of the present embodiment, respectively.
- the angle ⁇ formed by the axis V2 orthogonal to the molecular long axis V1 and the normal line of the first main surface 22a of the first light guide 22 is oriented so that the critical angle ⁇ m is not less than the critical angle ⁇ m. If so, it may be oriented slightly inclined with respect to the desired direction.
- the dichroic fluorescent dye 12 is oriented slightly tilted in this way, for example, when the solar cell module 21A is installed on a roof or the like and is arranged with the first main surface 22a facing upward, Compared to the embodiment, the solar light can be easily absorbed. That is, as shown in FIG. 39, the elevation angle ⁇ s of the sun S changes from about 30 ° to about 80 ° depending on the season in Japan, but the axis V2 shown in FIG. By arranging so as to face the sun, it is possible to easily absorb sunlight.
- the amount of light transmitted from the second main surface 22b side without being totally reflected increases.
- the second light guide 23 is provided behind the first light guide 22 (on the second main surface 22b side)
- the light transmitted from the second main surface 22b is second guided.
- the light is condensed by the light body 23 and can be generated by the second solar cell element 25. The most efficient one depends on the light emission profile of the dichroic fluorescent dye 12.
- the reflection structure of the second light guide 23 (shape light guide) shown in FIG. 38A. That is, by forming the angle of the inclined surface T1 of the groove T according to this, the light collection efficiency can be further increased. Therefore, according to the solar cell module 21A of the present embodiment, the inclination of the molecular major axis V1 is determined by taking into account the increase in the amount of absorption by tilting the dichroic fluorescent dye 12 and the decrease in the confinement rate. It is possible to achieve high power generation efficiency by increasing the extraction efficiency.
- the first solar cell element 16 may be installed on a plurality of end faces of the first light guide 22.
- the second light guide 23 a fluorescent light guide in which a phosphor is dispersed instead of the shape light guide, or a light guide using a dichroic fluorescent dye as the phosphor can be used.
- FIG. 40 is a side sectional view showing a schematic configuration of the solar cell module 21B of the thirteenth embodiment.
- the solar cell module 21B of the present embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc., in the solar cell module 21 of the eleventh embodiment of the first light guide body 22.
- the anisotropic optical functional material 12 has only one type of dichroic fluorescent dye
- the anisotropic optical functional material 12 of the first light guide 22 has two different absorption wavelength ranges. This is a point having (multiple types) of dichroic fluorescent dyes 12a and 12b (anisotropic optical functional material 12).
- the first light guide 22 since it has two types (plural types) of dichroic fluorescent dyes 12a and 12b (anisotropic light functional material 12) having different absorption wavelength ranges, the first light guide 22 has light in a wide wavelength range. Can be absorbed.
- dichroic fluorescent dyes 12a and 12b for example, materials shown in the above formulas (1) and (2) can be used.
- R in Formula (1) is H (hydrogen).
- the dichroic fluorescent dye 12a represented by the formula (1) has an absorption wavelength of 396 nm and a fluorescence wavelength of 526 nm.
- the dichroic fluorescent dye 12b shown in Formula (2) has an absorption wavelength of 516 nm and a fluorescence wavelength of 617 nm.
- R in the formula (1) also obtained by substituting the O (CH 2) 7 CH 3 .
- the energy of light absorbed by the dichroic fluorescent dye 12a can be moved to the dichroic fluorescent dye 12b by repetition of light emission and absorption. Therefore, by continuously causing this energy transfer, light can be guided to the first solar cell element 16 with high efficiency by anisotropic light emission by the dichroic fluorescent dye 12b.
- the light absorbed by the dichroic fluorescent dye 12 a is transferred to the dichroic fluorescent dye 12 b, thereby guiding the light to the first solar cell element 16 with higher efficiency. it can.
- the energy transfer in particular, when the excitation energy is transferred by the Forster mechanism between the optical functional materials, the optical functional material having the largest peak wavelength of the emission spectrum can emit light.
- the mechanism for causing energy transfer between a plurality of types of optical functional materials is as described with reference to FIGS. Although it is described that three kinds of general (commercially available) phosphors are used, the same forster is also obtained by using a plurality of types of dichroic fluorescent dyes 12 that are appropriately selected in this embodiment. It is possible to cause energy transfer by the mechanism.
- the first light guide 22 includes other optical functional materials (including phosphors) together with the dichroic fluorescent dye 12, the same applies to the optical functional material and the dichroic fluorescent dye 12. It is possible to cause energy transfer by the Förster mechanism.
- the first light guide includes phosphors having three different emission spectra (first phosphor, second phosphor, and third phosphor). Regardless, due to the energy transfer by the Förster mechanism, substantially only the emission of the third phosphor occurs.
- the emission quantum efficiency of the third phosphor is, for example, 92%. Therefore, by mixing the first phosphor, the second phosphor, and the third phosphor in the first light guide, the light in the wavelength region up to 620 nm is absorbed, and the red having a peak wavelength of 630 nm with an efficiency of 92%. Can be emitted.
- such an energy transfer phenomenon is a phenomenon peculiar to an organic phosphor, and generally does not occur in an inorganic phosphor.
- some inorganic nanoparticle phosphors such as quantum dots are known to cause energy transfer between inorganic materials or between an inorganic material and an organic material by a Forster mechanism.
- energy transfer by the Forster mechanism occurs not only in a luminescent material such as a phosphor, but also in a non-luminescent material that is excited by external light but deactivates without generating light.
- the final power generation amount depends on the fluorescence quantum yield of the guest molecule and does not depend on the fluorescence quantum yield of the host molecule. Therefore, even if only the guest molecule is composed of a phosphor having a high fluorescence quantum yield and the host molecule is composed of a phosphor having a low fluorescence quantum yield or a non-light emitting material that does not emit fluorescence, the same amount of power generation can be obtained. Therefore, as compared with the case where a high fluorescence quantum yield is required for all phosphors, such as when energy transfer is performed by photoluminescence, the range of material selection for the host molecule is widened.
- FIG. 18 is a diagram showing a spectral sensitivity curve of an amorphous silicon solar cell which is an example of the first solar cell element 16 together with an emission spectrum of the first phosphor, an emission spectrum of the second phosphor, and an emission spectrum of the third phosphor. is there.
- the spectrum of the light L1 emitted from the end face of the first light guide 22 substantially matches the emission spectrum of the third phosphor. Therefore, a solar cell element should just have a high sensitivity in the peak wavelength (630 nm) of the emission spectrum of 3rd fluorescent substance. As shown in FIG. 18, the amorphous silicon solar cell has the highest spectral sensitivity with respect to light having a wavelength near 600 nm.
- the peak wavelength of the emission spectrum of the third phosphor having the largest peak wavelength of the emission spectrum
- the spectral sensitivity of the amorphous silicon solar cell at is higher than the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of any of the other phosphors (first phosphor and second phosphor) provided in the light guide. large. Therefore, if an amorphous silicon solar cell is used as the first solar cell element 16, power generation can be performed with high efficiency.
- the type of solar cell applied to the first solar cell element 16 is determined according to the wavelength of light incident on the solar cell element.
- an amorphous silicon solar cell is used as the first solar cell element 16, but the first solar cell element 16 is not limited to this.
- the light guide has the spectral sensitivity and the energy conversion efficiency of the solar cell at the peak wavelength (630 nm) of the emission spectrum of the third phosphor having the largest emission spectrum peak wavelength. It is larger than the spectral sensitivity and energy conversion efficiency of the solar cell at the peak wavelength of the emission spectrum of any of the other phosphors (the first phosphor and the second phosphor b). Therefore, if these solar cells are used as the first solar cell element 16, power generation can be performed with high efficiency.
- the first solar cell element 16 such as a dye-sensitized solar cell or an organic solar cell, cannot have high spectral sensitivity with respect to the entire wavelength region of sunlight, but is limited to light in a specific narrow wavelength region.
- the anisotropic light functional material 12 of the first light guide 22 two types (plural types) of dichroic fluorescent dyes 12a and 12b (different types) having different absorption wavelength ranges are used. Since it has the isotropic light functional material 12), the first light guide 22 can absorb light in a wide wavelength range. Therefore, the light extraction efficiency can be increased and high power generation efficiency can be realized. In addition, the energy of light absorbed by one dichroic fluorescent dye 12a can be transferred to another dichroic fluorescent dye 12b by repetition of light emission and absorption, and thus this energy transfer is caused to continue. Thus, light can be guided to the first solar cell element 16 with high efficiency by anisotropic light emission by the dichroic fluorescent dye 12b.
- the light emitted from the dichroic fluorescent dye having the largest peak wavelength of the emission spectrum can be obtained by appropriately selecting multiple types of dichroic fluorescent dyes and configuring the energy transfer by the Forster mechanism.
- the light can be emitted to the first end face 22 c of the first light guide 22 and incident on the first solar cell element 16. Therefore, the light extraction efficiency can be increased and high power generation efficiency can be realized.
- the first solar cell element 4 may be installed on a plurality of end surfaces of the first light guide 22.
- the second light guide 23 a fluorescent light guide in which a phosphor is dispersed instead of the shape light guide, or a light guide using a dichroic fluorescent dye as the phosphor can be used.
- FIG. 41 is a side sectional view showing a schematic configuration of a solar cell module 21C of the fourteenth embodiment.
- the solar cell module 21C of the present embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS.
- the solar cell module 21 of the eleventh embodiment has only one kind of anisotropic light functional material 12 (dichroic fluorescent dye) as the light functional material of the first light guide 22.
- the optical functional material of the first light guide 22 includes the anisotropic optical functional material 12 made of the dichroic fluorescent dye and the isotropic optical functional material 29 that absorbs light isotropically. is doing.
- FIG. 41 only one type of isotropic optical functional material 29 is shown, but this embodiment includes a case where there are a plurality of types of isotropic optical functional material 29.
- the isotropic light functional material 29 has a property of absorbing light isotropically (absorption isotropic property) or a property of absorbing light anisotropically (absorption anisotropy). It is an optical functional material that is hardly oriented with respect to the material for forming the body 22 and is arranged in a random state. As this isotropic light functional material 29, it absorbs external light and emits fluorescence, and a phosphor having a predetermined absorption wavelength region is used.
- any of organic phosphors, inorganic phosphors, organic-inorganic hybrid phosphors (for example, organometallic complexes) can be used as the phosphor.
- Such an isotropic light functional material 29 and the dichroic fluorescent dye (anisotropic light functional material 12) are mixed, for example, when the first light guide 22 is molded, and are dispersed almost uniformly.
- the phosphor isotropic light functional material 29
- a material having the above-described energy transfer with the dichroic fluorescent dye anisotropic light functional material 12
- the dichroic fluorescent dye is preferably an optical functional material having the largest peak wavelength of the emission spectrum among the plural types of optical functional materials.
- FIG. 42 is a diagram showing how energy transfer occurs between the phosphor 29 (isotropic light functional material 29) and the dichroic fluorescent dye 12 (anisotropic light functional material 12). As shown in FIG. 42, a part of the external light incident on the first main surface 22 a of the first light guide 22 is absorbed by the phosphor 29. When the phosphor 29 absorbs part of the external light, the excitation energy moves from the phosphor 29 toward the dichroic fluorescent dye 12.
- the dichroic fluorescent dye 12 emits light anisotropically as shown in FIG. 5B in the eleventh embodiment.
- the dichroic fluorescent dye 12 of the present embodiment is also oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is maximum is parallel to the first main surface 22a of the first light guide 22 Has been. Therefore, light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the first solar cell element 16.
- the above-described ferrule is used between the dichroic fluorescent dye (anisotropic optical functional material 12) or a plurality of types of phosphors (isotropic optical functional material 29). More preferably, a material that causes energy transfer by a star mechanism is selected and used.
- the first phosphor (Lumogen F Violet 570 (trade name) manufactured by BASF)
- the second phosphor (Lumogen F Yellow 083 (trade name) manufactured by BASF)
- the third phosphor manufactured by BASF
- Lumogen F Red 305 (trade name)
- the dichroic fluorescent dye anisotropic light functional material 12
- three types of isotropic light functional materials 29 are provided. It is preferable that energy transfer is caused by the Förster mechanism between them, and light obtained therefrom is absorbed by the dichroic fluorescent dye 12 to emit light.
- the dichroic fluorescent dye (anisotropic light functional material 12) and the isotropic light functional material 29 are used in combination as the light functional material of the first light guide 22, By causing the isotropic light functional material 29 to perform energy transfer, light having a wide wavelength range and a wide angle can be absorbed. Therefore, the light extraction efficiency can be increased and high power generation efficiency can be realized.
- a phosphor having a predetermined absorption wavelength range that absorbs external light and emits fluorescence is used as the isotropic optical functional material 29.
- the isotropic optical functional material in the present embodiment It is not limited to this.
- a light emitter that emits light in any form of fluorescence or phosphorescence can be used.
- a non-light-emitting optical functional material may be used as long as it causes energy transfer.
- a phosphor is used for the optical functional material having the largest peak wavelength in the fluorescence spectrum.
- the anisotropic optical functional material and the isotropic optical functional material are described as examples of separate molecules, but the fourteenth embodiment or a modification of the eleventh embodiment is the present embodiment.
- an optical functional material anisotropic optical functional material in which an absorbing portion and a light emitting portion exist in one molecule may be used.
- the light emitting part has light emission anisotropy, and the emitted light efficiently reaches the end face.
- the absorbing part absorbs light isotropically, or has absorption anisotropy, but is oriented perpendicular to the light emitting part or in a random state.
- an optical functional material for example, as shown in FIG. 33, a polymer main chain 1181 corresponds to a light emitting portion and a side chain 1182 corresponds to an absorbing portion.
- the first solar cell element 16 may be installed on the plurality of end faces of the first light guide 22.
- the second light guide 23 a fluorescent light guide in which a phosphor is dispersed instead of the shape light guide, or a light guide using a dichroic fluorescent dye as the phosphor can be used.
- FIG. 43 is a side sectional view showing a schematic configuration of a solar cell module 21D of the fifth embodiment.
- the solar cell module 21D of this embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc., as shown in FIG. 43, the first main surface 22a of the first light guide 22
- the diffusion plate 13 is provided on the side.
- the diffusing plate 13 is provided on the first main surface 22a side of the first light guide 22 via an air layer, and diffuses the external light incident from the outside of the first light guide 22 to make the first guide.
- the light is incident on the light body 22. Since an air layer exists between the first light guide 22 and the diffusion plate 13, the light emitted from the dichroic fluorescent dye (anisotropic light functional material 12) is an interface between the first light guide 22 and the air layer. It becomes easy to satisfy the total reflection condition.
- the diffusion plate 13 may be brought into direct contact with the first main surface 22a of the first light guide 22 without interposing an air layer, or may be attached by adhesion or the like.
- the diffusion plate 13 is configured by dispersing a large number of light scatterers such as acrylic beads in a binder resin such as an acrylic resin.
- the thickness of the diffusion plate 13 is about 20 ⁇ m, for example, and the spherical diameter of the spherical light scatterer is about 0.5 to 20 ⁇ m.
- the diffuser plate 13 isotropically diffuses external light from the outside of the first light guide 22 toward the inside of the first light guide 22.
- the light scatterer is not limited to this, and the light scatterer described in the first embodiment can be used.
- FIG. 44 is a diagram for explaining the operation of the diffusion plate.
- the diffusion plate 13 is disposed on the first main surface 22a side of the first light guide 22.
- the light incident perpendicularly to the solar cell module 21 ⁇ / b> D (the diffusion plate 13) is diffused by the diffusion plate 13 and then enters the first light guide 22.
- light of various angles enters the dichroic fluorescent dye 12. That is, the proportion of light in a direction that is easily absorbed by the dichroic fluorescent dye 12 is larger than when the diffuser plate 13 is not provided.
- the dichroic fluorescent dye 12 having an absorption characteristic that is relatively small in the direction along the molecular long axis V1 and relatively large in the direction along the axis V2 orthogonal to the molecular long axis. Even if it exists, it becomes possible to absorb a part of light which enters perpendicularly with respect to solar cell module 21D (diffusion plate 13).
- the diffusion plate 13 since the diffusion plate 13 is provided, two colors of external light incident on the first main surface 22a of the first light guide 22 are compared with the eleventh embodiment.
- the proportion absorbed by the fluorescent fluorescent dye 12 increases.
- the dichroic fluorescent dye 12 emits light anisotropically when it absorbs external light.
- the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 22a of the first light guide 22. Since it is oriented, the light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the first solar cell element 16. Therefore, most of the sunlight incident on the first light guide 22 can be contributed to power generation. Therefore, high light generation efficiency can be realized by increasing light extraction efficiency.
- the diffusion plate 13 according to the present embodiment is not applied only to the solar cell module 21 of the eleventh embodiment, but is combined with the solar cell modules 21A to 21D of the twelfth to fourteenth embodiments. May be.
- FIG. 45 is a side sectional view showing a schematic configuration of a solar cell module 21E of the sixth embodiment.
- the solar cell module 21E of this embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc., as shown in FIG. 44, the second main surface 23b of the second light guide 23.
- the reflective layer 15 is provided on the side.
- the reflective layer 15 is provided on the second main surface 23b side of the second light guide 23 via an air layer or an adhesive layer, and the light transmitted through the second light guide 23 is secondly transmitted. The light is reflected inside the light guide 23.
- the reflective layer 15 the same one as the reflective layer 28 described above is used. That is, a reflective layer made of a metal film such as silver or aluminum, or a reflective layer made of a dielectric multilayer film such as an ESR (Enhanced Specular Reflector) reflective film (manufactured by 3M) can be used.
- the reflection layer 15 may also be a mirror reflection layer that specularly reflects incident light, or a scattering reflection layer that scatters and reflects incident light.
- a scattering reflection layer When a scattering reflection layer is used for the reflection layer 15, the amount of light directly going in the direction of the first solar cell element 16 increases, so that the light collection efficiency to the first solar cell element 16 increases and the amount of power generation increases. To do. In addition, since the reflected light is scattered, changes in the amount of power generation with time and season are averaged.
- microfoamed PET polyethylene terephthalate
- Furukawa Electric can be used as the scattering reflection layer.
- the reflective layer 15 since the reflective layer 15 is provided, the light transmitted from the second main surface 23b of the second light guide 23 is reflected again into the second light guide 23. be able to. Therefore, the reflected light mainly passes through the second light guide 23 and re-enters the first light guide 22 where it is absorbed by the dichroic fluorescent dye 12 (anisotropic light functional material) and emitted.
- the dichroic fluorescent dye 12 anisotropic light functional material
- One solar cell element 16 can emit light. Therefore, most of the sunlight incident on the first light guide 22 can contribute to power generation, and the light extraction efficiency can be increased to achieve high power generation efficiency. Further, if a scattering reflection layer is used as the reflection layer 15, the reflected light can be scattered, so that light incident again from the second main surface 22 b of the first light guide 22 is absorbed by the dichroic fluorescent dye 12. The ratio can be increased.
- the reflective layer 15 according to the present embodiment is not applied only to the solar cell module 21 of the eleventh embodiment, but is combined with the solar cell modules 21A to 21E of the twelfth to fifteenth embodiments. May be.
- FIG. 46 is a side sectional view showing a schematic configuration of a solar cell module 21F configured by combining the solar cell module 21E of the fifteenth embodiment with the reflective layer 15 of the sixteenth embodiment.
- the diffusion plate 13 is provided on the first main surface 22 a side of the first light guide 22, and the reflective layer 15 is provided on the second main surface 22 b side of the second light guide 23. Therefore, even in this solar cell module 21F, as described in the fifth and sixth embodiments, most of the sunlight incident on the first light guide 22 is contributed to power generation, and light extraction is performed. High power generation efficiency can be realized by increasing the efficiency.
- a 1 ⁇ 4 ⁇ plate 19 may be further provided between the second main surface 14 b of the light guide 14 and the reflective layer 15.
- FIG. 47 is a side sectional view showing a schematic configuration of a solar cell module 21G of the seventeenth embodiment.
- the solar cell module 21G of the present embodiment differs from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc. in the following points.
- the first solar cell element provided on the first end surface 22 c of the first light guide 22 and the second solar cell provided on the second end surface 23 c of the second light guide 23.
- the element is constituted by a common solar cell element, that is, a single solar cell element 212.
- the solar cell element 212 used in common various solar cells used as the first solar cell element 16 and the second solar cell element 25 can be used. That is, known solar cells such as silicon solar cells, compound solar cells, quantum dot solar cells, and organic solar cells can be used.
- the first light guide 22 and the second light guide 23 may have an air layer interposed between them as shown in FIG. It may be. However, if an air layer is interposed between the first light guide 22 and the second light guide 23, the light emitted from the dichroic fluorescent dye (anisotropic light functional material 12) is emitted from the first light guide 22. It is easy to satisfy the total reflection condition at the interface between the air layer and the air layer, which is preferable.
- the solar cell element of the first light guide 22 and the solar cell element of the second light guide 23 are shared to form a single solar cell element 212.
- the overall configuration can be simplified and the cost can be reduced.
- the first light guide 22 shown in the eleventh embodiment is used. Instead, the first light guide in any of the twelfth to fourteenth embodiments is used.
- the body 22 may be used. Moreover, it is good also as a structure provided with the any one or both of the diffuser plate 13 shown in 15th Embodiment, and the reflection layer 15 shown in 16th Embodiment.
- the second light guide 23 a fluorescent light guide in which a phosphor is dispersed instead of the shape light guide, or a light guide using a dichroic fluorescent dye as the phosphor can be used.
- FIG. 29 is a cross-sectional view of the light guide 124 applied to the solar cell module of the eighteenth embodiment.
- the configuration other than the light guide 124 is the same as that of the solar cell module 11B of the third embodiment. Therefore, only the configuration of the light guide 124 will be described here.
- symbol is attached
- the light guide 124 includes a transparent light guide 125, a fluorescent film 126 bonded to the first main surface 125 a of the transparent light guide 125, and a transparent protective film 127 that covers the surface of the fluorescent film 126. .
- the fluorescent film 126 is a film-like optical functional material layer in which the first fluorescent material 18a, the second fluorescent material 18b, and the third fluorescent material 18c are dispersed therein as the optical functional material described above.
- the fluorescent film 126 converts part of the external light (for example, sunlight) incident on the first main surface 126 a into fluorescence and radiates it toward the transparent light guide 125.
- the phosphor film 126 includes a PMMA resin in which 0.2% of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c are mixed in a volume ratio with respect to the PMMA resin to form a film having a thickness of 200 ⁇ m. Formed.
- the transparent light guide 125 and the transparent protective film 127 a highly transparent organic material or inorganic material such as acrylic resin, polycarbonate resin, or glass is used.
- the transparent light guide 125 is made of an acrylic plate having a thickness of 5 mm
- the transparent protective film 127 is made of a PMMA resin film having a thickness of 200 ⁇ m.
- the transparent protective film 127, the fluorescent film 126, and the transparent light guide 125 are arranged in this order from the incident side of the external light L. However, as shown in FIG. You may arrange
- the transparent light guide 125 and the transparent protective film 127 are made of a highly transparent material that does not contain an optical functional material. Part of the fluorescence emitted from the fluorescent film 126 (light having a spectrum substantially the same as the emission spectrum of the third phosphor 18c shown in FIG. 14) is totally reflected inside the transparent light guide 125 and the transparent protective film 127. However, it propagates toward the end surfaces of the transparent light guide 125 and the transparent protective film 127. Light emitted from the end faces of the transparent light guide 125 and the transparent protective film 127 is incident on the solar cell element and used for power generation.
- the fluorescent film 126 and the transparent light guide 125 are bonded by a peelable adhesive layer 128 as shown in FIG.
- the fluorescent film 126 is peeled off from the transparent light guide 125 and replaced when damage, deterioration, or foreign matter (such as dust or bird droppings) adheres.
- the refractive indexes of the fluorescent film 126, the adhesive layer 128, and the transparent light guide 125 are all 1.49.
- the fluorescence emitted from the fluorescent film 126 propagates through the fluorescent film 126, the adhesive layer 128, and the transparent light guide 125 without loss.
- the fluorescent film 126 and the transparent light guide 125 are bonded to each other with a peelable adhesive layer 128. Therefore, when the fluorescent film 126 is damaged, deteriorated, or has foreign matters attached (such as dust or bird droppings) and the power generation efficiency is reduced, only the fluorescent film 126 is peeled off from the transparent light guide 125 and replaced. Can do. Therefore, the maintenance cost can be reduced as compared with the case where the entire light guide is replaced.
- FIG. 48 is a side sectional view showing a schematic configuration of the first light guide 220 applied to the solar cell module of the nineteenth embodiment.
- the configuration other than the first light guide 220 is the same as that of the solar cell module 21 of the eleventh embodiment. Therefore, only the configuration of the first light guide 220 will be described here.
- the first light guide 220 includes a transparent light guide 221, a fluorescent film 222 bonded to the first main surface 221 a of the transparent light guide 221, and a transparent protective film 223 that covers the surface of the fluorescent film 222.
- the fluorescent film 222 is a film-like optical functional material layer in which a dichroic fluorescent pigment is dispersed as the anisotropic optical functional material 12 described above.
- a plurality of types of dichroic fluorescent dyes may be dispersed in the fluorescent film 222.
- the fluorescent film 222 converts a part of the external light (for example, sunlight) incident on the first main surface 222a into fluorescence and radiates it toward the transparent light guide 221.
- the fluorescent film 222 is formed, for example, with a thickness of about 200 ⁇ m by dispersing the dichroic fluorescent dye 12 and the like inside a PMMA resin.
- the transparent light guide 221 and the transparent protective film 223, a highly transparent organic material or inorganic material such as acrylic resin, polycarbonate resin, or glass is used.
- the transparent light guide 221 is made of an acrylic plate having a thickness of 5 mm
- the transparent protective film 223 is made of a PMMA resin film having a thickness of 200 ⁇ m.
- the transparent protective film 223, the fluorescent film 222, and the transparent light guide 221 are arranged in this order from the incident side of the external light L. However, as shown in FIG. You may arrange
- the transparent light guide 221 and the transparent protective film 223 are made of a highly transparent material that does not contain an optical functional material. Part of the fluorescence emitted from the fluorescent film 222 propagates toward the end surfaces of the transparent light guide 221 and the transparent protective film 223 while totally reflecting the inside of the transparent light guide 221 and the transparent protective film 223. Light emitted from the end surfaces of the transparent light guide 221 and the transparent protective film 223 is incident on the first solar cell element and used for power generation.
- the fluorescent film 222 and the transparent light guide 221 are bonded together by a peelable adhesive layer 128 as shown in FIG. 31 in the eighteenth embodiment. That is, in FIG. 31, the fluorescent film 126 and the transparent light guide 125 correspond to the fluorescent film 222 and the transparent light guide 221 of this embodiment.
- the fluorescent film 222 is peeled off from the transparent light guide 221 and replaced when damage, deterioration, or foreign matter (such as dust or bird droppings) adheres.
- the refractive indexes of the fluorescent film 222, the adhesive layer 224, and the transparent light guide 221 are all 1.49.
- the fluorescence emitted from the fluorescent film 222 propagates through the fluorescent film 222, the adhesive layer 224, and the transparent light guide 221 without loss.
- an adhesive layer 224 for example, Gel Poly (trade name) manufactured by Panac Co., Ltd. can be used.
- the fluorescent film 222 and the transparent light guide 221 are bonded to each other with a peelable adhesive layer 224. Therefore, when the fluorescent film 222 is damaged, deteriorated, or has foreign matter attached (such as dust or bird droppings) and the power generation efficiency is reduced, only the fluorescent film 222 is peeled off from the transparent light guide 221 and replaced. Can do. Therefore, the maintenance cost can be reduced as compared with the case where the entire first light guide is replaced.
- FIG. 32 is a schematic configuration diagram of the solar power generation device 11000.
- the solar power generation device 11000 includes a solar cell module 11001 that converts sunlight energy into electric power, an inverter (DC / AC converter) 11004 that converts DC power output from the solar cell module 11001 into AC power, A storage battery 11005 for storing DC power output from the battery module 11001.
- a solar cell module 11001 that converts sunlight energy into electric power
- an inverter (DC / AC converter) 11004 that converts DC power output from the solar cell module 11001 into AC power
- a storage battery 11005 for storing DC power output from the battery module 11001.
- the solar cell module 11001 includes a light guide body 1002 that condenses sunlight and a solar cell element 1003 that generates power using sunlight collected by the light guide body 1002.
- a solar cell module 11001 for example, the solar cell module described in the first to tenth embodiments is used.
- the solar power generation device 11000 supplies power to an external electronic device 11006.
- the electronic device 11006 is supplied with power from the auxiliary power source 11007 as necessary.
- the solar power generation device 11000 includes the solar cell module according to the above-described embodiment, the solar power generation device 11000 is a solar power generation device with high power generation efficiency.
- the aspect of the present invention can be applied not only to the case where the first main surface and the second main surface of the light guide are parallel, but also to a configuration where the light guide is not parallel. That is, the critical angle is the angle formed between the direction in which the emission intensity of light emitted from the first optical functional material (anisotropic optical functional material) is the largest and the normal of the first main surface of the light guide (first light guide). In the configuration in which the angle formed between the direction in which the emission intensity of the light emitted from the first optical functional material is the largest and the normal to the second main surface of the light guide is less than the critical angle
- the embodiments of the present invention can also be applied. Even in such a configuration, most of the sunlight incident on the light guide can be contributed to power generation.
- the material for forming the light guide is not limited to a liquid crystalline polymer, and a highly transparent organic material or inorganic material such as an acrylic resin, a polycarbonate resin, or glass can also be used.
- the optical functional material include a phosphor that absorbs ultraviolet light or visible light and emits visible light or infrared light, or is excited by absorbing ultraviolet light or visible light, but emits light.
- a non-luminous material that deactivates without being included may be included. Note that visible light is light in a wavelength region of 380 nm to 750 nm, ultraviolet light is light in a wavelength region less than 380 nm, and infrared light is light in a wavelength region larger than 750 nm.
- the material of the base material (transparent substrate) of the light guide has transparency to wavelengths of 400 nm or less so that external light can be taken in effectively.
- a material having a transmittance of 90% or more, more preferably 93% or more with respect to light in a wavelength region of 360 nm to 800 nm is suitable.
- “Acrylite” registered trademark manufactured by Mitsubishi Rayon is suitable because it has high transparency to light in a wide wavelength region. .
- the present invention is not limited thereto.
- it includes those in which an absorption part and a light emission part exist in one molecule.
- the light emitting part has light emission anisotropy, and the emitted light efficiently reaches the end face.
- the absorption part absorbs light isotropically, or has absorption anisotropy, but is oriented perpendicular to the light-emitting part or in a random state.
- the main chain 1181 of the polymer corresponds to the light emitting portion
- the side chain 1182 corresponds to the absorbing portion.
- the aspect of the present invention can be used for a solar cell module and a solar power generation device.
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Abstract
A light guide body (14) has a first principal surface (14a) and a first end surface (14c) and includes at least one optical functional material (12, 18). The at least one optical functional material includes a first optical functional material (12) that emits light anisotropically. The light guide body is configured at least so as to allow the light emitted from the first optical functional material to propagate and exit from the end surface. The first optical functional material is oriented so that an angle formed by a direction in which the emission intensity of the light emitted from the first optical functional material is the largest and the normal line of the first principal surface becomes a critical angle or more.
Description
本発明は、導光体、太陽電池モジュールおよび太陽光発電装置に関する。
本願は、２０１１年１１月１１日に、日本に出願された特願２０１１－２４７４７０号及び２０１１年１２月２２日に、日本に出願された特願２０１１－２８１５０２に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a light guide, a solar cell module, and a solar power generation device.
This application claims priority based on Japanese Patent Application No. 2011-247470 filed in Japan on November 11, 2011 and Japanese Patent Application No. 2011-281502 filed in Japan on December 22, 2011. The contents are incorporated herein.
本願は、２０１１年１１月１１日に、日本に出願された特願２０１１－２４７４７０号及び２０１１年１２月２２日に、日本に出願された特願２０１１－２８１５０２に基づき優先権を主張し、その内容をここに援用する。 The present invention relates to a light guide, a solar cell module, and a solar power generation device.
This application claims priority based on Japanese Patent Application No. 2011-247470 filed in Japan on November 11, 2011 and Japanese Patent Application No. 2011-281502 filed in Japan on December 22, 2011. The contents are incorporated herein.
導光体の端面に太陽電池素子を設置し、導光体の内部を伝播した光を太陽電池素子に入射させて発電を行う太陽光発電装置が知られている。
A solar power generation apparatus is known in which a solar cell element is installed on the end face of a light guide, and light that has propagated through the light guide is incident on the solar cell element to generate power.
特許文献１では、導光体の一主面から入射した太陽光の一部を導光体の内部に伝播させて太陽電池素子に導く構成となっている。導光体の表面には蛍光体が塗布されており、導光体に入射した太陽光によって蛍光体が励起される。蛍光体から放射された光（蛍光）は導光体の内部を伝播し、太陽電池素子に入射して発電が行われる。
In patent document 1, it has the structure which propagates a part of sunlight which injected from one main surface of the light guide to the inside of a light guide, and guides it to a solar cell element. A phosphor is applied to the surface of the light guide, and the phosphor is excited by sunlight incident on the light guide. Light (fluorescence) emitted from the phosphor propagates through the light guide and enters the solar cell element to generate power.
特許文献２では、導光体の一主面から入射した太陽光の一部を導光体の内部に伝播させて光電変換部に導く構成となっている。導光体の内部には指ｓ向性発光粒子が分散されている。導光体に入射した太陽光は、指向性発光粒子により、光電変換部の方向に指向性を持つように変換される。
In patent document 2, it has the structure which propagates a part of sunlight which injected from one main surface of the light guide to the inside of a light guide, and guides it to a photoelectric conversion part. The finger s-directional luminescent particles are dispersed inside the light guide. Sunlight incident on the light guide is converted by the directional luminescent particles so as to have directivity in the direction of the photoelectric conversion unit.
特許文献１では、蛍光体の励起に用いられる太陽光は、導光体に入射する太陽光のうちのごく僅かである。導光体に入射した太陽光の大部分は導光体を透過し、発電に寄与しない。
特許文献２では、導光体に入射した太陽光が１種類の指向性発光粒子により変換される構成である。そのため、発電に利用することができる波長域が限られてしまう。
また、特許文献２では、発光光の指向性（異方性）を利用しているが、この構成では吸収指向性の影響があり、垂直に近い角度の入射光が透過してしまう。
よって、これら特許文献１、２では、発電効率の高い太陽光発電装置を提供することができない。 Inpatent document 1, the sunlight used for excitation of a fluorescent substance is very little of the sunlight which injects into a light guide. Most of the sunlight incident on the light guide is transmitted through the light guide and does not contribute to power generation.
In patent document 2, it is the structure by which the sunlight which injected into the light guide is converted with one kind of directional light-emitting particle. Therefore, the wavelength range that can be used for power generation is limited.
In Patent Document 2, the directivity (anisotropy) of emitted light is used. However, this configuration has an effect of absorption directivity, and incident light having an angle close to vertical is transmitted.
Therefore, in thesepatent documents 1 and 2, a solar power generation device with high power generation efficiency cannot be provided.
特許文献２では、導光体に入射した太陽光が１種類の指向性発光粒子により変換される構成である。そのため、発電に利用することができる波長域が限られてしまう。
また、特許文献２では、発光光の指向性（異方性）を利用しているが、この構成では吸収指向性の影響があり、垂直に近い角度の入射光が透過してしまう。
よって、これら特許文献１、２では、発電効率の高い太陽光発電装置を提供することができない。 In
In patent document 2, it is the structure by which the sunlight which injected into the light guide is converted with one kind of directional light-emitting particle. Therefore, the wavelength range that can be used for power generation is limited.
In Patent Document 2, the directivity (anisotropy) of emitted light is used. However, this configuration has an effect of absorption directivity, and incident light having an angle close to vertical is transmitted.
Therefore, in these
本発明の態様における目的は、光の取り出し効率が高い導光体、発電効率の高い太陽電池モジュールおよびこれを用いた太陽光発電装置を提供することにある。
また、本発明の他の態様における目的は、光の取り出し効率が高く発電効率が高い太陽電池モジュールと、これを用いた太陽光発電装置を提供することにある。 The objective in the aspect of this invention is providing the light guide with high extraction efficiency of light, the solar cell module with high power generation efficiency, and a solar power generation device using the same.
Another object of the present invention is to provide a solar cell module having high light extraction efficiency and high power generation efficiency, and a solar power generation apparatus using the solar cell module.
また、本発明の他の態様における目的は、光の取り出し効率が高く発電効率が高い太陽電池モジュールと、これを用いた太陽光発電装置を提供することにある。 The objective in the aspect of this invention is providing the light guide with high extraction efficiency of light, the solar cell module with high power generation efficiency, and a solar power generation device using the same.
Another object of the present invention is to provide a solar cell module having high light extraction efficiency and high power generation efficiency, and a solar power generation apparatus using the solar cell module.
本発明の一態様における導光体は、第１主面と、第１端面を有し、少なくとも一つの光機能材料を含み、前記少なくとも一つの光機能材料が、光を異方的に発する第１光機能材料を含み、少なくとも前記第１光機能材料から放射された光を伝播させ前記端面から射出させるよう構成されており、前記第１光機能材料は、前記第１光機能材料から発せられる光の発光強度の最も大きい方向と前記第１主面の法線とのなす角度が臨界角以上になるように配向されている。
The light guide in one aspect of the present invention has a first main surface and a first end surface, includes at least one optical functional material, and the at least one optical functional material emits light anisotropically. A first optical functional material configured to propagate at least light emitted from the first optical functional material and emit the light from the end face, and the first optical functional material is emitted from the first optical functional material. The orientation is such that the angle formed between the direction of maximum light emission intensity and the normal line of the first main surface is greater than or equal to the critical angle.
本発明の一態様における導光体において、前記第１光機能材料は、前記第１主面から入射した外光の一部を吸収してもよい。
In the light guide according to an aspect of the present invention, the first optical functional material may absorb a part of external light incident from the first main surface.
本発明の一態様における導光体は、さらに入射した外光の一部を等方的に吸収する第２光機能材料を含んでもよい。
The light guide in one embodiment of the present invention may further include a second optical functional material that isotropically absorbs part of incident external light.
本発明の一態様における導光体において、前記第２光機能材料は、光を等方的に吸収する性質を有する材料、もしくは光を異方的に吸収する性質を有するが前記導光体に含まれる材料に対して配向しにくくランダムな状態の光機能材料、のいずれかであってもよい。
In the light guide in one embodiment of the present invention, the second optical functional material has a property of absorbing light isotropically or has a property of absorbing light anisotropically. Any of the optical functional materials in a random state that is difficult to be oriented with respect to the contained material may be used.
本発明の一態様における導光体は、前記光機能材料を複数含み、前記第１光機能材料は、前記複数の光機能材料のうち最も発光スペクトルのピーク波長が大きい光機能材料を含んでもよい。
The light guide in one aspect of the present invention may include a plurality of the optical functional materials, and the first optical functional material may include an optical functional material having a maximum emission spectrum peak wavelength among the plurality of optical functional materials. .
本発明の一態様における導光体において、前記第１光機能材料は、前記第１主面の法線方向から見て、前記第１光機能材料から発せられる光の発光強度の最も大きい方向が前記端面を向くように配向されていてもよい。
In the light guide according to the aspect of the present invention, the first optical functional material has a direction in which the emission intensity of the light emitted from the first optical functional material is the largest when viewed from the normal direction of the first main surface. You may orientate so that it may face the said end surface.
本発明の一態様における導光体において、前記第１光機能材料が、二色性蛍光色素からなる光機能材料を含んでもよい。
In the light guide in one embodiment of the present invention, the first optical functional material may include an optical functional material made of a dichroic fluorescent dye.
本発明の一態様における導光体において、前記二色性蛍光色素が、分子長軸と直交する方向が発光強度の最も大きい方向であるポジ型二色性蛍光色素を含んでもよい。
In the light guide in one embodiment of the present invention, the dichroic fluorescent dye may include a positive dichroic fluorescent dye in which the direction orthogonal to the molecular long axis is the direction with the highest emission intensity.
本発明の一態様における導光体は、さらに、前記第１主面側に設けられ、前記導光体の外部から入射する外光を拡散させる拡散板を含んでもよい。
The light guide in one embodiment of the present invention may further include a diffusion plate that is provided on the first main surface side and diffuses external light incident from the outside of the light guide.
本発明の一態様における導光体は、前記複数の光機能材料の間でフェルスター機構によるエネルギー移動を生じさせ、最も発光スペクトルのピーク波長の大きい光機能材料から放射された光を、前記第１端面から射出させてもよい。
The light guide in one embodiment of the present invention causes energy transfer by a Forster mechanism between the plurality of optical functional materials, and emits light emitted from the optical functional material having the largest peak wavelength of the emission spectrum. You may inject from one end surface.
本発明の一態様における導光体において、前記複数の光機能材料のうち、前記最も発光スペクトルのピーク波長の大きい光機能材料以外の１又は複数の光機能材料には、蛍光量子収率が８０％以下の光機能材料が含まれていてもよい。
In the light guide according to an aspect of the present invention, among the plurality of optical functional materials, one or a plurality of optical functional materials other than the optical functional material having the largest peak wavelength of the emission spectrum has a fluorescence quantum yield of 80. % Or less of optical functional material may be included.
本発明の一態様における導光体において、前記最も発光スペクトルのピーク波長が大きい光機能材料の蛍光量子収率は、前記導光体に含まれる他のいずれの光機能材料の蛍光量子収率よりも高くてもよい。
In the light guide in one aspect of the present invention, the fluorescence quantum yield of the optical functional material having the largest peak wavelength of the emission spectrum is greater than the fluorescence quantum yield of any other optical functional material included in the light guide. May be higher.
本発明の一態様における導光体において、前記光機能材料が、無機材料からなる光機能材料を含んでいてもよい。
In the light guide in one embodiment of the present invention, the optical functional material may include an optical functional material made of an inorganic material.
本発明の一態様における導光体において、前記無機材料からなる光機能材料が、量子ドットからなる光機能材料を含んでいてもよい。
In the light guide in one embodiment of the present invention, the optical functional material made of the inorganic material may include an optical functional material made of quantum dots.
本発明の一態様における導光体において、前記光機能材料が、有機無機ハイブリッド蛍光体からなる光機能材料をふくんでいてもよい。
In the light guide in one embodiment of the present invention, the optical functional material may include an optical functional material made of an organic-inorganic hybrid phosphor.
本発明の一態様における導光体は、さらに、前記導光体の内部を伝播する光を反射する反射層を含んでいてもよい。
The light guide in one embodiment of the present invention may further include a reflective layer that reflects light propagating through the light guide.
本発明の一態様における導光体において、前記反射層は、入射した光を散乱反射する散乱反射層であってもよい。
In the light guide according to an aspect of the present invention, the reflection layer may be a scattering reflection layer that scatters and reflects incident light.
本発明の一態様における導光体は、さらに、前記導光体と前記反射層の間に位相差板を含んでもよい。
The light guide in one embodiment of the present invention may further include a retardation plate between the light guide and the reflective layer.
本発明の一態様における導光体において、前記位相差板は、１／４λ板であってもよい。
In the light guide according to an aspect of the present invention, the retardation plate may be a 1 / 4λ plate.
本発明の一態様における導光体は、透明導光体と、前記透明導光体の内部に分散された前記複数の光機能材料と、を含んでもよい。
The light guide in one embodiment of the present invention may include a transparent light guide and the plurality of optical functional materials dispersed inside the transparent light guide.
本発明の一態様における導光体は、透明導光体と、前記透明導光体の有する第３主面に設けられ、内部に前記複数の光機能材料が分散された光機能材料層と、を含んでもよい。
The light guide in one aspect of the present invention is provided on the third main surface of the transparent light guide and the transparent light guide, and the optical functional material layer in which the plurality of optical functional materials are dispersed, May be included.
本発明の一態様における導光体は、さらに、剥離可能な粘着層を含み、前記透明導光体と前記光機能材料層とは、前記粘着層で接着されていてもよい。
The light guide in one embodiment of the present invention may further include a peelable adhesive layer, and the transparent light guide and the optical functional material layer may be bonded by the adhesive layer.
本発明の他の態様における太陽電池モジュールは、導光体と、前記導光体の前記第１端面から射出された前記光を受光する第１太陽電池素子と、を備えている。
A solar cell module according to another aspect of the present invention includes a light guide and a first solar cell element that receives the light emitted from the first end face of the light guide.
本発明の他の態様における太陽電池モジュールにおいて、前記光機能材料のうち最も発光スペクトルのピーク波長が大きい光機能材料の発光スペクトルのピーク波長における前記第１太陽電池素子の分光感度は、前記導光体に備えられた他のいずれの光機能材料の発光スペクトルのピーク波長における前記第１太陽電池素子の分光感度よりも大きくてもよい。
In the solar cell module according to another aspect of the present invention, the spectral sensitivity of the first solar cell element at the peak wavelength of the emission spectrum of the optical functional material having the largest emission spectrum peak wavelength among the optical functional materials is the light guide. It may be larger than the spectral sensitivity of the first solar cell element at the peak wavelength of the emission spectrum of any other optical functional material provided in the body.
本発明の他の態様における太陽電池モジュールは、さらに、第３主面と第２端面を有し、前記第２主面側に配置され、前記第２主面から透過した光を前記第３主面から入射し、伝播させて前記第２端面から射出する第２導光体と、前記第２端面に設けられて前記第２端面から射出された光を受光する第２太陽電池素子と、を備えてもよい。
The solar cell module according to another aspect of the present invention further includes a third main surface and a second end surface, is disposed on the second main surface side, and transmits light transmitted from the second main surface to the third main surface. A second light guide that is incident from the surface, propagates, and exits from the second end face; and a second solar cell element that is provided on the second end face and receives light emitted from the second end face. You may prepare.
本発明の一態様における導光体において、前記第２導光体は、前記第３主面と対向する第４主面を有し、前記第２導光体において、前記伝播させ端面から射出させるとは、前記第３主面で反射させ端面から射出させる、前記第４主面で反射させ端面から射出させる、前記第３主面と前記第４主面との間で反射させながら端面から射出させる、もしくは前記第３主面及び前記第４主面のいずれにも入射させることなく端面から射出させる、のいずれかであってもよい。
In the light guide according to the aspect of the present invention, the second light guide has a fourth main surface facing the third main surface, and the second light guide propagates and is emitted from the end surface. Are reflected from the third main surface and emitted from the end surface, reflected from the fourth main surface and emitted from the end surface, and emitted from the end surface while being reflected between the third main surface and the fourth main surface. Or may be emitted from an end face without being incident on any of the third main surface and the fourth main surface.
本発明の他の態様における太陽電池モジュールにおいて、前記異方性光機能材料は、前記第１主面の法線方向から見て、前記異方性光機能材料から発せられる光の発光強度の最も大きい方向が前記第１端面を向くように配向されていてもよい。
In the solar cell module according to another aspect of the present invention, the anisotropic light functional material has a direction in which the light emission intensity of light emitted from the anisotropic light functional material is the largest when viewed from the normal direction of the first main surface. It may be oriented to face the first end face.
本発明の他の態様における太陽電池モジュールにおいて、前記第２導光体は、前記第４主面に設けられた傾斜面で光を反射して伝播させ、前記第２端面から射出する形状導光体であってもよい。
In the solar cell module according to another aspect of the present invention, the second light guide reflects and propagates light at an inclined surface provided on the fourth main surface, and is emitted from the second end surface. It may be a body.
本発明の他の態様における太陽電池モジュールにおいて、前記第２導光体の前記第４主面側には、前記第２導光体の前記第４主面側から透過した光を反射する反射層が設けられていてもよい。
In the solar cell module according to another aspect of the present invention, a reflective layer that reflects light transmitted from the fourth main surface side of the second light guide on the fourth main surface side of the second light guide. May be provided.
本発明の他の態様における太陽電池モジュールにおいて、前記第１太陽電池素子と前記第２太陽電池素子とは、共通の太陽電池素子によって構成されていてもよい。
In the solar cell module according to another aspect of the present invention, the first solar cell element and the second solar cell element may be constituted by a common solar cell element.
本発明のさらに他の態様における太陽光発電装置は、前記太陽電池モジュールを備える。
A solar power generation device according to still another aspect of the present invention includes the solar cell module.
本発明のさらに他の態様における導光体は、第１主面と、端面を有し、複数の光機能材料を含み、前記複数の光機能材料が、少なくとも光を異方的に発する第１光機能材料と、光を等方的に吸収する第２光機能材料と、を含み、前記第１主面に入射した外光の一部を前記複数の光機能材料によって吸収し、少なくとも前記第１光機能材料から放射された光を伝播させ前記端面から射出させるよう構成されており、前記第１光機能材料は、前記第１光機能材料から発せられる光の発光強度の最も大きい方向と前記第１主面の法線とのなす角度が臨界角以上になるように配向されている。
The light guide in still another aspect of the present invention has a first main surface and an end surface, includes a plurality of optical functional materials, and the plurality of optical functional materials emit at least light anisotropically. An optical functional material and a second optical functional material that absorbs light isotropically, and a part of the external light incident on the first main surface is absorbed by the plurality of optical functional materials, The light emitted from one optical functional material is propagated and emitted from the end face, and the first optical functional material has a direction in which the emission intensity of light emitted from the first optical functional material is highest and the It is oriented so that the angle formed with the normal line of the first main surface is not less than the critical angle.
本発明のさらに他の態様における導光体は、前記第１主面と対向する第２主面を有し、前記伝播させ端面から射出させるとは、前記第１主面で反射させ前記端面から射出させる、前記第１主面と対向する第２主面で反射させ前記端面から射出させる、前記第１主面と前記第２主面との間で反射させながら前記端面から射出させる、もしくは前記第１主面及び前記第２主面のいずれにも入射させることなく前記端面から射出させる、のいずれかであってもよい。
The light guide in still another aspect of the present invention has a second main surface facing the first main surface, and the propagation and emission from the end surface means that the light is reflected from the first main surface and is reflected from the end surface. Injecting, reflecting from the second main surface opposite to the first main surface and emitting from the end surface, emitting from the end surface while reflecting between the first main surface and the second main surface, or the Either of the first main surface and the second main surface may be emitted from the end surface without being incident.
本発明のさらに他の態様における導光体において、前記第２光機能材料とは、光を等方的に吸収する性質を有する材料、もしくは光を異方的に吸収する性質を有するが前記導光体に含まれる材料に対して配向しにくくランダムな状態の光機能材料、のいずれかであってもよい。
In the light guide according to still another aspect of the present invention, the second optical functional material is a material having the property of absorbing light isotropically or having the property of absorbing light anisotropically. Any of the optical functional materials in a random state that is difficult to be oriented with respect to the material included in the light body may be used.
本発明のさらに他の態様における導光体において、前記第１光機能材料は、前記複数の光機能材料のうち最も発光スペクトルのピーク波長が大きい光機能材料を含んでもよい。
In the light guide according to still another aspect of the present invention, the first optical functional material may include an optical functional material having a peak wavelength of an emission spectrum that is the largest among the plurality of optical functional materials.
本発明のさらに他の態様における導光体において、前記第１光機能材料は、前記第１主面の法線方向から見て、前記第１光機能材料から発せられる光の発光強度の最も大きい方向が前記端面を向くように配向されていてもよい。
In the light guide according to still another aspect of the present invention, the first optical functional material has the highest light emission intensity of light emitted from the first optical functional material when viewed from the normal direction of the first main surface. You may orientate so that a direction may face the said end surface.
本発明のさらに他の態様における導光体において、前記第１光機能材料が、二色性蛍光色素からなる光機能材料を含んでもよい。
In the light guide in still another aspect of the present invention, the first optical functional material may include an optical functional material made of a dichroic fluorescent dye.
本発明のさらに他の態様における導光体において、前記二色性蛍光色素が、分子長軸と直交する方向が発光強度の最も大きい方向であるポジ型二色性蛍光色素を含んでもよい。
In the light guide in still another aspect of the present invention, the dichroic fluorescent dye may include a positive dichroic fluorescent dye in which the direction perpendicular to the molecular long axis is the direction with the highest emission intensity.
本発明のさらに他の態様における導光体は、さらに、前記第１主面側に設けられ、前記導光体の外部から入射する外光を拡散させる拡散板を含んでもよい。
The light guide in still another aspect of the present invention may further include a diffusion plate that is provided on the first main surface side and diffuses external light incident from the outside of the light guide.
本発明のさらに他の態様における導光体において、前記複数の光機能材料の間でフェルスター機構によるエネルギー移動を生じさせ、最も発光スペクトルのピーク波長の大きい光機能材料から放射された光を、前記端面から射出させてもよい。
In the light guide in yet another aspect of the present invention, energy is transferred by the Forster mechanism between the plurality of optical functional materials, and the light emitted from the optical functional material having the largest peak wavelength of the emission spectrum is obtained. You may inject from the said end surface.
本発明のさらに他の態様における導光体において、前記複数の光機能材料のうち、前記最も発光スペクトルのピーク波長の大きい光機能材料以外の１又は複数の光機能材料には、蛍光量子収率が８０％以下の光機能材料が含まれていてもよい。
In the light guide in still another aspect of the present invention, among the plurality of optical functional materials, one or a plurality of optical functional materials other than the optical functional material having the largest peak wavelength of the emission spectrum has a fluorescence quantum yield. 80% or less of the optical functional material may be included.
本発明のさらに他の態様における導光体において、前記最も発光スペクトルのピーク波長が大きい光機能材料の蛍光量子収率は、前記導光体に含まれる他のいずれの光機能材料の蛍光量子収率よりも高くてもよい。
In the light guide in yet another aspect of the present invention, the fluorescence quantum yield of the optical functional material having the largest peak wavelength of the emission spectrum is the fluorescence quantum yield of any other optical functional material included in the light guide. It may be higher than the rate.
本発明のさらに他の態様における導光体は、前記光機能材料が、無機材料からなる光機能材料を含んでもよい。
In the light guide in still another aspect of the present invention, the optical functional material may include an optical functional material made of an inorganic material.
本発明の一態様における導光体において、前記光機能材料が、有機無機ハイブリッド蛍光体からなる光機能材料をふくんでいてもよい。
In the light guide in one embodiment of the present invention, the optical functional material may include an optical functional material made of an organic-inorganic hybrid phosphor.
本発明のさらに他の態様における導光体は、前記無機材料からなる光機能材料が、量子ドットからなる光機能材料を含んでもよい。
In the light guide in still another aspect of the present invention, the optical functional material made of the inorganic material may include an optical functional material made of quantum dots.
本発明のさらに他の態様における導光体は、さらに前記導光体の内部を伝播する光を反射する反射層を含んでもよい。
The light guide in still another aspect of the present invention may further include a reflective layer that reflects light propagating through the light guide.
本発明のさらに他の態様における導光体において、前記反射層は、入射した光を散乱反射する散乱反射層であってもよい。
In the light guide body according to still another aspect of the present invention, the reflection layer may be a scattering reflection layer that scatters and reflects incident light.
本発明のさらに他の態様における導光体は、さらに前記導光体と前記反射層の間に位相差板を含んでもよい。
The light guide in still another aspect of the present invention may further include a retardation plate between the light guide and the reflective layer.
本発明のさらに他の態様における導光体において、前記位相差板は、１／４λ板であってもよい。
In the light guide body according to still another aspect of the present invention, the retardation plate may be a 1 / 4λ plate.
本発明のさらに他の態様における導光体は、透明導光体と、前記透明導光体の内部に分散された前記複数の光機能材料と、を含んでもよい。
The light guide in still another aspect of the present invention may include a transparent light guide and the plurality of optical functional materials dispersed inside the transparent light guide.
本発明のさらに他の態様における導光体は、透明導光体と、前記透明導光体の有する第３主面に設けられ、内部に前記複数の光機能材料が分散された光機能材料層と、を含んでもよい。
The light guide in still another aspect of the present invention is provided with a transparent light guide and a third main surface of the transparent light guide, and an optical functional material layer in which the plurality of optical functional materials are dispersed. And may be included.
本発明のさらに他の態様における導光体は、さらに、剥離可能な粘着層を含み、前記透明導光体と前記光機能材料層とは、前記粘着層で接着されていてもよい。
The light guide in still another aspect of the present invention may further include a peelable adhesive layer, and the transparent light guide and the optical functional material layer may be bonded together by the adhesive layer.
本発明のさらに他の態様における太陽電池モジュールは、前記導光体と、前記導光体の端面から射出された前記光を受光する太陽電池素子と、を備えている。
A solar cell module according to still another aspect of the present invention includes the light guide and a solar cell element that receives the light emitted from an end surface of the light guide.
本発明のさらに他の態様における太陽電池モジュールにおいて、前記複数の光機能材料のうち最も発光スペクトルのピーク波長が大きい光機能材料の発光スペクトルのピーク波長における前記太陽電池素子の分光感度は、前記導光体に備えられた他のいずれの光機能材料の発光スペクトルのピーク波長における前記太陽電池素子の分光感度よりも大きくてもよい。
In the solar cell module according to still another aspect of the present invention, the spectral sensitivity of the solar cell element at the peak wavelength of the emission spectrum of the optical functional material having the largest emission spectrum peak wavelength among the plurality of optical functional materials is calculated as It may be larger than the spectral sensitivity of the solar cell element at the peak wavelength of the emission spectrum of any other optical functional material provided in the light body.
本発明のさらに他の態様における太陽光発電装置は、前記太陽電池モジュールを備えている。
A solar power generation device according to still another aspect of the present invention includes the solar cell module.
本発明のさらに他の態様における太陽電池モジュールは、第１主面と、第２主面と、第１端面を有し、光機能材料を含み、前記第１主面から入射した外光の一部を前記光機能材料によって吸収し、前記光機能材料から放射された光を伝播させて前記第１端面から射出する第１導光体と、第３主面と、第２端面とを有し、前記第１主面と反対側に位置する前記第２主面側に配置され、前記第２主面から透過した光を前記第３主面から入射し、伝播させて前記第２端面から射出する第２導光体と、前記第１端面に設けられて前記第１端面から射出された光を受光する第１太陽電池素子と、前記第２端面に設けられて前記第２端面から射出された光を受光する第２太陽電池素子と、を備える。前記光機能材料は、光を異方的に発する異方性光機能材料を含む。前記異方性光機能材料は、前記異方性光機能材料から発せられる光の発光強度の最も大きい方向と前記第１導光体における前記第１主面の法線とのなす角度が臨界角以上になるように配向されている。
A solar cell module according to still another aspect of the present invention includes a first main surface, a second main surface, and a first end surface, includes an optical functional material, and includes one of external light incident from the first main surface. A first light guide that absorbs a portion by the optical functional material, propagates light emitted from the optical functional material, and exits from the first end surface; a third main surface; and a second end surface The light transmitted from the second main surface is incident on the third main surface, propagates, and is emitted from the second end surface, disposed on the second main surface side opposite to the first main surface. A second light guide body, a first solar cell element provided on the first end face for receiving light emitted from the first end face, and provided on the second end face and emitted from the second end face. A second solar cell element that receives the received light. The optical functional material includes an anisotropic optical functional material that emits light anisotropically. In the anisotropic light functional material, an angle formed by a direction in which the emission intensity of light emitted from the anisotropic light functional material is maximum and a normal line of the first main surface of the first light guide is equal to or greater than a critical angle. Is oriented.
本発明のさらに他の態様における太陽電池モジュールにおいて、前記第１導光体において、前記伝播させ端面から射出させるとは、前記第１主面で反射させ端面から射出させる、前記第２主面で反射させ端面から射出させる、前記第１主面と前記第２主面との間で反射させながら端面から射出させる、もしくは前記第１主面及び前記第２主面のいずれにも入射させることなく端面から射出させる、のいずれかであり、
前記第２導光体は、前記第３主面と対向する第４主面を有し、
前記第２導光体において、前記伝播させ端面から射出させるとは、前記第３主面で反射させ端面から射出させる、前記第４主面で反射させ端面から射出させる、前記第３主面と前記第４主面との間で反射させながら端面から射出させる、もしくは前記第３主面及び前記第４主面のいずれにも入射させることなく端面から射出させる、のいずれかであってもよい。 In the solar cell module according to still another aspect of the present invention, in the first light guide, the propagating and emitting from the end surface means reflecting the first main surface and emitting from the end surface. Reflecting and exiting from the end face, reflecting from between the first main face and the second main face, and exiting from the end face, or entering neither the first main face nor the second main face Either from the end face,
The second light guide has a fourth main surface facing the third main surface,
In the second light guide, the propagating and emitting from the end surface means reflecting from the third main surface and emitting from the end surface, reflecting from the fourth main surface and emitting from the end surface, and the third main surface Either the light is emitted from the end surface while being reflected from the fourth main surface, or the light is emitted from the end surface without being incident on either the third main surface or the fourth main surface. .
前記第２導光体は、前記第３主面と対向する第４主面を有し、
前記第２導光体において、前記伝播させ端面から射出させるとは、前記第３主面で反射させ端面から射出させる、前記第４主面で反射させ端面から射出させる、前記第３主面と前記第４主面との間で反射させながら端面から射出させる、もしくは前記第３主面及び前記第４主面のいずれにも入射させることなく端面から射出させる、のいずれかであってもよい。 In the solar cell module according to still another aspect of the present invention, in the first light guide, the propagating and emitting from the end surface means reflecting the first main surface and emitting from the end surface. Reflecting and exiting from the end face, reflecting from between the first main face and the second main face, and exiting from the end face, or entering neither the first main face nor the second main face Either from the end face,
The second light guide has a fourth main surface facing the third main surface,
In the second light guide, the propagating and emitting from the end surface means reflecting from the third main surface and emitting from the end surface, reflecting from the fourth main surface and emitting from the end surface, and the third main surface Either the light is emitted from the end surface while being reflected from the fourth main surface, or the light is emitted from the end surface without being incident on either the third main surface or the fourth main surface. .
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記異方性光機能材料は、前記第１主面の法線方向から見て、前記異方性光機能材料から発せられる光の発光強度の最も大きい方向が前記第１端面を向くように配向されていいてもよい。
In the solar cell module according to still another aspect of the present invention, the anisotropic light functional material has the highest light emission intensity of light emitted from the anisotropic light functional material when viewed from the normal direction of the first main surface. The direction may be oriented so as to face the first end face.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記異方性光機能材料が、二色性蛍光色素からなる光機能材料を含んでもよい。
Further, in the solar cell module according to still another aspect of the present invention, the anisotropic light functional material may include a light functional material made of a dichroic fluorescent dye.
また、本発明のさらに他の態様における太陽電池モジュールにおいては、前記二色性蛍光色素が、分子長軸と直交する方向が発光強度の最も大きい方向であるポジ型二色性蛍光色素を含んでいてもよい。
Moreover, in the solar cell module according to still another aspect of the present invention, the dichroic fluorescent dye includes a positive dichroic fluorescent dye in which the direction orthogonal to the molecular long axis is the direction with the highest emission intensity. May be.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記光機能材料が複数の光機能材料を含み、これら複数の光機能材料のうちの少なくとも一種が前記二色性蛍光色素からなってもよい。
Moreover, in the solar cell module according to still another aspect of the present invention, the optical functional material includes a plurality of optical functional materials, and at least one of the optical functional materials includes the dichroic fluorescent dye. Good.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記二色性蛍光色素が、前記複数の光機能材料のうち最も発光スペクトルのピーク波長が大きい光機能材料であってもよい。
Further, in the solar cell module according to still another aspect of the present invention, the dichroic fluorescent dye may be an optical functional material having the largest emission spectrum peak wavelength among the plurality of optical functional materials.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記光機能材料が、前記二色性蛍光色素からなる光機能材料と、光を等方的に吸収する等方性光機能材料とを含んでもよい。
In the solar cell module according to still another aspect of the present invention, the optical functional material may include an optical functional material composed of the dichroic fluorescent dye and an isotropic optical functional material that absorbs light isotropically. Good.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記等方性光機能材料は、光を等方的に吸収する吸収等方性を有する材料、もしくは光を異方的に吸収する吸収異方性を有するが、前記第１導光体に含まれる材料に対して配向しにくく、ランダムな状態に配置された光機能材料であってもよい。
Further, in the solar cell module according to still another aspect of the present invention, the isotropic light functional material is a material having absorption isotropic property to absorb light isotropically, or an absorption anisotropic material to absorb light anisotropically. However, it may be an optical functional material that is not easily oriented with respect to the material included in the first light guide and is arranged in a random state.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記光機能材料が、前記二色性蛍光色素からなる複数の光機能材料を含んでもよい。
In the solar cell module according to still another aspect of the present invention, the optical functional material may include a plurality of optical functional materials made of the dichroic fluorescent dye.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記第１導光体では、前記複数の光機能材料の間でフェルスター機構によるエネルギー移動を生じさせ、最も発光スペクトルのピーク波長の大きい光機能材料から放射された光を、前記第１端面から射出させてもよい。
In the solar cell module according to still another aspect of the present invention, the first light guide causes energy transfer by the Forster mechanism between the plurality of optical functional materials, and has the largest peak wavelength of the emission spectrum. The light emitted from the optical functional material may be emitted from the first end face.
また、本発明のさらに他の態様における太陽電池モジュールは、さらに前記第１主面側には、前記第１導光体の外部から入射する外光を拡散させる拡散板を含んでもよい。
Moreover, the solar cell module according to still another aspect of the present invention may further include a diffusion plate that diffuses external light incident from the outside of the first light guide on the first main surface side.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記第２導光体は、前記第３主面と前記第４主面に設けられた傾斜面とで光を反射して伝播させ、前記第２端面から射出する形状導光体であってもよい。
Moreover, in the solar cell module according to still another aspect of the present invention, the second light guide body reflects and propagates light between the third main surface and the inclined surface provided on the fourth main surface, The shape light guide body inject | emitted from the said 2nd end surface may be sufficient.
また、本発明のさらに他の態様における太陽電池モジュールは、さらに前記第４主面側には、前記第４主面側から透過した光を反射する反射層を含んでもよい。
The solar cell module according to still another aspect of the present invention may further include a reflective layer on the fourth main surface side, which reflects light transmitted from the fourth main surface side.
また、本発明のさらに他の態様における太陽電池モジュールにおいて、前記第１太陽電池素子と前記第２太陽電池素子とは、共通の太陽電池素子によって構成されていてもよい。
In the solar cell module according to still another aspect of the present invention, the first solar cell element and the second solar cell element may be configured by a common solar cell element.
本発明のさらに他の態様における太陽光発電装置は、前記の太陽電池モジュールを備えている。
A solar power generation device according to still another aspect of the present invention includes the solar cell module.
本発明の一態様によれば、光の取り出し効率が高い導光体、発電効率の高い太陽電池モジュールおよびこれを用いた太陽光発電装置を提供することができる。
According to one embodiment of the present invention, it is possible to provide a light guide with high light extraction efficiency, a solar cell module with high power generation efficiency, and a solar power generation device using the same.
本発明の他の態様によれば、第１導光体の後方に第２導光体を配置した構造としているので、入射角度が深い光に関しては第１導光体で集光し、垂直に近い角度の入射光に関しては第２導光体で集光することができる。したがって、光の取り出し効率が高く発電効率が高い太陽電池モジュールを提供するとともに、これを用いた太陽光発電装置を提供することができる。
According to another aspect of the present invention, since the second light guide is arranged behind the first light guide, the light having a deep incident angle is condensed by the first light guide and vertically Near-angle incident light can be condensed by the second light guide. Therefore, it is possible to provide a solar cell module with high light extraction efficiency and high power generation efficiency, and a solar power generation apparatus using the solar cell module.
［第１実施形態］
図１は、第１実施形態の太陽電池モジュール１１の概略斜視図である。 [First Embodiment]
FIG. 1 is a schematic perspective view of thesolar cell module 11 of the first embodiment.
図１は、第１実施形態の太陽電池モジュール１１の概略斜視図である。 [First Embodiment]
FIG. 1 is a schematic perspective view of the
太陽電池モジュール１１は、図１に示すように、導光体１４（蛍光導光体）と、太陽電池素子１６と、枠体１１０と、を備えている。太陽電池素子１６は、導光体１４の端面１４ｃから射出された光を受光する太陽電池素子１６。枠体１１０は、導光体１４と太陽電池素子１６とを一体に保持する枠体１１０。
As shown in FIG. 1, the solar cell module 11 includes a light guide 14 (fluorescent light guide), a solar cell element 16, and a frame 110. The solar cell element 16 is a solar cell element 16 that receives light emitted from the end face 14 c of the light guide 14. The frame 110 is a frame 110 that integrally holds the light guide 14 and the solar cell element 16.
導光体１４は、第１主面１４ａと、第２主面１４ｂと、端面１４ｃと、を備えている。第１主面１４ａは、外光Ｌが入射する光入射面である第１主面１４ａ。第２主面１４ｂは、第１主面１４ａと対向する。第２主面１４ｂ端面１４ｃは、光射出面である端面１４ｃ。
The light guide 14 includes a first main surface 14a, a second main surface 14b, and an end surface 14c. The first main surface 14a is a first main surface 14a that is a light incident surface on which external light L is incident. The second main surface 14b faces the first main surface 14a. The end surface 14c of the second main surface 14b is an end surface 14c that is a light emission surface.
なお、本実施形態において、導光体１４の第１主面１４ａの面内に平行な方向をｘ軸方向、ｘ軸方向と直交する方向をｙ軸方向、第１主面１４ａと直交する方向（導光体１４の厚み方向）をｚ軸方向、と定義する。
In the present embodiment, the direction parallel to the first main surface 14a of the light guide 14 is the x-axis direction, the direction orthogonal to the x-axis direction is the y-axis direction, and the direction orthogonal to the first main surface 14a. (Thickness direction of the light guide 14) is defined as the z-axis direction.
導光体１４は、第１主面１４ａ及び第２主面１４ｂを有する略矩形の板状部材である。導光体１４の第１主面１４ａ及び第２主面１４ｂは平坦な面である。本実施形態において、導光体１４は、液晶性ポリマーからなる基材（透明基板）の内部に、複数の光機能材料を分散させたものである。複数の光機能材料のうち少なくとも１つの光機能材料は蛍光体である。蛍光体から放射された光は、導光体１４の内部を伝播して端面１４ｃから射出され、太陽電池素子１６で発電に利用される。
The light guide 14 is a substantially rectangular plate-like member having a first main surface 14a and a second main surface 14b. The first main surface 14a and the second main surface 14b of the light guide 14 are flat surfaces. In this embodiment, the light guide 14 is obtained by dispersing a plurality of optical functional materials in a base material (transparent substrate) made of a liquid crystalline polymer. At least one of the plurality of optical functional materials is a phosphor. The light emitted from the phosphor propagates through the light guide 14 and is emitted from the end face 14 c, and is used for power generation by the solar cell element 16.
太陽電池素子１６は、受光面を導光体１４の４つの端面１４ｃと対向させて配置されている。
太陽電池素子１６は、端面１４ｃと光学接着されていることが好ましい。太陽電池素子１６としては、シリコン系太陽電池、化合物系太陽電池、有機系太陽電池などの公知の太陽電池を使用することができる。中でも、化合物半導体を用いた化合物系太陽電池は、高効率な発電が可能であることから、太陽電池素子１６として好適である。化合物系太陽電池としては、ＩｎＧａＰ、ＧａＡｓ、ＩｎＧａＡｓ，ＡｌＧａＡｓ、Ｃｕ（Ｉｎ，Ｇａ）Ｓｅ２、Ｃｕ（Ｉｎ，Ｇａ）（Ｓｅ，Ｓ）２、ＣｕＩｎＳ２、ＣｄＴｅ、ＣｄＳ等が挙げられる。また、量子ドット太陽電池としては、Ｓｉ、ＩｎＧａＡｓ等が挙げられる。 Thesolar cell element 16 is disposed with the light receiving surface facing the four end surfaces 14 c of the light guide 14.
Thesolar cell element 16 is preferably optically bonded to the end face 14c. As the solar cell element 16, a known solar cell such as a silicon solar cell, a compound solar cell, or an organic solar cell can be used. Among these, a compound solar cell using a compound semiconductor is suitable as the solar cell element 16 because it can generate power with high efficiency. Examples of compound solar cells include InGaP, GaAs, InGaAs, AlGaAs, Cu (In, Ga) Se 2 , Cu (In, Ga) (Se, S) 2 , CuInS 2 , CdTe, CdS, and the like. Examples of the quantum dot solar cell include Si and InGaAs.
太陽電池素子１６は、端面１４ｃと光学接着されていることが好ましい。太陽電池素子１６としては、シリコン系太陽電池、化合物系太陽電池、有機系太陽電池などの公知の太陽電池を使用することができる。中でも、化合物半導体を用いた化合物系太陽電池は、高効率な発電が可能であることから、太陽電池素子１６として好適である。化合物系太陽電池としては、ＩｎＧａＰ、ＧａＡｓ、ＩｎＧａＡｓ，ＡｌＧａＡｓ、Ｃｕ（Ｉｎ，Ｇａ）Ｓｅ２、Ｃｕ（Ｉｎ，Ｇａ）（Ｓｅ，Ｓ）２、ＣｕＩｎＳ２、ＣｄＴｅ、ＣｄＳ等が挙げられる。また、量子ドット太陽電池としては、Ｓｉ、ＩｎＧａＡｓ等が挙げられる。 The
The
図１では、太陽電池素子１６を導光体１４の４つの端面に設置した例を示したが、太陽電池素子１６は導光体１４の４の端面のうち一部の端面に設置してもよい。太陽電池素子１６を導光体１４の一部の端面（１辺、２辺または３辺）に設置する場合には、太陽電池素子が設置されていない端面には、導光体１４の内部から導光体１４の外部に向けて進行する光を導光体１４の内部に向けて反射する反射層を設置することが好ましい。
In FIG. 1, an example in which the solar cell element 16 is installed on the four end surfaces of the light guide 14 is shown, but the solar cell element 16 may be installed on a part of the four end surfaces of the light guide 14. Good. In the case where the solar cell element 16 is installed on a part of the end face (one side, two sides, or three sides) of the light guide body 14, the end face where the solar cell element is not installed is provided from the inside of the light guide body 14. It is preferable to install a reflective layer that reflects light traveling toward the outside of the light guide 14 toward the inside of the light guide 14.
枠体１１０は、導光体１４の第１主面１４ａと対向する面に光Ｌを透過する透過面１１０ａを備えている。透過面１１０ａは枠体１１０の開口部であってもよく、枠体１１０の開口部に嵌め込まれたガラス等の透明部材であってもよい。導光体１４の第１主面１４ａが光入射面である。
第１主面１４ａのうち枠体１１０の透過面１１０ａとＺ方向から見て重なる部分が光入射領域である。導光体１４の４つの端面１４ｃが導光体１４の光射出面である。 Theframe body 110 includes a transmission surface 110 a that transmits the light L on a surface facing the first main surface 14 a of the light guide body 14. The transmission surface 110a may be an opening of the frame 110, or may be a transparent member such as glass fitted into the opening of the frame 110. The first main surface 14a of the light guide 14 is a light incident surface.
A portion of the firstmain surface 14a that overlaps the transmission surface 110a of the frame 110 when viewed from the Z direction is a light incident region. The four end faces 14 c of the light guide body 14 are the light exit faces of the light guide body 14.
第１主面１４ａのうち枠体１１０の透過面１１０ａとＺ方向から見て重なる部分が光入射領域である。導光体１４の４つの端面１４ｃが導光体１４の光射出面である。 The
A portion of the first
図２は、太陽電池モジュール１１の断面図である。
FIG. 2 is a cross-sectional view of the solar cell module 11.
導光体１４の内部には、複数の光機能材料が含まれている。複数の光機能材料は、第１光機能材料１２と、第２光機能材料１８と、を含む。
The light guide body 14 includes a plurality of optical functional materials. The plurality of optical functional materials include a first optical functional material 12 and a second optical functional material 18.
第２光機能材料１８は、光を等方的に吸収する性質（吸収等方性）を有する材料である。
または、光を異方的に吸収する性質（吸収異方性）を有するが、導光体の形成材料に対して配向しにくく、ランダムな状態の光機能材料である。 The second opticalfunctional material 18 is a material having a property of absorbing light isotropically (absorption isotropic property).
Alternatively, the optical functional material has a property of absorbing light anisotropically (absorption anisotropy) but is difficult to be oriented with respect to the light guide forming material and is in a random state.
または、光を異方的に吸収する性質（吸収異方性）を有するが、導光体の形成材料に対して配向しにくく、ランダムな状態の光機能材料である。 The second optical
Alternatively, the optical functional material has a property of absorbing light anisotropically (absorption anisotropy) but is difficult to be oriented with respect to the light guide forming material and is in a random state.
第１光機能材料１２は、光を異方的に発光する性質（発光異方性）を有する材料である。
The first optical functional material 12 is a material having a property of emitting light anisotropically (light emission anisotropy).
本実施形態の場合、導光体１４の内部には、光機能材料として、光を等方的に吸収する第２光機能材料１８と、光を異方的に発する第１光機能材料１２とが含まれている。
In the case of the present embodiment, in the light guide 14, as the optical functional material, a second optical functional material 18 that absorbs light isotropically, and a first optical functional material 12 that emits light anisotropically, It is included.
第２光機能材料１８としては、所定の吸収波長域の蛍光体を用いる。蛍光体１８は、外光を吸収して蛍光を放射する。蛍光体１８は、例えば、導光体１４を成型する際に混入される。
As the second optical functional material 18, a phosphor having a predetermined absorption wavelength region is used. The phosphor 18 absorbs external light and emits fluorescence. For example, the phosphor 18 is mixed when the light guide 14 is molded.
第１光機能材料１２としては、二色性蛍光色素からなる光機能材料を用いる。「二色性蛍光色素」とは、光を異方的に吸収する性質（吸収異方性）と光を異方的に発する性質（発光異方性）とを有する色素である。本実施形態においては、二色性蛍光色素からなる第１光機能材料として、分子長軸と直交する方向が発光強度の最も大きい方向であるポジ型二色性蛍光色素を用いている。
As the first optical functional material 12, an optical functional material made of a dichroic fluorescent dye is used. The “dichroic fluorescent dye” is a dye having a property of absorbing light anisotropically (absorption anisotropy) and a property of emitting light anisotropically (light emission anisotropy). In the present embodiment, a positive dichroic fluorescent dye having a direction with the highest emission intensity is used as the first optical functional material made of the dichroic fluorescent dye.
なお、二色性蛍光色素としては、ポジ型二色性蛍光色素に限らず、種々の二色性蛍光色素を用いることができる。例えば、分子長軸の方向が発光強度の最も大きい方向であるネガ型二色性蛍光色素を用いることもできる。
The dichroic fluorescent dye is not limited to a positive dichroic fluorescent dye, and various dichroic fluorescent dyes can be used. For example, a negative dichroic fluorescent dye in which the direction of the molecular long axis is the direction in which the emission intensity is the highest can also be used.
図３Ａ及び図３Ｂは、二色性蛍光色素の特性を示す図である。図３Ａは、二色性蛍光色素の吸収特性を示す図である。図３Ｂは、二色性蛍光色素の発光特性を示す図である。なお、図３Ａ、図３Ｂにおいて、符号Ｖ１は二色性蛍光色素１２の分子長軸であり、符号Ｖ２は分子長軸Ｖ１と直交する軸である。
3A and 3B are diagrams showing the characteristics of the dichroic fluorescent dye. FIG. 3A is a diagram showing the absorption characteristics of a dichroic fluorescent dye. FIG. 3B is a diagram showing the light emission characteristics of the dichroic fluorescent dye. 3A and 3B, the symbol V1 is the molecular long axis of the dichroic fluorescent dye 12, and the symbol V2 is an axis orthogonal to the molecular long axis V1.
本実施形態の二色性蛍光色素１２は、図３Ａに示すように、吸収異方性を有している。例えば、二色性蛍光色素１２に対して下方から分子長軸Ｖ１に沿う方向に入射する光の吸収特性を見ると、二色性蛍光色素１２に入射する前と二色性蛍光色素１２を経由した後とにおいて吸収特性を示す曲線の高さがほとんど変化しない。二色性蛍光色素１２は、下方から分子長軸Ｖ１に沿う方向に入射する光をほとんど吸収しない。
一方、二色性蛍光色素１２に対して左側から分子長軸と直交する軸Ｖ２に沿う方向に入射する光の吸収特性を見ると、二色性蛍光色素１２に入射する前と二色性蛍光色素１２を経由した後とでは二色性蛍光色素１２を経由した後の方が吸収特性を示す曲線の高さが小さい。二色性蛍光色素１２は、左側から分子長軸と直交する軸Ｖ２に沿う方向に入射する光については大部分を吸収する。このように、本実施形態の二色性蛍光色素１２は、分子長軸Ｖ１に沿う方向においては相対的に吸収特性が小さく、分子長軸と直交する軸Ｖ２に沿う方向においては相対的に吸収特性が大きい。 As shown in FIG. 3A, the dichroicfluorescent dye 12 of this embodiment has absorption anisotropy. For example, when the absorption characteristics of light incident on the dichroic fluorescent dye 12 from below in the direction along the molecular long axis V1 are viewed, before entering the dichroic fluorescent dye 12 and via the dichroic fluorescent dye 12 The height of the curve showing the absorption characteristics hardly changes after and after. The dichroic fluorescent dye 12 hardly absorbs light incident in the direction along the molecular long axis V1 from below.
On the other hand, when the absorption characteristics of light incident on the dichroicfluorescent dye 12 from the left side in the direction along the axis V2 orthogonal to the molecular long axis are seen, the dichroic fluorescence before entering the dichroic fluorescent dye 12 After passing through the dye 12, the height of the curve showing the absorption characteristics is smaller after passing through the dichroic fluorescent dye 12. The dichroic fluorescent dye 12 absorbs most of the light incident in the direction along the axis V2 orthogonal to the molecular long axis from the left side. As described above, the dichroic fluorescent dye 12 of the present embodiment has relatively small absorption characteristics in the direction along the molecular long axis V1, and relatively absorbs in the direction along the axis V2 orthogonal to the molecular long axis. Great characteristics.
一方、二色性蛍光色素１２に対して左側から分子長軸と直交する軸Ｖ２に沿う方向に入射する光の吸収特性を見ると、二色性蛍光色素１２に入射する前と二色性蛍光色素１２を経由した後とでは二色性蛍光色素１２を経由した後の方が吸収特性を示す曲線の高さが小さい。二色性蛍光色素１２は、左側から分子長軸と直交する軸Ｖ２に沿う方向に入射する光については大部分を吸収する。このように、本実施形態の二色性蛍光色素１２は、分子長軸Ｖ１に沿う方向においては相対的に吸収特性が小さく、分子長軸と直交する軸Ｖ２に沿う方向においては相対的に吸収特性が大きい。 As shown in FIG. 3A, the dichroic
On the other hand, when the absorption characteristics of light incident on the dichroic
本実施形態の二色性蛍光色素１２は、図３Ｂに示すように、発光異方性を有している。分子長軸Ｖ１に沿う方向が発光強度の最も小さい方向となっている。一方、分子長軸と直交する軸Ｖ２に沿う方向が発光強度の最も大きい方向となっている。このように、本実施形態の二色性蛍光色素１２は、分子長軸Ｖ１に沿う方向においては相対的に発光強度が小さく、分子長軸と直交する軸Ｖ２に沿う方向においては相対的に発光強度が大きい。
The dichroic fluorescent dye 12 of the present embodiment has emission anisotropy as shown in FIG. 3B. The direction along the molecular long axis V1 is the direction with the smallest emission intensity. On the other hand, the direction along the axis V2 orthogonal to the molecular long axis is the direction with the highest emission intensity. As described above, the dichroic fluorescent dye 12 of the present embodiment has a relatively small emission intensity in the direction along the molecular long axis V1, and relatively emits light in the direction along the axis V2 orthogonal to the molecular long axis. High strength.
図４は、二色性蛍光色素の配向状態を示す図である。なお、図４において、符号Ｖ１は二色性蛍光色素１２の分子長軸であり、符号Ｖ２は分子長軸Ｖ１と直交する軸である。
FIG. 4 is a diagram showing the orientation state of the dichroic fluorescent dye. In FIG. 4, the symbol V1 is the molecular long axis of the dichroic fluorescent dye 12, and the symbol V2 is an axis orthogonal to the molecular long axis V1.
本実施形態の二色性蛍光色素１２は、図４に示すように、分子長軸と直交する軸Ｖ２と導光体１４の第１主面１４ａとが平行になるように配向されている。つまり、本実施形態の二色性蛍光色素１２は、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が導光体１４の第１主面１４ａと平行になるように配向されている。
As shown in FIG. 4, the dichroic fluorescent dye 12 of this embodiment is oriented so that the axis V2 orthogonal to the molecular long axis and the first main surface 14a of the light guide 14 are parallel to each other. That is, the dichroic fluorescent dye 12 of this embodiment is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 14a of the light guide 14. Has been.
なお、本実施形態の導光体１４は、Ｚ軸に垂直な（ＸＹ平面と平行な）第１主面１４ａ及び第２主面１４ｂを有する略矩形の板状部材である。そのため、本実施形態の二色性蛍光色素１２は、分子長軸と直交する軸Ｖ２と導光体１４の第２主面１４ｂとが平行になるように配向されている。つまり、本実施形態の二色性蛍光色素１２は、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が導光体１４の第２主面１４ｂと平行になるように配向されている。
In addition, the light guide 14 of this embodiment is a substantially rectangular plate-like member having a first main surface 14a and a second main surface 14b that are perpendicular to the Z axis (parallel to the XY plane). Therefore, the dichroic fluorescent dye 12 of this embodiment is oriented so that the axis V2 orthogonal to the molecular long axis and the second main surface 14b of the light guide 14 are parallel to each other. That is, the dichroic fluorescent dye 12 of this embodiment is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the second main surface 14b of the light guide 14. Has been.
ここで、二色性蛍光色素１２を配向させるための方法について一例を挙げて説明する。
二色性蛍光色素１２を配向させるため、導光体の形成材料としては液晶高分子等を用いる。例えば、ＤＩＣ社製の液晶性ポリマー（ＵＣＬ０１８）を用いる。
先ず、ＵＣＬ０１８（ＤＩＣ社製高分子液晶）、Ｃｏｕｍａｒｉｎ６（二色性蛍光色素）、ＦＣ－４４３０（界面活性剤）、及びトルエンを混合する。各材料の混合割合は、ＵＣＬ０１８（４０％）、Ｃｏｕｍａｒｉｎ６（０．４０％）、ＦＣ－４４３０（０．４０％）、トルエン（５９．２％）とする。
次に、生成した混合溶液を、基板上にスピンキャスト製法を用いて塗布する。塗布条件は２０ｓｅｃ、５００ｒｐｍで製膜し、厚さ１μmの膜を形成する。ただし、製膜条件はこれに限らず、回転時間、回転速度は適宜変更し、膜厚も蛍光色素の光の吸収量に合わせて変えることとする。ここではスピンキャスト製法についての一例の詳細を記載したが、製法はこれに限定せず、スリットコート、ディップコート、ロールコート、バーコート等の製法をとってもよい。
次に、混合溶液を塗布した基板を、ホットプレート上に載置し、処理温度５０℃、処理時間１ｍｉｎの条件で熱処理し、混合溶液中の溶媒を蒸発させる。
次に、処理温度を室温まで下げる。
次に、ＵＶランプを用いてｉ線（３６５ｎｍ）を照射し、処理時間２ｍｉｎで露光する。
以上の工程により、二色性蛍光色素１２を配向させることができる。 Here, a method for orienting the dichroicfluorescent dye 12 will be described with an example.
In order to align the dichroicfluorescent dye 12, a liquid crystal polymer or the like is used as a light guide forming material. For example, a liquid crystal polymer (UCL018) manufactured by DIC is used.
First, UCL018 (polymer liquid crystal manufactured by DIC), Coumarin 6 (dichroic fluorescent dye), FC-4430 (surfactant), and toluene are mixed. The mixing ratio of each material is UCL018 (40%), Coumarin 6 (0.40%), FC-4430 (0.40%), and toluene (59.2%).
Next, the produced mixed solution is applied onto the substrate using a spin cast manufacturing method. The coating conditions are 20 sec and film formation at 500 rpm to form a film having a thickness of 1 μm. However, the film forming conditions are not limited to this, and the rotation time and the rotation speed are appropriately changed, and the film thickness is also changed in accordance with the light absorption amount of the fluorescent dye. Although details of an example of the spin cast manufacturing method are described here, the manufacturing method is not limited to this, and a manufacturing method such as slit coating, dip coating, roll coating, or bar coating may be used.
Next, the substrate on which the mixed solution is applied is placed on a hot plate and heat-treated under the conditions of a processing temperature of 50 ° C. and a processing time of 1 min to evaporate the solvent in the mixed solution.
Next, the processing temperature is lowered to room temperature.
Next, i-line (365 nm) is irradiated using a UV lamp, and exposure is performed for a processing time of 2 min.
Through the above steps, the dichroicfluorescent dye 12 can be oriented.
二色性蛍光色素１２を配向させるため、導光体の形成材料としては液晶高分子等を用いる。例えば、ＤＩＣ社製の液晶性ポリマー（ＵＣＬ０１８）を用いる。
先ず、ＵＣＬ０１８（ＤＩＣ社製高分子液晶）、Ｃｏｕｍａｒｉｎ６（二色性蛍光色素）、ＦＣ－４４３０（界面活性剤）、及びトルエンを混合する。各材料の混合割合は、ＵＣＬ０１８（４０％）、Ｃｏｕｍａｒｉｎ６（０．４０％）、ＦＣ－４４３０（０．４０％）、トルエン（５９．２％）とする。
次に、生成した混合溶液を、基板上にスピンキャスト製法を用いて塗布する。塗布条件は２０ｓｅｃ、５００ｒｐｍで製膜し、厚さ１μmの膜を形成する。ただし、製膜条件はこれに限らず、回転時間、回転速度は適宜変更し、膜厚も蛍光色素の光の吸収量に合わせて変えることとする。ここではスピンキャスト製法についての一例の詳細を記載したが、製法はこれに限定せず、スリットコート、ディップコート、ロールコート、バーコート等の製法をとってもよい。
次に、混合溶液を塗布した基板を、ホットプレート上に載置し、処理温度５０℃、処理時間１ｍｉｎの条件で熱処理し、混合溶液中の溶媒を蒸発させる。
次に、処理温度を室温まで下げる。
次に、ＵＶランプを用いてｉ線（３６５ｎｍ）を照射し、処理時間２ｍｉｎで露光する。
以上の工程により、二色性蛍光色素１２を配向させることができる。 Here, a method for orienting the dichroic
In order to align the dichroic
First, UCL018 (polymer liquid crystal manufactured by DIC), Coumarin 6 (dichroic fluorescent dye), FC-4430 (surfactant), and toluene are mixed. The mixing ratio of each material is UCL018 (40%), Coumarin 6 (0.40%), FC-4430 (0.40%), and toluene (59.2%).
Next, the produced mixed solution is applied onto the substrate using a spin cast manufacturing method. The coating conditions are 20 sec and film formation at 500 rpm to form a film having a thickness of 1 μm. However, the film forming conditions are not limited to this, and the rotation time and the rotation speed are appropriately changed, and the film thickness is also changed in accordance with the light absorption amount of the fluorescent dye. Although details of an example of the spin cast manufacturing method are described here, the manufacturing method is not limited to this, and a manufacturing method such as slit coating, dip coating, roll coating, or bar coating may be used.
Next, the substrate on which the mixed solution is applied is placed on a hot plate and heat-treated under the conditions of a processing temperature of 50 ° C. and a processing time of 1 min to evaporate the solvent in the mixed solution.
Next, the processing temperature is lowered to room temperature.
Next, i-line (365 nm) is irradiated using a UV lamp, and exposure is performed for a processing time of 2 min.
Through the above steps, the dichroic
ここで、二色性蛍光色素１２の配向状態を検証するための方法について一例を挙げて説明する。
先ず、二色性蛍光色素１２を含む導光体１４に対して各方向から所定の波長帯域の光を入射させ、光の入射方向によって光の吸収量が異なるところがあるか否かを検証する。光の吸収量が異なるところがある場合には、その光の波長を調べる。この光の波長が二色性蛍光色素１２の吸収波長となる。
次に、導光体１４に対して二色性蛍光色素１２の吸収波長に相当する光を入射させ、閉じ込め効率（二色性蛍光色素１２の光の吸収効率）が、等方発光していると仮定した場合に比べて、高い値を示していることを確認する。（等方発光している場合、導光体の屈折率が１．５のとき閉じ込め効率は７５%となる。）
次に、導光体１４に対して二色性蛍光色素１２の吸収波長以外の波長の光を入射させ、導光体１４の端面から射出される光が二色性蛍光色素１２の発光波長であることを確認する。
以上のフローにより、二色性蛍光色素１２の配向状態を検証することができる。 Here, an example is given and demonstrated about the method for verifying the orientation state of the dichroicfluorescent dye 12. FIG.
First, light of a predetermined wavelength band is incident on thelight guide body 14 including the dichroic fluorescent dye 12 from each direction, and it is verified whether or not there is a place where the amount of light absorption differs depending on the light incident direction. If there is a difference in the amount of light absorption, the wavelength of the light is examined. The wavelength of this light becomes the absorption wavelength of the dichroic fluorescent dye 12.
Next, light corresponding to the absorption wavelength of the dichroicfluorescent dye 12 is incident on the light guide body 14, and confinement efficiency (light absorption efficiency of the dichroic fluorescent dye 12) is isotropically emitted. It is confirmed that the value is higher than that assumed. (When isotropic light is emitted, the confinement efficiency is 75% when the refractive index of the light guide is 1.5.)
Next, light having a wavelength other than the absorption wavelength of the dichroicfluorescent dye 12 is incident on the light guide 14, and the light emitted from the end face of the light guide 14 is the emission wavelength of the dichroic fluorescent dye 12. Make sure that there is.
With the above flow, the orientation state of the dichroicfluorescent dye 12 can be verified.
先ず、二色性蛍光色素１２を含む導光体１４に対して各方向から所定の波長帯域の光を入射させ、光の入射方向によって光の吸収量が異なるところがあるか否かを検証する。光の吸収量が異なるところがある場合には、その光の波長を調べる。この光の波長が二色性蛍光色素１２の吸収波長となる。
次に、導光体１４に対して二色性蛍光色素１２の吸収波長に相当する光を入射させ、閉じ込め効率（二色性蛍光色素１２の光の吸収効率）が、等方発光していると仮定した場合に比べて、高い値を示していることを確認する。（等方発光している場合、導光体の屈折率が１．５のとき閉じ込め効率は７５%となる。）
次に、導光体１４に対して二色性蛍光色素１２の吸収波長以外の波長の光を入射させ、導光体１４の端面から射出される光が二色性蛍光色素１２の発光波長であることを確認する。
以上のフローにより、二色性蛍光色素１２の配向状態を検証することができる。 Here, an example is given and demonstrated about the method for verifying the orientation state of the dichroic
First, light of a predetermined wavelength band is incident on the
Next, light corresponding to the absorption wavelength of the dichroic
Next, light having a wavelength other than the absorption wavelength of the dichroic
With the above flow, the orientation state of the dichroic
図５Ａ～図５Ｃは、二色性蛍光色素の作用を説明するための図である。図５Ａは、蛍光体１８（第２光機能材料）と二色性蛍光色素１２（第１光機能材料）との間でエネルギー移動が生じる様子を示した図である。図５Ｂおよび図５Ｃは、二色性蛍光色素１２が発した光が導光体１４の内部を伝播する様子を示した図である。なお、図５Ｃにおいて、符号θは、二色性蛍光色素１２が発する光の一部の光Ｌ１の進行方向と導光体１４の第２主面１４ｂの法線とのなす角度、符号θｍは、臨界角である。
5A to 5C are diagrams for explaining the action of the dichroic fluorescent dye. FIG. 5A is a diagram illustrating how energy transfer occurs between the phosphor 18 (second optical functional material) and the dichroic fluorescent dye 12 (first optical functional material). FIG. 5B and FIG. 5C are diagrams showing how the light emitted from the dichroic fluorescent dye 12 propagates inside the light guide 14. In FIG. 5C, the symbol θ is an angle formed by the traveling direction of a part of the light L1 emitted from the dichroic fluorescent dye 12 and the normal line of the second main surface 14b of the light guide 14, and the symbol θm is Is the critical angle.
図５Ａに示すように、導光体１４の第１主面１４ａに入射した外光の一部は、蛍光体１８によって吸収される。蛍光体１８が外光の一部を吸収すると、蛍光体１８から二色性蛍光色素１２に向けて励起エネルギーが移動する。
As shown in FIG. 5A, a part of the external light incident on the first main surface 14 a of the light guide 14 is absorbed by the phosphor 18. When the phosphor 18 absorbs part of the external light, the excitation energy moves from the phosphor 18 toward the dichroic fluorescent dye 12.
図５Ｂに示すように、二色性蛍光色素１２は、蛍光体１８からの励起エネルギーによって光を異方的に発する。本実施形態の二色性蛍光色素１２は、この二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が導光体１４の第１主面１４ａと平行になるように配向されている。そのため、二色性蛍光色素１２が発する光のうち発光強度の最も大きい光は、太陽電池素子１６に直接導かれる。なお、二色性蛍光色素１２が蛍光体１８からの励起エネルギーによって光を異方的に発する機構については後述する。
As shown in FIG. 5B, the dichroic fluorescent dye 12 emits light anisotropically by excitation energy from the phosphor 18. The dichroic fluorescent dye 12 of this embodiment is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 14a of the light guide 14. Yes. Therefore, light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the solar cell element 16. The mechanism by which the dichroic fluorescent dye 12 emits light anisotropically by excitation energy from the phosphor 18 will be described later.
図５Ｃに示すように、二色性蛍光色素１２が発する光のうちの大部分の光は、導光体１４の第１主面１４ａまたは第２主面１４ｂへの入射角θが大きくなる。
As shown in FIG. 5C, most of the light emitted from the dichroic fluorescent dye 12 has a large incident angle θ on the first main surface 14 a or the second main surface 14 b of the light guide 14.
ここで、例えば導光体１４を構成する液晶性ポリマーの屈折率が１．５、空気の屈折率を１．０とすると、導光体１４の第２主面１４ｂにおける臨界角θｍ、すなわち導光体１４を構成する液晶性ポリマーと空気との界面における臨界角は、スネルの法則から４２°程度となる。二色性蛍光色素１２が発する光の一部の光Ｌ１が第２主面１４ｂに入射した際、第２主面１４ｂへの光Ｌ１の入射角が臨界角である４２°よりも大きい場合は全反射条件を満たすため、光Ｌは第２主面１４ｂで全反射する。その後、光Ｌが第１主面１４ａと第２主面１４ｂとの間で反射を繰り返し、太陽電池素子１６に導かれる。
Here, for example, when the refractive index of the liquid crystalline polymer constituting the light guide 14 is 1.5 and the refractive index of air is 1.0, the critical angle θm in the second main surface 14b of the light guide 14, that is, the guide The critical angle at the interface between the liquid crystalline polymer constituting the light body 14 and air is about 42 ° from Snell's law. When a part of the light L1 emitted from the dichroic fluorescent dye 12 is incident on the second main surface 14b, the incident angle of the light L1 on the second main surface 14b is larger than 42 ° which is a critical angle. Since the total reflection condition is satisfied, the light L is totally reflected by the second main surface 14b. Thereafter, the light L is repeatedly reflected between the first main surface 14 a and the second main surface 14 b and guided to the solar cell element 16.
なお、本実施形態の二色性蛍光色素１２は、この二色性蛍光色素１２から発せられる光の発光強度の最も小さい方向が導光体１４の第１主面１４ａと直交する。二色性蛍光色素１２が発する光のうち分子長軸に沿う方向からの光Ｌ２が第２主面１４ｂに入射した際、第２主面１４ｂへの光Ｌ２の入射角が臨界角である４２°よりも小さくなり、全反射条件を満たさなくなるため、光Ｌ２は外部空間に射出される。
Note that, in the dichroic fluorescent dye 12 of the present embodiment, the direction in which the emission intensity of light emitted from the dichroic fluorescent dye 12 is the smallest is orthogonal to the first main surface 14 a of the light guide 14. When light L2 from the direction along the molecular long axis of light emitted from the dichroic fluorescent dye 12 is incident on the second main surface 14b, the incident angle of the light L2 on the second main surface 14b is a critical angle 42. Since it becomes smaller than ° and does not satisfy the total reflection condition, the light L2 is emitted to the external space.
すなわち、二色性蛍光色素１２が発する光は、第１主面１４ａまたは第２主面１４ｂへの入射角が臨界角よりも大きい場合は導光体１４の内部に閉じ込められ、第１主面１４ａまたは第２主面１４ｂへの入射角が臨界角よりも小さい場合は外部に射出される。本実施形態において、二色性蛍光色素１２は、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が導光体１４の第１主面１４ａと平行になるように配向されている。そのため、二色性蛍光色素１２が発する光のうちの大部分の光は、導光体１４の第１主面１４ａまたは第２主面１４ｂへの入射角θが大きくなり、全反射条件を満たすこととなる。よって、二色性蛍光色素１２が発する光のうちの大部分の光が、導光体１４の内部に閉じ込められ、外部に射出されることなく、太陽電池素子１６に導かれる。
That is, the light emitted from the dichroic fluorescent dye 12 is confined inside the light guide 14 when the angle of incidence on the first main surface 14a or the second main surface 14b is larger than the critical angle, and the first main surface When the incident angle to 14a or the second main surface 14b is smaller than the critical angle, the light is emitted to the outside. In the present embodiment, the dichroic fluorescent dye 12 is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 14 a of the light guide 14. ing. Therefore, most of the light emitted from the dichroic fluorescent dye 12 has a large incident angle θ on the first main surface 14a or the second main surface 14b of the light guide 14 and satisfies the total reflection condition. It will be. Therefore, most of the light emitted from the dichroic fluorescent dye 12 is confined inside the light guide 14 and guided to the solar cell element 16 without being emitted outside.
以上のように、本実施形態の太陽電池モジュール１１では、導光体１４の内部に、二色性蛍光色素１２が含まれており、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が導光体１４の太陽電池素子１６が配置された端面を向くように配向されている。本実施形態においては、二色性蛍光色素１２が発する光のうち発光強度の最も大きい方向が導光体１４の第１主面１４ａに平行であるため、導光体１４に入射した太陽光の大部分が太陽電池素子１６に直接導かれる。これにより、導光体１４に入射した太陽光の大部分が太陽電池素子１６に到達するまでに導光体１４を透過してしまうことが抑制される。よって、導光体１４に入射した太陽光の大部分を発電に寄与させることができる。したがって、発電効率の高い太陽電池モジュールを提供することができる。
As described above, in the solar cell module 11 of the present embodiment, the dichroic fluorescent dye 12 is included in the light guide 14, and the light emission intensity of the light emitted from the dichroic fluorescent dye 12 is increased. It is oriented so that the largest direction faces the end surface of the light guide 14 on which the solar cell element 16 is disposed. In the present embodiment, the direction in which the emission intensity is the largest among the light emitted from the dichroic fluorescent dye 12 is parallel to the first main surface 14a of the light guide 14, so that the sunlight incident on the light guide 14 is Most of them are directly led to the solar cell element 16. Thereby, it is suppressed that most of the sunlight incident on the light guide body 14 is transmitted through the light guide body 14 before reaching the solar cell element 16. Therefore, most of the sunlight incident on the light guide 14 can be contributed to power generation. Therefore, a solar cell module with high power generation efficiency can be provided.
なお、本実施形態においては、分子長軸と直交する軸Ｖ２と導光体１４の第１主面１４ａとが平行になるように配向されている構成を例に挙げて説明したが、これに限らない。
In the present embodiment, the configuration in which the axis V2 orthogonal to the molecular long axis and the first main surface 14a of the light guide 14 are aligned in parallel has been described as an example. Not exclusively.
図６は、二色性蛍光色素の配向状態の他の例を示す図である。なお、図６において、符号Ｖ１は二色性蛍光色素１２の分子長軸であり、符号Ｖ２は分子長軸Ｖ１と直交する軸である。
FIG. 6 is a diagram showing another example of the orientation state of the dichroic fluorescent dye. In FIG. 6, symbol V1 is a molecular long axis of the dichroic fluorescent dye 12, and symbol V2 is an axis orthogonal to the molecular long axis V1.
例えば、本実施形態の二色性蛍光色素１２は、図６に示すように、分子長軸と直交する軸Ｖ２と導光体１４の第２主面１４ｂの法線とのなす角度θが臨界角θｍ以上となるように配向されていてもよい。つまり、本実施形態の二色性蛍光色素１２は、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向と導光体１４の第２主面１４ｂの法線のなす角度θが臨界角θｍ以上となるように配向されていればよい。
For example, in the dichroic fluorescent dye 12 of the present embodiment, as shown in FIG. 6, the angle θ formed by the axis V2 orthogonal to the molecular long axis and the normal line of the second main surface 14b of the light guide 14 is critical. It may be oriented so that it has an angle θm or more. In other words, the dichroic fluorescent dye 12 of the present embodiment has an angle θ formed by the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is highest and the normal line of the second main surface 14b of the light guide 14. May be oriented so as to be not less than the critical angle θm.
なお、本実施形態の導光体１４は、第１主面１４ａ及び第２主面１４ｂを有する略矩形の板状部材である。そのため、本実施形態の二色性蛍光色素１２は、分子長軸と直交する軸Ｖ２と導光体１４の第１主面１４ａの法線とのなす角度θが臨界角θｍ以上となるように配向されていてもよい。つまり、本実施形態の二色性蛍光色素１２は、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向と導光体１４の第１主面１４ａの法線のなす角度θが臨界角θｍ以上となるように配向されていればよい。
In addition, the light guide 14 of the present embodiment is a substantially rectangular plate-like member having a first main surface 14a and a second main surface 14b. Therefore, in the dichroic fluorescent dye 12 of the present embodiment, the angle θ formed by the axis V2 orthogonal to the molecular long axis and the normal line of the first main surface 14a of the light guide 14 is not less than the critical angle θm. It may be oriented. That is, the dichroic fluorescent dye 12 of the present embodiment has an angle θ formed by the direction in which the light emission intensity of the light emitted from the dichroic fluorescent dye 12 is highest and the normal line of the first main surface 14a of the light guide 14. May be oriented so as to be not less than the critical angle θm.
このような配向状態においても、導光体１４に入射した太陽光の大部分が太陽電池素子１６に到達するまでに導光体１４を透過してしまうことが抑制される。よって、導光体１４に入射した太陽光の大部分を発電に寄与させることができる。
Even in such an orientation state, it is suppressed that most of the sunlight incident on the light guide body 14 is transmitted through the light guide body 14 before reaching the solar cell element 16. Therefore, most of the sunlight incident on the light guide 14 can be contributed to power generation.
例えば太陽電池モジュール１１を屋根などに設置して第１主面１４ａを上に向けて配置した場合に、分子長軸と直交する軸Ｖ２と導光体１４の第１主面１４ａとが平行になるように配向されている構成に比べて太陽光を吸収し易い構成とすることが可能となる。すなわち、図３９に示すように太陽Ｓの仰角θｓは日本の場合、季節によって約３０°～約８０°と変わるが、方向としては分子を傾けて図６中に示した軸Ｖ２が太陽Ｓ方向に向くように配置することにより、太陽光を吸収し易くすることができる。
For example, when the solar cell module 11 is installed on a roof or the like and arranged with the first main surface 14a facing upward, the axis V2 orthogonal to the molecular long axis and the first main surface 14a of the light guide 14 are parallel to each other. It becomes possible to set it as the structure which absorbs sunlight compared with the structure orientated so that it may become. That is, as shown in FIG. 39, the elevation angle θs of the sun S changes from about 30 ° to about 80 ° depending on the season in Japan, but the axis V2 shown in FIG. By arranging so as to face the sun, it is possible to easily absorb sunlight.
また、本実施形態においては、導光体１４と太陽電池素子１６とを備えた太陽電池モジュール１１を挙げて説明したが、これに限らない。例えば、太陽電池素子１６を備えていない構成、すなわち導光体１４のみの構成においても本実施形態を適用することができる。この構成によれば、端面からの光の取り出し効率が高い導光体１４を提供することができる。
In the present embodiment, the solar cell module 11 including the light guide 14 and the solar cell element 16 has been described. However, the present invention is not limited to this. For example, the present embodiment can be applied to a configuration that does not include the solar cell element 16, that is, a configuration that includes only the light guide 14. According to this configuration, it is possible to provide the light guide 14 having high light extraction efficiency from the end face.
［第２実施形態］
図７は、第２実施形態の太陽電池モジュール１１Ａの断面図である。
本実施形態の太陽電池モジュール１１Ａの基本構成は第１実施形態と同様であり、導光体１４の内部に２種類の蛍光体（第１蛍光体１８ａ、第２蛍光体１８ｂ）が設けられている点が第１実施形態と異なる。図７において、第１実施形態の太陽電池モジュール１１と共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Second Embodiment]
FIG. 7 is a cross-sectional view of thesolar cell module 11A of the second embodiment.
The basic configuration of thesolar cell module 11A of the present embodiment is the same as that of the first embodiment, and two types of phosphors (first phosphor 18a and second phosphor 18b) are provided inside the light guide body 14. This is different from the first embodiment. In FIG. 7, about the structure which is common in the solar cell module 11 of 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
図７は、第２実施形態の太陽電池モジュール１１Ａの断面図である。
本実施形態の太陽電池モジュール１１Ａの基本構成は第１実施形態と同様であり、導光体１４の内部に２種類の蛍光体（第１蛍光体１８ａ、第２蛍光体１８ｂ）が設けられている点が第１実施形態と異なる。図７において、第１実施形態の太陽電池モジュール１１と共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Second Embodiment]
FIG. 7 is a cross-sectional view of the
The basic configuration of the
本実施形態の太陽電池モジュール１１Ａにおいては、第２光機能材料１８として、互いに吸収波長域の異なる複数種類の蛍光体（図７では例えば第１蛍光体１８ａ、第２蛍光体１８ｂ）を用いる。
第１蛍光体１８ａとしては、例えばBASF社製Lumogen F Violet 570（商品名）を用いることができる。
第２蛍光体１８ｂとしては、例えばBASF社製Lumogen F Yellow 083（商品名）を用いることができる。 In thesolar cell module 11 </ b> A of the present embodiment, a plurality of types of phosphors having different absorption wavelength ranges (for example, the first phosphor 18 a and the second phosphor 18 b in FIG. 7) are used as the second optical functional material 18.
As thefirst phosphor 18a, for example, Lumogen F Violet 570 (trade name) manufactured by BASF can be used.
As thesecond phosphor 18b, for example, Lumogen F Yellow 083 (trade name) manufactured by BASF can be used.
第１蛍光体１８ａとしては、例えばBASF社製Lumogen F Violet 570（商品名）を用いることができる。
第２蛍光体１８ｂとしては、例えばBASF社製Lumogen F Yellow 083（商品名）を用いることができる。 In the
As the
As the
図８は、第２実施形態の太陽電池モジュール１１Ａで用いられる第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ）の発光スペクトルを示す図である。
図９は、第２実施形態の太陽電池モジュール１１Ａで用いられる第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ）の吸収スペクトルを示す図である。 FIG. 8 is a diagram showing an emission spectrum of the second optical functional material (first phosphor 18a, second phosphor 18b) used in the solar cell module 11A of the second embodiment.
FIG. 9 is a diagram showing an absorption spectrum of the second optical functional material (first phosphor 18a, second phosphor 18b) used in the solar cell module 11A of the second embodiment.
図９は、第２実施形態の太陽電池モジュール１１Ａで用いられる第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ）の吸収スペクトルを示す図である。 FIG. 8 is a diagram showing an emission spectrum of the second optical functional material (
FIG. 9 is a diagram showing an absorption spectrum of the second optical functional material (
図８に示すように、第１蛍光体１８ａの発光スペクトル１１０１は、４３０ｎｍにピーク波長を有し、第２蛍光体１８ｂの発光スペクトル１１０２は、５００ｎｍにピーク波長を有する。
図９に示すように、第１蛍光体１８ａの吸収スペクトル１１１１は、３８０ｎｍにピーク波長を有し、第２蛍光体１８ｂの吸収スペクトル１１１２は、４８０ｎｍにピーク波長を有する。 As shown in FIG. 8, theemission spectrum 1101 of the first phosphor 18a has a peak wavelength at 430 nm, and the emission spectrum 1102 of the second phosphor 18b has a peak wavelength at 500 nm.
As shown in FIG. 9, theabsorption spectrum 1111 of the first phosphor 18a has a peak wavelength at 380 nm, and the absorption spectrum 1112 of the second phosphor 18b has a peak wavelength at 480 nm.
図９に示すように、第１蛍光体１８ａの吸収スペクトル１１１１は、３８０ｎｍにピーク波長を有し、第２蛍光体１８ｂの吸収スペクトル１１１２は、４８０ｎｍにピーク波長を有する。 As shown in FIG. 8, the
As shown in FIG. 9, the
本実施形態の二色性蛍光色素１２は、第１蛍光体１８ａ及び第２蛍光体１８ｂからのエネルギー移動によって光を異方的に発する。
二色性蛍光色素１２としては、例えば下記の化学式（１）に示す材料を用いることができる。 The dichroicfluorescent dye 12 of the present embodiment emits light anisotropically by energy transfer from the first phosphor 18a and the second phosphor 18b.
As the dichroicfluorescent dye 12, for example, a material represented by the following chemical formula (1) can be used.
二色性蛍光色素１２としては、例えば下記の化学式（１）に示す材料を用いることができる。 The dichroic
As the dichroic
以下、化学式（１）に示す材料の生成方法について説明する。
先ず下記の化学式（２）に示す材料を用意する。 Hereinafter, the production | generation method of the material shown to Chemical formula (1) is demonstrated.
First, a material represented by the following chemical formula (2) is prepared.
先ず下記の化学式（２）に示す材料を用意する。 Hereinafter, the production | generation method of the material shown to Chemical formula (1) is demonstrated.
First, a material represented by the following chemical formula (2) is prepared.
次に、化学式（２）に示す材料を、
5-fromylthiophene-2-ylboronic acid,Pd(PPh3)2Cl2,2 M Na2CO3,benzene/EtOHにより化学反応させる。これにより、下記の化学式（３）に示す材料を生成する。 Next, the material represented by the chemical formula (2) is
It is chemically reacted with 5-fromylthiophene-2-ylboronic acid, Pd (PPh 3 ) 2 Cl 2 , 2 M Na 2 CO 3 , benzene / EtOH. Thereby, the material shown in the following chemical formula (3) is generated.
5-fromylthiophene-2-ylboronic acid,Pd(PPh3)2Cl2,2 M Na2CO3,benzene/EtOHにより化学反応させる。これにより、下記の化学式（３）に示す材料を生成する。 Next, the material represented by the chemical formula (2) is
It is chemically reacted with 5-fromylthiophene-2-ylboronic acid, Pd (PPh 3 ) 2 Cl 2 , 2 M Na 2 CO 3 , benzene / EtOH. Thereby, the material shown in the following chemical formula (3) is generated.
次に、化学式（３）に示す材料を、
arylmethyltriphenylphosphonium bromide,KOH,DMSOにより化学反応させる。これにより、本実施形態における化学式（１）に示す二色性蛍光色素１２を生成することができる。 Next, the material represented by the chemical formula (3) is
Chemical reaction with arylmethyltriphenylphosphonium bromide, KOH, DMSO. Thereby, the dichroicfluorescent dye 12 shown to Chemical formula (1) in this embodiment can be produced | generated.
arylmethyltriphenylphosphonium bromide,KOH,DMSOにより化学反応させる。これにより、本実施形態における化学式（１）に示す二色性蛍光色素１２を生成することができる。 Next, the material represented by the chemical formula (3) is
Chemical reaction with arylmethyltriphenylphosphonium bromide, KOH, DMSO. Thereby, the dichroic
図１０は、第２実施形態の太陽電池モジュール１１Ａで用いられる第１光機能材料（二色性蛍光色素１２）の発光スペクトル及び吸収スペクトルを示す図である。なお、図１０において、記号Ｆ//は、二色性蛍光色素１２の分子長軸に平行な方向における発光特性である。記号Ｆ⊥は、二色性蛍光色素１２の分子長軸に直交する方向における発光特性である。記号ＮＦは、Ｆ//とＦ⊥の比（Ｆ//／Ｆ⊥）である。また、記号Ａ//は、二色性蛍光色素１２の分子長軸に平行な方向における吸収特性である。記号Ａ⊥は、二色性蛍光色素１２の分子長軸に直交する方向における吸収特性である。記号ＮＡは、Ａ//とＡ⊥の比（Ａ//／Ａ⊥）である。
FIG. 10 is a diagram showing an emission spectrum and an absorption spectrum of the first optical functional material (dichroic fluorescent dye 12) used in the solar cell module 11A of the second embodiment. In FIG. 10, the symbol F // is a light emission characteristic in a direction parallel to the molecular long axis of the dichroic fluorescent dye 12. The symbol F ⊥ is a light emission characteristic in a direction orthogonal to the molecular long axis of the dichroic fluorescent dye 12. Symbol N F is the ratio of F // and F ⊥ (F // / F ⊥ ). The symbol A // is an absorption characteristic in a direction parallel to the molecular long axis of the dichroic fluorescent dye 12. The symbol A 吸収 is an absorption characteristic in a direction orthogonal to the molecular long axis of the dichroic fluorescent dye 12. Symbol N A is the ratio of A // and A ⊥ (A // / A ⊥ ).
図１０に示すように、二色性蛍光色素１２の発光スペクトルは、分子長軸に平行な方向において（Ｆ//）、６４０ｎｍにピーク波長を有する。また、分子長軸に直交する方向において（Ｆ⊥）、６３０ｎｍにピーク波長を有する。
一方、二色性蛍光色素１２の吸収スペクトルは、分子長軸に平行な方向において（Ａ//）、５３０ｎｍにピーク波長を有する。また、分子長軸に直交する方向において（Ａ⊥）、５２０ｎｍにピーク波長を有する。 As shown in FIG. 10, the emission spectrum of the dichroicfluorescent dye 12 has a peak wavelength at 640 nm in a direction parallel to the molecular long axis (F // ). Moreover, it has a peak wavelength at 630 nm in the direction orthogonal to the molecular long axis (F ⊥ ).
On the other hand, the absorption spectrum of the dichroicfluorescent dye 12 has a peak wavelength at 530 nm (A // ) in the direction parallel to the molecular long axis. Moreover, it has a peak wavelength at 520 nm (A ⊥ ) in the direction orthogonal to the molecular long axis.
一方、二色性蛍光色素１２の吸収スペクトルは、分子長軸に平行な方向において（Ａ//）、５３０ｎｍにピーク波長を有する。また、分子長軸に直交する方向において（Ａ⊥）、５２０ｎｍにピーク波長を有する。 As shown in FIG. 10, the emission spectrum of the dichroic
On the other hand, the absorption spectrum of the dichroic
本実施形態の太陽電池モジュール１１Ａにおいても、導光体１４に入射した太陽光の大部分を発電に寄与させることができる。
さらに、本実施形態においては、導光体１４の内部に、複数種類（２種類）の第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ）が含まれている。これにより、導光体１４に入射した太陽光を広い波長範囲で発電に利用することができる。
したがって、発電効率の高い太陽電池モジュールを提供することができる。 Also in thesolar cell module 11A of the present embodiment, most of the sunlight incident on the light guide 14 can be contributed to power generation.
Further, in the present embodiment, a plurality of types (two types) of second optical functional materials (first phosphor 18 a and second phosphor 18 b) are included in the light guide 14. Thereby, the sunlight which injected into the light guide 14 can be utilized for electric power generation in a wide wavelength range.
Therefore, a solar cell module with high power generation efficiency can be provided.
さらに、本実施形態においては、導光体１４の内部に、複数種類（２種類）の第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ）が含まれている。これにより、導光体１４に入射した太陽光を広い波長範囲で発電に利用することができる。
したがって、発電効率の高い太陽電池モジュールを提供することができる。 Also in the
Further, in the present embodiment, a plurality of types (two types) of second optical functional materials (
Therefore, a solar cell module with high power generation efficiency can be provided.
［第３実施形態］
図１１は、第３実施形態の太陽電池モジュール１１Ｂの断面図である。
本実施形態の太陽電池モジュール１１Ｂの基本構成は第１実施形態と同様であり、導光体１４の内部に３種類の蛍光体（第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃ）が設けられている点が第１実施形態と異なる。図１１において、第１実施形態の太陽電池モジュール１１と共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Third Embodiment]
FIG. 11 is a cross-sectional view of thesolar cell module 11B of the third embodiment.
The basic configuration of thesolar cell module 11B of this embodiment is the same as that of the first embodiment, and there are three types of phosphors (first phosphor 18a, second phosphor 18b, and third phosphor) inside the light guide body 14. 18c) is different from the first embodiment. In FIG. 11, about the structure which is common in the solar cell module 11 of 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
図１１は、第３実施形態の太陽電池モジュール１１Ｂの断面図である。
本実施形態の太陽電池モジュール１１Ｂの基本構成は第１実施形態と同様であり、導光体１４の内部に３種類の蛍光体（第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃ）が設けられている点が第１実施形態と異なる。図１１において、第１実施形態の太陽電池モジュール１１と共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Third Embodiment]
FIG. 11 is a cross-sectional view of the
The basic configuration of the
第２光機能材料１８としては、互いに吸収波長域の異なる複数種類の蛍光体（図１１では例えば第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃ）が分散されている。第１蛍光体１８ａは、紫外光を吸収して青色の蛍光を放射する。第２蛍光体１８ｂは、青色光を吸収して緑色の蛍光を放射する。第３蛍光体１８ｃは、緑色光を吸収して赤色の蛍光を放射する。第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃは、例えば、導光体を成型する際に混入される。第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃの混合比率は以下の通りである。なお、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃの混合比率は導光体に対する体積比率で示している。
As the second optical functional material 18, a plurality of types of phosphors having different absorption wavelength ranges (for example, the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c in FIG. 11) are dispersed. The first phosphor 18a absorbs ultraviolet light and emits blue fluorescence. The second phosphor 18b absorbs blue light and emits green fluorescence. The third phosphor 18c absorbs green light and emits red fluorescence. For example, the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c are mixed when the light guide is molded. The mixing ratio of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c is as follows. The mixing ratio of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c is shown as a volume ratio with respect to the light guide.
第１蛍光体１８ａ：BASF社製Lumogen F Violet 570（商品名）０．０２％、第２蛍光体１８ｂ：BASF社製Lumogen F Yellow 083（商品名）０．０２％、第３蛍光体１８ｃ：BASF社製Lumogen F Red 305（商品名）０．０２％。
First phosphor 18a: BASF Lumogen F Violet 570 (trade name) 0.02%, second phosphor 18b: BASF Lumogen F Yellow 083 (trade name) 0.02%, third phosphor 18c: BASF Lumogen F Red 305 (trade name) 0.02%.
本実施形態の二色性蛍光色素１２は、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃからのエネルギー移動によって光を異方的に発する。
以下、二色性蛍光色素１２が蛍光体１８ａ，１８ｂ，１８ｃからの励起エネルギーによって光を異方的に発する機構について説明する。 The dichroicfluorescent dye 12 of this embodiment emits light anisotropically by energy transfer from the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c.
Hereinafter, a mechanism in which the dichroicfluorescent dye 12 emits light anisotropically by excitation energy from the phosphors 18a, 18b, and 18c will be described.
以下、二色性蛍光色素１２が蛍光体１８ａ，１８ｂ，１８ｃからの励起エネルギーによって光を異方的に発する機構について説明する。 The dichroic
Hereinafter, a mechanism in which the dichroic
図１２ないし図１５は、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃの発光特性及び吸収特性を示す図である。
図１２において、曲線１１２１は、第１蛍光体１８ａによって紫外光が吸収された後の太陽光のスペクトルを示す。曲線１１２２は、第２蛍光体１８ｂによって青色光が吸収された後の太陽光のスペクトルを示す。曲線１１２３は、第３蛍光体１８ｃによって緑色光が吸収された後の太陽光のスペクトルを示す。曲線１１２４は、太陽光のスペクトルを示す。
図１３において、曲線１１２５は、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃによって紫外光、青色光及び緑色光が吸収された後の太陽光のスペクトルを示す。曲線１１２４は、太陽光のスペクトルを示す。
図１４において、曲線１１２６は、第１蛍光体１８ａの発光スペクトルである。曲線１１２７は、第２蛍光体１８ｂの発光スペクトルである。曲線１１２８は、第３蛍光体１８ｃの発光スペクトルである。
図１５において、曲線１１２９は、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃを含む導光体の端面から射出される光のスペクトルである。 12 to 15 are diagrams showing the emission characteristics and absorption characteristics of thefirst phosphor 18a, the second phosphor 18b, and the third phosphor 18c.
In FIG. 12, acurve 1121 shows the spectrum of sunlight after the ultraviolet light is absorbed by the first phosphor 18a. A curve 1122 shows the spectrum of sunlight after the blue light is absorbed by the second phosphor 18b. A curve 1123 indicates the spectrum of sunlight after the green light is absorbed by the third phosphor 18c. A curve 1124 shows the spectrum of sunlight.
In FIG. 13, acurve 1125 shows the spectrum of sunlight after ultraviolet light, blue light, and green light are absorbed by the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c. A curve 1124 shows the spectrum of sunlight.
In FIG. 14, acurve 1126 is an emission spectrum of the first phosphor 18a. A curve 1127 is an emission spectrum of the second phosphor 18b. A curve 1128 is an emission spectrum of the third phosphor 18c.
In FIG. 15, acurve 1129 is a spectrum of light emitted from the end face of the light guide including the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c.
図１２において、曲線１１２１は、第１蛍光体１８ａによって紫外光が吸収された後の太陽光のスペクトルを示す。曲線１１２２は、第２蛍光体１８ｂによって青色光が吸収された後の太陽光のスペクトルを示す。曲線１１２３は、第３蛍光体１８ｃによって緑色光が吸収された後の太陽光のスペクトルを示す。曲線１１２４は、太陽光のスペクトルを示す。
図１３において、曲線１１２５は、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃによって紫外光、青色光及び緑色光が吸収された後の太陽光のスペクトルを示す。曲線１１２４は、太陽光のスペクトルを示す。
図１４において、曲線１１２６は、第１蛍光体１８ａの発光スペクトルである。曲線１１２７は、第２蛍光体１８ｂの発光スペクトルである。曲線１１２８は、第３蛍光体１８ｃの発光スペクトルである。
図１５において、曲線１１２９は、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃを含む導光体の端面から射出される光のスペクトルである。 12 to 15 are diagrams showing the emission characteristics and absorption characteristics of the
In FIG. 12, a
In FIG. 13, a
In FIG. 14, a
In FIG. 15, a
図１２及び図１３に示すように、第１蛍光体１８ａは、概ね４２０ｎｍ以下の波長の光を吸収する。第２蛍光体１８ｂは、概ね４２０ｎｍ以上５２０ｎｍ以下の波長の光を吸収する。第３蛍光体１８ｃは、概ね５２０ｎｍ以上６２０ｎｍ以下の波長の光を吸収する。第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃによって、導光体に入射した太陽光のうち６２０ｎｍ以下の波長の光が概ね全て吸収される。太陽光のスペクトルにおいて波長が６２０ｎｍ以下の光の割合は４８％程度である。よって、導光体の光入射面に入射した光のうち４８％は導光体に含まれる第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃに吸収される。
As shown in FIGS. 12 and 13, the first phosphor 18a absorbs light having a wavelength of approximately 420 nm or less. The second phosphor 18b absorbs light having a wavelength of approximately 420 nm or more and 520 nm or less. The third phosphor 18c absorbs light having a wavelength of approximately 520 nm or more and 620 nm or less. The first phosphor 18a, the second phosphor 18b, and the third phosphor 18c absorb almost all light having a wavelength of 620 nm or less in the sunlight incident on the light guide. In the sunlight spectrum, the proportion of light having a wavelength of 620 nm or less is about 48%. Therefore, 48% of the light incident on the light incident surface of the light guide is absorbed by the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c included in the light guide.
図１４に示すように、第１蛍光体１８ａの発光スペクトルは、４３０ｎｍにピーク波長を有する。第２蛍光体１８ｂの発光スペクトルは、５２０ｎｍにピーク波長を有する。第３蛍光体１８ｃの発光スペクトルは、６３０ｎｍにピーク波長を有する。
しかしながら、図１５に示すように、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃを含む導光体の端面から射出される光のスペクトルは、第３蛍光体１８ｃの発光スペクトルのピーク波長（６３０ｎｍ）に対応する波長にのみピーク波長を有し、第１蛍光体１８ａの発光スペクトルのピーク波長（４３０ｎｍ）及び第２蛍光体１８ｂの発光スペクトルのピーク波長（５２０ｎｍ）に対応する波長にはピーク波長を有しない。
したがって、ここで用いた３種類の蛍光体間では、フェルスター機構による励起エネルギーの移動が起こり、最も蛍光スペクトルのピーク波長が大きい第３蛍光体から放射された蛍光が得られている。 As shown in FIG. 14, the emission spectrum of thefirst phosphor 18a has a peak wavelength at 430 nm. The emission spectrum of the second phosphor 18b has a peak wavelength at 520 nm. The emission spectrum of the third phosphor 18c has a peak wavelength at 630 nm.
However, as shown in FIG. 15, the spectrum of light emitted from the end face of the light guide including thefirst phosphor 18a, the second phosphor 18b, and the third phosphor 18c is the emission spectrum of the third phosphor 18c. The peak wavelength has only a wavelength corresponding to the peak wavelength (630 nm) of the first phosphor 18a, and corresponds to the peak wavelength (430 nm) of the emission spectrum of the first phosphor 18a and the peak wavelength (520 nm) of the emission spectrum of the second phosphor 18b. The wavelength does not have a peak wavelength.
Accordingly, excitation energy is transferred between the three types of phosphors used here by the Forster mechanism, and fluorescence emitted from the third phosphor having the largest peak wavelength of the fluorescence spectrum is obtained.
しかしながら、図１５に示すように、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃを含む導光体の端面から射出される光のスペクトルは、第３蛍光体１８ｃの発光スペクトルのピーク波長（６３０ｎｍ）に対応する波長にのみピーク波長を有し、第１蛍光体１８ａの発光スペクトルのピーク波長（４３０ｎｍ）及び第２蛍光体１８ｂの発光スペクトルのピーク波長（５２０ｎｍ）に対応する波長にはピーク波長を有しない。
したがって、ここで用いた３種類の蛍光体間では、フェルスター機構による励起エネルギーの移動が起こり、最も蛍光スペクトルのピーク波長が大きい第３蛍光体から放射された蛍光が得られている。 As shown in FIG. 14, the emission spectrum of the
However, as shown in FIG. 15, the spectrum of light emitted from the end face of the light guide including the
Accordingly, excitation energy is transferred between the three types of phosphors used here by the Forster mechanism, and fluorescence emitted from the third phosphor having the largest peak wavelength of the fluorescence spectrum is obtained.
第１蛍光体１８ａに対応する発光スペクトルのピーク及び第２蛍光体１８ｂに対応する発光スペクトルのピークが消失した原因は、フォトルミネッセンス（Photoluminescence ;PL）による蛍光体間のエネルギー移動や、フェルスター機構（蛍光共鳴エネルギー移動）による蛍光体間のエネルギー移動などが挙げられる。フォトルミネッセンスによるエネルギー移動は、一の蛍光体から放射された蛍光が他の蛍光体の励起エネルギーとして利用されることにより生じるものである。フェルスター機構は、このような光の発光及び吸収のプロセスを経ずに、近接した２つの蛍光体の間で励起エネルギーが電子の共鳴により直接移動するものである。
The cause of the disappearance of the peak of the emission spectrum corresponding to the first phosphor 18a and the peak of the emission spectrum corresponding to the second phosphor 18b is the energy transfer between the phosphors due to photoluminescence (PL) and the Forster mechanism. Examples thereof include energy transfer between phosphors by (fluorescence resonance energy transfer). Energy transfer by photoluminescence occurs when fluorescence emitted from one phosphor is used as excitation energy for another phosphor. In the Förster mechanism, excitation energy directly moves between two adjacent phosphors by electron resonance without going through such light emission and absorption processes.
本実施形態の二色性蛍光色素１２は、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃからのエネルギー移動によって光を異方的に発する。本実施形態において、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃから二色性蛍光色素１２へのエネルギー移動としては、フォトルミネッセンスによるエネルギー移動、フェルスター機構よるエネルギー移動、のいずれも採用することができる。
The dichroic fluorescent dye 12 of this embodiment emits light anisotropically by energy transfer from the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c. In the present embodiment, the energy transfer from the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c to the dichroic fluorescent dye 12 includes energy transfer by photoluminescence, energy transfer by Forster mechanism. Either can be adopted.
フェルスター機構による蛍光体間のエネルギー移動は、光の発光及び吸収のプロセスを介さずに行われるため、最適条件ではエネルギーのロスが小さい。よって、太陽電池モジュールの発電効率の向上に寄与する。本実施形態では、エネルギーロスを抑制して効率よく発電を行うために、第１蛍光体１８ａ、第２蛍光体１８ｂおよび第３蛍光体１８ｃの密度を高くし、蛍光体間でフェルスター機構によるエネルギー移動が行われるようにしている。
The energy transfer between the phosphors by the Förster mechanism is performed without going through the process of light emission and absorption, so that the energy loss is small under the optimum conditions. Therefore, it contributes to the improvement of the power generation efficiency of the solar cell module. In the present embodiment, in order to efficiently generate power while suppressing energy loss, the density of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c is increased, and the Forster mechanism is used between the phosphors. Energy transfer is performed.
ここで、図１６Ａ～図１７Ｂを用いてフェルスター機構について説明する。図１６Ａは、フォトルミネッセンスによるエネルギー移動（フォトルミネッセンスによる色変換）を示す図である。図１６Ｂは、フェルスター機構によるエネルギー移動（エネルギー移動による色変換）を示す図である。図１７Ａは、フェルスター機構によるエネルギー移動の発生機構を説明するための図である。図１７Ｂは、フェルスター機構によるエネルギー移動を示す図である。
Here, the Förster mechanism will be described with reference to FIGS. 16A to 17B. FIG. 16A is a diagram illustrating energy transfer by photoluminescence (color conversion by photoluminescence). FIG. 16B is a diagram illustrating energy transfer (color conversion by energy transfer) by the Forster mechanism. FIG. 17A is a diagram for explaining a generation mechanism of energy transfer by the Forster mechanism. FIG. 17B is a diagram showing energy transfer by the Forster mechanism.
図１６Ｂに示すように、有機分子、無機ナノ粒子、または有機無機ハイブリットの蛍光体では、励起状態にある分子Ａから基底状態の分子Ｂに対してフェルスター機構によってエネルギー移動が生じることがある。蛍光体では、分子Ａが励起されたときに、分子Ｂにエネルギー移動を起こすと、分子Ｂが発光する。このエネルギー移動は、分子間の距離と分子Ａの発光スペクトルと分子Ｂの吸収スペクトルに依存する。分子Ａをホスト分子、分子Ｂをゲスト分子とするとき、エネルギー移動するときの速度定数ｋH→G（移動確率）は式（１）のようになる。
As shown in FIG. 16B, in an organic molecule, inorganic nanoparticle, or organic-inorganic hybrid phosphor, energy transfer may occur from a molecule A in an excited state to a molecule B in a ground state by a Forster mechanism. In the phosphor, when the molecule A is excited and undergoes energy transfer to the molecule B, the molecule B emits light. This energy transfer depends on the distance between molecules, the emission spectrum of molecule A, and the absorption spectrum of molecule B. When the molecule A is a host molecule and the molecule B is a guest molecule, the rate constant k H → G (movement probability) when energy is transferred is as shown in Equation (1).
なお、式（１）において、νは振動数、ｆ′Ｈ（ν）はホスト分子Ａの発光スペクトル、ε（ν）はゲスト分子Ｂの吸収スペクトル、Ｎはアボガドロ定数、ｎは屈折率、τ０はホスト分子Ａの蛍光寿命、Ｒは分子間距離、Ｋ２は遷移双極子モーメント（ランダム時２／３）である。
In equation (1), ν is the frequency, f ′ H (ν) is the emission spectrum of the host molecule A, ε (ν) is the absorption spectrum of the guest molecule B, N is the Avogadro constant, n is the refractive index, τ 0 is the fluorescence lifetime of the host molecule A, R is the intermolecular distance, and K 2 is the transition dipole moment (2/3 at random).
速度定数が大きいと、蛍光体間でエネルギー移動が生じやすくなる。大きな速度定数を得るためには、以下の条件が満たされることが望ましい。
［１］ホスト分子Ａの発光スペクトルとゲスト分子の吸収スペクトルの重なりが大きい。
［２］ゲスト分子Ｂの吸光係数が大きい。
［３］ホスト分子Ａとゲスト分子Ｂとの間の距離が小さい。 When the rate constant is large, energy transfer tends to occur between the phosphors. In order to obtain a large rate constant, it is desirable that the following conditions are satisfied.
[1] The overlap between the emission spectrum of the host molecule A and the absorption spectrum of the guest molecule is large.
[2] The extinction coefficient of guest molecule B is large.
[3] The distance between the host molecule A and the guest molecule B is small.
［１］ホスト分子Ａの発光スペクトルとゲスト分子の吸収スペクトルの重なりが大きい。
［２］ゲスト分子Ｂの吸光係数が大きい。
［３］ホスト分子Ａとゲスト分子Ｂとの間の距離が小さい。 When the rate constant is large, energy transfer tends to occur between the phosphors. In order to obtain a large rate constant, it is desirable that the following conditions are satisfied.
[1] The overlap between the emission spectrum of the host molecule A and the absorption spectrum of the guest molecule is large.
[2] The extinction coefficient of guest molecule B is large.
[3] The distance between the host molecule A and the guest molecule B is small.
上記［１］は、近接した２つの蛍光体間での共鳴のし易さを表すものである。例えば、図１７Ａに示すように、ホスト分子Ａの発光スペクトルのピーク波長とゲスト分子Ｂの吸収スペクトルのピーク波長とが近いと、フェルスター機構によるエネルギー移動が生じやすくなる。図１７Ｂに示すように、励起状態のホスト分子Ａの近くに基底状態のゲスト分子Ｂが存在すると、共鳴的性質によりゲスト分子Ａの波動関数が変化し、基底状態のホスト分子Ａと励起状態のゲスト分子Ｂができる。これにより、ホスト分子Ａとゲスト分子Ｂとの間でエネルギー移動が生じ、ゲスト分子Ｂが発光する。
[1] represents the ease of resonance between two adjacent phosphors. For example, as shown in FIG. 17A, when the peak wavelength of the emission spectrum of the host molecule A is close to the peak wavelength of the absorption spectrum of the guest molecule B, energy transfer due to the Forster mechanism is likely to occur. As shown in FIG. 17B, when the guest molecule B in the ground state exists near the host molecule A in the excited state, the wave function of the guest molecule A changes due to the resonance property, and the host molecule A in the ground state and the excited state in the excited state. Guest molecule B is formed. Thereby, energy transfer occurs between the host molecule A and the guest molecule B, and the guest molecule B emits light.
上記［３］において、フェルスター機構によるエネルギー移動が起こる分子間距離は、通常、１０ｎｍ程度である。条件が合えば、分子間距離が２０ｎｍ程度であってもエネルギー移動は起きる。上述した第１蛍光体、第２蛍光体及び第３蛍光体の混合比率であれば、蛍光体間の距離は２０ｎｍよりも短くなる。よって、フェルスター機構によるエネルギー移動は十分に生じうる。また、図１３及び図１５に示した第１蛍光体、第２蛍光体及び第３蛍光体の発光スペクトル及び吸収スペクトルは、上記［１］の条件を十分に満たしている。よって、第１蛍光体から第２蛍光体へのエネルギー移動、及び、第２蛍光体から第３蛍光体へのエネルギー移動が生じ、第１蛍光体、第２蛍光体、第３蛍光体の順にカスケード型のエネルギー移動が生じる。
In the above [3], the intermolecular distance at which energy transfer by the Forster mechanism occurs is usually about 10 nm. If the conditions are met, energy transfer occurs even when the intermolecular distance is about 20 nm. If the mixing ratio of the first phosphor, the second phosphor, and the third phosphor described above is used, the distance between the phosphors is shorter than 20 nm. Therefore, energy transfer by the Forster mechanism can occur sufficiently. Moreover, the emission spectrum and absorption spectrum of the first phosphor, the second phosphor, and the third phosphor shown in FIGS. 13 and 15 sufficiently satisfy the condition [1]. Therefore, energy transfer from the first phosphor to the second phosphor and energy transfer from the second phosphor to the third phosphor occur, and the first phosphor, the second phosphor, and the third phosphor in this order. Cascade type energy transfer occurs.
導光体では、３つの異なる発光スペクトルを有する蛍光体（第１蛍光体、第２蛍光体、第３蛍光体）を混入しているにもかかわらず、フェルスター機構によるエネルギー移動により、実質的には第３蛍光体の発光のみが生じる。第３蛍光体の発光量子効率は例えば９２％である。よって、導光体に第１蛍光体、第２蛍光体及び第３蛍光体を混入することで、６２０ｎｍまでの波長領域の光を吸収し、９２％の効率でピーク波長が６３０ｎｍの赤色の発光を生じさせることができる。
In the light guide, although the phosphors having the three different emission spectra (the first phosphor, the second phosphor, and the third phosphor) are mixed, the light guide is substantially affected by the energy transfer by the Förster mechanism. In this case, only the emission of the third phosphor occurs. The emission quantum efficiency of the third phosphor is, for example, 92%. Therefore, by mixing the first phosphor, the second phosphor, and the third phosphor in the light guide, light in the wavelength region up to 620 nm is absorbed, and red light emission with a peak wavelength of 630 nm is achieved with an efficiency of 92%. Can be generated.
このようなエネルギー移動現象は、有機の蛍光体に特有の現象で、一般的に無機の蛍光体では起こらないとされているが、量子ドットなどのいくつかの無機ナノ粒子の蛍光体においてはフェルスター機構により、無機材料間、或いは、無機材料と有機材料との間でエネルギー移動を生じるものが知られている。
This type of energy transfer phenomenon is unique to organic phosphors and is generally considered not to occur in inorganic phosphors, but in some inorganic nanoparticle phosphors such as quantum dots, Those that cause energy transfer between inorganic materials or between inorganic materials and organic materials by a star mechanism are known.
例えば、ＺｎＯ／ＭｇＺｎＯコア・シェル構造の２種類の異なったサイズの量子ドットの間でエネルギー移動が起こる。１：√２の寸法比を持つ量子ドットは共鳴する励起子準位を持つため、例えば半径３ｎｍ（発光スペクトルのピーク波長：３５０ｎｍ）と半径４．５ｎｍ（発光スペクトルのピーク波長：３５７ｎｍ）の２種類の量子ドットの間では、小さい量子ドットから大きい量子ドットへエネルギー移動が起こる。またＣｄＳｅ／ＺｎＳコア・シェル構造の２種類の異なったサイズの量子ドットの間でもエネルギー移動が起こる。また、直径８ｎｍないし９ｎｍのＭｎ２＋ドープＺｎＳｅ量子ドットは、４５０ｎｍと５８０ｎｍに発光ピークを持ち、色素分子である１’，３’－ｄｉｈｙｄｒｏ－１’，３’，３’－ｔｒｉｍｅｔｈｙｌ－６－ｎｉｔｒｏｓｐｉｒｏ[２Ｈ－１－ｂｅｎｚｏｐｙｒａｎ－‘２，２’－(２Ｈ]－ｉｎｄｏｌｅ] に紫外線を照射して得られる開環型のSpiropyran分子（SPO open; Merocynanine form）の光吸収スペクトルとよく一致し、量子ドットから色素分子へのエネルギー移動が起こる。一般に、無機の蛍光体は、有機の蛍光体に比べて耐光性が優れるため、長期間使用する場合に有利である。
For example, energy transfer occurs between two types of quantum dots having different sizes of ZnO / MgZnO core / shell structure. Since a quantum dot having a dimensional ratio of 1: √2 has a resonating exciton level, for example, 2 having a radius of 3 nm (peak wavelength of emission spectrum: 350 nm) and a radius of 4.5 nm (peak wavelength of emission spectrum: 357 nm). Between types of quantum dots, energy transfer occurs from small to large quantum dots. Energy transfer also occurs between two different sized quantum dots of the CdSe / ZnS core-shell structure. Further, Mn2 + doped ZnSe quantum dots having a diameter of 8 nm to 9 nm have emission peaks at 450 nm and 580 nm, and are dye molecules 1 ′, 3′-dihydro-1 ′, 3 ′, 3′-trimethyl-6-nitrospiro [ 2H-1-benzopyran-'2,2 '-(2H] -indole] is in good agreement with the light absorption spectrum of the ring-opened Spiropyran molecule (SPO open; Merocynanine form) obtained by irradiating ultraviolet rays to the quantum dot In general, inorganic phosphors have an excellent light resistance compared to organic phosphors, and are therefore advantageous when used for a long period of time.
通常、２種類の蛍光体を混入した場合には、図１６Ａのように、まず蛍光体Ａがある効率で発光し、蛍光体Ｂに入射し、蛍光体Ｂで光の吸収及び発光のプロセスを経ることによって、蛍光体Ｂから光が放射される。このようなフォトルミネッセンスによるエネルギー移動は、蛍光体Ａにおける光の発光プロセス及び蛍光体Ｂにおける光の吸収プロセスでエネルギーのロスが生じ、エネルギー移動効率が小さい。
Normally, when two kinds of phosphors are mixed, as shown in FIG. 16A, the phosphor A first emits light with a certain efficiency, enters the phosphor B, and the phosphor B absorbs and emits light. As a result, light is emitted from the phosphor B. In such energy transfer by photoluminescence, energy loss occurs in the light emission process in the phosphor A and the light absorption process in the phosphor B, and the energy transfer efficiency is small.
一方、図１６Ｂに示したフェルスター機構によるエネルギー移動は、蛍光体間でダイレクトにエネルギーのみが移動するので、エネルギー移動効率はほぼ１００％にすることが可能であり、高効率にエネルギー移動を生じさせることができる。
On the other hand, in the energy transfer by the Forster mechanism shown in FIG. 16B, only the energy moves directly between the phosphors, so that the energy transfer efficiency can be almost 100%, resulting in the energy transfer with high efficiency. Can be made.
また、フェルスター機構によるエネルギー移動は、蛍光体のような発光材料だけでなく、外光によって励起されるが、光を発生せずに失活する非発光体においても生じる。最終的な発電量は、ゲスト分子の蛍光量子収率によって決まり、ホスト分子の蛍光量子収率には依存しない。よって、ゲスト分子のみを蛍光量子収率の高い蛍光体で構成し、ホスト分子を蛍光量子収率の低い蛍光体又は蛍光を発しない非発光体で構成しても、同じ発電量が得られる。よって、フォトルミネッセンスによりエネルギー移動を行う場合のように、全ての蛍光体に対して高い蛍光量子収率が求められる場合に比べて、ホスト分子の材料選択の幅が広がる。
In addition, energy transfer by the Forster mechanism occurs not only in a luminescent material such as a phosphor, but also in a non-luminescent material that is excited by external light but deactivates without generating light. The final power generation amount depends on the fluorescence quantum yield of the guest molecule and does not depend on the fluorescence quantum yield of the host molecule. Therefore, even if only the guest molecule is composed of a phosphor having a high fluorescence quantum yield and the host molecule is composed of a phosphor having a low fluorescence quantum yield or a non-light emitting material that does not emit fluorescence, the same amount of power generation can be obtained. Therefore, as compared with the case where a high fluorescence quantum yield is required for all phosphors, such as when energy transfer is performed by photoluminescence, the range of material selection for the host molecule is widened.
図１８は、太陽電池素子１６の一例であるアモルファスシリコン太陽電池の分光感度曲線１１３４を、第１蛍光体の発光スペクトル１１３１、第２蛍光体の発光スペクトル１１３２および第３蛍光体の発光スペクトル１１３３とともに示す図である。
FIG. 18 shows a spectral sensitivity curve 1134 of an amorphous silicon solar cell which is an example of the solar cell element 16 together with an emission spectrum 1131 of the first phosphor, an emission spectrum 1132 of the second phosphor, and an emission spectrum 1133 of the third phosphor. FIG.
導光体１４の端面１４ｃから射出される光Ｌ１のスペクトルは、第３蛍光体１８ｃの発光スペクトル１１３３と概ね一致する。よって、太陽電池素子１６は、第３蛍光体１８ｃの発光スペクトル１１３３のピーク波長（６３０ｎｍ）において高い感度を有するものであればよい。図１８に示すように、アモルファスシリコン太陽電池は６００ｎｍ付近の波長の光に対して最も高い分光感度を有する。第１蛍光体の発光スペクトル１１３１のピーク波長、第２蛍光体の発光スペクトル１１３２のピーク波長および第３蛍光体の発光スペクトル１１３３のピーク波長におけるアモルファスシリコン太陽電池の分光感度１１３４を比較すると、最も発光スペクトルのピーク波長の大きい第３蛍光体の発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度は、導光体に備えられた他のいずれの蛍光体（第１蛍光体、第２蛍光体）の発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度よりも大きい。そのため、太陽電池素子１６としてアモルファスシリコン太陽電池を用いれば、高い効率で発電を行うことができる。
The spectrum of the light L1 emitted from the end face 14c of the light guide body 14 substantially matches the emission spectrum 1133 of the third phosphor 18c. Therefore, the solar cell element 16 should just have a high sensitivity in the peak wavelength (630 nm) of the emission spectrum 1133 of the 3rd fluorescent substance 18c. As shown in FIG. 18, the amorphous silicon solar cell has the highest spectral sensitivity with respect to light having a wavelength near 600 nm. When the spectral sensitivity 1134 of the amorphous silicon solar cell at the peak wavelength of the emission spectrum 1131 of the first phosphor, the peak wavelength of the emission spectrum 1132 of the second phosphor, and the peak wavelength of the emission spectrum 1133 of the third phosphor is compared, the light emission is highest. The spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of the third phosphor having a large spectrum peak wavelength is any other phosphor (first phosphor or second phosphor) provided in the light guide. It is larger than the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum. Therefore, if an amorphous silicon solar cell is used as the solar cell element 16, power generation can be performed with high efficiency.
太陽電池素子１６に適用する太陽電池の種類は、前記太陽電池素子に入射する光の波長に応じて決定される。図１８では、太陽電池素子１６としてアモルファスシリコン太陽電池を用いたが、太陽電池素子１６はこれに限られない。
The type of solar cell applied to the solar cell element 16 is determined according to the wavelength of light incident on the solar cell element. In FIG. 18, an amorphous silicon solar cell is used as the solar cell element 16, but the solar cell element 16 is not limited to this.
図１９は、太陽電池素子１６として利用可能な種々の太陽電池の分光感度曲線を示す図である。図２０は、これらの太陽電池のエネルギー変換効率ηλを示す図である。図１９において、符号１１４１は、単結晶シリコン太陽電池の分光感度曲線を示す。符号１１４２は、アモルファスシリコン太陽電池（単接合）の分光感度曲線を示す。符号１１４３は、ガリウムヒ素太陽電池（単接合）の分光感度曲線を示す。符号１１４４は、カドミウムテルル太陽電池の分光感度曲線を示す。符号１１４５は、Ｃｕ（Ｉｎ，Ｇａ）（Ｓｅ，Ｓ）２太陽電池の分光感度曲線を示す。図２０において、符号１１５１は、単結晶シリコン太陽電池のエネルギー変換効率ηλを示す。符号１１５２は、アモルファスシリコン太陽電池（単接合）のエネルギー変換効率ηλを示す。符号１１５３は、ガリウムヒ素太陽電池（単接合）のエネルギー変換効率ηλを示す。符号１１５４は、カドミウムテルル太陽電池のエネルギー変換効率ηλを示す。符号１１５５は、Ｃｕ（Ｉｎ，Ｇａ）（Ｓｅ，Ｓ）２太陽電池のエネルギー変換効率ηλを示す。
FIG. 19 is a diagram showing spectral sensitivity curves of various solar cells that can be used as the solar cell element 16. FIG. 20 is a diagram showing the energy conversion efficiency η λ of these solar cells. In FIG. 19, reference numeral 1141 indicates a spectral sensitivity curve of the single crystal silicon solar cell. Reference numeral 1142 indicates a spectral sensitivity curve of the amorphous silicon solar cell (single junction). Reference numeral 1143 indicates a spectral sensitivity curve of the gallium arsenide solar cell (single junction). Reference numeral 1144 denotes a spectral sensitivity curve of the cadmium tellurium solar cell. Reference numeral 1145 indicates a spectral sensitivity curve of the Cu (In, Ga) (Se, S) 2 solar cell. In FIG. 20, reference numeral 1151 indicates the energy conversion efficiency η λ of the single crystal silicon solar cell. Reference numeral 1152 indicates the energy conversion efficiency η λ of the amorphous silicon solar cell (single junction). Reference numeral 1153 indicates the energy conversion efficiency η λ of the gallium arsenide solar cell (single junction). Reference numeral 1154 indicates the energy conversion efficiency η λ of the cadmium tellurium solar cell. Reference numeral 1155 indicates the energy conversion efficiency η λ of the Cu (In, Ga) (Se, S) 2 solar cell.
図１９および図２０に示した太陽電池では、最も発光スペクトルのピーク波長が大きい第３蛍光体１８ｃの発光スペクトルのピーク波長（６３０ｎｍ）における太陽電池の分光感度およびエネルギー変換効率は、導光体１４に備えられた他のいずれの蛍光体（第１蛍光体１８ａ、第２蛍光体１８ｂ）の発光スペクトルのピーク波長における太陽電池の分光感度およびエネルギー変換効率よりも大きい。そのため、太陽電池素子１６として、これらの太陽電池を用いれば、高い効率で発電を行うことができる。
In the solar cells shown in FIGS. 19 and 20, the spectral sensitivity and energy conversion efficiency of the solar cell at the peak wavelength (630 nm) of the emission spectrum of the third phosphor 18c having the largest emission spectrum peak wavelength are as follows. Is larger than the spectral sensitivity and energy conversion efficiency of the solar cell at the peak wavelength of the emission spectrum of any of the other phosphors (first phosphor 18a, second phosphor 18b). Therefore, if these solar cells are used as the solar cell element 16, power generation can be performed with high efficiency.
図１９および図２０は、太陽電池素子１６として利用可能な太陽電池の一例であり、これ以外の太陽電池を用いることも勿論可能である。太陽電池素子１６としては、色素増感型太陽電池や有機系太陽電池など、太陽光の全波長領域に対しては高い分光感度を有することはできないが、特定の狭い波長領域の光に対しては非常に高い分光感度を有するような太陽電池を積極的に使用することも可能である。
19 and 20 are examples of solar cells that can be used as the solar cell element 16, and other solar cells can of course be used. The solar cell element 16 cannot have high spectral sensitivity with respect to the entire wavelength region of sunlight, such as a dye-sensitized solar cell or an organic solar cell, but with respect to light in a specific narrow wavelength region. It is also possible to actively use solar cells having very high spectral sensitivity.
本実施形態の太陽電池モジュール１１Ｂにおいても、導光体１４に入射した太陽光の大部分を発電に寄与させることができる。
さらに、本実施形態においては、導光体１４の内部に、複数種類（３種類）の第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ、第３蛍光体１８ｃ）が含まれている。これにより、導光体１４に入射した太陽光を広い波長範囲で発電に利用することができる。
したがって、発電効率の高い太陽電池モジュールを提供することができる。 Also in thesolar cell module 11B of this embodiment, most of the sunlight incident on the light guide 14 can be contributed to power generation.
Further, in the present embodiment, a plurality of types (three types) of second optical functional materials (first phosphor 18a, second phosphor 18b, and third phosphor 18c) are included in the light guide body 14. ing. Thereby, the sunlight which injected into the light guide 14 can be utilized for electric power generation in a wide wavelength range.
Therefore, a solar cell module with high power generation efficiency can be provided.
さらに、本実施形態においては、導光体１４の内部に、複数種類（３種類）の第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ、第３蛍光体１８ｃ）が含まれている。これにより、導光体１４に入射した太陽光を広い波長範囲で発電に利用することができる。
したがって、発電効率の高い太陽電池モジュールを提供することができる。 Also in the
Further, in the present embodiment, a plurality of types (three types) of second optical functional materials (
Therefore, a solar cell module with high power generation efficiency can be provided.
また、本実施形態の太陽電池モジュール１１Ｂでは、第１主面１４ａに入射した外光Ｌの一部を複数の光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ、第３蛍光体１８ｃ）によって吸収し、複数の光機能材料の間でフェルスター機構によるエネルギー移動を生じさせ、最も発光スペクトルのピーク波長の大きい光機能材料（第３蛍光体１８ｃ）から放射された光を二色性蛍光色素１２により指向性を高めて導光体１４の端面１４ｃに集光させて太陽電池素子１６に入射させている。そのため、太陽電池素子１６としては、限定された狭い波長範囲において非常に高い分光感度を有する太陽電池を用いることができる。
In the solar cell module 11B of the present embodiment, a part of the external light L incident on the first main surface 14a is converted into a plurality of optical functional materials (first phosphor 18a, second phosphor 18b, and third phosphor 18c. ) To cause energy transfer by a Forster mechanism among a plurality of optical functional materials, and light emitted from the optical functional material (third phosphor 18c) having the largest peak wavelength of the emission spectrum is dichroic. The directivity is enhanced by the fluorescent dye 12, the light is condensed on the end surface 14 c of the light guide 14, and is incident on the solar cell element 16. Therefore, as the solar cell element 16, a solar cell having very high spectral sensitivity in a limited narrow wavelength range can be used.
なお、本実施形態においては、導光体１４の内部に、３種類の第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ、第３蛍光体１８ｃ）が含まれている構成を例に挙げたが、これに限らない。例えば、導光体１４の内部に、４種類以上の複数種類の第２光機能材料が含まれている構成においても本実施形態を適用可能である。
In the present embodiment, the light guide body 14 includes three types of second optical functional materials (first phosphor 18a, second phosphor 18b, and third phosphor 18c). Although it gave an example, it is not restricted to this. For example, the present embodiment can also be applied to a configuration in which four or more types of second optical functional materials are included in the light guide 14.
［第４実施形態］
図２１は、第４実施形態の太陽電池モジュール１１Ｃの断面図である。本実施形態の太陽電池モジュール１１Ｃの基本構成は第３実施形態と同様であり、導光体１４の第１主面１４ａ側に拡散板１３が設けられている点が第１実施形態と異なる。図２１において、第３実施形態の太陽電池モジュール１１Ｂと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Fourth Embodiment]
FIG. 21 is a cross-sectional view of thesolar cell module 11C of the fourth embodiment. The basic configuration of the solar cell module 11C of the present embodiment is the same as that of the third embodiment, and is different from the first embodiment in that a diffusion plate 13 is provided on the first main surface 14a side of the light guide 14. In FIG. 21, the same reference numerals are given to the configurations common to the solar cell module 11 </ b> B of the third embodiment, and detailed description thereof is omitted.
図２１は、第４実施形態の太陽電池モジュール１１Ｃの断面図である。本実施形態の太陽電池モジュール１１Ｃの基本構成は第３実施形態と同様であり、導光体１４の第１主面１４ａ側に拡散板１３が設けられている点が第１実施形態と異なる。図２１において、第３実施形態の太陽電池モジュール１１Ｂと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Fourth Embodiment]
FIG. 21 is a cross-sectional view of the
図２１に示すように、本実施形態の太陽電池モジュール１１Ｃにおいては、導光体１４の第１主面１４ａ側に、拡散板１３が空気層を介して設けられている。導光体１４と拡散板１３との間に空気層が存在することにより、二色性蛍光色素１２が発する光が導光体１４と空気層との界面で全反射条件を満たしやすくなる。
As shown in FIG. 21, in the solar cell module 11C of the present embodiment, a diffusion plate 13 is provided on the first main surface 14a side of the light guide 14 via an air layer. The presence of an air layer between the light guide 14 and the diffusion plate 13 makes it easy for light emitted from the dichroic fluorescent dye 12 to satisfy the total reflection condition at the interface between the light guide 14 and the air layer.
なお、本実施形態においては、導光体１４の第１主面１４ａ側に拡散板１３が空気層を介して設けられているが、これに限らない。例えば、導光体１４の第１主面１４ａに拡散板１３が空気層を介さずに直接接触して設けられていてもよい。
In the present embodiment, the diffusion plate 13 is provided on the first main surface 14a side of the light guide 14 via the air layer, but the present invention is not limited to this. For example, the diffusion plate 13 may be provided in direct contact with the first main surface 14a of the light guide body 14 without using an air layer.
拡散板１３は、例えばアクリル樹脂等のバインダー樹脂の内部に多数のアクリルビーズ等の光散乱体が分散されて構成されている。拡散板１３の厚みは一例として２０μｍ程度であり、球状の光散乱体の球径は０．５μｍ～２０μｍ程度である。拡散板１３は、外光を導光体１４の外部から導光体１４の内部に向けて等方的に拡散させる。
The diffusion plate 13 is configured by dispersing a large number of light scatterers such as acrylic beads in a binder resin such as an acrylic resin. For example, the thickness of the diffusion plate 13 is about 20 μm, and the spherical diameter of the spherical light scatterer is about 0.5 μm to 20 μm. The diffuser plate 13 diffuses external light isotropically from the outside of the light guide 14 toward the inside of the light guide 14.
なお、光散乱体は、これに限らず、アクリル系ポリマー、オレフィン系ポリマー、ビニル系ポリマー、セルロース系ポリマー、アミド系ポリマー、フッ素系ポリマー、ウレタン系ポリマー、シリコーン系ポリマー、イミド系ポリマーなどからなる樹脂片、ガラスビーズ等の適宜な透明の物質で構成されていてもよい。また、これら透明な物質以外でも、光の吸収の無い散乱体、反射体を用いることができる。個々の光散乱体の形状は、例えば、球形、楕円球形、平板形、多角形立方体など、各種形状に形成することができる。光散乱体のサイズも均一あるいは不均一になるように形成されていればよい。
The light scatterer is not limited to this, and is made of an acrylic polymer, an olefin polymer, a vinyl polymer, a cellulose polymer, an amide polymer, a fluorine polymer, a urethane polymer, a silicone polymer, an imide polymer, or the like. You may be comprised with appropriate transparent substances, such as a resin piece and a glass bead. In addition to these transparent substances, scatterers and reflectors that do not absorb light can be used. The shape of each light scatterer can be formed in various shapes such as a spherical shape, an elliptical spherical shape, a flat plate shape, and a polygonal cube. It is only necessary that the size of the light scatterer is uniform or nonuniform.
図２２は、拡散板の作用を説明するための図である。なお、図２２においては、便宜上、蛍光体の図示を省略している。
本実施形態の場合、図２２に示すように、導光体１４の第１主面１４ａ側には拡散板１３が配置されている。これにより、太陽電池モジュール１１Ｃ（拡散板１３）に対して垂直に入射する光は、拡散板１３で拡散した後、導光体１４の内部に入射する。このため、二色性蛍光色素１２には様々な角度の光が入射する。つまり、二色性蛍光色素１２が吸収しやすい方向の光の割合が拡散板がないときと比べて大きくなる。そのため、分子長軸Ｖ１に沿う方向においては相対的に吸収特性が小さく、分子長軸と直交する軸Ｖ２に沿う方向においては相対的に吸収特性が大きい吸収特性を有する二色性蛍光色素１２であっても、太陽電池モジュール１１Ａ（拡散板１３）に対して垂直に入射する光の一部を吸収することが可能となる。 FIG. 22 is a diagram for explaining the operation of the diffusion plate. In FIG. 22, the phosphor is not shown for convenience.
In the case of the present embodiment, as shown in FIG. 22, thediffusion plate 13 is disposed on the first main surface 14 a side of the light guide 14. As a result, the light incident perpendicularly to the solar cell module 11 </ b> C (the diffusion plate 13) is diffused by the diffusion plate 13 and then enters the light guide body 14. For this reason, light of various angles enters the dichroic fluorescent dye 12. In other words, the proportion of light in the direction in which the dichroic fluorescent dye 12 is easy to absorb is larger than when there is no diffuser. Therefore, the dichroic fluorescent dye 12 has an absorption characteristic that is relatively small in the direction along the molecular long axis V1 and relatively large in the direction along the axis V2 orthogonal to the molecular long axis. Even if it exists, it becomes possible to absorb a part of light which enters perpendicularly with respect to solar cell module 11A (diffusion plate 13).
本実施形態の場合、図２２に示すように、導光体１４の第１主面１４ａ側には拡散板１３が配置されている。これにより、太陽電池モジュール１１Ｃ（拡散板１３）に対して垂直に入射する光は、拡散板１３で拡散した後、導光体１４の内部に入射する。このため、二色性蛍光色素１２には様々な角度の光が入射する。つまり、二色性蛍光色素１２が吸収しやすい方向の光の割合が拡散板がないときと比べて大きくなる。そのため、分子長軸Ｖ１に沿う方向においては相対的に吸収特性が小さく、分子長軸と直交する軸Ｖ２に沿う方向においては相対的に吸収特性が大きい吸収特性を有する二色性蛍光色素１２であっても、太陽電池モジュール１１Ａ（拡散板１３）に対して垂直に入射する光の一部を吸収することが可能となる。 FIG. 22 is a diagram for explaining the operation of the diffusion plate. In FIG. 22, the phosphor is not shown for convenience.
In the case of the present embodiment, as shown in FIG. 22, the
本実施形態の太陽電池モジュール１１Ｃでは、拡散板１３が設けられているため、第３実施形態の構成に比べて、導光体１４の第１主面１４ａに入射した外光の一部が二色性蛍光色素１２に吸収される割合が多くなる。二色性蛍光色素１２が外光の一部を吸収すると、光を異方的に発する。本実施形態の二色性蛍光色素１２においても、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が導光体１４の第１主面１４ａと平行になるように配向されているため、二色性蛍光色素１２が発する光のうち発光強度の最も大きい光は、太陽電池素子１６に直接導かれる。したがって、導光体１４に入射した太陽光の大部分を発電に寄与させることができる。
In the solar cell module 11C of the present embodiment, since the diffusion plate 13 is provided, a part of the external light incident on the first main surface 14a of the light guide 14 is two compared to the configuration of the third embodiment. The proportion absorbed by the chromatic fluorescent dye 12 increases. When the dichroic fluorescent dye 12 absorbs part of external light, it emits light anisotropically. Also in the dichroic fluorescent dye 12 of the present embodiment, the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is oriented so as to be parallel to the first main surface 14a of the light guide 14. Therefore, light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the solar cell element 16. Therefore, most of the sunlight incident on the light guide 14 can be contributed to power generation.
［第５実施形態］
図２３は、第５実施形態の太陽電池モジュール１１Ｄの断面図である。本実施形態の太陽電池モジュール１１Ｄの基本構成は第４実施形態と同様であり、導光体１４の第２主面１４ｂ側に反射層１５が設けられている点が第４実施形態と異なる。図２３において、第４実施形態の太陽電池モジュール１１Ｃと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Fifth Embodiment]
FIG. 23 is a cross-sectional view of thesolar cell module 11D of the fifth embodiment. The basic configuration of the solar cell module 11D of the present embodiment is the same as that of the fourth embodiment, and is different from the fourth embodiment in that the reflective layer 15 is provided on the second main surface 14b side of the light guide 14. In FIG. 23, about the structure which is common in the solar cell module 11C of 4th Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
図２３は、第５実施形態の太陽電池モジュール１１Ｄの断面図である。本実施形態の太陽電池モジュール１１Ｄの基本構成は第４実施形態と同様であり、導光体１４の第２主面１４ｂ側に反射層１５が設けられている点が第４実施形態と異なる。図２３において、第４実施形態の太陽電池モジュール１１Ｃと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Fifth Embodiment]
FIG. 23 is a cross-sectional view of the
図２３に示すように、本実施形態の太陽電池モジュール１１Ｄにおいては、導光体１４の第２主面１４ｂ側に、反射層１５が空気層を介して設けられている。導光体１４と反射層１５との間に空気層が存在することにより、二色性蛍光色素１２が発する光が導光体１４と空気層との界面で全反射条件を満たしやすくなる。
23, in the solar cell module 11D of the present embodiment, the reflective layer 15 is provided on the second main surface 14b side of the light guide 14 via an air layer. The presence of an air layer between the light guide 14 and the reflective layer 15 makes it easier for light emitted from the dichroic fluorescent dye 12 to satisfy the total reflection condition at the interface between the light guide 14 and the air layer.
なお、本実施形態においては、導光体１４の第２主面１４ｂ側に反射層１５が空気層を介して設けられているが、これに限らない。例えば、導光体１４の第２主面１４ｂに反射層１５が空気層を介さずに直接接触して設けられていてもよい。
In the present embodiment, the reflective layer 15 is provided on the second main surface 14b side of the light guide 14 via an air layer, but the present invention is not limited to this. For example, the reflective layer 15 may be provided in direct contact with the second main surface 14b of the light guide 14 without an air layer.
反射層１５は、導光体１４の内部を伝播する光を反射する。また、第１主面１４ａから入射したが光機能材料に吸収されずに第２主面１４ｂから射出した光も導光体１４の内部に向けて反射する。
The reflective layer 15 reflects light propagating through the light guide 14. In addition, light that is incident from the first main surface 14 a but is not absorbed by the optical functional material and is emitted from the second main surface 14 b is also reflected toward the inside of the light guide 14.
反射層１５としては、銀やアルミニウムなどの金属膜からなる反射層や、ＥＳＲ（Ｅｎｈａｎｃｅｄ Ｓｐｅｃｕｌａｒ Ｒｅｆｌｅｃｔｏｒ）反射フィルム（３Ｍ社製）などの誘電体多層膜からなる反射層などを用いることができる。反射層１５は、入射した光を鏡面反射する鏡面反射層でもよいし、入射した光を散乱反射する散乱反射層でもよい。反射層１５に散乱反射層を用いた場合には、太陽電池素子１６の方向に直接向かう光の光量が増えるため、太陽電池素子１６への集光効率が高まり、発電量が増加する。また、反射光が散乱されるため、時間や季節による発電量の変化が平均化される。なお、散乱反射層としては、マイクロ発泡ＰＥＴ（ポリエチレン－テレフタレート）（古河電工社製）などを用いることができる。
As the reflective layer 15, a reflective layer made of a metal film such as silver or aluminum, or a reflective layer made of a dielectric multilayer film such as an ESR (Enhanced Specular Reflector) reflective film (manufactured by 3M) can be used. The reflection layer 15 may be a specular reflection layer that specularly reflects incident light, or may be a scattering reflection layer that scatters and reflects incident light. When a scattering reflection layer is used for the reflection layer 15, the amount of light that goes directly in the direction of the solar cell element 16 increases, so that the light collection efficiency to the solar cell element 16 increases and the amount of power generation increases. In addition, since the reflected light is scattered, changes in the amount of power generation with time and season are averaged. As the scattering reflection layer, microfoamed PET (polyethylene terephthalate) (manufactured by Furukawa Electric) can be used.
本実施形態の太陽電池モジュール１１Ｄによれば、反射層１５により、導光体１４の内部から導光体１４の外部に向けて進行する光、第１主面１４ａから入射し光機能材料に吸収されずに第２主面１４ｂから射出した光が導光体１４の内部に向けて反射される。そのため、導光体１４に入射した太陽光の大部分が太陽電池素子１６に到達するまでに外部に漏れてしまうことが抑制される。よって、導光体１４に入射した太陽光の大部分を発電に寄与させることができる。
According to the solar cell module 11D of the present embodiment, the light that travels from the inside of the light guide body 14 toward the outside of the light guide body 14 by the reflective layer 15, is incident from the first main surface 14a, and is absorbed by the optical functional material. Instead, the light emitted from the second main surface 14 b is reflected toward the inside of the light guide 14. Therefore, it is suppressed that most of the sunlight incident on the light guide body 14 leaks outside before reaching the solar cell element 16. Therefore, most of the sunlight incident on the light guide 14 can be contributed to power generation.
また、反射層１５に散乱反射層を用いることにより、反射光が散乱されるため、導光体１４の第１主面１４ａに入射した外光の一部が二色性蛍光色素１２に吸収される割合が多くなる。
二色性蛍光色素１２が外光の一部を吸収すると、光を異方的に発し、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい光は太陽電池素子１６に直接導かれる。したがって、導光体１４に入射した太陽光の大部分を発電に寄与させることができる。 Further, since the reflected light is scattered by using the scattering reflection layer for thereflection layer 15, a part of the external light incident on the first main surface 14 a of the light guide 14 is absorbed by the dichroic fluorescent dye 12. The ratio increases.
When the dichroicfluorescent dye 12 absorbs a part of the external light, the dichroic fluorescent dye 12 emits light anisotropically, and the light having the highest light emission intensity emitted from the dichroic fluorescent dye 12 is directly guided to the solar cell element 16. It is burned. Therefore, most of the sunlight incident on the light guide 14 can be contributed to power generation.
二色性蛍光色素１２が外光の一部を吸収すると、光を異方的に発し、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい光は太陽電池素子１６に直接導かれる。したがって、導光体１４に入射した太陽光の大部分を発電に寄与させることができる。 Further, since the reflected light is scattered by using the scattering reflection layer for the
When the dichroic
［第６実施形態］
図２４は、第６実施形態の太陽電池モジュール１１Ｅの断面図である。本実施形態の太陽電池モジュール１１Ｅの基本構成は第５実施形態と同様であり、導光体１４の第２主面１４ｂ側に拡散板１３が設けられている点が第５実施形態と異なる。図２４において、第５実施形態の太陽電池モジュール１１Ｄと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Sixth Embodiment]
FIG. 24 is a cross-sectional view of thesolar cell module 11E of the sixth embodiment. The basic configuration of the solar cell module 11E of the present embodiment is the same as that of the fifth embodiment, and is different from the fifth embodiment in that a diffusion plate 13 is provided on the second main surface 14b side of the light guide 14. In FIG. 24, about the structure which is common in the solar cell module 11D of 5th Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
図２４は、第６実施形態の太陽電池モジュール１１Ｅの断面図である。本実施形態の太陽電池モジュール１１Ｅの基本構成は第５実施形態と同様であり、導光体１４の第２主面１４ｂ側に拡散板１３が設けられている点が第５実施形態と異なる。図２４において、第５実施形態の太陽電池モジュール１１Ｄと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Sixth Embodiment]
FIG. 24 is a cross-sectional view of the
図２４に示すように、本実施形態の太陽電池モジュール１１Ｅにおいては、導光体１４の第２主面１４ｂ側に、反射層１５が空気層を介して設けられている。つまり、本実施形態の太陽電池モジュール１１Ｅは、第３実施形態の構成において、第４実施形態に係る導光体１４の第１主面１４ａ側に拡散板１３が設けられた構成と、第５実施形態に係る導光体１４の第２主面１４ｂ側に反射層１５が設けられた構成とが組み合わされた構成となっている。
As shown in FIG. 24, in the solar cell module 11E of the present embodiment, the reflective layer 15 is provided on the second main surface 14b side of the light guide 14 via an air layer. That is, the solar cell module 11E of the present embodiment has a configuration in which the diffusion plate 13 is provided on the first main surface 14a side of the light guide body 14 according to the fourth embodiment in the configuration of the third embodiment. The configuration is a combination of the configuration in which the reflective layer 15 is provided on the second main surface 14b side of the light guide body 14 according to the embodiment.
本実施形態の太陽電池モジュール１１Ｅにおいても、導光体１４に入射した太陽光の大部分を発電に寄与させることができる、といった上記第４実施形態及び第５実施形態と同様の効果を奏する。なお、本実施形態においては、拡散板１３及び反射層１５が設けられているため、前記効果は顕著なものとなる。
Also in the solar cell module 11E of the present embodiment, the same effects as those of the fourth embodiment and the fifth embodiment can be achieved, such that most of the sunlight incident on the light guide 14 can be contributed to power generation. In the present embodiment, since the diffusing plate 13 and the reflective layer 15 are provided, the above effect is remarkable.
［第７実施形態］
図３４は、第７実施形態の太陽電池モジュール１１Ｈの断面図である。本実施形態の太陽電池モジュール１１Ｈの基本構成は第５実施形態と同様であり、導光体１４の第２主面１４ｂと反射層１５との間に１／４λ板１９が設けられている点が第５実施形態と異なる。図３４において、第５実施形態の太陽電池モジュール１１Ｄと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Seventh Embodiment]
FIG. 34 is a cross-sectional view of thesolar cell module 11H of the seventh embodiment. The basic configuration of the solar cell module 11H of the present embodiment is the same as that of the fifth embodiment, and a quarter λ plate 19 is provided between the second main surface 14b of the light guide 14 and the reflective layer 15. Is different from the fifth embodiment. In FIG. 34, about the structure which is common in solar cell module 11D of 5th Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
図３４は、第７実施形態の太陽電池モジュール１１Ｈの断面図である。本実施形態の太陽電池モジュール１１Ｈの基本構成は第５実施形態と同様であり、導光体１４の第２主面１４ｂと反射層１５との間に１／４λ板１９が設けられている点が第５実施形態と異なる。図３４において、第５実施形態の太陽電池モジュール１１Ｄと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Seventh Embodiment]
FIG. 34 is a cross-sectional view of the
図２４に示すように、本実施形態の太陽電池モジュール１１Ｅにおいては、導光体１４の第２主面１４ｂと反射層１５との間に、それぞれ空気層を介して１／４λ板１９が設けられている。つまり、１／４λ板１９は、空気層を介して導光体１４の第２主面１４ｂと隣接する。１／４λ板１９は、空気層を介して反射層１５と隣接する。
As shown in FIG. 24, in the solar cell module 11E of the present embodiment, the quarter λ plate 19 is provided between the second main surface 14b of the light guide 14 and the reflective layer 15 via an air layer. It has been. That is, the ¼λ plate 19 is adjacent to the second main surface 14b of the light guide 14 through the air layer. The quarter λ plate 19 is adjacent to the reflective layer 15 through an air layer.
導光体１４の第２主面１４ｂと反射層１５との間に、１／４λ板１９を設けた場合の光の伝播について図３５Ａ～図３５Ｅを参照して説明する。
The propagation of light when the quarter λ plate 19 is provided between the second main surface 14b of the light guide 14 and the reflective layer 15 will be described with reference to FIGS. 35A to 35E.
導光体１４は、二色性蛍光色素１２が垂直配向しているため、Ｚ軸と平行に入射した光に対しては偏光板として機能しないが、Ｚ軸に対して斜めに入射した光に対しては偏光板として機能する。そのため図３５Ａおよび図３５Ｂに示すように、非偏光である太陽光Ｌが導光体１４を透過すると、直線偏光Ｌ１１となる。直線偏光Ｌ１１は、図３５Ｃに示すように、１／４λ板１９を透過することで円偏光Ｌ１２となる。円偏光Ｌ１２は、図３５Ｄに示すように、反射層１５で反射され、円偏光１２とは旋光方向が異なる円偏光Ｌ１３となる。図３５Ｅに示すように、円偏光Ｌ１３が再度１／４λ板１９に入射することで直線偏光Ｌ１４となるが、直線偏光Ｌ１４は、直線偏光Ｌ１１とは偏向方向が異なる（理想的には９０°異なる）。したがって、導光体１４から射出され１／４λ板１９を介することなく反射層１５で反射した光と比較して、直線偏光Ｌ１４は、二色性蛍光色素１２に吸収されやすくなる。
Since the dichroic fluorescent dye 12 is vertically aligned, the light guide 14 does not function as a polarizing plate for light incident in parallel to the Z axis, but does not function as light incident obliquely to the Z axis. On the other hand, it functions as a polarizing plate. Therefore, as shown in FIGS. 35A and 35B, when the non-polarized sunlight L passes through the light guide body 14, it becomes linearly polarized light L11. As shown in FIG. 35C, the linearly polarized light L11 passes through the ¼λ plate 19 to become circularly polarized light L12. As shown in FIG. 35D, the circularly polarized light L12 is reflected by the reflective layer 15, and becomes circularly polarized light L13 having a different optical rotation direction from the circularly polarized light 12. As shown in FIG. 35E, the circularly polarized light L13 is incident on the ¼λ plate 19 again to become the linearly polarized light L14. However, the linearly polarized light L14 has a deflection direction different from that of the linearly polarized light L11 (ideally 90 °). Different). Therefore, the linearly polarized light L14 is easily absorbed by the dichroic fluorescent dye 12 as compared with the light emitted from the light guide 14 and reflected by the reflective layer 15 without passing through the ¼λ plate 19.
なお、本実施形態においては１／４λ板１９を用いたが、本実施形態はこれに限定されず、その他の位相差板を用いてもよい。例えば、１／４λ板１９の代わりに、１／８λ板、５／８λ板、３／４λ板等を用いてもよい。
In the present embodiment, the quarter λ plate 19 is used. However, the present embodiment is not limited to this, and other phase difference plates may be used. For example, instead of the 1 / 4λ plate 19, a 1 / 8λ plate, a 5 / 8λ plate, a 3 / 4λ plate, or the like may be used.
また第５実施形態と同様に、反射層１５は、散乱反射層であってもよい。
As in the fifth embodiment, the reflection layer 15 may be a scattering reflection layer.
本実施形態の太陽電池モジュール１１Ｈにおいても、導光体１４に入射した太陽光の大部分を発電に寄与させることができる、といった上記第４実施形態及び第５実施形態と同様の効果を奏する。なお、本実施形態においては、反射層１５及び１／４λ板１９が設けられているため、前記効果は顕著なものとなる。
Also in the solar cell module 11H of the present embodiment, the same effects as those of the fourth embodiment and the fifth embodiment can be achieved, such that most of the sunlight incident on the light guide 14 can be contributed to power generation. In the present embodiment, since the reflection layer 15 and the ¼λ plate 19 are provided, the above-described effect becomes remarkable.
［第８実施形態］
図２５は、第８実施形態の太陽電池モジュール１１Ｆの断面図である。本実施形態の太陽電池モジュール１１Ｆの基本構成は第３実施形態と同様であり、導光体１４の内部に２種類の二色性蛍光色素（第１二色性蛍光色素１１２ａ、第２二色性蛍光色素１１２ｂ）が設けられている点が第３実施形態と異なる。図２５において、第３実施形態の太陽電池モジュール１１Ｂと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Eighth Embodiment]
FIG. 25 is a cross-sectional view of thesolar cell module 11F of the eighth embodiment. The basic configuration of the solar cell module 11F of the present embodiment is the same as that of the third embodiment, and two types of dichroic fluorescent dyes (first dichroic fluorescent dye 112a and second dichroic dye are provided inside the light guide body 14. The third embodiment is different from the third embodiment in that a fluorescent fluorescent dye 112b) is provided. In FIG. 25, about the structure which is common in the solar cell module 11B of 3rd Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
図２５は、第８実施形態の太陽電池モジュール１１Ｆの断面図である。本実施形態の太陽電池モジュール１１Ｆの基本構成は第３実施形態と同様であり、導光体１４の内部に２種類の二色性蛍光色素（第１二色性蛍光色素１１２ａ、第２二色性蛍光色素１１２ｂ）が設けられている点が第３実施形態と異なる。図２５において、第３実施形態の太陽電池モジュール１１Ｂと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Eighth Embodiment]
FIG. 25 is a cross-sectional view of the
第３実施形態の太陽電池モジュール１１Ｂでは、第１主面１４ａに入射した外光Ｌの一部を複数の第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ、第３蛍光体１８ｃ）によって吸収し、複数の第２光機能材料の間でフェルスター機構によるエネルギー移動を生じさせていた。そして、最も発光スペクトルのピーク波長の大きい第２光機能材料（第３蛍光体１８ｃ）から放射された光を二色性蛍光色素１２（第１光機能材料）により指向性を高めて導光体１４の端面１４ｃに集光させて太陽電池素子１６に入射させていた。
In the solar cell module 11B of the third embodiment, a part of the external light L incident on the first main surface 14a is converted into a plurality of second optical functional materials (first phosphor 18a, second phosphor 18b, third phosphor). 18c), energy transfer was caused by the Forster mechanism between the plurality of second optical functional materials. Then, the light emitted from the second optical functional material (third phosphor 18c) having the largest peak wavelength of the emission spectrum is enhanced in directivity by the dichroic fluorescent dye 12 (first optical functional material), and the light guide 14 was condensed on the end face 14 c of the solar cell element 16 and made incident on the solar cell element 16.
これに対し、本実施形態の太陽電池モジュール１１Ｆでは、第１主面１４ａに入射した外光Ｌの一部を複数の第２光機能材料（第１蛍光体１８ａ、第２蛍光体１８ｂ、第３蛍光体１８ｃ）によって吸収し、複数の第２光機能材料の一部の第２光機能材料の間でフェルスター機構によるエネルギー移動を生じさせている。そして、最も発光スペクトルのピーク波長の大きい第２光機能材料から放射された光を第１二色性蛍光色素１１２ａ（第１光機能材料）により指向性を高めて導光体１４の端面１４ｃに集光させて太陽電池素子１６に入射させている。さらに、複数の第２光機能材料の残りの一部の第２光機能材料の間でフォトルミネッセンス機構によるエネルギー移動を生じさせている。そして、最も発光スペクトルのピーク波長の大きい第２光機能材料から放射された光を第２二色性蛍光色素１１２ｂ（第１光機能材料）により指向性を高めて導光体１４の端面１４ｃに集光させて太陽電池素子１６に入射させている。すなわち、本実施形態においては、フェルスター機構によるエネルギー移動及びフォトルミネッセンス機構によるエネルギー移動の双方のエネルギー移動を生じさせている。
On the other hand, in the solar cell module 11F of the present embodiment, a part of the external light L incident on the first main surface 14a is converted into a plurality of second optical functional materials (first phosphor 18a, second phosphor 18b, first 3 phosphor 18c), and energy transfer is caused by the Förster mechanism between some second optical functional materials of the plurality of second optical functional materials. Then, the light emitted from the second optical functional material having the largest peak wavelength of the emission spectrum is enhanced in directivity by the first dichroic fluorescent dye 112a (first optical functional material) and applied to the end face 14c of the light guide body 14. The light is condensed and made incident on the solar cell element 16. Furthermore, energy transfer is caused by the photoluminescence mechanism between the remaining second optical functional materials of the plurality of second optical functional materials. Then, the light emitted from the second optical functional material having the largest peak wavelength of the emission spectrum is enhanced in directivity by the second dichroic fluorescent dye 112b (first optical functional material) and applied to the end face 14c of the light guide body 14. The light is condensed and made incident on the solar cell element 16. That is, in this embodiment, both energy transfer by the Forster mechanism and energy transfer by the photoluminescence mechanism are caused.
本実施形態の太陽電池モジュール１１Ｆにおいても、導光体１４に入射した太陽光の大部分を発電に寄与させることができる、といった第３実施形態と同様の効果を奏する。さらに、本実施形態においては、２種類の二色性蛍光色素１１２ａ，１１２ｂを用いることで、フェルスター機構によるエネルギー移動に加えてフォトルミネッセンス機構によるエネルギー移動により第１主面１４ａに入射した外光のエネルギーを伝播することを可能にしている。
したがって、発電効率の高い太陽電池モジュールを提供することができる。 Also in thesolar cell module 11F of the present embodiment, the same effect as that of the third embodiment, in which most of the sunlight incident on the light guide body 14 can be contributed to power generation, is achieved. Furthermore, in this embodiment, by using two types of dichroic fluorescent dyes 112a and 112b, external light incident on the first major surface 14a by energy transfer by the photoluminescence mechanism in addition to energy transfer by the Forster mechanism. It is possible to propagate energy.
Therefore, a solar cell module with high power generation efficiency can be provided.
したがって、発電効率の高い太陽電池モジュールを提供することができる。 Also in the
Therefore, a solar cell module with high power generation efficiency can be provided.
［第９実施形態］
図２６は、第９実施形態の太陽電池モジュール１１Ｇの断面図である。
図２７は、第９実施形態の太陽電池モジュール１１Ｇで用いられる光機能材料の発光スペクトルおよび太陽電池素子の分光感度を示す図である。
本実施形態の太陽電池モジュール１１Ｇの基本構成は第１実施形態と同様であり、導光体１４の内部に２種類の蛍光体（第１蛍光体１８ｄ、第２蛍光体１８ｅ）が設けられている点が第１実施形態と異なる。図２６において、第１実施形態の太陽電池モジュール１１と共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Ninth Embodiment]
FIG. 26 is a cross-sectional view of thesolar cell module 11G of the ninth embodiment.
FIG. 27 is a diagram illustrating an emission spectrum of an optical functional material used in thesolar cell module 11G of the ninth embodiment and a spectral sensitivity of the solar cell element.
The basic configuration of thesolar cell module 11G of this embodiment is the same as that of the first embodiment, and two types of phosphors (first phosphor 18d and second phosphor 18e) are provided inside the light guide body 14. This is different from the first embodiment. In FIG. 26, about the structure which is common in the solar cell module 11 of 1st Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
図２６は、第９実施形態の太陽電池モジュール１１Ｇの断面図である。
図２７は、第９実施形態の太陽電池モジュール１１Ｇで用いられる光機能材料の発光スペクトルおよび太陽電池素子の分光感度を示す図である。
本実施形態の太陽電池モジュール１１Ｇの基本構成は第１実施形態と同様であり、導光体１４の内部に２種類の蛍光体（第１蛍光体１８ｄ、第２蛍光体１８ｅ）が設けられている点が第１実施形態と異なる。図２６において、第１実施形態の太陽電池モジュール１１と共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Ninth Embodiment]
FIG. 26 is a cross-sectional view of the
FIG. 27 is a diagram illustrating an emission spectrum of an optical functional material used in the
The basic configuration of the
第３実施形態の太陽電池モジュール１１Ｂでは、導光体１４に備えられる複数の第２光機能材料として、いずれも蛍光量子収率の高い３つの蛍光体（第１蛍光体１８ａ、第２蛍光体１８ｂ、第３蛍光体１８ｃ）を用いた。それに対して、本実施形態の太陽電池モジュール１１Ｇでは、導光体に備えられる複数の第２光機能材料として、蛍光量子収率の低い第１蛍光体１８ｄと、蛍光量子収率の高い第２蛍光体１８ｅが用いられている。第１蛍光体１８ｄはホスト分子であり、第２蛍光体１８ｅはゲスト分子であり、第１蛍光体１８ｄと第２蛍光体１８ｅとの間でフェルスター機構によるエネルギー移動が生じ、実質的に、ゲスト分子である第２蛍光体１８ｅのみが発光する。本実施形態においては、第２蛍光体１８ｅから放射された光を二色性蛍光色素１２（第１光機能材料）により指向性を高めて導光体１４の端面１４ｃに集光させて太陽電池素子１６に入射させている。
In the solar cell module 11B of the third embodiment, as the plurality of second optical functional materials provided in the light guide 14, each of the three phosphors (the first phosphor 18a and the second phosphor) having a high fluorescence quantum yield. 18b, the third phosphor 18c) was used. On the other hand, in the solar cell module 11G of the present embodiment, as the plurality of second optical functional materials provided in the light guide, the first phosphor 18d having a low fluorescence quantum yield and the second having a high fluorescence quantum yield. A phosphor 18e is used. The first phosphor 18d is a host molecule, the second phosphor 18e is a guest molecule, energy transfer occurs due to the Forster mechanism between the first phosphor 18d and the second phosphor 18e, and substantially, Only the second phosphor 18e, which is a guest molecule, emits light. In the present embodiment, the light emitted from the second phosphor 18e is enhanced in directivity by the dichroic fluorescent dye 12 (first optical functional material) and condensed on the end surface 14c of the light guide 14 so as to be solar cells. The light is incident on the element 16.
第１蛍光体１８ｄは、例えばＮＰＢ（N,N-di(naphthalene-1-yl)-N,N-diphenyl-benzidene）である。第１蛍光体１８ｄの蛍光量子収率は４２％であり、第１蛍光体１８ｄの発光スペクトルのピーク波長１１６１は４３０ｎｍである。第２蛍光体１８ｅは、例えばルブレンである。第２蛍光体１８ｅの蛍光量子収率は１００％近い高い蛍光量子収率であり、第２蛍光体１８ｅの発光スペクトル１１６２のピーク波長は５６０ｎｍである。第１蛍光体１８ｄに対して第２蛍光体１８ｅの含有量は２％とされている。本実施形態の導光体は、例えば、厚さ２ｍｍのガラス基板などからなる透明導光体の第１主面に、第１蛍光体１８ｄと第２蛍光体１８ｅとを含む光機能材料層を５μｍの厚みで成膜し、光機能材料層の表面に透明保護膜としてパリレンを１μｍの厚みで成膜することにより形成される。
The first phosphor 18d is, for example, NPB (N, N-di (naphthalene-1-yl) -N, N-diphenyl-benzidene). The fluorescence quantum yield of the first phosphor 18d is 42%, and the peak wavelength 1161 of the emission spectrum of the first phosphor 18d is 430 nm. The second phosphor 18e is, for example, rubrene. The fluorescence quantum yield of the second phosphor 18e is a high fluorescence quantum yield close to 100%, and the peak wavelength of the emission spectrum 1162 of the second phosphor 18e is 560 nm. The content of the second phosphor 18e is 2% with respect to the first phosphor 18d. In the light guide of this embodiment, for example, an optical functional material layer including a first phosphor 18d and a second phosphor 18e is formed on a first main surface of a transparent light guide made of a glass substrate having a thickness of 2 mm. The film is formed to a thickness of 5 μm, and parylene is formed to a thickness of 1 μm as a transparent protective film on the surface of the optical functional material layer.
太陽電池素子１６としては、アモルファスシリコン太陽電池が用いられている。第１蛍光体１８ｄおよび第２蛍光体１８ｅの発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度１１６３を比較すると、最も発光スペクトルのピーク波長の大きい第２蛍光体１８ｅの発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度は、第１蛍光体１８ｄの発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度よりも大きい。そのため、太陽電池素子１６としてアモルファスシリコン太陽電池を用いれば、高い効率で発電を行うことができる。
As the solar cell element 16, an amorphous silicon solar cell is used. Comparing the spectral sensitivities 1163 of the amorphous silicon solar cells at the peak wavelengths of the emission spectra of the first phosphor 18d and the second phosphor 18e, at the peak wavelength of the emission spectrum of the second phosphor 18e having the largest peak wavelength of the emission spectrum. The spectral sensitivity of the amorphous silicon solar cell is larger than the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of the first phosphor 18d. Therefore, if an amorphous silicon solar cell is used as the solar cell element 16, power generation can be performed with high efficiency.
本実施形態の太陽電池モジュール１１Ｇにおいては、ホスト分子である第１蛍光体１８ｄの蛍光量子収率は４２％と非常に小さいが、フェルスター機構によるエネルギー移動では、最終的な発電量は、ゲスト分子の蛍光量子収率によって決まり、ホスト分子の蛍光量子収率には依存しない。よって、ゲスト分子のみを蛍光量子収率の高い蛍光体で構成すれば、ホスト分子を蛍光量子収率の低い蛍光体で構成しても、同じ発電量が得られる。一般に、蛍光体は発光体として利用されるので、蛍光量子収率の低い蛍光体は使用することができないが、本実施形態のように、発光させずにエネルギーのみをダイレクトに移動させる場合には、蛍光量子収率が低くても、最終的な発電量は変わらないので、使用することが可能となる。一般に、蛍光量子収率の高い蛍光体は、価格が高く、耐光性が低く、寿命の短いものが多いので、保守の費用が高くなる。一方で蛍光量子収率の低い蛍光体は、価格が低く、材料も豊富で、耐光性が高く、寿命の長いものが多いので、保守の費用を少なくすることができる。
In the solar cell module 11G of the present embodiment, the fluorescence quantum yield of the first phosphor 18d, which is a host molecule, is very small as 42%. However, in the energy transfer by the Forster mechanism, the final power generation amount is the guest It depends on the fluorescence quantum yield of the molecule and does not depend on the fluorescence quantum yield of the host molecule. Therefore, if only the guest molecule is composed of a phosphor having a high fluorescence quantum yield, the same power generation amount can be obtained even if the host molecule is composed of a phosphor having a low fluorescence quantum yield. In general, since a phosphor is used as a light emitter, a phosphor with a low fluorescence quantum yield cannot be used, but when only energy is directly transferred without emitting light as in this embodiment. Even if the fluorescence quantum yield is low, the final power generation amount does not change, so it can be used. In general, phosphors having a high fluorescence quantum yield are expensive, have low light resistance, and have a short lifetime, so that maintenance costs are high. On the other hand, phosphors with low fluorescence quantum yields are low in price, abundant in materials, high in light resistance, and long in life, so that maintenance costs can be reduced.
第１蛍光体１８ｄとしては、蛍光量子収率が９０％未満のもの、より好ましくは、蛍光量子収率が８０％以下のものを用いることが好ましい。一般に、太陽電池の寿命は変換効率が初期値の９０％になるまでの時間とされていることから、導光体においても蛍光体の発光強度が１０％落ちるまでの時間を寿命とみなすことができる。蛍光体は、通常、発光体としての利用が前提となるので、蛍光量子収率としては、１００％～９０％の高い蛍光量子収率が求められる。よって、蛍光体の寿命は、蛍光量子収率が初期値から１０％落ちるまでの時間、すなわち、蛍光量子収率が９０％から８１％になるまでの時間とみなすことができる。よって、蛍光量子収率が８０％以下の蛍光体は、通常は使用されることはなく、このような蛍光体が存在したとしても、性能の悪い蛍光体として安価に入手することができる。よって、このような蛍光量子収率の低い蛍光体を用いれば、発電効率の高い太陽電池モジュールを安価に提供することができる。
As the first phosphor 18d, it is preferable to use a fluorescent quantum yield of less than 90%, more preferably a fluorescent quantum yield of 80% or less. In general, since the lifetime of a solar cell is the time until the conversion efficiency reaches 90% of the initial value, the time until the emission intensity of the phosphor decreases by 10% in the light guide can also be regarded as the lifetime. it can. Since phosphors are usually premised on use as light emitters, a high fluorescence quantum yield of 100% to 90% is required as a fluorescence quantum yield. Therefore, the lifetime of the phosphor can be regarded as the time until the fluorescence quantum yield drops by 10% from the initial value, that is, the time until the fluorescence quantum yield drops from 90% to 81%. Therefore, a phosphor having a fluorescence quantum yield of 80% or less is not usually used, and even if such a phosphor exists, it can be obtained at a low cost as a phosphor with poor performance. Therefore, if such a phosphor with a low fluorescence quantum yield is used, a solar cell module with high power generation efficiency can be provided at low cost.
本実施形態では、第１蛍光体１８ｄの一例としてＮＰＢを用いたが、第１蛍光体１８ｄはこれに限定されない。他の材料としては、N,N’-bis(3-methylphenyl)-N,N’-diphenyl- [1,1’-biphenyl]-4,4’-diamine (TPD)、4,4’-bis-[N-(1-naphthyl)-N-phenylamino]-biphenyl) (a-NPD)、4,4’-bis-[N-(9-phenanthyl)-N-phenylamino]-biphenyl (PPD)、N,N,N’,N’-tetra-tolyl-1,1’-cyclohexyl-4,4’-diamine (TPAC)、1,1,4,4-tetraphenyl-1,3-butadiene（TPB）、TACP, Poly(N-vinylcarbazole) (PVK)、4,4',4''-tri(N-carbazolyl)triphenylamine (TCTA)、1,3,5-tris[4-(3-methylphenylphenylamino)phenyl]benzene(m-MTDAPB)、1,3,5-tris[N-(4-diphenylaminophenyl)phenylamino]benzene (p-DPA-TDAB)、4,4,4''-tris(3-methylphenylphenylamino)triphenylamine (m-MTDATA)、4,4',4''-tris(1-naphthylphenylamino)triphenylamine (1-TNATA)、4,4',4''-tris(2-naphthylphenylamino)triphenylamine (2-TNATA)、1,3,5-tris(4-tert-butylphenyl-1,3,4-oxadiazolyl)benzene (TPOB)、tri(p-terphenyl-4-yl)amine (p-TTA)、bis{4-[bis(4-methylphenyl)amino]phenyl}oligothiophene (BMA-nT)、2,5-bis{4-[bis(4-methylphenyl)amino]phenyl}thiophene (BMA-1T)、5,5''-bis{4-[bis(4-methylphenyl)amino]phenyl}-2,2'-bithiophene (BMA-2T)、5,5''-bis{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2''-terthiophene (BMA-3T)、5,5'''-bis{4-[bis(4-methylphenyl)amino]phenyl}-2,2':5',2'':5'',2''-quaterthiophene (BMA-4T)、
2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD)、2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)、4,7-diphenyl-1,10-phenanthroline (Bphen)、2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBphen)、1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene (OXD-7)、3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ)、4,4'-bis(4,6-diphenyl-1,3,5-triazin-2-yl)biphenyl (BTB)、2,5-Bis(1-naphthyl)-1,3,4-oxadiazole (BND)、4,4'-bis(carbazol-9-yl)biphenyl (CBP)、2,2',7,7'-tetrakis(carbazol-9-yl)-9,9-spirobifluorene (Spiro-CBP)、1,3,5-tris(carbazol-9-yl)benzene (TCP), 1,3-bis(carbazol-9-yl)benzene (MCP)、
4,4'-di(triphenylsilyl)-biphenyl (BSB)、1,4-bis(triphenylsilyl)benzene (UGH-2)、1,3-bis(triphenylsilyl)benzene (UGH-3)などの有機蛍光体や、ZnO、CdSe、 ZnSe、 AlN, GaN, InN, InP, GaP, GaAs, ZnS, CdSなどで構成される量子ドットからなる無機蛍光体などが挙げられるが、これらに限定されるものでもない。本実施形態において、有機無機ハイブリット蛍光体（例えば有機金属錯体）を用いてもよい。 In the present embodiment, NPB is used as an example of thefirst phosphor 18d, but the first phosphor 18d is not limited to this. Other materials include N, N'-bis (3-methylphenyl) -N, N'-diphenyl- [1,1'-biphenyl] -4,4'-diamine (TPD), 4,4'-bis -[N- (1-naphthyl) -N-phenylamino] -biphenyl) (a-NPD), 4,4'-bis- [N- (9-phenanthyl) -N-phenylamino] -biphenyl (PPD), N , N, N ', N'-tetra-tolyl-1,1'-cyclohexyl-4,4'-diamine (TPAC), 1,1,4,4-tetraphenyl-1,3-butadiene (TPB), TCAP , Poly (N-vinylcarbazole) (PVK), 4,4 ', 4``-tri (N-carbazolyl) triphenylamine (TCTA), 1,3,5-tris [4- (3-methylphenylphenylamino) phenyl] benzene ( m-MTDAPB), 1,3,5-tris [N- (4-diphenylaminophenyl) phenylamino] benzene (p-DPA-TDAB), 4,4,4 ''-tris (3-methylphenylphenylamino) triphenylamine (m-MTDATA ), 4,4 ', 4``-tris (1-naphthylphenylamino) triphenylamine (1-TNATA), 4,4', 4 ''-tris (2-naphthylphenylamino) triphenylamine (2-TNATA), 1,3, 5-tris (4-tert-butylphenyl-1,3,4-oxadiazolyl) benzene (TPOB), tri (p-terphenyl-4-yl) amine (p-TTA), bis {4- [bis (4-methylphenyl ) amino] phenyl} oligothiophene (BMA-nT), 2,5-bis {4- [bis (4-methylphenyl) amino] phenyl} thiophene (BMA-1T), 5,5 ''-bis {4- [bis (4-meth ylphenyl) amino] phenyl} -2,2'-bithiophene (BMA-2T), 5,5 ''-bis {4- [bis (4-methylphenyl) amino] phenyl} -2,2 ': 5', 2 '' -terthiophene (BMA-3T), 5,5 '''-bis {4- [bis (4-methylphenyl) amino] phenyl} -2,2': 5 ', 2'':5'', 2 '' -quaterthiophene (BMA-4T),
2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2,9-bis (naphthalen-2-yl) -4,7-diphenyl-1,10-phenanthroline (NBphen), 1,3-bis [2 -(4-tert-butylphenyl) -1,3,4-oxadiazo-5-yl] benzene (OXD-7), 3- (4-biphenyl) -4-phenyl-5-tert-butylphenyl-1,2, 4-triazole (TAZ), 4,4'-bis (4,6-diphenyl-1,3,5-triazin-2-yl) biphenyl (BTB), 2,5-Bis (1-naphthyl) -1, 3,4-oxadiazole (BND), 4,4'-bis (carbazol-9-yl) biphenyl (CBP), 2,2 ', 7,7'-tetrakis (carbazol-9-yl) -9,9- spirobifluorene (Spiro-CBP), 1,3,5-tris (carbazol-9-yl) benzene (TCP), 1,3-bis (carbazol-9-yl) benzene (MCP),
Organic phosphors such as 4,4'-di (triphenylsilyl) -biphenyl (BSB), 1,4-bis (triphenylsilyl) benzene (UGH-2), 1,3-bis (triphenylsilyl) benzene (UGH-3) Inorganic phosphors composed of quantum dots composed of ZnO, CdSe, ZnSe, AlN, GaN, InN, InP, GaP, GaAs, ZnS, CdS, and the like, but are not limited thereto. In the present embodiment, an organic-inorganic hybrid phosphor (for example, an organometallic complex) may be used.
2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD)、2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP)、4,7-diphenyl-1,10-phenanthroline (Bphen)、2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (NBphen)、1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene (OXD-7)、3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole (TAZ)、4,4'-bis(4,6-diphenyl-1,3,5-triazin-2-yl)biphenyl (BTB)、2,5-Bis(1-naphthyl)-1,3,4-oxadiazole (BND)、4,4'-bis(carbazol-9-yl)biphenyl (CBP)、2,2',7,7'-tetrakis(carbazol-9-yl)-9,9-spirobifluorene (Spiro-CBP)、1,3,5-tris(carbazol-9-yl)benzene (TCP), 1,3-bis(carbazol-9-yl)benzene (MCP)、
4,4'-di(triphenylsilyl)-biphenyl (BSB)、1,4-bis(triphenylsilyl)benzene (UGH-2)、1,3-bis(triphenylsilyl)benzene (UGH-3)などの有機蛍光体や、ZnO、CdSe、 ZnSe、 AlN, GaN, InN, InP, GaP, GaAs, ZnS, CdSなどで構成される量子ドットからなる無機蛍光体などが挙げられるが、これらに限定されるものでもない。本実施形態において、有機無機ハイブリット蛍光体（例えば有機金属錯体）を用いてもよい。 In the present embodiment, NPB is used as an example of the
2- (4-biphenyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), 2,9-bis (naphthalen-2-yl) -4,7-diphenyl-1,10-phenanthroline (NBphen), 1,3-bis [2 -(4-tert-butylphenyl) -1,3,4-oxadiazo-5-yl] benzene (OXD-7), 3- (4-biphenyl) -4-phenyl-5-tert-butylphenyl-1,2, 4-triazole (TAZ), 4,4'-bis (4,6-diphenyl-1,3,5-triazin-2-yl) biphenyl (BTB), 2,5-Bis (1-naphthyl) -1, 3,4-oxadiazole (BND), 4,4'-bis (carbazol-9-yl) biphenyl (CBP), 2,2 ', 7,7'-tetrakis (carbazol-9-yl) -9,9- spirobifluorene (Spiro-CBP), 1,3,5-tris (carbazol-9-yl) benzene (TCP), 1,3-bis (carbazol-9-yl) benzene (MCP),
Organic phosphors such as 4,4'-di (triphenylsilyl) -biphenyl (BSB), 1,4-bis (triphenylsilyl) benzene (UGH-2), 1,3-bis (triphenylsilyl) benzene (UGH-3) Inorganic phosphors composed of quantum dots composed of ZnO, CdSe, ZnSe, AlN, GaN, InN, InP, GaP, GaAs, ZnS, CdS, and the like, but are not limited thereto. In the present embodiment, an organic-inorganic hybrid phosphor (for example, an organometallic complex) may be used.
本実施形態では、ホスト分子を１種類の第２光機能材料（第１蛍光体１８ｄ）のみで構成したが、２種類以上の第２光機能材料をホスト材料として用いることもできる。その場合、最終的な発電量は、最も発光スペクトルのピーク波長が大きい第２光機能材料の蛍光量子収率によって決まる。そのため、最も発光スペクトルのピーク波長が大きい第２光機能材料の蛍光量子収率は、導光体に備えられた他のいずれの第２光機能材料の蛍光量子収率よりも高いことが望ましい。
In the present embodiment, the host molecule is composed of only one type of second optical functional material (first phosphor 18d), but two or more types of second optical functional material may be used as the host material. In that case, the final power generation amount is determined by the fluorescence quantum yield of the second optical functional material having the largest peak wavelength of the emission spectrum. Therefore, it is desirable that the fluorescence quantum yield of the second optical functional material having the largest peak wavelength of the emission spectrum is higher than the fluorescence quantum yield of any other second optical functional material provided in the light guide.
［第１０実施形態］
図２８は、第１０実施形態の太陽電池モジュールで用いられる光機能材料の発光スペクトルおよび太陽電池素子の分光感度を示す図である。 [Tenth embodiment]
FIG. 28 is a diagram illustrating an emission spectrum of an optical functional material used in the solar cell module of the tenth embodiment and a spectral sensitivity of the solar cell element.
図２８は、第１０実施形態の太陽電池モジュールで用いられる光機能材料の発光スペクトルおよび太陽電池素子の分光感度を示す図である。 [Tenth embodiment]
FIG. 28 is a diagram illustrating an emission spectrum of an optical functional material used in the solar cell module of the tenth embodiment and a spectral sensitivity of the solar cell element.
第９実施形態の太陽電池モジュールでは、ホスト分子として、蛍光量子収率が４２％の第１蛍光体１８ｄが用いられていた。それに対して、本実施形態の太陽電池モジュールでは、ホスト分子として、蛍光量子収率が３％の第１蛍光体が用いられている。第１蛍光体は、蛍光量子収率が非常に低く、実質的に光を発しない非発光体とみなすことができる。第１蛍光体はホスト分子であり、第２蛍光体はゲスト分子であり、第１蛍光体と第２蛍光体との間でフェルスター機構によるエネルギー移動が生じ、実質的に、ゲスト分子である第２蛍光体のみが発光する。
In the solar cell module of the ninth embodiment, the first phosphor 18d having a fluorescence quantum yield of 42% was used as the host molecule. On the other hand, in the solar cell module of the present embodiment, a first phosphor having a fluorescence quantum yield of 3% is used as a host molecule. The first phosphor can be regarded as a non-light emitter that has a very low fluorescence quantum yield and does not emit light substantially. The first phosphor is a host molecule, the second phosphor is a guest molecule, energy transfer occurs by the Forster mechanism between the first phosphor and the second phosphor, and is substantially a guest molecule. Only the second phosphor emits light.
第１蛍光体は、例えばＴＰＤＳ（N,N,N’,N’-tetra-tolyl-1,1’-diphenylsulphide-4,4’-diamine）である。第１蛍光体の蛍光量子収率は３％であり、第１蛍光体の発光スペクトル１１７１のピーク波長は４２０ｎｍである。本実施形態の第２蛍光体は、第８実施形態の第２蛍光体と同じルブレンである。符号１１７２は、第２蛍光体の発光スペクトルを示す。第１蛍光体に対して第２蛍光体の含有量は３％とされている。本実施形態の導光体は、例えば、厚さ２ｍｍのガラス基板などからなる透明導光体の第１主面に、第１蛍光体と第２蛍光体とを含む光機能材料層を５μｍの厚みで成膜し、光機能材料層の表面に透明保護膜としてパリレンを１μｍの厚みで成膜することにより形成される。
The first phosphor is, for example, TPDS (N, N, N ′, N′-tetra-tolyl-1,1′-diphenylsulphide-4,4′-diamine). The fluorescence quantum yield of the first phosphor is 3%, and the peak wavelength of the emission spectrum 1171 of the first phosphor is 420 nm. The second phosphor of the present embodiment is the same rubrene as the second phosphor of the eighth embodiment. Reference numeral 1172 indicates the emission spectrum of the second phosphor. The content of the second phosphor is 3% with respect to the first phosphor. In the light guide of this embodiment, for example, an optical functional material layer including a first phosphor and a second phosphor is formed on a first main surface of a transparent light guide made of a glass substrate having a thickness of 2 mm. The film is formed with a thickness, and parylene is formed with a thickness of 1 μm as a transparent protective film on the surface of the optical functional material layer.
太陽電池素子としては、アモルファスシリコン太陽電池が用いられている。第１蛍光体および第２蛍光体の発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度１１７３を比較すると、最も発光スペクトルのピーク波長の大きい第２蛍光体の発光スペクトル１１７２のピーク波長におけるアモルファスシリコン太陽電池の分光感度１１７３は、導光体に備えられた他のいずれの蛍光体（第１蛍光体）の発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度よりも大きい。そのため、太陽電池素子としてアモルファスシリコン太陽電池を用いれば、高い効率で発電を行うことができる。
An amorphous silicon solar cell is used as the solar cell element. Comparing the spectral sensitivity 1173 of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of the first phosphor and the second phosphor, the amorphous silicon at the peak wavelength of the emission spectrum 1172 of the second phosphor having the largest peak wavelength of the emission spectrum The spectral sensitivity 1173 of the solar cell is higher than the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of any of the other phosphors (first phosphors) provided in the light guide. Therefore, if an amorphous silicon solar cell is used as the solar cell element, power generation can be performed with high efficiency.
本実施形態によれば、第１蛍光体（例えばＴＰＤＳ）のように蛍光量子収率の低い蛍光体は安価に入手でき、耐光性が高いので、発電効率の高い太陽電池モジュールを安価に提供できる。
According to this embodiment, a phosphor having a low fluorescence quantum yield such as the first phosphor (for example, TPDS) can be obtained at low cost and has high light resistance, so that a solar cell module with high power generation efficiency can be provided at low cost. .
［第１１実施形態］
図３６は、第１１実施形態の太陽電池モジュール２１の概略斜視図である。
図３６において、第１実施形態の太陽電池モジュール１１と共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Eleventh embodiment]
FIG. 36 is a schematic perspective view of thesolar cell module 21 of the eleventh embodiment.
In FIG. 36, the same reference numerals are given to configurations common to thesolar cell module 11 of the first embodiment, and detailed description thereof is omitted.
図３６は、第１１実施形態の太陽電池モジュール２１の概略斜視図である。
図３６において、第１実施形態の太陽電池モジュール１１と共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Eleventh embodiment]
FIG. 36 is a schematic perspective view of the
In FIG. 36, the same reference numerals are given to configurations common to the
太陽電池モジュール２１は、第１導光体（蛍光導光体）２２と、第２導光体（形状導光体）２３と、第１太陽電池素子１６と、第２太陽電池素子２５と、枠体２６と、を備えている。第１太陽電池素子１６は、第１導光体２２の第１端面２２ｃから射出された光を受光する。以下、「出射」という表現も、「射出」と同様の意味で使うものとする。第２太陽電池素子２５は、第２導光体２３の第２端面２３ｃから射出された光を受光する。枠体２６は、これら第１導光体２２、第２導光体２３、第１太陽電池素子１６、第２太陽電池素子２５を一体に保持する。 なお、本実施形態では、第１導光体２２の第１主面２２ａの面内に平行な方向をｘ軸方向、第１主面２２ａの面内に平行な方向で、かつｘ軸方向と直交する方向をｙ軸方向、前記第１主面２２ａと直交する方向（第１導光体２２の厚み方向）をｚ軸方向、と定義する。
The solar cell module 21 includes a first light guide (fluorescent light guide) 22, a second light guide (shape light guide) 23, a first solar cell element 16, a second solar cell element 25, And a frame body 26. The first solar cell element 16 receives light emitted from the first end face 22 c of the first light guide 22. Hereinafter, the expression “exit” is also used in the same meaning as “injection”. The second solar cell element 25 receives light emitted from the second end surface 23 c of the second light guide 23. The frame 26 integrally holds the first light guide 22, the second light guide 23, the first solar cell element 16, and the second solar cell element 25. In the present embodiment, the direction parallel to the first main surface 22a of the first light guide 22 is the x-axis direction, the direction parallel to the first main surface 22a, and the x-axis direction. The direction orthogonal to the first axis is defined as the y-axis direction, and the direction orthogonal to the first main surface 22a (thickness direction of the first light guide 22) is defined as the z-axis direction. *
第１導光体２２は、第１主面２２ａと、第２主面２２ｂと、第１端面２２ｃと、を備えている。第１主面２２ａは、外光Ｌが入射する光入射面である。第２主面２２ｂは、第１主面２３ａの反対側に位置する。第１端面２２ｃは、光射出面である。第２導光体２３は、前記第１導光体２２の第２主面２２ｂ側に配置される。第２導光体２３は、第１主面２３ａと、第２主面２３ｂと、第２端面２３ｃと、を備えている。第１主面２３ａは、前記第２主面２２ｂから透過してきた光を入射する光入射面である。第２主面２３ｂは、第１主面２３ａの反対側に位置する。第２端面２３ｃは、光射出面である。第１導光体２２と第２導光体２３とは、第１導光体２２の第２主面２２ｂと第２導光体２３の第１主面２３ａとが対向するように、第１導光体２２及び第２導光体２３よりも屈折率の小さい空気層Ｋ（低屈折率層）を介してＺ方向に積層されている。
The first light guide 22 includes a first main surface 22a, a second main surface 22b, and a first end surface 22c. The first main surface 22a is a light incident surface on which external light L is incident. The second main surface 22b is located on the opposite side of the first main surface 23a. The first end surface 22c is a light exit surface. The second light guide 23 is disposed on the second main surface 22 b side of the first light guide 22. The second light guide 23 includes a first main surface 23a, a second main surface 23b, and a second end surface 23c. The first main surface 23a is a light incident surface on which light transmitted from the second main surface 22b is incident. The second main surface 23b is located on the opposite side of the first main surface 23a. The second end surface 23c is a light exit surface. The first light guide 22 and the second light guide 23 are arranged such that the second main surface 22b of the first light guide 22 and the first main surface 23a of the second light guide 23 face each other. The light guide 22 and the second light guide 23 are stacked in the Z direction via an air layer K (low refractive index layer) having a refractive index smaller than that of the second light guide 23.
第１導光体２２の第１主面２２ａと第２導光体２３の第１主面２３ａとは、互いに同じ方向（光入射側：－Ｚ方向）を向いて配置されている。このように第１導光体２２と第２導光体２３とを光Ｌの入射方向に沿って積層することで、前段側（光Ｌが入射する側に近い側）の第１導光体２２で取り込めなかった光を後段側（光Ｌが入射する側から遠い側）の第２導光体２３で取り込むことが可能になっている。
The first main surface 22a of the first light guide 22 and the first main surface 23a of the second light guide 23 are arranged to face each other in the same direction (light incident side: -Z direction). Thus, the 1st light guide 22 and the 2nd light guide 23 are laminated | stacked along the incident direction of the light L, The 1st light guide of the front | former stage side (side near the side into which the light L injects). The light that could not be captured at 22 can be captured by the second light guide 23 on the rear stage side (the side far from the side where the light L is incident).
また、第１導光体２２の第１端面２２ｃと第２導光体２３の第２端面２３ｃは、互いに同じ向きを向いている。第１導光体２２の第１端面２２ｃと第２導光体２３の第２端面２３ｃとは、ＸＺ平面と平行な同一平面上に配置されている。これによって第１導光体２２の第１端面２２ｃから射出された光を受光する第１太陽電池素子１６と第２導光体２３の第２端面２３ｃから射出された光を受光する第２太陽電池素子２５とは、一箇所に配置されるようになっている。なお、これら太陽電池素子１６、２５は、対応する端面２２ｃ（２３ｃ）に光学接着されているのが好ましい。
Further, the first end face 22c of the first light guide 22 and the second end face 23c of the second light guide 23 are oriented in the same direction. The first end face 22c of the first light guide 22 and the second end face 23c of the second light guide 23 are arranged on the same plane parallel to the XZ plane. Accordingly, the first solar cell element 16 that receives the light emitted from the first end face 22c of the first light guide 22 and the second sun that receives the light emitted from the second end face 23c of the second light guide 23. The battery element 25 is arranged in one place. In addition, it is preferable that these solar cell elements 16 and 25 are optically bonded to the corresponding end face 22c (23c).
第１導光体２２は、Ｚ軸に垂直な（ＸＹ平面と平行な）第１主面２２ａ及び第２主面２２ｂを有する略矩形の板状部材である。第１導光体２２の第１主面２２ａ及び第２主面２２ｂは概ねＸＹ平面と平行な平坦な面である。本実施形態において、第１導光体２２は、図３７に示すように液晶性ポリマーからなる透明基材の内部に異方性光機能材料１２を分散させたものである。
The first light guide 22 is a substantially rectangular plate-like member having a first main surface 22a and a second main surface 22b perpendicular to the Z axis (parallel to the XY plane). The first main surface 22a and the second main surface 22b of the first light guide 22 are flat surfaces substantially parallel to the XY plane. In the present embodiment, the first light guide 22 is obtained by dispersing the anisotropic light functional material 12 inside a transparent substrate made of a liquid crystalline polymer as shown in FIG.
異方性光機能材料１２は、第１実施形態の第１光機能材料１２と同じものを用いることができる。つまり、異方性光機能材料１２は、光を異方的に発光する性質（発光異方性）を有する材料であり、本実施形態では二色性蛍光色素が用いられている。二色性蛍光色素とは、光を異方的に吸収する性質（吸収異方性）と光を異方的に発する性質（発光異方性）とを共に有する色素である。本実施形態では、二色性蛍光色素（異方性光機能材料１２）として、分子長軸と直交する方向が発光強度の最も大きい方向であるポジ型二色性蛍光色素が用いられている。
The anisotropic optical functional material 12 can be the same as the first optical functional material 12 of the first embodiment. That is, the anisotropic light functional material 12 is a material having a property of emitting light anisotropically (light emission anisotropy), and a dichroic fluorescent dye is used in the present embodiment. The dichroic fluorescent dye is a dye having both the property of absorbing light anisotropically (absorption anisotropy) and the property of emitting light anisotropically (light emission anisotropy). In the present embodiment, as the dichroic fluorescent dye (anisotropic optical functional material 12), a positive dichroic fluorescent dye in which the direction orthogonal to the molecular long axis is the direction with the highest emission intensity is used.
なお、二色性蛍光色素としては、ポジ型二色性蛍光色素に限らず、種々の二色性蛍光色素を用いることができる。例えば、分子長軸の方向が発光強度の最も大きい方向であるネガ型二色性蛍光色素を用いることもできる。
このような二色性蛍光色素は、例えば紫外光又は可視光を吸収して可視光又は赤外光を放射するものであり、この二色性蛍光色素から放射された光は、第１導光体２２の内部を伝播して第１端面２２ｃから射出され、第１太陽電池素子１６で発電に利用される。 The dichroic fluorescent dye is not limited to the positive dichroic fluorescent dye, and various dichroic fluorescent dyes can be used. For example, a negative dichroic fluorescent dye in which the direction of the molecular long axis is the direction in which the emission intensity is the highest can also be used.
Such a dichroic fluorescent dye absorbs, for example, ultraviolet light or visible light and emits visible light or infrared light. The light emitted from the dichroic fluorescent dye is a first light guide. It propagates through the inside of thebody 22 and is emitted from the first end face 22 c and is used for power generation by the first solar cell element 16.
このような二色性蛍光色素は、例えば紫外光又は可視光を吸収して可視光又は赤外光を放射するものであり、この二色性蛍光色素から放射された光は、第１導光体２２の内部を伝播して第１端面２２ｃから射出され、第１太陽電池素子１６で発電に利用される。 The dichroic fluorescent dye is not limited to the positive dichroic fluorescent dye, and various dichroic fluorescent dyes can be used. For example, a negative dichroic fluorescent dye in which the direction of the molecular long axis is the direction in which the emission intensity is the highest can also be used.
Such a dichroic fluorescent dye absorbs, for example, ultraviolet light or visible light and emits visible light or infrared light. The light emitted from the dichroic fluorescent dye is a first light guide. It propagates through the inside of the
本実施形態の異方性光機能材料１２として用いる二色性蛍光色素は、上述の図３に示す特性を有する。 また、本実施形態の二色性蛍光色素は、第１実施形態の二色性蛍光色素と同様の配光状態を示す。具体的には、二色性蛍光色素は、図４で示すような配向状態を示す。なお、図４で示す導光体１４、第１主面１４ａ、第２主面１４ｂは、それぞれ本実施形態の第１導光体２２、第１主面２２ａ、第２主面２２ｂに対応する。 本実施形態の二色性蛍光色素１２は、図４に示すように、分子長軸と直交する軸Ｖ２と第１導光体２２の第１主面２２ａとが平行になるように配向されている。つまり、本実施形態の二色性蛍光色素１２は、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が、第１導光体２２の第１主面２２ａと平行になるように配向されている。
The dichroic fluorescent dye used as the anisotropic light functional material 12 of the present embodiment has the characteristics shown in FIG. Also, the dichroic fluorescent dye of the present embodiment exhibits a light distribution state similar to that of the dichroic fluorescent dye of the first embodiment. Specifically, the dichroic fluorescent dye exhibits an orientation state as shown in FIG. In addition, the light guide 14, the first main surface 14a, and the second main surface 14b illustrated in FIG. 4 correspond to the first light guide 22, the first main surface 22a, and the second main surface 22b of the present embodiment, respectively. . As shown in FIG. 4, the dichroic fluorescent dye 12 of the present embodiment is oriented so that the axis V2 orthogonal to the molecular long axis and the first main surface 22a of the first light guide 22 are parallel to each other. Yes. That is, in the dichroic fluorescent dye 12 of this embodiment, the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is largest is parallel to the first main surface 22a of the first light guide 22. Are oriented as follows.
なお、本実施形態の第１導光体２２は、Ｚ軸に垂直な（ＸＹ平面と平行な）第１主面２２ａ及び第２主面２２ｂを有する略矩形の板状部材である。そのため、本実施形態の二色性蛍光色素１２は、分子長軸と直交する軸Ｖ２と第１導光体２２の第２主面２２ｂとが平行になるように配向されている。つまり、本実施形態の二色性蛍光色素１２は、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が、第１導光体２２の第２主面２２ｂとも平行になるように配向されている。
In addition, the 1st light guide 22 of this embodiment is a substantially rectangular plate-shaped member which has the 1st main surface 22a perpendicular | vertical to a Z-axis (parallel to XY plane) and the 2nd main surface 22b. Therefore, the dichroic fluorescent dye 12 of this embodiment is oriented so that the axis V2 orthogonal to the molecular long axis and the second major surface 22b of the first light guide 22 are parallel. That is, in the dichroic fluorescent dye 12 of this embodiment, the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the highest is parallel to the second main surface 22b of the first light guide 22. Are oriented as follows.
二色性蛍光色素１２を配向させるための方法および二色性蛍光色素１２の配向状態を検証するための方法は、第１実施形態に記載された方法と同様である。
The method for aligning the dichroic fluorescent dye 12 and the method for verifying the alignment state of the dichroic fluorescent dye 12 are the same as the method described in the first embodiment.
図５Ｂに示すように、二色性蛍光色素１２は、第１主面２２ａから入射した外光の励起エネルギーによって光を異方的に発する。本実施形態の二色性蛍光色素１２は、前記二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと平行になるように配向されている。そのため、二色性蛍光色素１２が発する光のうち発光強度の最も大きい光は、第１太陽電池素子１６に直接導かれる。
As shown in FIG. 5B, the dichroic fluorescent dye 12 emits light anisotropically by the excitation energy of external light incident from the first main surface 22a. The dichroic fluorescent dye 12 of the present embodiment is oriented so that the direction in which the light emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 22a of the first light guide 22. Has been. Therefore, light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the first solar cell element 16.
図５Ｃに示すように、二色性蛍光色素１２が発する光のうちの大部分の光は、第１導光体２２の第１主面２２ａまたは第２主面２２ｂへの入射角θが大きくなる。
ここで、例えば第１導光体２２を構成する液晶性ポリマーの屈折率が１．５、空気の屈折率が１．０とすると、第１導光体２２の第１主面２２ａにおける臨界角θｍ、すなわち第１導光体２２を構成する液晶性ポリマーと空気との界面における臨界角は、スネルの法則から４２°程度となる。二色性蛍光色素１２が発する光の一部の光Ｌ１が第１主面２２ａに入射した際、第１主面２２ａへの光Ｌ１の入射角が臨界角である４２°よりも大きい場合は全反射条件を満たすため、光Ｌは第１主面２２ａで全反射する。その後、光Ｌ１は第１主面２２ａと第２主面２２ｂとの間で反射を繰り返し、第１太陽電池素子１６に導かれる。 As shown in FIG. 5C, most of the light emitted from the dichroicfluorescent dye 12 has a large incident angle θ on the first main surface 22a or the second main surface 22b of the first light guide 22. Become.
Here, for example, when the refractive index of the liquid crystalline polymer constituting thefirst light guide 22 is 1.5 and the refractive index of air is 1.0, the critical angle on the first main surface 22a of the first light guide 22 is set. θm, that is, the critical angle at the interface between the liquid crystalline polymer constituting the first light guide 22 and air is about 42 ° from Snell's law. When a part of the light L1 emitted from the dichroic fluorescent dye 12 is incident on the first main surface 22a, the incident angle of the light L1 on the first main surface 22a is larger than 42 ° which is a critical angle. Since the total reflection condition is satisfied, the light L is totally reflected by the first main surface 22a. Thereafter, the light L1 is repeatedly reflected between the first main surface 22a and the second main surface 22b, and is guided to the first solar cell element 16.
ここで、例えば第１導光体２２を構成する液晶性ポリマーの屈折率が１．５、空気の屈折率が１．０とすると、第１導光体２２の第１主面２２ａにおける臨界角θｍ、すなわち第１導光体２２を構成する液晶性ポリマーと空気との界面における臨界角は、スネルの法則から４２°程度となる。二色性蛍光色素１２が発する光の一部の光Ｌ１が第１主面２２ａに入射した際、第１主面２２ａへの光Ｌ１の入射角が臨界角である４２°よりも大きい場合は全反射条件を満たすため、光Ｌは第１主面２２ａで全反射する。その後、光Ｌ１は第１主面２２ａと第２主面２２ｂとの間で反射を繰り返し、第１太陽電池素子１６に導かれる。 As shown in FIG. 5C, most of the light emitted from the dichroic
Here, for example, when the refractive index of the liquid crystalline polymer constituting the
なお、本実施形態の二色性蛍光色素１２は、この二色性蛍光色素１２から発せられる光の発光強度の最も小さい方向が第１導光体２２の第１主面２２ａ、第２主面２２ｂとそれぞれ直交する。二色性蛍光色素１２が発する光のうち分子長軸に沿う方向からの光Ｌ２が第２主面２２ｂに入射した際、第２主面２２ｂへの光Ｌ２の入射角が臨界角である４２°よりも小さくなり、全反射条件を満たさなくなるため、光Ｌ２は第２導光体２３側に射出される。
In the dichroic fluorescent dye 12 of the present embodiment, the direction in which the emission intensity of light emitted from the dichroic fluorescent dye 12 is the smallest is the first main surface 22a and the second main surface of the first light guide 22. 22b is orthogonal to each other. When light L2 from the direction along the molecular long axis of light emitted from the dichroic fluorescent dye 12 is incident on the second main surface 22b, the incident angle of the light L2 on the second main surface 22b is a critical angle 42. The light L2 is emitted to the second light guide 23 side because it becomes smaller than ° and does not satisfy the total reflection condition.
すなわち、二色性蛍光色素１２が発する光は、第１主面２２ａまたは第２主面２２ｂへの入射角が臨界角よりも大きい場合は第１導光体２２の内部に閉じ込められ、第１主面２２ａまたは第２主面２２ｂへの入射角が臨界角よりも小さい場合は外部に射出される。本実施形態において二色性蛍光色素１２は、この二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと平行になるように配向されている。そのため、二色性蛍光色素１２が発する光のうちの大部分の光は、第１導光体２２の第１主面２２ａまたは第２主面２２ｂへの入射角θが大きくなり、全反射条件を満たすこととなる。よって、二色性蛍光色素１２が発する光のうちの大部分の光が、第１導光体２２の内部に閉じ込められ、外部に射出されることなく、第１太陽電池素子１６側に伝播する。
That is, the light emitted from the dichroic fluorescent dye 12 is confined in the first light guide 22 when the incident angle to the first main surface 22a or the second main surface 22b is larger than the critical angle, and the first When the incident angle to the main surface 22a or the second main surface 22b is smaller than the critical angle, the light is emitted to the outside. In the present embodiment, the dichroic fluorescent dye 12 is oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is maximum is parallel to the first main surface 22a of the first light guide 22. Has been. Therefore, most of the light emitted from the dichroic fluorescent dye 12 has a large incident angle θ on the first main surface 22a or the second main surface 22b of the first light guide 22, and the total reflection condition. Will be satisfied. Therefore, most of the light emitted from the dichroic fluorescent dye 12 is confined inside the first light guide 22 and propagates toward the first solar cell element 16 without being emitted outside. .
ここで、「伝播する」とは、第１主面２２ａで反射して第１端面２２ｃに達する場合、第２主面２２ｂで反射して第１端面２２ｃに達する場合、第１主面２２ａと第２主面２２ｂの両方で反射しながら第１端面２２ｃに達する場合、もしくはどの主面１４ａ、１４ｂにも当たることなく第１端面２２ｃに達する場合のいずれかを意味している。
Here, “propagating” means that the first main surface 22a is reflected on the first end surface 22c, the second main surface 22b is reflected on the first end surface 22c, and the first main surface 22a is reflected on the first main surface 22a. It means either the case where the first end surface 22c is reached while being reflected by both of the second main surfaces 22b, or the case where the first end surface 22c is reached without hitting any of the main surfaces 14a, 14b.
図３６、図３７に示すように第１導光体２２の第１端面２２ｃ以外の端面には、異方性光機能材料１２（二色性蛍光色素）から放射された（発せられた）光（蛍光）を反射する反射層２８が設けられている。
反射層２８としては、銀やアルミニウムなどの金属膜からなる反射層や、ＥＳＲ（Ｅｎｈａｎｃｅｄ Ｓｐｅｃｕｌａｒ Ｒｅｆｌｅｃｔｏｒ）反射フィルム（３Ｍ社製）などの誘電体多層膜からなる反射層などを用いることができる。反射層２８は、入射した光を鏡面反射する鏡面反射層でもよいし、入射した光を散乱反射する散乱反射層でもよい。 As shown in FIGS. 36 and 37, light (fluorescent light) emitted (emitted) from the anisotropic light functional material 12 (dichroic fluorescent dye) is formed on the end surface of thefirst light guide 22 other than the first end surface 22c. ) Is provided.
As thereflective layer 28, a reflective layer made of a metal film such as silver or aluminum, or a reflective layer made of a dielectric multilayer film such as an ESR (Enhanced Specular Reflector) reflective film (manufactured by 3M) can be used. The reflection layer 28 may be a specular reflection layer that specularly reflects incident light, or may be a scattering reflection layer that scatters and reflects incident light.
反射層２８としては、銀やアルミニウムなどの金属膜からなる反射層や、ＥＳＲ（Ｅｎｈａｎｃｅｄ Ｓｐｅｃｕｌａｒ Ｒｅｆｌｅｃｔｏｒ）反射フィルム（３Ｍ社製）などの誘電体多層膜からなる反射層などを用いることができる。反射層２８は、入射した光を鏡面反射する鏡面反射層でもよいし、入射した光を散乱反射する散乱反射層でもよい。 As shown in FIGS. 36 and 37, light (fluorescent light) emitted (emitted) from the anisotropic light functional material 12 (dichroic fluorescent dye) is formed on the end surface of the
As the
第２導光体２３は、Ｚ軸に垂直な（ＸＹ平面と平行な）第１主面２３ａ及び該第１主面２３ａと反対の側の第２主面２３ｂを有する略矩形の板状部材である。第２導光体２３としては、アクリル樹脂、ポリカーボネート樹脂、ガラスなどの透明性の高い有機材料もしくは無機材料が用いられる。
The second light guide 23 is a substantially rectangular plate-like member having a first main surface 23a perpendicular to the Z-axis (parallel to the XY plane) and a second main surface 23b opposite to the first main surface 23a. It is. As the second light guide 23, a highly transparent organic material or inorganic material such as acrylic resin, polycarbonate resin, or glass is used.
第２導光体２３の第２主面２３ｂには、Ｘ方向に延びる複数の溝Ｔが設けられている。溝Ｔは、ＸＹ平面と平行な面に対して斜めに傾斜した傾斜面Ｔ１と、傾斜面Ｔ１と交差する面Ｔ２と、を有するＶ字状の溝である。図３６では、図面を簡略化するために、溝Ｔを数本しか記載していないが、実際には、幅１００μｍ程度の細かい溝Ｔが多数本形成されている。溝Ｔは、例えば、金型を用いて樹脂（例えばポリメタクリル酸メチル樹脂：ＰＭＭＡ）を射出成形することで形成されている。
The second main surface 23b of the second light guide 23 is provided with a plurality of grooves T extending in the X direction. The groove T is a V-shaped groove having an inclined surface T1 that is inclined with respect to a plane parallel to the XY plane and a surface T2 that intersects the inclined surface T1. In FIG. 36, only a few grooves T are shown in order to simplify the drawing, but in practice, a large number of fine grooves T having a width of about 100 μm are formed. The groove T is formed, for example, by injection molding a resin (for example, polymethyl methacrylate resin: PMMA) using a mold.
傾斜面Ｔ１は、図３８Ａに示すように第１主面２３ａから入射した光Ｌ２（第１導光体２２から透過してきた光Ｌ２）を全反射して光の進行方向を第２端面２３ｃに向かう方向に変更する反射面である。第１主面２３ａに対して垂直に近い角度で入射した光Ｌ２は、傾斜面Ｔ１で反射して第２導光体２３の内部を概ねＹ方向に伝播する。このような構成のもとに、第２導光体２３は第２主面２３ｂに設けられた傾斜面Ｔ１で光を反射して伝播させ、第２端面２３ｃから射出する形状導光体となっている。
第２導光体２３の第２主面２３ｂには、このような溝Ｔが、傾斜面Ｔ１と面Ｔ２とが互いに接するようにＹ方向に複数設けられている。第２主面２３ｂに設けられた複数の溝Ｔの形状及び大きさは、全て同じである。 As shown in FIG. 38A, the inclined surface T1 totally reflects the light L2 incident from the firstmain surface 23a (the light L2 transmitted from the first light guide 22), and the traveling direction of the light is directed to the second end surface 23c. It is a reflective surface that changes in the direction it heads. The light L2 incident at an angle close to perpendicular to the first main surface 23a is reflected by the inclined surface T1 and propagates in the second light guide 23 in the Y direction. Based on such a configuration, the second light guide 23 is a shape light guide that reflects and propagates light at the inclined surface T1 provided on the second main surface 23b and emits the light from the second end surface 23c. ing.
A plurality of such grooves T are provided in the Y direction on the secondmain surface 23b of the second light guide 23 so that the inclined surfaces T1 and T2 are in contact with each other. The shapes and sizes of the plurality of grooves T provided on the second main surface 23b are all the same.
第２導光体２３の第２主面２３ｂには、このような溝Ｔが、傾斜面Ｔ１と面Ｔ２とが互いに接するようにＹ方向に複数設けられている。第２主面２３ｂに設けられた複数の溝Ｔの形状及び大きさは、全て同じである。 As shown in FIG. 38A, the inclined surface T1 totally reflects the light L2 incident from the first
A plurality of such grooves T are provided in the Y direction on the second
なお、図３８Ａに示した例では、傾斜面Ｔ１の傾斜角θは３０°であり、１本の溝ＴのＹ方向の幅ｗは１００μｍであり、溝ＴのＺ方向の深さｄは９０μｍであり、第２導光体２３の屈折率は１．５である。ただし、傾斜角θ、溝Ｔの幅ｗ、溝Ｔの深さｄ、及び第２導光体２３の屈折率は、これらに限定されないのはもちろんである。
例えば、図３８Ｂに示すように溝Ｔを左右対称のＶ字状とし、傾斜角θを４０°としてもよい。その場合には、第２端面２３ｃと反対の側の端面２３ｄにも第２太陽電池素子２５を配設するのが好ましい。また、第２太陽電池素子２５に代えて反射層を設けるようにしてもよい。 In the example shown in FIG. 38A, the inclination angle θ of the inclined surface T1 is 30 °, the width w in the Y direction of one groove T is 100 μm, and the depth d in the Z direction of the groove T is 90 μm. And the refractive index of the secondlight guide 23 is 1.5. However, the inclination angle θ, the width w of the groove T, the depth d of the groove T, and the refractive index of the second light guide 23 are of course not limited thereto.
For example, as shown in FIG. 38B, the groove T may have a symmetrical V-shape and the inclination angle θ may be 40 °. In that case, it is preferable to arrange the secondsolar cell element 25 also on the end surface 23d opposite to the second end surface 23c. Further, a reflective layer may be provided instead of the second solar cell element 25.
例えば、図３８Ｂに示すように溝Ｔを左右対称のＶ字状とし、傾斜角θを４０°としてもよい。その場合には、第２端面２３ｃと反対の側の端面２３ｄにも第２太陽電池素子２５を配設するのが好ましい。また、第２太陽電池素子２５に代えて反射層を設けるようにしてもよい。 In the example shown in FIG. 38A, the inclination angle θ of the inclined surface T1 is 30 °, the width w in the Y direction of one groove T is 100 μm, and the depth d in the Z direction of the groove T is 90 μm. And the refractive index of the second
For example, as shown in FIG. 38B, the groove T may have a symmetrical V-shape and the inclination angle θ may be 40 °. In that case, it is preferable to arrange the second
なお、本実施形態では、図示しないものの、第２導光体２３の第２端面２３ｃ（２３ｄ）以外の端面、すなわち第２太陽電池素子２５が配置されない端面には、この端面から第２導光体２３の外部に漏れ出す光を第２導光体２３の内部に反射する反射層が設けられている。これら反射層としては、前記の反射層２８と同様のものが用いられる。
また、第１導光体２２と第２導光体２３とは、図３７に示すようにこれらの間に空気層Ｋを介在させているが、これらの間は接着等によって接していてもよい。ただし、第１導光体２２と第２導光体２３との間に空気層Ｋを介在させれば、二色性蛍光色素（異方性光機能材料１２）が発する光が、第１導光体２２と空気層との界面で全反射条件を満たしやすくなり、好ましい。 In the present embodiment, although not shown, the second light guide is provided from the end face to the end face other than thesecond end face 23c (23d) of the second light guide 23, that is, the end face where the second solar cell element 25 is not disposed. A reflection layer is provided that reflects light leaking out of the body 23 to the inside of the second light guide 23. As these reflective layers, the same layers as those of the reflective layer 28 are used.
Thefirst light guide 22 and the second light guide 23 have an air layer K interposed between them as shown in FIG. 37, but they may be in contact with each other by adhesion or the like. . However, if the air layer K is interposed between the first light guide 22 and the second light guide 23, the light emitted from the dichroic fluorescent dye (anisotropic light functional material 12) is transmitted to the first light guide. The total reflection condition is easily satisfied at the interface between the air layer 22 and the air layer, which is preferable.
また、第１導光体２２と第２導光体２３とは、図３７に示すようにこれらの間に空気層Ｋを介在させているが、これらの間は接着等によって接していてもよい。ただし、第１導光体２２と第２導光体２３との間に空気層Ｋを介在させれば、二色性蛍光色素（異方性光機能材料１２）が発する光が、第１導光体２２と空気層との界面で全反射条件を満たしやすくなり、好ましい。 In the present embodiment, although not shown, the second light guide is provided from the end face to the end face other than the
The
第１太陽電池素子１６、第２太陽電池素子２５としては、シリコン系太陽電池、化合物系太陽電池、量子ドット太陽電池、有機系太陽電池などの公知の太陽電池を使用することができる。中でも、化合物半導体を用いた化合物系太陽電池や量子ドット太陽電池は、高効率な発電が可能であることから、これら太陽電池素子４、５として好適である。化合物系太陽電池としては、ＩｎＧａＰ、ＧａＡｓ、ＩｎＧａＡｓ，ＡｌＧａＡｓ、Ｃｕ（Ｉｎ，Ｇａ）Ｓｅ２、Ｃｕ（Ｉｎ，Ｇａ）（Ｓｅ，Ｓ）２、ＣｕＩｎＳ２、ＣｄＴｅ、ＣｄＳ等が挙げられる。また、量子ドット太陽電池としては、Ｓｉ、ＩｎＧａＡｓ等が挙げられる。
As the 1st solar cell element 16 and the 2nd solar cell element 25, well-known solar cells, such as a silicon type solar cell, a compound type solar cell, a quantum dot solar cell, and an organic type solar cell, can be used. Among these, compound solar cells and quantum dot solar cells using compound semiconductors are suitable as these solar cell elements 4 and 5 because they can generate power with high efficiency. Examples of compound solar cells include InGaP, GaAs, InGaAs, AlGaAs, Cu (In, Ga) Se 2 , Cu (In, Ga) (Se, S) 2 , CuInS 2 , CdTe, CdS, and the like. Examples of the quantum dot solar cell include Si and InGaAs.
ただし、価格や用途に応じて、Ｓｉ系や有機系など他の種類の太陽電池を用いることもできる。また、第１太陽電池素子１６と第２太陽電池素子２５とは、各導光体１４、２３から射出される光の波長域に対応して、より高い効率で光電変換できる太陽電池素子を適宜選択して用いるのが好ましい。ただし、同一種類の太陽電池素子を用いてもよいのはもちろんである。
However, other types of solar cells such as Si and organic can be used depending on the price and application. In addition, the first solar cell element 16 and the second solar cell element 25 are appropriately solar cell elements that can perform photoelectric conversion with higher efficiency corresponding to the wavelength range of light emitted from the light guides 14 and 23. It is preferable to select and use. However, it goes without saying that the same type of solar cell element may be used.
図３６に示すように枠体２６は、アルミニウム等のフレームからなり、第１導光体２２の第１主面２２ａを外部に臨ませ、その状態で第１導光体２２、第２導光体２３の四周を保持するとともに、第１太陽電池素子１６、第２太陽電池素子２５も導光体１４、２３とともに保持している。
第１導光体２２の第１主面２２ａを外部に臨ませる開口部２６ａには、ガラス等の透明部材が嵌め込まれていてもよい。このような構成のもとに第１導光体２２は、枠体２６から外部に臨む第１主面２２ａが光入射面となっている。また、第１導光体２２の第１端面２２ｃと第２導光体２３の第２端面２３ｃが光射出面となっている。 As shown in FIG. 36, theframe body 26 is made of a frame such as aluminum, and the first main surface 22a of the first light guide 22 is exposed to the outside, and the first light guide 22 and the second light guide are in that state. While holding the four circumferences of the body 23, the first solar cell element 16 and the second solar cell element 25 are also held together with the light guides 14 and 23.
A transparent member such as glass may be fitted into theopening 26a that allows the first main surface 22a of the first light guide 22 to face the outside. With this configuration, the first light guide 22 has a first main surface 22a facing the outside from the frame 26 as a light incident surface. Further, the first end face 22c of the first light guide 22 and the second end face 23c of the second light guide 23 are light emission surfaces.
第１導光体２２の第１主面２２ａを外部に臨ませる開口部２６ａには、ガラス等の透明部材が嵌め込まれていてもよい。このような構成のもとに第１導光体２２は、枠体２６から外部に臨む第１主面２２ａが光入射面となっている。また、第１導光体２２の第１端面２２ｃと第２導光体２３の第２端面２３ｃが光射出面となっている。 As shown in FIG. 36, the
A transparent member such as glass may be fitted into the
以上のように本実施形態の太陽電池モジュール２１では、第１導光体２２の内部に二色性蛍光色素（異方性光機能材料１２）が含まれており、この二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が第１導光体２２の第１太陽電池素子１６が配置された第１端面２２ｃを向くように配向されている。すなわち、二色性蛍光色素１２が発する光のうち発光強度の最も大きい方向が第１導光体２２の第１主面２２ａに平行となり、したがってこの発光強度の最も大きい方向と第１導光体２２における第１主面２２ａの法線とのなす角度が臨界角以上になるように配向されている。
As described above, in the solar cell module 21 of the present embodiment, the dichroic fluorescent dye (anisotropic light functional material 12) is included in the first light guide 22, and emitted from the dichroic fluorescent dye 12. The direction in which the emission intensity of the emitted light is the largest is oriented so as to face the first end face 22c of the first light guide 22 on which the first solar cell element 16 is disposed. That is, the direction in which the emission intensity is the largest among the light emitted from the dichroic fluorescent dye 12 is parallel to the first main surface 22a of the first light guide 22, and therefore the direction in which the emission intensity is the highest and the first light guide. 22 is oriented so that the angle formed with the normal line of the first major surface 22a at 22 is not less than the critical angle.
よって、本実施形態の太陽電池モジュール２１にあっては、比較的大きい（深い）入射角で第１導光体２２に入射した外光（太陽光）の大部分を第１端面２２ｃ側に伝播させ、第１太陽電池素子１６に導くことができる。また、垂直に近い角度（小さい入射角）で第１導光体２２に入射した光に関しては、二色性蛍光色素１２の吸収異方性のため吸収できず、透過して第２主面２２ｂから射出する光もあるものの、この第２主面２２ｂから射出した光は第２導光体２３で集光し、第２太陽電池素子２５に導くことができる。すなわち、第２導光体２３に入射してくる光の角度は垂直光が主になるので、形状導光体である第２導光体２３の傾斜面Ｔ１の角度などを適宜に設定することで、より集光効率を高めることができる。したがって、本実施形態の太陽電池モジュール２１によれば、光の取り出し効率を高くして高い発電効率を実現することができる。
Therefore, in the solar cell module 21 of the present embodiment, most of the external light (sunlight) incident on the first light guide 22 at a relatively large (deep) incident angle propagates to the first end face 22c side. To the first solar cell element 16. In addition, light incident on the first light guide 22 at an angle close to perpendicular (small incident angle) cannot be absorbed due to the absorption anisotropy of the dichroic fluorescent dye 12, and is transmitted through the second main surface 22b. However, the light emitted from the second main surface 22 b can be condensed by the second light guide 23 and guided to the second solar cell element 25. That is, since the angle of light incident on the second light guide 23 is mainly vertical light, the angle of the inclined surface T1 of the second light guide 23 which is a shape light guide is appropriately set. Thus, the light collection efficiency can be further increased. Therefore, according to the solar cell module 21 of the present embodiment, high power generation efficiency can be realized by increasing the light extraction efficiency.
なお、本実施形態では、図３６に示したように第１導光体２２に対して第１太陽電池素子１６を一つの端面（第１端面２２ｃ）のみに設置した例を示したが、第１太陽電池素子１６は第１導光体２２の４つの端面のうち、複数（２ないし４）の端面に設置してもよい。
In the present embodiment, as shown in FIG. 36, the first solar cell element 16 is installed only on one end face (first end face 22c) with respect to the first light guide 22; One solar cell element 16 may be installed on a plurality of (2 to 4) end faces among the four end faces of the first light guide 22.
また、本実施形態では、第２導光体２３として、その第２主面２３ｂに設けられた傾斜面Ｔ１で光を反射して伝播させ、第２端面２３ｃから射出する形状導光体を用いているが、このような形状導光体に代えて、後述するような蛍光体を分散させた蛍光導光体を用いてもよい。なお、蛍光導光体としては、蛍光体として二色性蛍光色素を用いたものも使用可能である。ただし、その場合には、二色性蛍光色素を第１導光体２２と同じ方向に配向させることなく、すなわち二色性蛍光色素が発する光のうち発光強度の最も大きい方向が第２導光体２３の第１主面２３ａに平行となることなく、発光強度の最も大きい方向がある程度第１主面２３ａ側に向くように配向させるのが好ましい。
Further, in the present embodiment, as the second light guide 23, a shape light guide that reflects and propagates light at the inclined surface T1 provided on the second main surface 23b and emits from the second end surface 23c is used. However, instead of such a shape light guide, a fluorescent light guide in which phosphors to be described later are dispersed may be used. As the fluorescent light guide, one using a dichroic fluorescent dye as the fluorescent material can be used. However, in that case, the dichroic fluorescent dye is not oriented in the same direction as the first light guide 22, that is, the direction with the highest emission intensity among the light emitted from the dichroic fluorescent dye is the second light guide. Preferably, the body 23 is oriented so that the direction with the highest emission intensity is directed to the first main surface 23a side to some extent without being parallel to the first main surface 23a.
［第１２実施形態］
図３９は、第１２実施形態の太陽電池モジュール２１Ａの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ａが図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と異なるところは、第１１実施形態の太陽電池モジュール２１ではその第１導光体２２の二色性蛍光色素（異方性光機能材料１２）を、前記二色性蛍光色素１２が発する光のうち発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと平行になるように配向させたのに対し、本実施形態では、発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと非平行になるように配向させた点である。 [Twelfth embodiment]
FIG. 39 is a side sectional view showing a schematic configuration of asolar cell module 21A of the twelfth embodiment.
Thesolar cell module 21A of the present embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc., in the solar cell module 21 of the eleventh embodiment of the first light guide body 22. The dichroic fluorescent dye (anisotropic light functional material 12) is arranged such that the direction in which the emission intensity is the largest among the light emitted from the dichroic fluorescent dye 12 is parallel to the first main surface 22a of the first light guide 22. In contrast, in this embodiment, the first light guide 22 is oriented so that the direction with the highest light emission intensity is not parallel to the first main surface 22a.
図３９は、第１２実施形態の太陽電池モジュール２１Ａの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ａが図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と異なるところは、第１１実施形態の太陽電池モジュール２１ではその第１導光体２２の二色性蛍光色素（異方性光機能材料１２）を、前記二色性蛍光色素１２が発する光のうち発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと平行になるように配向させたのに対し、本実施形態では、発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと非平行になるように配向させた点である。 [Twelfth embodiment]
FIG. 39 is a side sectional view showing a schematic configuration of a
The
二色性蛍光色素１２の配向は、前述したように配向材（液晶性ポリマー）の作用によって所定方向に配向させる。しかし、この配向材による配向制御が所望の方向（二色性蛍光色素１２が発する光のうち発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと平行になる方向）とならずに、少し傾いて配向する場合がある。本実施形態は、このように二色性蛍光色素１２が発する光のうち発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと平行にならずに、少し傾いて配向している場合である。
The orientation of the dichroic fluorescent dye 12 is oriented in a predetermined direction by the action of the orientation material (liquid crystalline polymer) as described above. However, the orientation control by this orientation material is in a desired direction (the direction in which the emission intensity is the largest in the light emitted from the dichroic fluorescent dye 12 is parallel to the first main surface 22a of the first light guide 22). Instead, it may be oriented slightly tilted. In this embodiment, the direction in which the emission intensity is the largest among the light emitted from the dichroic fluorescent dye 12 is not parallel to the first main surface 22a of the first light guide 22 but is slightly inclined and oriented. It is a case.
二色性蛍光色素１２は、第１実施形態と同様に、図６に示すように配光されていてもよい。なお、図６の導光体１４、第１主面１４ａ、第２主面１４ｂは、それぞれ本実施形態の第１導光体２２、第１主面２２ａ、第２主面２２ｂに対応する。図６に示すように、分子長軸Ｖ１と直交する軸Ｖ２と、第１導光体２２の第１主面２２ａの法線とのなす角度θが、臨界角θｍ以上となるように配向されていれば、前記所望方向に対して少し傾いて配向されていてもよい。
The dichroic fluorescent dye 12 may be light-distributed as shown in FIG. 6 as in the first embodiment. In addition, the light guide 14, the first main surface 14a, and the second main surface 14b of FIG. 6 correspond to the first light guide 22, the first main surface 22a, and the second main surface 22b of the present embodiment, respectively. As shown in FIG. 6, the angle θ formed by the axis V2 orthogonal to the molecular long axis V1 and the normal line of the first main surface 22a of the first light guide 22 is oriented so that the critical angle θm is not less than the critical angle θm. If so, it may be oriented slightly inclined with respect to the desired direction.
このように二色性蛍光色素１２を少し傾けて配向させた本実施形態では、例えば太陽電池モジュール２１Ａを屋根などに設置して第１主面２２ａを上に向けて配置した場合に、第１１実施形態に比べて太陽光を吸収し易く構成することが可能となる。すなわち、図３９に示すように太陽Ｓの仰角θｓは日本の場合、季節によって約３０°～約８０°と変わるが、方向としては分子を傾けて図６中に示した軸Ｖ２が太陽Ｓ方向に向くように配置することにより、太陽光を吸収し易くすることができる。
In this embodiment in which the dichroic fluorescent dye 12 is oriented slightly tilted in this way, for example, when the solar cell module 21A is installed on a roof or the like and is arranged with the first main surface 22a facing upward, Compared to the embodiment, the solar light can be easily absorbed. That is, as shown in FIG. 39, the elevation angle θs of the sun S changes from about 30 ° to about 80 ° depending on the season in Japan, but the axis V2 shown in FIG. By arranging so as to face the sun, it is possible to easily absorb sunlight.
ただし、その場合には、二色性蛍光色素１２を傾けることで全反射せずに第２主面２２ｂ側から透過する光の量も増える。しかし、本実施形態では、第１導光体２２の後方（第２主面２２ｂ側）に第２導光体２３を備えているので、第２主面２２ｂから透過してきた光を第２導光体２３で集光し、第２太陽電池素子２５で発電することができる。なお、最も高効率なものは、二色性蛍光色素１２の発光プロフィールによって変わってくる。
However, in that case, by tilting the dichroic fluorescent dye 12, the amount of light transmitted from the second main surface 22b side without being totally reflected increases. However, in the present embodiment, since the second light guide 23 is provided behind the first light guide 22 (on the second main surface 22b side), the light transmitted from the second main surface 22b is second guided. The light is condensed by the light body 23 and can be generated by the second solar cell element 25. The most efficient one depends on the light emission profile of the dichroic fluorescent dye 12.
また、第１導光体２２を透過してきた光がある角度を持って第２導光体２３に入射するので、図３８Ａに示した第２導光体２３（形状導光体）の反射構造、すなわち溝Ｔの傾斜面Ｔ１の角度などをこれに合わせて形成することで、より集光効率を高めることができる。
よって、本実施形態の太陽電池モジュール２１Ａによれば、二色性蛍光色素１２を傾けることによる吸収量の増加と、閉じ込め率の低下を加味して分子長軸Ｖ１の傾きを決めることで、光の取り出し効率を高くして高い発電効率を実現することができる。 Further, since the light transmitted through thefirst light guide 22 enters the second light guide 23 at a certain angle, the reflection structure of the second light guide 23 (shape light guide) shown in FIG. 38A. That is, by forming the angle of the inclined surface T1 of the groove T according to this, the light collection efficiency can be further increased.
Therefore, according to thesolar cell module 21A of the present embodiment, the inclination of the molecular major axis V1 is determined by taking into account the increase in the amount of absorption by tilting the dichroic fluorescent dye 12 and the decrease in the confinement rate. It is possible to achieve high power generation efficiency by increasing the extraction efficiency.
よって、本実施形態の太陽電池モジュール２１Ａによれば、二色性蛍光色素１２を傾けることによる吸収量の増加と、閉じ込め率の低下を加味して分子長軸Ｖ１の傾きを決めることで、光の取り出し効率を高くして高い発電効率を実現することができる。 Further, since the light transmitted through the
Therefore, according to the
なお、本実施形態においても、第１導光体２２に対してその複数の端面に第１太陽電池素子１６を設置してもよい。
また、第２導光体２３として、形状導光体に代えて蛍光体を分散させた蛍光導光体や、蛍光体として二色性蛍光色素を用いた導光体を用いることができる。 Also in the present embodiment, the firstsolar cell element 16 may be installed on a plurality of end faces of the first light guide 22.
Further, as the secondlight guide 23, a fluorescent light guide in which a phosphor is dispersed instead of the shape light guide, or a light guide using a dichroic fluorescent dye as the phosphor can be used.
また、第２導光体２３として、形状導光体に代えて蛍光体を分散させた蛍光導光体や、蛍光体として二色性蛍光色素を用いた導光体を用いることができる。 Also in the present embodiment, the first
Further, as the second
［第１３実施形態］
図４０は、第１３実施形態の太陽電池モジュール２１Ｂの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｂが図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と異なるところは、第１１実施形態の太陽電池モジュール２１ではその第１導光体２２の異方性光機能材料１２として一種類の二色性蛍光色素しか有していないのに対し、本実施形態では、第１導光体２２の異方性光機能材料１２として、互いに吸収波長域の異なる二種類（複数種）の二色性蛍光色素１２ａ、１２ｂ（異方性光機能材料１２）を有している点である。 [Thirteenth embodiment]
FIG. 40 is a side sectional view showing a schematic configuration of thesolar cell module 21B of the thirteenth embodiment.
Thesolar cell module 21B of the present embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc., in the solar cell module 21 of the eleventh embodiment of the first light guide body 22. While the anisotropic optical functional material 12 has only one type of dichroic fluorescent dye, in the present embodiment, the anisotropic optical functional material 12 of the first light guide 22 has two different absorption wavelength ranges. This is a point having (multiple types) of dichroic fluorescent dyes 12a and 12b (anisotropic optical functional material 12).
図４０は、第１３実施形態の太陽電池モジュール２１Ｂの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｂが図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と異なるところは、第１１実施形態の太陽電池モジュール２１ではその第１導光体２２の異方性光機能材料１２として一種類の二色性蛍光色素しか有していないのに対し、本実施形態では、第１導光体２２の異方性光機能材料１２として、互いに吸収波長域の異なる二種類（複数種）の二色性蛍光色素１２ａ、１２ｂ（異方性光機能材料１２）を有している点である。 [Thirteenth embodiment]
FIG. 40 is a side sectional view showing a schematic configuration of the
The
このように互いに吸収波長域の異なる二種類（複数種）の二色性蛍光色素１２ａ、１２ｂ（異方性光機能材料１２）を有しているため、第１導光体２２は広い波長範囲の光を吸収することができる。二色性蛍光色素１２ａ、１２ｂとしては、例えば上述の式（１）、式（２）に示す材料を用いることができる。
Thus, since it has two types (plural types) of dichroic fluorescent dyes 12a and 12b (anisotropic light functional material 12) having different absorption wavelength ranges, the first light guide 22 has light in a wide wavelength range. Can be absorbed. As the dichroic fluorescent dyes 12a and 12b, for example, materials shown in the above formulas (1) and (2) can be used.
ただし、式（１）中のＲはＨ（水素）である。
式（１）に示す二色性蛍光色素１２ａは、吸収波長が３９６ｎｍであり、蛍光波長が５２６ｎｍである。また、式（２）に示す二色性蛍光色素１２ｂは、吸収波長が５１６ｎｍであり、蛍光波長が６１７ｎｍである。
なお、式（１）中のＲを、Ｏ（ＣＨ２）７ＣＨ３に置換したものも用いることができる。 However, R in Formula (1) is H (hydrogen).
The dichroicfluorescent dye 12a represented by the formula (1) has an absorption wavelength of 396 nm and a fluorescence wavelength of 526 nm. Moreover, the dichroic fluorescent dye 12b shown in Formula (2) has an absorption wavelength of 516 nm and a fluorescence wavelength of 617 nm.
Incidentally, it is possible to use R in the formula (1), also obtained by substituting the O (CH 2) 7 CH 3 .
式（１）に示す二色性蛍光色素１２ａは、吸収波長が３９６ｎｍであり、蛍光波長が５２６ｎｍである。また、式（２）に示す二色性蛍光色素１２ｂは、吸収波長が５１６ｎｍであり、蛍光波長が６１７ｎｍである。
なお、式（１）中のＲを、Ｏ（ＣＨ２）７ＣＨ３に置換したものも用いることができる。 However, R in Formula (1) is H (hydrogen).
The dichroic
Incidentally, it is possible to use R in the formula (1), also obtained by substituting the O (CH 2) 7 CH 3 .
また、第１導光体２２では、例えば二色性蛍光色素１２ａが吸収した光のエネルギーを、発光、吸収の繰り返しによって二色性蛍光色素１２ｂに移動させることができる。したがって、このエネルギーの移動を続けて起こさせることにより、二色性蛍光色素１２ｂによる異方性発光によって第１太陽電池素子１６に光を高い効率で導くことができる。
Further, in the first light guide 22, for example, the energy of light absorbed by the dichroic fluorescent dye 12a can be moved to the dichroic fluorescent dye 12b by repetition of light emission and absorption. Therefore, by continuously causing this energy transfer, light can be guided to the first solar cell element 16 with high efficiency by anisotropic light emission by the dichroic fluorescent dye 12b.
さらに、第１導光体２２では、二色性蛍光色素１２ａが吸収した光を二色性蛍光色素１２ｂにエネルギー移動させることで、より高い効率で光を第１太陽電池素子１６に導くことができる。エネルギー移動として、特に光機能材料間のフェルスター機構によって励起エネルギーが移動することにより、最も発光スペクトルのピーク波長が大きい光機能材料で発光させることができる。
Further, in the first light guide 22, the light absorbed by the dichroic fluorescent dye 12 a is transferred to the dichroic fluorescent dye 12 b, thereby guiding the light to the first solar cell element 16 with higher efficiency. it can. As the energy transfer, in particular, when the excitation energy is transferred by the Forster mechanism between the optical functional materials, the optical functional material having the largest peak wavelength of the emission spectrum can emit light.
複数種の光機能材料の間でエネルギー移動を生じさせる機構、特にフェルスター機構でエネルギー移動を生じさせる機構については、図１２ないし図１５で説明した通りである。なお３種類の一般的な（市販の）蛍光体を用いるものとして説明しているが、本実施形態においても適宜に選択した複数種の二色性蛍光色素１２を用いることで、同様のフェルスター機構によるエネルギー移動を生じさせることが可能である。また、第１導光体２２に二色性蛍光色素１２とともに他の光機能材料（蛍光体を含む）も含有させた場合にも、この光機能材料と二色性蛍光色素１２とによって、同様のフェルスター機構によるエネルギー移動を生じさせることが可能になる。
The mechanism for causing energy transfer between a plurality of types of optical functional materials, particularly the mechanism for causing energy transfer by the Förster mechanism, is as described with reference to FIGS. Although it is described that three kinds of general (commercially available) phosphors are used, the same forster is also obtained by using a plurality of types of dichroic fluorescent dyes 12 that are appropriately selected in this embodiment. It is possible to cause energy transfer by the mechanism. In addition, when the first light guide 22 includes other optical functional materials (including phosphors) together with the dichroic fluorescent dye 12, the same applies to the optical functional material and the dichroic fluorescent dye 12. It is possible to cause energy transfer by the Förster mechanism.
図１２ないし図１５で説明した例において、第１導光体では、３つの異なる発光スペクトルを有する蛍光体（第１蛍光体、第２蛍光体、第３蛍光体）を混入しているにもかかわらず、フェルスター機構によるエネルギー移動により、実質的には第３蛍光体の発光のみが生じる。第３蛍光体の発光量子効率は例えば９２％である。よって、第１導光体に第１蛍光体、第２蛍光体及び第３蛍光体を混入することで、６２０ｎｍまでの波長領域の光を吸収し、９２％の効率でピーク波長が６３０ｎｍの赤色の発光を生じさせることができる。
In the example described with reference to FIGS. 12 to 15, the first light guide includes phosphors having three different emission spectra (first phosphor, second phosphor, and third phosphor). Regardless, due to the energy transfer by the Förster mechanism, substantially only the emission of the third phosphor occurs. The emission quantum efficiency of the third phosphor is, for example, 92%. Therefore, by mixing the first phosphor, the second phosphor, and the third phosphor in the first light guide, the light in the wavelength region up to 620 nm is absorbed, and the red having a peak wavelength of 630 nm with an efficiency of 92%. Can be emitted.
第１実施形態の図１６Ａおよび図１６Ｂで説明されているように、このようなエネルギー移動現象は、有機の蛍光体に特有の現象で、一般的に無機の蛍光体では起こらないとされているが、量子ドットなどのいくつかの無機ナノ粒子の蛍光体においてはフェルスター機構により、無機材料間、あるいは、無機材料と有機材料との間でエネルギー移動を生じるものが知られている。
As described with reference to FIGS. 16A and 16B of the first embodiment, such an energy transfer phenomenon is a phenomenon peculiar to an organic phosphor, and generally does not occur in an inorganic phosphor. However, some inorganic nanoparticle phosphors such as quantum dots are known to cause energy transfer between inorganic materials or between an inorganic material and an organic material by a Forster mechanism.
また、フェルスター機構によるエネルギー移動は、蛍光体のような発光材料だけでなく、外光によって励起されるが、光を発生せずに失活する非発光体においても生じる。最終的な発電量は、ゲスト分子の蛍光量子収率によって決まり、ホスト分子の蛍光量子収率には依存しない。よって、ゲスト分子のみを蛍光量子収率の高い蛍光体で構成し、ホスト分子を蛍光量子収率の低い蛍光体又は蛍光を発しない非発光体で構成しても、同じ発電量が得られる。よって、フォトルミネッセンスによりエネルギー移動を行う場合のように、全ての蛍光体に対して高い蛍光量子収率が求められる場合に比べて、ホスト分子の材料選択の幅が広がる。
In addition, energy transfer by the Forster mechanism occurs not only in a luminescent material such as a phosphor, but also in a non-luminescent material that is excited by external light but deactivates without generating light. The final power generation amount depends on the fluorescence quantum yield of the guest molecule and does not depend on the fluorescence quantum yield of the host molecule. Therefore, even if only the guest molecule is composed of a phosphor having a high fluorescence quantum yield and the host molecule is composed of a phosphor having a low fluorescence quantum yield or a non-light emitting material that does not emit fluorescence, the same amount of power generation can be obtained. Therefore, as compared with the case where a high fluorescence quantum yield is required for all phosphors, such as when energy transfer is performed by photoluminescence, the range of material selection for the host molecule is widened.
図１８は、第１太陽電池素子１６の一例であるアモルファスシリコン太陽電池の分光感度曲線を第１蛍光体の発光スペクトル、第２蛍光体の発光スペクトルおよび第３蛍光体の発光スペクトルとともに示す図である。
FIG. 18 is a diagram showing a spectral sensitivity curve of an amorphous silicon solar cell which is an example of the first solar cell element 16 together with an emission spectrum of the first phosphor, an emission spectrum of the second phosphor, and an emission spectrum of the third phosphor. is there.
第１導光体２２の端面から射出される光Ｌ１のスペクトルは、第３蛍光体の発光スペクトルと概ね一致する。よって、太陽電池素子は、第３蛍光体の発光スペクトルのピーク波長（６３０ｎｍ）において高い感度を有するものであればよい。図１８に示すように、アモルファスシリコン太陽電池は６００ｎｍ付近の波長の光に対して最も高い分光感度を有する。第１蛍光体、第２蛍光体および第３蛍光体の発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度を比較すると、最も発光スペクトルのピーク波長の大きい第３蛍光体の発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度は、導光体に備えられた他のいずれの蛍光体（第１蛍光体、第２蛍光体）の発光スペクトルのピーク波長におけるアモルファスシリコン太陽電池の分光感度よりも大きい。そのため、第１太陽電池素子１６としてアモルファスシリコン太陽電池を用いれば、高い効率で発電を行うことができる。
The spectrum of the light L1 emitted from the end face of the first light guide 22 substantially matches the emission spectrum of the third phosphor. Therefore, a solar cell element should just have a high sensitivity in the peak wavelength (630 nm) of the emission spectrum of 3rd fluorescent substance. As shown in FIG. 18, the amorphous silicon solar cell has the highest spectral sensitivity with respect to light having a wavelength near 600 nm. Comparing the spectral sensitivities of the amorphous silicon solar cells at the peak wavelengths of the emission spectra of the first phosphor, the second phosphor and the third phosphor, the peak wavelength of the emission spectrum of the third phosphor having the largest peak wavelength of the emission spectrum The spectral sensitivity of the amorphous silicon solar cell at is higher than the spectral sensitivity of the amorphous silicon solar cell at the peak wavelength of the emission spectrum of any of the other phosphors (first phosphor and second phosphor) provided in the light guide. large. Therefore, if an amorphous silicon solar cell is used as the first solar cell element 16, power generation can be performed with high efficiency.
第１太陽電池素子１６に適用する太陽電池の種類は、前記太陽電池素子に入射する光の波長に応じて決定される。図１８では、第１太陽電池素子１６としてアモルファスシリコン太陽電池を用いたが、第１太陽電池素子１６はこれに限られない。
The type of solar cell applied to the first solar cell element 16 is determined according to the wavelength of light incident on the solar cell element. In FIG. 18, an amorphous silicon solar cell is used as the first solar cell element 16, but the first solar cell element 16 is not limited to this.
図１９および図２０に示した太陽電池では、最も発光スペクトルのピーク波長が大きい第３蛍光体の発光スペクトルのピーク波長（６３０ｎｍ）における太陽電池の分光感度およびエネルギー変換効率は、導光体に備えられた他のいずれの蛍光体（第１蛍光体、第２蛍光体ｂ）の発光スペクトルのピーク波長における太陽電池の分光感度およびエネルギー変換効率よりも大きい。そのため、第１太陽電池素子１６として、これらの太陽電池を用いれば、高い効率で発電を行うことができる。
In the solar cell shown in FIGS. 19 and 20, the light guide has the spectral sensitivity and the energy conversion efficiency of the solar cell at the peak wavelength (630 nm) of the emission spectrum of the third phosphor having the largest emission spectrum peak wavelength. It is larger than the spectral sensitivity and energy conversion efficiency of the solar cell at the peak wavelength of the emission spectrum of any of the other phosphors (the first phosphor and the second phosphor b). Therefore, if these solar cells are used as the first solar cell element 16, power generation can be performed with high efficiency.
図１９および図２０は、第１太陽電池素子１６として利用可能な太陽電池の一例であり、これ以外の太陽電池を用いることももちろん可能である。第１太陽電池素子１６としては、色素増感型太陽電池や有機系太陽電池など、太陽光の全波長領域に対しては高い分光感度を有することはできないが、特定の狭い波長領域の光に対しては非常に高い分光感度を有するような太陽電池を積極的に使用することも可能である。
19 and 20 are examples of solar cells that can be used as the first solar cell element 16, and other solar cells can be used as a matter of course. The first solar cell element 16, such as a dye-sensitized solar cell or an organic solar cell, cannot have high spectral sensitivity with respect to the entire wavelength region of sunlight, but is limited to light in a specific narrow wavelength region. On the other hand, it is possible to actively use a solar cell having a very high spectral sensitivity.
本実施形態の太陽電池モジュール２１Ｂにあっては、第１導光体２２の異方性光機能材料１２として、互いに吸収波長域の異なる二種類（複数種）の二色性蛍光色素１２ａ、１２ｂ（異方性光機能材料１２）を有しているので、第１導光体２２が広い波長範囲の光を吸収することができる。したがって、光の取り出し効率を高くして高い発電効率を実現することができる。
また、一の二色性蛍光色素１２ａが吸収した光のエネルギーを、発光、吸収の繰り返しによって他の二色性蛍光色素１２ｂに移動させることができ、したがってこのエネルギーの移動を続けて起こさせることにより、二色性蛍光色素１２ｂによる異方性発光によって第１太陽電池素子１６に光を高い効率で導くことができる。
さらに、複数種の二色性蛍光色素を適宜に選択し、フェルスター機構によるエネルギー移動が生じるように構成することで、最も発光スペクトルのピーク波長の大きい二色性蛍光色素から放射された光を第１導光体２２の第１端面２２ｃに射出させて第１太陽電池素子１６に入射させることができる。したがって、光の取り出し効率を高くして高い発電効率を実現することができる。 In thesolar cell module 21B of the present embodiment, as the anisotropic light functional material 12 of the first light guide 22, two types (plural types) of dichroic fluorescent dyes 12a and 12b (different types) having different absorption wavelength ranges are used. Since it has the isotropic light functional material 12), the first light guide 22 can absorb light in a wide wavelength range. Therefore, the light extraction efficiency can be increased and high power generation efficiency can be realized.
In addition, the energy of light absorbed by onedichroic fluorescent dye 12a can be transferred to another dichroic fluorescent dye 12b by repetition of light emission and absorption, and thus this energy transfer is caused to continue. Thus, light can be guided to the first solar cell element 16 with high efficiency by anisotropic light emission by the dichroic fluorescent dye 12b.
Furthermore, the light emitted from the dichroic fluorescent dye having the largest peak wavelength of the emission spectrum can be obtained by appropriately selecting multiple types of dichroic fluorescent dyes and configuring the energy transfer by the Forster mechanism. The light can be emitted to thefirst end face 22 c of the first light guide 22 and incident on the first solar cell element 16. Therefore, the light extraction efficiency can be increased and high power generation efficiency can be realized.
また、一の二色性蛍光色素１２ａが吸収した光のエネルギーを、発光、吸収の繰り返しによって他の二色性蛍光色素１２ｂに移動させることができ、したがってこのエネルギーの移動を続けて起こさせることにより、二色性蛍光色素１２ｂによる異方性発光によって第１太陽電池素子１６に光を高い効率で導くことができる。
さらに、複数種の二色性蛍光色素を適宜に選択し、フェルスター機構によるエネルギー移動が生じるように構成することで、最も発光スペクトルのピーク波長の大きい二色性蛍光色素から放射された光を第１導光体２２の第１端面２２ｃに射出させて第１太陽電池素子１６に入射させることができる。したがって、光の取り出し効率を高くして高い発電効率を実現することができる。 In the
In addition, the energy of light absorbed by one
Furthermore, the light emitted from the dichroic fluorescent dye having the largest peak wavelength of the emission spectrum can be obtained by appropriately selecting multiple types of dichroic fluorescent dyes and configuring the energy transfer by the Forster mechanism. The light can be emitted to the
なお、本実施形態においても、第１導光体２２に対してその複数の端面に第１の太陽電池素子４を設置してもよい。
また、第２導光体２３として、形状導光体に代えて蛍光体を分散させた蛍光導光体や、蛍光体として二色性蛍光色素を用いた導光体を用いることができる。 In the present embodiment also, the first solar cell element 4 may be installed on a plurality of end surfaces of thefirst light guide 22.
Further, as the secondlight guide 23, a fluorescent light guide in which a phosphor is dispersed instead of the shape light guide, or a light guide using a dichroic fluorescent dye as the phosphor can be used.
また、第２導光体２３として、形状導光体に代えて蛍光体を分散させた蛍光導光体や、蛍光体として二色性蛍光色素を用いた導光体を用いることができる。 In the present embodiment also, the first solar cell element 4 may be installed on a plurality of end surfaces of the
Further, as the second
［第１４実施形態］
図４１は、第１４実施形態の太陽電池モジュール２１Ｃの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｃは、図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と以下の点で異なる。第１１実施形態の太陽電池モジュール２１ではその第１導光体２２の光機能材料として一種類の異方性光機能材料１２（二色性蛍光色素）しか有していない。一方で本実施形態では、第１導光体２２の光機能材料として、前記二色性蛍光色素からなる異方性光機能材料１２と、光を等方的に吸収する等方性光機能材料２９とを有している。なお、図４１では、等方性光機能材料２９を１種類しか示していないが、本実施形態は等方性光機能材料２９が複数種ある場合も含むものとする。 [Fourteenth embodiment]
FIG. 41 is a side sectional view showing a schematic configuration of asolar cell module 21C of the fourteenth embodiment.
Thesolar cell module 21C of the present embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. The solar cell module 21 of the eleventh embodiment has only one kind of anisotropic light functional material 12 (dichroic fluorescent dye) as the light functional material of the first light guide 22. On the other hand, in the present embodiment, the optical functional material of the first light guide 22 includes the anisotropic optical functional material 12 made of the dichroic fluorescent dye and the isotropic optical functional material 29 that absorbs light isotropically. is doing. In FIG. 41, only one type of isotropic optical functional material 29 is shown, but this embodiment includes a case where there are a plurality of types of isotropic optical functional material 29.
図４１は、第１４実施形態の太陽電池モジュール２１Ｃの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｃは、図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と以下の点で異なる。第１１実施形態の太陽電池モジュール２１ではその第１導光体２２の光機能材料として一種類の異方性光機能材料１２（二色性蛍光色素）しか有していない。一方で本実施形態では、第１導光体２２の光機能材料として、前記二色性蛍光色素からなる異方性光機能材料１２と、光を等方的に吸収する等方性光機能材料２９とを有している。なお、図４１では、等方性光機能材料２９を１種類しか示していないが、本実施形態は等方性光機能材料２９が複数種ある場合も含むものとする。 [Fourteenth embodiment]
FIG. 41 is a side sectional view showing a schematic configuration of a
The
等方性光機能材料２９は、光を等方的に吸収する性質（吸収等方性）を有する材料、もしくは光を異方的に吸収する性質（吸収異方性）を有するが、第１導光体２２の形成材料に対して配向しにくく、ランダムな状態に配置された光機能材料である。この等方性光機能材料２９としては、外光を吸収して蛍光を放射するもので、所定の吸収波長域の蛍光体が用いられる。ここで、蛍光体としては、有機蛍光体、無機蛍光体、有機無機ハイブリッド蛍光体（例えば有機金属錯体）等のいずれも使用可能である。
このような等方性光機能材料２９と前記二色性蛍光色素（異方性光機能材料１２）とは、例えば第１導光体２２を成型する際に混入され、ほぼ均一に分散されている。 The isotropic lightfunctional material 29 has a property of absorbing light isotropically (absorption isotropic property) or a property of absorbing light anisotropically (absorption anisotropy). It is an optical functional material that is hardly oriented with respect to the material for forming the body 22 and is arranged in a random state. As this isotropic light functional material 29, it absorbs external light and emits fluorescence, and a phosphor having a predetermined absorption wavelength region is used. Here, any of organic phosphors, inorganic phosphors, organic-inorganic hybrid phosphors (for example, organometallic complexes) can be used as the phosphor.
Such an isotropic lightfunctional material 29 and the dichroic fluorescent dye (anisotropic light functional material 12) are mixed, for example, when the first light guide 22 is molded, and are dispersed almost uniformly.
このような等方性光機能材料２９と前記二色性蛍光色素（異方性光機能材料１２）とは、例えば第１導光体２２を成型する際に混入され、ほぼ均一に分散されている。 The isotropic light
Such an isotropic light
また、前記蛍光体（等方性光機能材料２９）としては、前記二色性蛍光色素（異方性光機能材料１２）との間で、前述したエネルギー移動を生じさせる性状のものが適宜選択され、好適に用いられる。その場合に、前記二色性蛍光色素（異方性光機能材料１２）は、複数種の光機能材料のうち、最も発光スペクトルのピーク波長が大きい光機能材料であるのが好ましい。図４２は、蛍光体２９（等方性光機能材料２９）と二色性蛍光色素１２（異方性光機能材料１２）との間でエネルギー移動が生じる様子を示した図である。図４２に示すように、第１導光体２２の第１主面２２ａに入射した外光の一部は、蛍光体２９によって吸収される。蛍光体２９が外光の一部を吸収すると、蛍光体２９から二色性蛍光色素１２に向けて励起エネルギーが移動する。
Further, as the phosphor (isotropic light functional material 29), a material having the above-described energy transfer with the dichroic fluorescent dye (anisotropic light functional material 12) is appropriately selected and suitably used. Used. In that case, the dichroic fluorescent dye (anisotropic optical functional material 12) is preferably an optical functional material having the largest peak wavelength of the emission spectrum among the plural types of optical functional materials. FIG. 42 is a diagram showing how energy transfer occurs between the phosphor 29 (isotropic light functional material 29) and the dichroic fluorescent dye 12 (anisotropic light functional material 12). As shown in FIG. 42, a part of the external light incident on the first main surface 22 a of the first light guide 22 is absorbed by the phosphor 29. When the phosphor 29 absorbs part of the external light, the excitation energy moves from the phosphor 29 toward the dichroic fluorescent dye 12.
これにより、二色性蛍光色素１２は第１１実施形態において図５Ｂに示したように、光を異方的に発する。本実施形態の二色性蛍光色素１２も、この二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと平行になるように配向されている。そのため、二色性蛍光色素１２が発する光のうち発光強度の最も大きい光は、第１太陽電池素子１６に直接導かれる。
Thereby, the dichroic fluorescent dye 12 emits light anisotropically as shown in FIG. 5B in the eleventh embodiment. The dichroic fluorescent dye 12 of the present embodiment is also oriented so that the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is maximum is parallel to the first main surface 22a of the first light guide 22 Has been. Therefore, light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the first solar cell element 16.
なお、蛍光体（等方性光機能材料２９）としては、前記二色性蛍光色素（異方性光機能材料１２）との間、もしくは複数種の蛍光体（等方性光機能材料２９）間で、前述したフェルスター機構によるエネルギー移動を生じさせる性状のものが選択され、用いられるのがより好ましい。例えば、先に示した第１蛍光体（BASF社製Lumogen F Violet 570（商品名））、第２蛍光体（BASF社製Lumogen F Yellow 083（商品名））、第３蛍光体（BASF社製Lumogen F Red 305（商品名））を等方性光機能材料２９として用いることができる。これら第１蛍光体、第２蛍光体、および第３蛍光体を二色性蛍光色素（異方性光機能材料１２）とともに第１導光体２２に分散させることで、３種類の等方性光機能材料２９間でフェルスター機構によるエネルギー移動を生じさせ、これから得られた光を二色性蛍光色素１２で吸収させ、発光させるように構成するのが好ましい。
As the phosphor (isotropic optical functional material 29), the above-described ferrule is used between the dichroic fluorescent dye (anisotropic optical functional material 12) or a plurality of types of phosphors (isotropic optical functional material 29). More preferably, a material that causes energy transfer by a star mechanism is selected and used. For example, the first phosphor (Lumogen F Violet 570 (trade name) manufactured by BASF), the second phosphor (Lumogen F Yellow 083 (trade name) manufactured by BASF), and the third phosphor (manufactured by BASF) Lumogen F Red 305 (trade name)) can be used as the isotropic optical functional material 29. By dispersing the first phosphor, the second phosphor, and the third phosphor in the first light guide 22 together with the dichroic fluorescent dye (anisotropic light functional material 12), three types of isotropic light functional materials 29 are provided. It is preferable that energy transfer is caused by the Förster mechanism between them, and light obtained therefrom is absorbed by the dichroic fluorescent dye 12 to emit light.
本実施形態の太陽電池モジュール２１Ｃにあっては、第１導光体２２の光機能材料として、二色性蛍光色素（異方性光機能材料１２）と等方性光機能材料２９とを併用したので、特に等方性光機能材料２９によってエネルギー移動を行わせることにより、広い波長域でかつ広角度の光を吸収することができる。したがって、光の取り出し効率を高くして高い発電効率を実現することができる。
In the solar cell module 21C of the present embodiment, since the dichroic fluorescent dye (anisotropic light functional material 12) and the isotropic light functional material 29 are used in combination as the light functional material of the first light guide 22, By causing the isotropic light functional material 29 to perform energy transfer, light having a wide wavelength range and a wide angle can be absorbed. Therefore, the light extraction efficiency can be increased and high power generation efficiency can be realized.
なお、本実施形態においては、前記等方性光機能材料２９として、外光を吸収して蛍光を放射する所定の吸収波長域の蛍光体を用いたが、本実施形態における等方性光機能材料としては、これに限定されない。本実施形態における等方性光機能材料として、蛍光、燐光のいずれの形態の発光をなす発光体を用いることができる。さらには、エネルギー移動を起こすものであれば、非発光の光機能材料であってもよい。ただし、蛍光スペクトルのピーク波長が最も大きい光機能材料については、蛍光体を用いるものとする。
In the present embodiment, a phosphor having a predetermined absorption wavelength range that absorbs external light and emits fluorescence is used as the isotropic optical functional material 29. However, as the isotropic optical functional material in the present embodiment, It is not limited to this. As the isotropic optical functional material in the present embodiment, a light emitter that emits light in any form of fluorescence or phosphorescence can be used. Furthermore, a non-light-emitting optical functional material may be used as long as it causes energy transfer. However, a phosphor is used for the optical functional material having the largest peak wavelength in the fluorescence spectrum.
また、本実施形態においては、異方性光機能材料と等方性光機能材料とが別々の分子である例を挙げて説明したが、本実施形態である第１４実施形態又は前記第１１実施形態の変形例として、一つの分子の中に吸収部と発光部とが存在するような光機能材料（異方性光機能材料）を用いてもよい。発光部は、発光異方性を有し、端面に発光光が効率的に届くようなものである。吸収部は、光を等方的に吸収するもの、または、吸収異方性を有していても、発光部に対して垂直に配向するか、ランダムな状態となっているようなものである。このような光機能材料としては、例えば図３３に示すように、高分子の主鎖１１８１が発光部に相当し、側鎖１１８２が吸収部に相当するようなものが挙げられる。
In the present embodiment, the anisotropic optical functional material and the isotropic optical functional material are described as examples of separate molecules, but the fourteenth embodiment or a modification of the eleventh embodiment is the present embodiment. Alternatively, an optical functional material (anisotropic optical functional material) in which an absorbing portion and a light emitting portion exist in one molecule may be used. The light emitting part has light emission anisotropy, and the emitted light efficiently reaches the end face. The absorbing part absorbs light isotropically, or has absorption anisotropy, but is oriented perpendicular to the light emitting part or in a random state. . As such an optical functional material, for example, as shown in FIG. 33, a polymer main chain 1181 corresponds to a light emitting portion and a side chain 1182 corresponds to an absorbing portion.
また、本実施形態においても、第１導光体２２に対してその複数の端面に第１太陽電池素子１６を設置してもよい。
また、第２導光体２３として、形状導光体に代えて蛍光体を分散させた蛍光導光体や、蛍光体として二色性蛍光色素を用いた導光体を用いることができる。 Also in the present embodiment, the firstsolar cell element 16 may be installed on the plurality of end faces of the first light guide 22.
Further, as the secondlight guide 23, a fluorescent light guide in which a phosphor is dispersed instead of the shape light guide, or a light guide using a dichroic fluorescent dye as the phosphor can be used.
また、第２導光体２３として、形状導光体に代えて蛍光体を分散させた蛍光導光体や、蛍光体として二色性蛍光色素を用いた導光体を用いることができる。 Also in the present embodiment, the first
Further, as the second
［第１５実施形態］
図４３は、第５実施形態の太陽電池モジュール２１Ｄの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｄが図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と異なるところは、図４３に示すように第１導光体２２の第１主面２２ａ側に拡散板１３が設けられている点である。 [Fifteenth embodiment]
FIG. 43 is a side sectional view showing a schematic configuration of asolar cell module 21D of the fifth embodiment.
Thesolar cell module 21D of this embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc., as shown in FIG. 43, the first main surface 22a of the first light guide 22 The diffusion plate 13 is provided on the side.
図４３は、第５実施形態の太陽電池モジュール２１Ｄの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｄが図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と異なるところは、図４３に示すように第１導光体２２の第１主面２２ａ側に拡散板１３が設けられている点である。 [Fifteenth embodiment]
FIG. 43 is a side sectional view showing a schematic configuration of a
The
拡散板１３は、第１導光体２２の第１主面２２ａ側に空気層を介して設けられたもので、第１導光体２２の外部から入射する外光を拡散させて第１導光体２２に入射させるものである。
第１導光体２２と拡散板１３との間に空気層が存在することにより、二色性蛍光色素（異方性光機能材料１２）が発する光が第１導光体２２と空気層との界面で全反射条件を満たしやすくなる。ただし、空気層を介在させることなく、拡散板１３を第１導光体２２の第１主面２２ａに直接当接させてもよく、接着等によって貼設してもよい。 The diffusingplate 13 is provided on the first main surface 22a side of the first light guide 22 via an air layer, and diffuses the external light incident from the outside of the first light guide 22 to make the first guide. The light is incident on the light body 22.
Since an air layer exists between thefirst light guide 22 and the diffusion plate 13, the light emitted from the dichroic fluorescent dye (anisotropic light functional material 12) is an interface between the first light guide 22 and the air layer. It becomes easy to satisfy the total reflection condition. However, the diffusion plate 13 may be brought into direct contact with the first main surface 22a of the first light guide 22 without interposing an air layer, or may be attached by adhesion or the like.
第１導光体２２と拡散板１３との間に空気層が存在することにより、二色性蛍光色素（異方性光機能材料１２）が発する光が第１導光体２２と空気層との界面で全反射条件を満たしやすくなる。ただし、空気層を介在させることなく、拡散板１３を第１導光体２２の第１主面２２ａに直接当接させてもよく、接着等によって貼設してもよい。 The diffusing
Since an air layer exists between the
拡散板１３は、例えばアクリル樹脂等のバインダー樹脂の内部に多数のアクリルビーズ等の光散乱体が分散されて構成されたものである。この拡散板１３の厚みは例えば２０μｍ程度であり、球状の光散乱体の球径は０．５～２０μｍ程度である。拡散板１３は、外光を第１導光体２２の外部から第１導光体２２の内部に向けて等方的に拡散させるようになっている。
The diffusion plate 13 is configured by dispersing a large number of light scatterers such as acrylic beads in a binder resin such as an acrylic resin. The thickness of the diffusion plate 13 is about 20 μm, for example, and the spherical diameter of the spherical light scatterer is about 0.5 to 20 μm. The diffuser plate 13 isotropically diffuses external light from the outside of the first light guide 22 toward the inside of the first light guide 22.
なお、光散乱体は、これに限らず、第１実施形態に記載されている光散乱体を用いることができる。
The light scatterer is not limited to this, and the light scatterer described in the first embodiment can be used.
図４４は、拡散板の作用を説明するための図である。
本実施形態の場合、図４４に示すように、第１導光体２２の第１主面２２ａ側には拡散板１３が配置されている。これにより、太陽電池モジュール２１Ｄ（拡散板１３）に対して垂直に入射する光は、拡散板１３で拡散した後、第１導光体２２の内部に入射する。このため、二色性蛍光色素１２には様々な角度の光が入射する。つまり、二色性蛍光色素１２が吸収しやすい方向の光の割合が、拡散板１３がないときと比べて多くなる。そのため、分子長軸Ｖ１に沿う方向においては相対的に吸収特性が小さく、分子長軸と直交する軸Ｖ２に沿う方向においては相対的に吸収特性が大きい吸収特性を有する二色性蛍光色素１２であっても、太陽電池モジュール２１Ｄ（拡散板１３）に対して垂直に入射する光の一部を吸収することが可能となる。 FIG. 44 is a diagram for explaining the operation of the diffusion plate.
In the case of this embodiment, as shown in FIG. 44, thediffusion plate 13 is disposed on the first main surface 22a side of the first light guide 22. Thereby, the light incident perpendicularly to the solar cell module 21 </ b> D (the diffusion plate 13) is diffused by the diffusion plate 13 and then enters the first light guide 22. For this reason, light of various angles enters the dichroic fluorescent dye 12. That is, the proportion of light in a direction that is easily absorbed by the dichroic fluorescent dye 12 is larger than when the diffuser plate 13 is not provided. Therefore, the dichroic fluorescent dye 12 having an absorption characteristic that is relatively small in the direction along the molecular long axis V1 and relatively large in the direction along the axis V2 orthogonal to the molecular long axis. Even if it exists, it becomes possible to absorb a part of light which enters perpendicularly with respect to solar cell module 21D (diffusion plate 13).
本実施形態の場合、図４４に示すように、第１導光体２２の第１主面２２ａ側には拡散板１３が配置されている。これにより、太陽電池モジュール２１Ｄ（拡散板１３）に対して垂直に入射する光は、拡散板１３で拡散した後、第１導光体２２の内部に入射する。このため、二色性蛍光色素１２には様々な角度の光が入射する。つまり、二色性蛍光色素１２が吸収しやすい方向の光の割合が、拡散板１３がないときと比べて多くなる。そのため、分子長軸Ｖ１に沿う方向においては相対的に吸収特性が小さく、分子長軸と直交する軸Ｖ２に沿う方向においては相対的に吸収特性が大きい吸収特性を有する二色性蛍光色素１２であっても、太陽電池モジュール２１Ｄ（拡散板１３）に対して垂直に入射する光の一部を吸収することが可能となる。 FIG. 44 is a diagram for explaining the operation of the diffusion plate.
In the case of this embodiment, as shown in FIG. 44, the
本実施形態の太陽電池モジュール２１Ｄにあっては、拡散板１３を設けているため、第１１実施形態に比べて、第１導光体２２の第１主面２２ａに入射した外光の二色性蛍光色素１２に吸収される割合が多くなる。二色性蛍光色素１２は外光を吸収すると光を異方的に発する。本実施形態の二色性蛍光色素１２においても、この二色性蛍光色素１２から発せられる光の発光強度の最も大きい方向が第１導光体２２の第１主面２２ａと平行になるように配向されているため、二色性蛍光色素１２が発する光のうち発光強度の最も大きい光は、第１太陽電池素子１６に直接導かれる。したがって、第１導光体２２に入射した太陽光の大部分を発電に寄与させることができる。よって、光の取り出し効率を高くして高い発電効率を実現することができる。
In the solar cell module 21D of the present embodiment, since the diffusion plate 13 is provided, two colors of external light incident on the first main surface 22a of the first light guide 22 are compared with the eleventh embodiment. The proportion absorbed by the fluorescent fluorescent dye 12 increases. The dichroic fluorescent dye 12 emits light anisotropically when it absorbs external light. Also in the dichroic fluorescent dye 12 of the present embodiment, the direction in which the emission intensity of the light emitted from the dichroic fluorescent dye 12 is the largest is parallel to the first main surface 22a of the first light guide 22. Since it is oriented, the light having the highest emission intensity among the light emitted from the dichroic fluorescent dye 12 is directly guided to the first solar cell element 16. Therefore, most of the sunlight incident on the first light guide 22 can be contributed to power generation. Therefore, high light generation efficiency can be realized by increasing light extraction efficiency.
なお、本実施形態に係る拡散板１３については、第１１実施形態の太陽電池モジュール２１にのみ適用することなく、第１２実施形態～第１４実施形態の各太陽電池モジュール２１Ａ～２１Ｄに組み合わせて構成してもよい。
Note that the diffusion plate 13 according to the present embodiment is not applied only to the solar cell module 21 of the eleventh embodiment, but is combined with the solar cell modules 21A to 21D of the twelfth to fourteenth embodiments. May be.
［第１６実施形態］
図４５は、第６実施形態の太陽電池モジュール２１Ｅの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｅが図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と異なるところは、図４４に示すように第２導光体２３の第２主面２３ｂ側に反射層１５が設けられている点である。 [Sixteenth Embodiment]
FIG. 45 is a side sectional view showing a schematic configuration of asolar cell module 21E of the sixth embodiment.
Thesolar cell module 21E of this embodiment is different from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc., as shown in FIG. 44, the second main surface 23b of the second light guide 23. The reflective layer 15 is provided on the side.
図４５は、第６実施形態の太陽電池モジュール２１Ｅの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｅが図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と異なるところは、図４４に示すように第２導光体２３の第２主面２３ｂ側に反射層１５が設けられている点である。 [Sixteenth Embodiment]
FIG. 45 is a side sectional view showing a schematic configuration of a
The
反射層１５は、第２導光体２３の第２主面２３ｂ側に空気層を介して、あるいは接着層を介して設けられたもので、第２導光体２３を透過した光を第２導光体２３の内部に反射するものである。
反射層１５としては、前述した反射層２８と同様のものが用いられる。すなわち、銀やアルミニウムなどの金属膜からなる反射層や、ＥＳＲ（Ｅｎｈａｎｃｅｄ Ｓｐｅｃｕｌａｒ Ｒｅｆｌｅｃｔｏｒ）反射フィルム（３Ｍ社製）などの誘電体多層膜からなる反射層などを用いることができる。
この反射層１５についても、入射した光を鏡面反射する鏡面反射層でもよいし、入射した光を散乱反射する散乱反射層でもよい。反射層１５に散乱反射層を用いた場合には、第１太陽電池素子１６の方向に直接向かう光の光量が増えるため、第１太陽電池素子１６への集光効率が高まり、発電量が増加する。また、反射光が散乱されるため、時間や季節による発電量の変化が平均化される。なお、散乱反射層としては、マイクロ発泡ＰＥＴ（ポリエチレン－テレフタレート）（古河電工社製）などを用いることができる。 Thereflective layer 15 is provided on the second main surface 23b side of the second light guide 23 via an air layer or an adhesive layer, and the light transmitted through the second light guide 23 is secondly transmitted. The light is reflected inside the light guide 23.
As thereflective layer 15, the same one as the reflective layer 28 described above is used. That is, a reflective layer made of a metal film such as silver or aluminum, or a reflective layer made of a dielectric multilayer film such as an ESR (Enhanced Specular Reflector) reflective film (manufactured by 3M) can be used.
Thereflection layer 15 may also be a mirror reflection layer that specularly reflects incident light, or a scattering reflection layer that scatters and reflects incident light. When a scattering reflection layer is used for the reflection layer 15, the amount of light directly going in the direction of the first solar cell element 16 increases, so that the light collection efficiency to the first solar cell element 16 increases and the amount of power generation increases. To do. In addition, since the reflected light is scattered, changes in the amount of power generation with time and season are averaged. As the scattering reflection layer, microfoamed PET (polyethylene terephthalate) (manufactured by Furukawa Electric) can be used.
反射層１５としては、前述した反射層２８と同様のものが用いられる。すなわち、銀やアルミニウムなどの金属膜からなる反射層や、ＥＳＲ（Ｅｎｈａｎｃｅｄ Ｓｐｅｃｕｌａｒ Ｒｅｆｌｅｃｔｏｒ）反射フィルム（３Ｍ社製）などの誘電体多層膜からなる反射層などを用いることができる。
この反射層１５についても、入射した光を鏡面反射する鏡面反射層でもよいし、入射した光を散乱反射する散乱反射層でもよい。反射層１５に散乱反射層を用いた場合には、第１太陽電池素子１６の方向に直接向かう光の光量が増えるため、第１太陽電池素子１６への集光効率が高まり、発電量が増加する。また、反射光が散乱されるため、時間や季節による発電量の変化が平均化される。なお、散乱反射層としては、マイクロ発泡ＰＥＴ（ポリエチレン－テレフタレート）（古河電工社製）などを用いることができる。 The
As the
The
本実施形態の太陽電池モジュール２１Ｅにあっては、反射層１５を設けたので、第２導光体２３の第２主面２３ｂから透過してきた光を再度第２導光体２３内に反射することができる。
したがって、第２導光体２３を通過させて主に反射光を第１導光体２２に再入射させ、ここで二色性蛍光色素１２（異方性光機能材料）に吸収させ、発光させて第１太陽電池素子１６に光を射出することができる。よって、第１導光体２２に入射した太陽光の大部分を発電に寄与させ、光の取り出し効率を高くして高い発電効率を実現することができる。
また、反射層１５として散乱反射層を用いれば、反射光を散乱させることができるため、第１導光体２２の第２主面２２ｂから再入射した光が二色性蛍光色素１２に吸収される割合を多くすることができる。 In thesolar cell module 21E of the present embodiment, since the reflective layer 15 is provided, the light transmitted from the second main surface 23b of the second light guide 23 is reflected again into the second light guide 23. be able to.
Therefore, the reflected light mainly passes through the secondlight guide 23 and re-enters the first light guide 22 where it is absorbed by the dichroic fluorescent dye 12 (anisotropic light functional material) and emitted. One solar cell element 16 can emit light. Therefore, most of the sunlight incident on the first light guide 22 can contribute to power generation, and the light extraction efficiency can be increased to achieve high power generation efficiency.
Further, if a scattering reflection layer is used as thereflection layer 15, the reflected light can be scattered, so that light incident again from the second main surface 22 b of the first light guide 22 is absorbed by the dichroic fluorescent dye 12. The ratio can be increased.
したがって、第２導光体２３を通過させて主に反射光を第１導光体２２に再入射させ、ここで二色性蛍光色素１２（異方性光機能材料）に吸収させ、発光させて第１太陽電池素子１６に光を射出することができる。よって、第１導光体２２に入射した太陽光の大部分を発電に寄与させ、光の取り出し効率を高くして高い発電効率を実現することができる。
また、反射層１５として散乱反射層を用いれば、反射光を散乱させることができるため、第１導光体２２の第２主面２２ｂから再入射した光が二色性蛍光色素１２に吸収される割合を多くすることができる。 In the
Therefore, the reflected light mainly passes through the second
Further, if a scattering reflection layer is used as the
なお、本実施形態に係る反射層１５については、第１１実施形態の太陽電池モジュール２１にのみ適用することなく、第１２実施形態～第１５実施形態の各太陽電池モジュール２１Ａ～２１Ｅに組み合わせて構成してもよい。
The reflective layer 15 according to the present embodiment is not applied only to the solar cell module 21 of the eleventh embodiment, but is combined with the solar cell modules 21A to 21E of the twelfth to fifteenth embodiments. May be.
さらに、第７実施形態で説明した１／４λ板１９を導光体１４の第２主面１４ｂと反射層１５との間に設けてもよい。この構成にすることで、第２導光体２３から射出され１／４λ板１９を介することなく反射層１５で反射した光と比較して、二色性蛍光色素１２に光が吸収されやすくなる。
Furthermore, you may provide the quarter-lambda board 19 demonstrated in 7th Embodiment between the 2nd main surface 14b of the light guide 14, and the reflection layer 15. FIG. With this configuration, light is more easily absorbed by the dichroic fluorescent dye 12 as compared with light emitted from the second light guide 23 and reflected by the reflective layer 15 without passing through the ¼λ plate 19. .
図４６は、第１５実施形態の太陽電池モジュール２１Ｅに第１６実施形態の反射層１５を組み合わせて構成した太陽電池モジュール２１Ｆの概略構成を示す側断面図である。
図４６に示すように第１導光体２２の第１主面２２ａ側に拡散板１３を設け、第２導光体２３の第２主面２２ｂ側に反射層１５を設けている。よって、この太陽電池モジュール２１Ｆにあっても、第５実施形態、第６実施形態で述べたように、第１導光体２２に入射した太陽光の大部分を発電に寄与させ、光の取り出し効率を高くして高い発電効率を実現することができる。また、太陽電池モジュール２１Ｅにおいて、さらに１／４λ板１９を導光体１４の第２主面１４ｂと反射層１５との間に設けてもよい。 FIG. 46 is a side sectional view showing a schematic configuration of asolar cell module 21F configured by combining the solar cell module 21E of the fifteenth embodiment with the reflective layer 15 of the sixteenth embodiment.
As shown in FIG. 46, thediffusion plate 13 is provided on the first main surface 22 a side of the first light guide 22, and the reflective layer 15 is provided on the second main surface 22 b side of the second light guide 23. Therefore, even in this solar cell module 21F, as described in the fifth and sixth embodiments, most of the sunlight incident on the first light guide 22 is contributed to power generation, and light extraction is performed. High power generation efficiency can be realized by increasing the efficiency. Further, in the solar cell module 21 </ b> E, a ¼λ plate 19 may be further provided between the second main surface 14 b of the light guide 14 and the reflective layer 15.
図４６に示すように第１導光体２２の第１主面２２ａ側に拡散板１３を設け、第２導光体２３の第２主面２２ｂ側に反射層１５を設けている。よって、この太陽電池モジュール２１Ｆにあっても、第５実施形態、第６実施形態で述べたように、第１導光体２２に入射した太陽光の大部分を発電に寄与させ、光の取り出し効率を高くして高い発電効率を実現することができる。また、太陽電池モジュール２１Ｅにおいて、さらに１／４λ板１９を導光体１４の第２主面１４ｂと反射層１５との間に設けてもよい。 FIG. 46 is a side sectional view showing a schematic configuration of a
As shown in FIG. 46, the
［第１７実施形態］
図４７は、第１７実施形態の太陽電池モジュール２１Ｇの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｇは、図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と以下の点で異なる。本実施形態では、図４７に示すように、第１導光体２２の第１端面２２ｃに設けられる第１太陽電池素子と第２導光体２３の第２端面２３ｃに設けられる第２太陽電池素子とを共通の太陽電池素子、すなわち単一の太陽電池素子２１２によって構成している。 [Seventeenth embodiment]
FIG. 47 is a side sectional view showing a schematic configuration of asolar cell module 21G of the seventeenth embodiment.
Thesolar cell module 21G of the present embodiment differs from the solar cell module 21 of the eleventh embodiment shown in FIGS. 36, 37, etc. in the following points. In the present embodiment, as shown in FIG. 47, the first solar cell element provided on the first end surface 22 c of the first light guide 22 and the second solar cell provided on the second end surface 23 c of the second light guide 23. The element is constituted by a common solar cell element, that is, a single solar cell element 212.
図４７は、第１７実施形態の太陽電池モジュール２１Ｇの概略構成を示す側断面図である。
本実施形態の太陽電池モジュール２１Ｇは、図３６、図３７等に示した第１１実施形態の太陽電池モジュール２１と以下の点で異なる。本実施形態では、図４７に示すように、第１導光体２２の第１端面２２ｃに設けられる第１太陽電池素子と第２導光体２３の第２端面２３ｃに設けられる第２太陽電池素子とを共通の太陽電池素子、すなわち単一の太陽電池素子２１２によって構成している。 [Seventeenth embodiment]
FIG. 47 is a side sectional view showing a schematic configuration of a
The
共通に用いる太陽電池素子２１２としては、前記の第１太陽電池素子１６、第２太陽電池素子２５として用いられる種々の太陽電池が使用可能である。すなわち、シリコン系太陽電池、化合物系太陽電池、量子ドット太陽電池、有機系太陽電池などの公知の太陽電池を使用することができる。
なお、本実施形態においても、第１導光体２２と第２導光体２３とは、図４７に示すようにこれらの間に空気層が介在していてもよく、また、接着等によって接していてもよい。ただし、第１導光体２２と第２導光体２３との間に空気層を介在させれば、二色性蛍光色素（異方性光機能材料１２）が発する光が、第１導光体２２と空気層との界面で全反射条件を満たしやすくなり、好ましい。 As thesolar cell element 212 used in common, various solar cells used as the first solar cell element 16 and the second solar cell element 25 can be used. That is, known solar cells such as silicon solar cells, compound solar cells, quantum dot solar cells, and organic solar cells can be used.
Also in this embodiment, thefirst light guide 22 and the second light guide 23 may have an air layer interposed between them as shown in FIG. It may be. However, if an air layer is interposed between the first light guide 22 and the second light guide 23, the light emitted from the dichroic fluorescent dye (anisotropic light functional material 12) is emitted from the first light guide 22. It is easy to satisfy the total reflection condition at the interface between the air layer and the air layer, which is preferable.
なお、本実施形態においても、第１導光体２２と第２導光体２３とは、図４７に示すようにこれらの間に空気層が介在していてもよく、また、接着等によって接していてもよい。ただし、第１導光体２２と第２導光体２３との間に空気層を介在させれば、二色性蛍光色素（異方性光機能材料１２）が発する光が、第１導光体２２と空気層との界面で全反射条件を満たしやすくなり、好ましい。 As the
Also in this embodiment, the
本実施形態の太陽電池モジュール２１Ｇにあっては、第１導光体２２の太陽電池素子と第２導光体２３の太陽電池素子とを共通化して単一の太陽電池素子２１２で構成している、全体の構成を簡素化してコストの低減化を図ることができる。
In the solar cell module 21G of the present embodiment, the solar cell element of the first light guide 22 and the solar cell element of the second light guide 23 are shared to form a single solar cell element 212. The overall configuration can be simplified and the cost can be reduced.
なお、本実施形態においては、第１導光体２２として第１１実施形態に示したものを用いたが、これに代えて、第１２実施形態ないし第１４実施形態のいずれかの第１導光体２２を用いるようにしてもよい。また、第１５実施形態に示した拡散板１３、第１６実施形態に示した反射層１５のいずれか一方あるいは両方を備える構成としてもよい。
また、第２導光体２３として、形状導光体に代えて蛍光体を分散させた蛍光導光体や、蛍光体として二色性蛍光色素を用いた導光体を用いることができる。 In the present embodiment, thefirst light guide 22 shown in the eleventh embodiment is used. Instead, the first light guide in any of the twelfth to fourteenth embodiments is used. The body 22 may be used. Moreover, it is good also as a structure provided with the any one or both of the diffuser plate 13 shown in 15th Embodiment, and the reflection layer 15 shown in 16th Embodiment.
Further, as the secondlight guide 23, a fluorescent light guide in which a phosphor is dispersed instead of the shape light guide, or a light guide using a dichroic fluorescent dye as the phosphor can be used.
また、第２導光体２３として、形状導光体に代えて蛍光体を分散させた蛍光導光体や、蛍光体として二色性蛍光色素を用いた導光体を用いることができる。 In the present embodiment, the
Further, as the second
［第１８実施形態］
図２９は、第１８実施形態の太陽電池モジュールに適用される導光体１２４の断面図である。導光体１２４以外の構成は、第３実施形態の太陽電池モジュール１１Ｂと同じである。よって、ここでは導光体１２４の構成のみを説明する。また、第３実施形態の太陽電池モジュール１１Ｂと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Eighteenth embodiment]
FIG. 29 is a cross-sectional view of thelight guide 124 applied to the solar cell module of the eighteenth embodiment. The configuration other than the light guide 124 is the same as that of the solar cell module 11B of the third embodiment. Therefore, only the configuration of the light guide 124 will be described here. Moreover, about the structure which is common in the solar cell module 11B of 3rd Embodiment, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.
図２９は、第１８実施形態の太陽電池モジュールに適用される導光体１２４の断面図である。導光体１２４以外の構成は、第３実施形態の太陽電池モジュール１１Ｂと同じである。よって、ここでは導光体１２４の構成のみを説明する。また、第３実施形態の太陽電池モジュール１１Ｂと共通する構成については、同じ符号を付し、詳細な説明は省略する。 [Eighteenth embodiment]
FIG. 29 is a cross-sectional view of the
導光体１２４は、透明導光体１２５と、透明導光体１２５の第１主面１２５ａに接着された蛍光フィルム１２６と、蛍光フィルム１２６の表面を覆う透明保護膜１２７と、を備えている。
The light guide 124 includes a transparent light guide 125, a fluorescent film 126 bonded to the first main surface 125 a of the transparent light guide 125, and a transparent protective film 127 that covers the surface of the fluorescent film 126. .
蛍光フィルム１２６は、内部に、前述した光機能材料として、第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃが分散されたフィルム状の光機能材料層である。蛍光フィルム１２６は、第１主面１２６ａに入射した外光（例えば太陽光）の一部を蛍光に変換し、透明導光体１２５に向けて放射する。蛍光フィルム１２６は、例えば、ＰＭＭＡ樹脂の内部に第１蛍光体１８ａ、第２蛍光体１８ｂ及び第３蛍光体１８ｃをそれぞれＰＭＭＡ樹脂に対する体積比率で０．２％混入し、２００μｍの厚みのフィルムに形成したものである。
The fluorescent film 126 is a film-like optical functional material layer in which the first fluorescent material 18a, the second fluorescent material 18b, and the third fluorescent material 18c are dispersed therein as the optical functional material described above. The fluorescent film 126 converts part of the external light (for example, sunlight) incident on the first main surface 126 a into fluorescence and radiates it toward the transparent light guide 125. For example, the phosphor film 126 includes a PMMA resin in which 0.2% of the first phosphor 18a, the second phosphor 18b, and the third phosphor 18c are mixed in a volume ratio with respect to the PMMA resin to form a film having a thickness of 200 μm. Formed.
透明導光体１２５及び透明保護膜１２７としては、アクリル樹脂、ポリカーボネート樹脂、ガラスなどの透明性の高い有機材料もしくは無機材料が用いられる。例えば、透明導光体１２５は、厚さ５ｍｍのアクリル板からなり、透明保護膜１２７は、厚さ２００μｍのＰＭＭＡ樹脂の膜からなる。図２９では、透明保護膜１２７と蛍光フィルム１２６と透明導光体１２５とをこの順に外光Ｌの入射側から配置しているが、図３０のように透明導光体１２５と蛍光フィルム１２６と透明保護膜１２７とをこの順に外光Ｌの入射側から配置してもよい。
As the transparent light guide 125 and the transparent protective film 127, a highly transparent organic material or inorganic material such as acrylic resin, polycarbonate resin, or glass is used. For example, the transparent light guide 125 is made of an acrylic plate having a thickness of 5 mm, and the transparent protective film 127 is made of a PMMA resin film having a thickness of 200 μm. In FIG. 29, the transparent protective film 127, the fluorescent film 126, and the transparent light guide 125 are arranged in this order from the incident side of the external light L. However, as shown in FIG. You may arrange | position the transparent protective film 127 from the incident side of the external light L in this order.
透明導光体１２５及び透明保護膜１２７は、光機能材料を含まない透明性の高い材料で構成されている。蛍光フィルム１２６から放射された蛍光（図１４に示した第３蛍光体１８ｃの発光スペクトルと概ね同じスペクトルの光）の一部は、透明導光体１２５及び透明保護膜１２７の内部を全反射しながら透明導光体１２５及び透明保護膜１２７の端面に向けて伝播する。透明導光体１２５及び透明保護膜１２７の端面から射出された光は、太陽電池素子に入射し、発電に利用される。
The transparent light guide 125 and the transparent protective film 127 are made of a highly transparent material that does not contain an optical functional material. Part of the fluorescence emitted from the fluorescent film 126 (light having a spectrum substantially the same as the emission spectrum of the third phosphor 18c shown in FIG. 14) is totally reflected inside the transparent light guide 125 and the transparent protective film 127. However, it propagates toward the end surfaces of the transparent light guide 125 and the transparent protective film 127. Light emitted from the end faces of the transparent light guide 125 and the transparent protective film 127 is incident on the solar cell element and used for power generation.
蛍光フィルム１２６と透明導光体１２５とは、図３１に示すような剥離可能な粘着層１２８によって接着されている。蛍光フィルム１２６は、破損、劣化、又は異物（砂埃や鳥の糞など）の付着などが生じた場合に、透明導光体１２５から剥離して交換される。蛍光フィルム１２６と粘着層１２８と透明導光体１２５の屈折率はいずれも１．４９である。蛍光フィルム１２６から放射された蛍光は、蛍光フィルム１２６、粘着層１２８及び透明導光体１２５の内部をロスなく伝播する。このような粘着層１２８としては、例えば、パナック社製のゲルポリ（商品名）などが利用できる。
The fluorescent film 126 and the transparent light guide 125 are bonded by a peelable adhesive layer 128 as shown in FIG. The fluorescent film 126 is peeled off from the transparent light guide 125 and replaced when damage, deterioration, or foreign matter (such as dust or bird droppings) adheres. The refractive indexes of the fluorescent film 126, the adhesive layer 128, and the transparent light guide 125 are all 1.49. The fluorescence emitted from the fluorescent film 126 propagates through the fluorescent film 126, the adhesive layer 128, and the transparent light guide 125 without loss. As such an adhesive layer 128, for example, Gel Poly (trade name) manufactured by Panac Corporation can be used.
上記構成の導光体１２４では、蛍光フィルム１２６と透明導光体１２５とが剥離可能な粘着層１２８で接着されている。そのため、蛍光フィルム１２６に破損、劣化、又は異物の付着（砂埃や鳥の糞など）などが生じ発電効率が低下した場合には、蛍光フィルム１２６のみを透明導光体１２５から剥がして交換することができる。よって、導光体全体を交換する場合に比べて、保守の費用を少なくすることができる。
In the light guide 124 configured as described above, the fluorescent film 126 and the transparent light guide 125 are bonded to each other with a peelable adhesive layer 128. Therefore, when the fluorescent film 126 is damaged, deteriorated, or has foreign matters attached (such as dust or bird droppings) and the power generation efficiency is reduced, only the fluorescent film 126 is peeled off from the transparent light guide 125 and replaced. Can do. Therefore, the maintenance cost can be reduced as compared with the case where the entire light guide is replaced.
［第１９実施形態］
図４８は、第１９実施形態の太陽電池モジュールに適用される第１導光体２２０の概略構成を示す側断面図である。第１導光体２２０以外の構成は、第１１実施形態の太陽電池モジュール２１と同じである。よって、ここでは第１導光体２２０の構成のみを説明する。 [Nineteenth Embodiment]
FIG. 48 is a side sectional view showing a schematic configuration of thefirst light guide 220 applied to the solar cell module of the nineteenth embodiment. The configuration other than the first light guide 220 is the same as that of the solar cell module 21 of the eleventh embodiment. Therefore, only the configuration of the first light guide 220 will be described here.
図４８は、第１９実施形態の太陽電池モジュールに適用される第１導光体２２０の概略構成を示す側断面図である。第１導光体２２０以外の構成は、第１１実施形態の太陽電池モジュール２１と同じである。よって、ここでは第１導光体２２０の構成のみを説明する。 [Nineteenth Embodiment]
FIG. 48 is a side sectional view showing a schematic configuration of the
第１導光体２２０は、透明導光体２２１と、透明導光体２２１の第１主面２２１ａに接着された蛍光フィルム２２２と、蛍光フィルム２２２の表面を覆う透明保護膜２２３と、を備えている。
蛍光フィルム２２２は、その内部に、前記した異方性光機能材料１２として、二色性蛍光色素が分散されたフィルム状の光機能材料層である。なお、この蛍光フィルム２２２には、複数種の二色性蛍光色素（異方性光機能材料１２）が分散されていてもよく、また、異方性光機能材料１２に加えて、前記した等方性光機能材料２９が１種または複数種分散されていてもよい。 Thefirst light guide 220 includes a transparent light guide 221, a fluorescent film 222 bonded to the first main surface 221 a of the transparent light guide 221, and a transparent protective film 223 that covers the surface of the fluorescent film 222. ing.
Thefluorescent film 222 is a film-like optical functional material layer in which a dichroic fluorescent pigment is dispersed as the anisotropic optical functional material 12 described above. In addition, a plurality of types of dichroic fluorescent dyes (anisotropic light functional material 12) may be dispersed in the fluorescent film 222. In addition to the anisotropic light functional material 12, the isotropic light functional material 29 described above. 1 type or multiple types may be disperse | distributed.
蛍光フィルム２２２は、その内部に、前記した異方性光機能材料１２として、二色性蛍光色素が分散されたフィルム状の光機能材料層である。なお、この蛍光フィルム２２２には、複数種の二色性蛍光色素（異方性光機能材料１２）が分散されていてもよく、また、異方性光機能材料１２に加えて、前記した等方性光機能材料２９が１種または複数種分散されていてもよい。 The
The
蛍光フィルム２２２は、第１主面２２２ａに入射した外光（例えば太陽光）の一部を蛍光に変換し、透明導光体２２１に向けて放射するものである。この蛍光フィルム２２２は、例えば、ＰＭＭＡ樹脂の内部に二色性蛍光色素１２等が分散され、２００μｍ程度の厚みに形成されたものである。
The fluorescent film 222 converts a part of the external light (for example, sunlight) incident on the first main surface 222a into fluorescence and radiates it toward the transparent light guide 221. The fluorescent film 222 is formed, for example, with a thickness of about 200 μm by dispersing the dichroic fluorescent dye 12 and the like inside a PMMA resin.
透明導光体２２１及び透明保護膜２２３としては、アクリル樹脂、ポリカーボネート樹脂、ガラスなどの透明性の高い有機材料もしくは無機材料が用いられる。例えば、透明導光体２２１は、厚さ５ｍｍのアクリル板からなり、透明保護膜２２３は、厚さ２００μｍのＰＭＭＡ樹脂の膜からなる。図４８では、透明保護膜２２３と蛍光フィルム２２２と透明導光体２２１とをこの順に外光Ｌの入射側から配置しているが、図４９のように透明導光体２２１と蛍光フィルム２２２と透明保護膜２２３とをこの順に外光Ｌの入射側から配置してもよい。
As the transparent light guide 221 and the transparent protective film 223, a highly transparent organic material or inorganic material such as acrylic resin, polycarbonate resin, or glass is used. For example, the transparent light guide 221 is made of an acrylic plate having a thickness of 5 mm, and the transparent protective film 223 is made of a PMMA resin film having a thickness of 200 μm. In FIG. 48, the transparent protective film 223, the fluorescent film 222, and the transparent light guide 221 are arranged in this order from the incident side of the external light L. However, as shown in FIG. You may arrange | position the transparent protective film 223 from the incident side of the external light L in this order.
透明導光体２２１及び透明保護膜２２３は、光機能材料を含まない透明性の高い材料で構成されている。蛍光フィルム２２２から放射された蛍光の一部は、透明導光体２２１及び透明保護膜２２３の内部を全反射しながら透明導光体２２１及び透明保護膜２２３の端面に向けて伝播する。透明導光体２２１及び透明保護膜２２３の端面から射出された光は、第１太陽電池素子に入射し、発電に利用される。
The transparent light guide 221 and the transparent protective film 223 are made of a highly transparent material that does not contain an optical functional material. Part of the fluorescence emitted from the fluorescent film 222 propagates toward the end surfaces of the transparent light guide 221 and the transparent protective film 223 while totally reflecting the inside of the transparent light guide 221 and the transparent protective film 223. Light emitted from the end surfaces of the transparent light guide 221 and the transparent protective film 223 is incident on the first solar cell element and used for power generation.
蛍光フィルム２２２と透明導光体２２１とは、第１８実施形態にて図３１に示すような剥離可能な粘着層１２８によって接着されている。つまり、図３１において、蛍光フィルム１２６と透明導光体１２５は、本実施形態の蛍光フィルム２２２と透明導光体２２１に相当する。蛍光フィルム２２２は、破損、劣化、又は異物（砂埃や鳥の糞など）の付着などが生じた場合に、透明導光体２２１から剥離して交換される。蛍光フィルム２２２と粘着層２２４と透明導光体２２１の屈折率はいずれも１．４９である。蛍光フィルム２２２から放射された蛍光は、蛍光フィルム２２２、粘着層２２４及び透明導光体２２１の内部をロスなく伝播する。このような粘着層２２４としては、例えば、パナック社製のゲルポリ（商品名）などが利用できる。
The fluorescent film 222 and the transparent light guide 221 are bonded together by a peelable adhesive layer 128 as shown in FIG. 31 in the eighteenth embodiment. That is, in FIG. 31, the fluorescent film 126 and the transparent light guide 125 correspond to the fluorescent film 222 and the transparent light guide 221 of this embodiment. The fluorescent film 222 is peeled off from the transparent light guide 221 and replaced when damage, deterioration, or foreign matter (such as dust or bird droppings) adheres. The refractive indexes of the fluorescent film 222, the adhesive layer 224, and the transparent light guide 221 are all 1.49. The fluorescence emitted from the fluorescent film 222 propagates through the fluorescent film 222, the adhesive layer 224, and the transparent light guide 221 without loss. As such an adhesive layer 224, for example, Gel Poly (trade name) manufactured by Panac Co., Ltd. can be used.
前記構成の第１導光体２２０では、蛍光フィルム２２２と透明導光体２２１とが剥離可能な粘着層２２４で接着されている。そのため、蛍光フィルム２２２に破損、劣化、又は異物の付着（砂埃や鳥の糞など）などが生じ発電効率が低下した場合には、蛍光フィルム２２２のみを透明導光体２２１から剥がして交換することができる。よって、第１導光体全体を交換する場合に比べて、保守の費用を少なくすることができる。
In the first light guide 220 configured as described above, the fluorescent film 222 and the transparent light guide 221 are bonded to each other with a peelable adhesive layer 224. Therefore, when the fluorescent film 222 is damaged, deteriorated, or has foreign matter attached (such as dust or bird droppings) and the power generation efficiency is reduced, only the fluorescent film 222 is peeled off from the transparent light guide 221 and replaced. Can do. Therefore, the maintenance cost can be reduced as compared with the case where the entire first light guide is replaced.
［太陽光発電装置］
図３２は、太陽光発電装置１１０００の概略構成図である。 [Solar power generator]
FIG. 32 is a schematic configuration diagram of the solarpower generation device 11000.
図３２は、太陽光発電装置１１０００の概略構成図である。 [Solar power generator]
FIG. 32 is a schematic configuration diagram of the solar
太陽光発電装置１１０００は、太陽光のエネルギーを電力に変換する太陽電池モジュール１１００１と、太陽電池モジュール１１００１から出力された直流電力を交流電力に変換するインバータ（直流／交流変換器）１１００４と、太陽電池モジュール１１００１から出力された直流電力を蓄える蓄電池１１００５と、を備えている。
The solar power generation device 11000 includes a solar cell module 11001 that converts sunlight energy into electric power, an inverter (DC / AC converter) 11004 that converts DC power output from the solar cell module 11001 into AC power, A storage battery 11005 for storing DC power output from the battery module 11001.
太陽電池モジュール１１００１は、太陽光を集光する導光体１００２と、導光体１００２によって集光された太陽光によって発電を行う太陽電池素子１００３と、を備えている。
太陽電池モジュール１１００１としては、例えば、第１実施形態ないし第１０実施形態で説明した太陽電池モジュールが用いられる。 Thesolar cell module 11001 includes a light guide body 1002 that condenses sunlight and a solar cell element 1003 that generates power using sunlight collected by the light guide body 1002.
As thesolar cell module 11001, for example, the solar cell module described in the first to tenth embodiments is used.
太陽電池モジュール１１００１としては、例えば、第１実施形態ないし第１０実施形態で説明した太陽電池モジュールが用いられる。 The
As the
太陽光発電装置１１０００は外部の電子機器１１００６に対して電力を供給する。電子機器１１００６には、必要に応じて補助電力源１１００７から電力が供給される。
The solar power generation device 11000 supplies power to an external electronic device 11006. The electronic device 11006 is supplied with power from the auxiliary power source 11007 as necessary.
太陽光発電装置１１０００は、上述した実施形態に係る太陽電池モジュールを備えているため、発電効率の高い太陽光発電装置となる。
Since the solar power generation device 11000 includes the solar cell module according to the above-described embodiment, the solar power generation device 11000 is a solar power generation device with high power generation efficiency.
なお、本発明の態様における技術範囲は上記実施形態に限定されるものではなく、本発明の態様の趣旨を逸脱しない範囲において種々の変更を加えることが可能である。
Note that the technical scope of the aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the aspect of the present invention.
例えば、導光体の第１主面と第２主面とが平行の場合に限らず、非平行の場合の構成においても本発明の態様を適用することができる。すなわち、第１光機能材料（異方性光機能材料）から発せられる光の発光強度の最も大きい方向と導光体（第１導光体）の第１主面の法線とのなす角度が臨界角以上になっており、かつ、第１光機能材料から発せられる光の発光強度の最も大きい方向と導光体の第２主面の法線とのなす角度が臨界角未満になっている構成においても本発明の態様を適用することができる。このような構成においても、導光体に入射した太陽光の大部分を発電に寄与させることができる。
For example, the aspect of the present invention can be applied not only to the case where the first main surface and the second main surface of the light guide are parallel, but also to a configuration where the light guide is not parallel. That is, the critical angle is the angle formed between the direction in which the emission intensity of light emitted from the first optical functional material (anisotropic optical functional material) is the largest and the normal of the first main surface of the light guide (first light guide). In the configuration in which the angle formed between the direction in which the emission intensity of the light emitted from the first optical functional material is the largest and the normal to the second main surface of the light guide is less than the critical angle The embodiments of the present invention can also be applied. Even in such a configuration, most of the sunlight incident on the light guide can be contributed to power generation.
例えば、導光体（第１導光体）の形成材料としては、液晶性ポリマーに限らず、アクリル樹脂、ポリカーボネート樹脂、ガラスなどの透明性の高い有機材料もしくは無機材料を用いることもできる。
また、光機能材料としては、例えば、紫外光又は可視光を吸収して可視光又は赤外光を放射する蛍光体、または、紫外光又は可視光を吸収して励起されるが、光を放射せずに失活する非発光体が含まれていてもよい。なお、可視光は３８０ｎｍ以上７５０ｎｍ以下の波長領域の光であり、紫外光は３８０ｎｍ未満の波長領域の光であり、赤外光は７５０ｎｍよりも大きい波長領域の光である。 For example, the material for forming the light guide (first light guide) is not limited to a liquid crystalline polymer, and a highly transparent organic material or inorganic material such as an acrylic resin, a polycarbonate resin, or glass can also be used.
Examples of the optical functional material include a phosphor that absorbs ultraviolet light or visible light and emits visible light or infrared light, or is excited by absorbing ultraviolet light or visible light, but emits light. A non-luminous material that deactivates without being included may be included. Note that visible light is light in a wavelength region of 380 nm to 750 nm, ultraviolet light is light in a wavelength region less than 380 nm, and infrared light is light in a wavelength region larger than 750 nm.
また、光機能材料としては、例えば、紫外光又は可視光を吸収して可視光又は赤外光を放射する蛍光体、または、紫外光又は可視光を吸収して励起されるが、光を放射せずに失活する非発光体が含まれていてもよい。なお、可視光は３８０ｎｍ以上７５０ｎｍ以下の波長領域の光であり、紫外光は３８０ｎｍ未満の波長領域の光であり、赤外光は７５０ｎｍよりも大きい波長領域の光である。 For example, the material for forming the light guide (first light guide) is not limited to a liquid crystalline polymer, and a highly transparent organic material or inorganic material such as an acrylic resin, a polycarbonate resin, or glass can also be used.
Examples of the optical functional material include a phosphor that absorbs ultraviolet light or visible light and emits visible light or infrared light, or is excited by absorbing ultraviolet light or visible light, but emits light. A non-luminous material that deactivates without being included may be included. Note that visible light is light in a wavelength region of 380 nm to 750 nm, ultraviolet light is light in a wavelength region less than 380 nm, and infrared light is light in a wavelength region larger than 750 nm.
外光を有効に取り込めるように、導光体（第１導光体、第２導光体）の基材（透明基板）の材料は４００ｎｍ以下の波長に対して透過性を有することが望ましい。例えば、３６０ｎｍ以上８００ｎｍ以下の波長領域の光に対して９０％以上、より好ましくは９３％以上の透過率を有するものが好適である。例えば、シリコン樹脂基板や石英基板、或いは、ＰＭＭＡ樹脂基板においては三菱レイヨン社製の「アクリライト」（登録商標）は、広い波長領域に光に対して高い透明性を有することから、好適である。
It is desirable that the material of the base material (transparent substrate) of the light guide (first light guide, second light guide) has transparency to wavelengths of 400 nm or less so that external light can be taken in effectively. For example, a material having a transmittance of 90% or more, more preferably 93% or more with respect to light in a wavelength region of 360 nm to 800 nm is suitable. For example, in the case of a silicon resin substrate, a quartz substrate, or a PMMA resin substrate, “Acrylite” (registered trademark) manufactured by Mitsubishi Rayon is suitable because it has high transparency to light in a wide wavelength region. .
なお、上記実施形態においては、第１光機能材料と第２光機能材料とが別々の分子である例を挙げて説明したがこれに限らない。例えば、一つの分子の中に吸収部と発光部が存在するようなものも含む。発光部は、発光異方性を有し、端面に発光光が効率的に届くようなものである。吸収部は、光を等方的に吸収するもの、または、吸収異方性を有していても、発光部に対して垂直に配向するか、ランダムな状態となっているようなものである。例えば、図３３に示すように、高分子の主鎖１１８１が発光部に相当し、側鎖１１８２が吸収部に相当するようなものが挙げられる。
In the above embodiment, the example in which the first optical functional material and the second optical functional material are separate molecules has been described, but the present invention is not limited thereto. For example, it includes those in which an absorption part and a light emission part exist in one molecule. The light emitting part has light emission anisotropy, and the emitted light efficiently reaches the end face. The absorption part absorbs light isotropically, or has absorption anisotropy, but is oriented perpendicular to the light-emitting part or in a random state. . For example, as shown in FIG. 33, the main chain 1181 of the polymer corresponds to the light emitting portion, and the side chain 1182 corresponds to the absorbing portion.
本発明の態様は、太陽電池モジュールおよび太陽光発電装置に利用することができる。
The aspect of the present invention can be used for a solar cell module and a solar power generation device.
１１，１１Ａ，１１Ｂ，１１Ｃ，１１Ｄ，１１Ｅ，１１Ｆ，１１Ｇ…太陽電池モジュール、１２…二色性蛍光色素（第１光機能材料）、１３…拡散板、１４…導光体、１４ａ…第１主面、１４ｂ…第２主面、１４ｃ…端面、１５…反射層、１６…太陽電池素子、１８，１８ａ，１８ｂ，１８ｃ…蛍光体（第２光機能材料）、１２４…導光体、１２５…透明導光体、１２５ａ…第１主面、１２６…蛍光フィルム（光機能材料層）、１２８…粘着層、１１０００…太陽光発電装置、Ｌ，Ｌ１，Ｌ２…光
11, 11A, 11B, 11C, 11D, 11E, 11F, 11G ... solar cell module, 12 ... dichroic fluorescent dye (first optical functional material), 13 ... diffusion plate, 14 ... light guide, 14a ... first Main surface, 14b ... second main surface, 14c ... end surface, 15 ... reflective layer, 16 ... solar cell element, 18, 18a, 18b, 18c ... phosphor (second optical functional material), 124 ... light guide, 125 ... Transparent light guide, 125a ... First main surface, 126 ... Fluorescent film (optical functional material layer), 128 ... Adhesive layer, 11000 ... Solar power generator, L, L1, L2 ... Light
Claims (20)
- 第１主面と、第１端面を有し、
少なくとも一つの光機能材料を含み、
前記少なくとも一つの光機能材料が、光を異方的に発する第１光機能材料を含み、
少なくとも前記第１光機能材料から放射された光を伝播させ前記端面から射出させるよう構成されており、
前記第１光機能材料は、前記第１光機能材料から発せられる光の発光強度の最も大きい方向と前記第１主面の法線とのなす角度が臨界角以上になるように配向されている導光体。 A first main surface and a first end surface;
Including at least one optical functional material,
The at least one optical functional material includes a first optical functional material that emits light anisotropically,
At least light emitted from the first optical functional material is propagated and emitted from the end face;
The first optical functional material is oriented so that an angle formed by a direction in which the emission intensity of light emitted from the first optical functional material is maximum and a normal line of the first main surface is equal to or greater than a critical angle. Light guide. - 前記第１光機能材料は、前記第１主面から入射した外光の一部を吸収する請求項１に記載の導光体。 The light guide according to claim 1, wherein the first optical functional material absorbs part of external light incident from the first main surface.
- さらに、入射した外光の一部を等方的に吸収する第２光機能材料を含む請求項１または２に記載の導光体。 The light guide according to claim 1 or 2, further comprising a second optical functional material that isotropically absorbs part of the incident external light.
- 前記第２光機能材料は、光を等方的に吸収する性質を有する材料、もしくは光を異方的に吸収する性質を有するが前記導光体に含まれる材料に対して配向しにくくランダムな状態の光機能材料、のいずれかである請求項３に記載の導光体。 The second optical functional material has a property of absorbing light isotropically, or has a property of absorbing light anisotropically, but is difficult to be oriented with respect to the material included in the light guide body and is random. The light guide according to claim 3, which is one of the optical functional materials in a state.
- 前記光機能材料を複数含み、
前記第１光機能材料は、前記複数の光機能材料のうち最も発光スペクトルのピーク波長が大きい光機能材料を含む請求項１ないし４のいずれか一項に記載の導光体。 Including a plurality of the optical functional materials,
5. The light guide according to claim 1, wherein the first optical functional material includes an optical functional material having a maximum peak wavelength of an emission spectrum among the plurality of optical functional materials. - 前記第１光機能材料は、前記第１主面の法線方向から見て、前記第１光機能材料から発せられる光の発光強度の最も大きい方向が前記端面を向くように配向されている請求項１ないし５のいずれか一項に記載の導光体。 The first optical functional material is oriented so that the direction in which the light emission intensity of light emitted from the first optical functional material is the largest faces the end surface when viewed from the normal direction of the first main surface. Item 6. The light guide according to any one of Items 1 to 5.
- 前記第１光機能材料が、二色性蛍光色素からなる光機能材料を含む請求項１ないし６のいずれか一項に記載の導光体。 The light guide according to any one of claims 1 to 6, wherein the first optical functional material includes an optical functional material made of a dichroic fluorescent dye.
- 前記二色性蛍光色素が、分子長軸と直交する方向が発光強度の最も大きい方向であるポジ型二色性蛍光色素を含む請求項７に記載の導光体。 The light guide according to claim 7, wherein the dichroic fluorescent dye includes a positive dichroic fluorescent dye in which the direction perpendicular to the molecular long axis is the direction in which the emission intensity is the highest.
- さらに、前記第１主面側に設けられ、前記導光体の外部から入射する外光を拡散させる拡散板を含む請求項１ないし８のいずれか１項に記載の導光体。 The light guide according to any one of claims 1 to 8, further comprising a diffusion plate that is provided on the first main surface side and diffuses external light incident from outside the light guide.
- 前記複数の光機能材料の間でフェルスター機構によるエネルギー移動を生じさせ、最も発光スペクトルのピーク波長の大きい光機能材料から放射された光を、前記第１端面から射出させる請求項３ないし９のいずれか１項に記載の導光体。 The energy transfer by the Forster mechanism is caused between the plurality of optical functional materials, and light emitted from the optical functional material having the largest peak wavelength of the emission spectrum is emitted from the first end surface. The light guide according to any one of the above.
- 前記光機能材料のうち、前記最も発光スペクトルのピーク波長の大きい光機能材料以外の１又は複数の光機能材料には、蛍光量子収率が８０％以下の光機能材料が含まれている請求項３ないし１０のいずれか一項に記載の導光体。 The optical functional material having a fluorescence quantum yield of 80% or less is included in one or more optical functional materials other than the optical functional material having the largest peak wavelength of the emission spectrum among the optical functional materials. The light guide according to any one of 3 to 10.
- 前記最も発光スペクトルのピーク波長が大きい光機能材料の蛍光量子収率は、前記導光体に含まれる他のいずれの光機能材料の蛍光量子収率よりも高い請求項１１に記載の導光体。 The light guide according to claim 11, wherein a fluorescence quantum yield of the optical functional material having the largest peak wavelength of the emission spectrum is higher than a fluorescence quantum yield of any other optical functional material included in the light guide. .
- さらに、前記導光体の内部を伝播する光を反射する反射層を含む請求項１ないし１２のいずれか１項に記載の導光体。 The light guide according to any one of claims 1 to 12, further comprising a reflective layer that reflects light propagating through the light guide.
- さらに、前記導光体と前記反射層の間に位相差板を含む請求項１３に記載の導光体。 The light guide according to claim 13, further comprising a retardation plate between the light guide and the reflective layer.
- 前記位相差板は、１／４λ板である請求項１４に記載の導光体。 The light guide according to claim 14, wherein the retardation plate is a ¼λ plate.
- 請求項１ないし１５のいずれか一項に記載の導光体と、
前記導光体の前記第１端面から射出された前記光を受光する第１太陽電池素子と、を備えている太陽電池モジュール。 A light guide according to any one of claims 1 to 15,
And a first solar cell element that receives the light emitted from the first end face of the light guide. - 前記光機能材料のうち最も発光スペクトルのピーク波長が大きい光機能材料の発光スペクトルのピーク波長における前記第１太陽電池素子の分光感度は、前記導光体に備えられた他のいずれの光機能材料の発光スペクトルのピーク波長における前記第１太陽電池素子の分光感度よりも大きい請求項１６に記載の太陽電池モジュール。 Among the optical functional materials, the spectral sensitivity of the first solar cell element at the peak wavelength of the emission spectrum of the optical functional material having the largest emission spectrum peak wavelength is any other optical functional material provided in the light guide. The solar cell module according to claim 16, wherein the solar cell module has a spectral sensitivity greater than a spectral sensitivity of the first solar cell element at a peak wavelength of the emission spectrum.
- さらに、第３主面と第２端面を有し、前記第２主面側に配置され、前記第２主面から透過した光を前記第３主面から入射し、伝播させて前記第２端面から射出する第２導光体と、前記第２端面に設けられて前記第２端面から射出された光を受光する第２太陽電池素子と、を備える請求項１６または１７に記載の太陽電池モジュール。 Furthermore, it has a 3rd main surface and a 2nd end surface, is arrange | positioned at the said 2nd main surface side, the light which permeate | transmitted from the said 2nd main surface enters from the said 3rd main surface, is propagated, and said 2nd end surface The solar cell module according to claim 16 or 17, further comprising: a second light guide that is emitted from the second light guide body; and a second solar cell element that is provided on the second end surface and receives light emitted from the second end surface. .
- 前記異方性光機能材料は、前記第１主面の法線方向から見て、前記異方性光機能材料から発せられる光の発光強度の最も大きい方向が前記第１端面を向くように配向されている請求項１８に記載の太陽電池モジュール。 The anisotropic optical functional material is oriented so that a direction in which a light emission intensity of light emitted from the anisotropic optical functional material is maximum is directed to the first end surface when viewed from a normal direction of the first main surface. Item 19. The solar cell module according to Item 18.
- 前記第２導光体は、前記第４主面に設けられた傾斜面で光を反射して伝播させ、前記第２端面から射出する形状導光体である請求項１８または１９に記載の太陽電池モジュール。 20. The sun according to claim 18, wherein the second light guide is a shape light guide that reflects and propagates light at an inclined surface provided on the fourth main surface and emits the light from the second end surface. Battery module.
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