WO2023145280A1 - Solar cell, solar cell module, and method for manufacturing solar cell - Google Patents

Solar cell, solar cell module, and method for manufacturing solar cell Download PDF

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Publication number
WO2023145280A1
WO2023145280A1 PCT/JP2022/045649 JP2022045649W WO2023145280A1 WO 2023145280 A1 WO2023145280 A1 WO 2023145280A1 JP 2022045649 W JP2022045649 W JP 2022045649W WO 2023145280 A1 WO2023145280 A1 WO 2023145280A1
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Prior art keywords
solar cell
photoelectric conversion
metal layer
conversion substrate
metal
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PCT/JP2022/045649
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French (fr)
Japanese (ja)
Inventor
怜志 砂廣
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株式会社カネカ
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Publication of WO2023145280A1 publication Critical patent/WO2023145280A1/en

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    • 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
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • 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
    • H01L31/06—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 characterised by at least one potential-jump barrier or surface barrier
    • H01L31/072—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 characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type
    • H01L31/0745—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 characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type comprising a AIVBIV heterojunction, e.g. Si/Ge, SiGe/Si or Si/SiC solar cells
    • H01L31/0747—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 characterised by at least one potential-jump barrier or surface barrier the potential barriers being only of the PN heterojunction type comprising a AIVBIV heterojunction, e.g. Si/Ge, SiGe/Si or Si/SiC solar cells comprising a heterojunction of crystalline and amorphous materials, e.g. heterojunction with intrinsic thin layer or HIT® solar cells; solar cells

Definitions

  • the present invention relates to a solar cell, a solar cell module, and a method for manufacturing a solar cell.
  • a solar cell has a structure in which unevenness is provided on the surface of a photoelectric conversion substrate so that light taken into the photoelectric conversion substrate is confined within the photoelectric conversion substrate (see, for example, Patent Documents 1).
  • a comb-like collecting electrode is formed on the light-receiving side surface for extracting electricity from the photoelectric conversion substrate.
  • silver paste having a particle size in the range of 0.1 to 0.5 ⁇ m is applied to the light-receiving side surface of a photoelectric conversion substrate having fine unevenness on the surface, and is baked to form a collecting electrode. forming In this way, Patent Document 1 states that the contact resistance between the collecting electrode and the photoelectric conversion substrate can be reduced.
  • the solar cell of Patent Document 1 the silver paste is applied thicker than the height of the convex portions of the surface unevenness, and light cannot be received in the portions where the silver paste is applied. Therefore, the solar cell of Patent Literature 1 has room for improvement to further improve the light-receiving area.
  • One aspect of the present invention for solving the above-described problems is a solar cell in which a metal layer is laminated on a photoelectric conversion substrate, the photoelectric conversion substrate having a plurality of protrusions on its first main surface. a textured structure, wherein the metal layer is thinner than the height of the protrusions and covers a part of the protrusions, and the protrusions have tops exposed from the metal layer. Battery.
  • the apex of the convex portion of the photoelectric conversion substrate is exposed from the metal layer, light can be incident from the apex portion, and the light receiving area can be increased compared to the conventional case.
  • the photoelectric conversion substrate has a transparent conductive oxide layer laminated on the photoelectric conversion part, and the transparent conductive oxide layer constitutes the convex part.
  • the texture structure has a plurality of recesses formed adjacent to the plurality of protrusions, the depth of the recesses is 1 ⁇ m or more, and the metal layer includes a plurality of metal particles.
  • the metal particles have a number average particle diameter of 10 nm or more and less than 100 nm, and are filled from the bottom of the recess to a height of 1/20 or more and 2/3 or less of the depth of the recess.
  • a preferable aspect is that the metal layer surrounds the top of the convex portion when the photoelectric conversion substrate is viewed from above.
  • a preferred aspect has a wiring member and a conductive adhesive, the wiring member is connected to a part of the metal layer via the conductive adhesive, and the convex portion exposed from the metal layer is , is covered while being in contact with the conductive adhesive.
  • One aspect of the present invention has the above solar cell, a first sealing member, and a second sealing member, and the solar cell is sandwiched between the first sealing member and the second sealing member.
  • the first sealing member has an adhesive portion, and the solar cell is adhered to the first sealing member with the metal layer in close contact with the adhesive portion,
  • the projecting portion exposed from the metal layer is a solar cell module that is covered while being in contact with the adhesive portion.
  • an anchor effect works between the convex portion of the photoelectric conversion substrate and the adhesive portion of the first sealing member, and the adhesive strength between the photoelectric conversion substrate and the first sealing member is improved compared to the conventional art. can.
  • One aspect of the present invention is the above-described method for manufacturing a solar cell, comprising: a coating step of coating a metal ink containing metal particles having a number average particle size of 10 nm or more and less than 100 nm on the photoelectric conversion substrate;
  • the method for manufacturing a solar cell includes a heating step of heating the photoelectric conversion substrate coated with ink at a heating temperature of 100° C. or higher and 180° C. or lower.
  • the metal layer can be formed at a relatively low temperature, and the manufacturing cost can be reduced.
  • the light-receiving area per unit area can be improved compared to the conventional art.
  • FIG. 1 is an explanatory diagram of a solar cell module according to a first embodiment of the present invention, where (a) is a schematic perspective view of the solar cell module and (b) is a cross-sectional view taken along the line AA of (a). . Note that hatching is omitted for easy understanding.
  • FIG. 2 is an end view of the BB section of the solar cell of FIG. 1(a); Note that hatching is omitted for easy understanding.
  • FIG. 2 is an end view of the cross section CC of the solar cell of FIG. 1(a); Note that hatching is omitted for easy understanding.
  • Fig. 1(a) is an exploded perspective view of the main part of the solar cell of Fig.
  • FIG. 5 is a cross-sectional view of the photoelectric conversion substrate of FIG. 4; Note that hatching is omitted for easy understanding. It is explanatory drawing of the solar cell of Fig.1 (a), (a) is the top view seen from the surface side, (b) is the top view seen from the back surface side.
  • FIG. 2 is an explanatory diagram of an optical path in the solar cell when the solar cell module of FIG. 1 is irradiated with light, and is a cross-sectional view of a main part of the solar cell. To facilitate understanding, hatching is omitted and the optical paths are indicated by arrows.
  • a solar cell module 1 according to the first embodiment of the present invention is a photoelectric conversion device that converts light into electricity, and receives light on at least one main surface. As shown in FIG. 1(a), the solar cell module 1 includes a solar cell string 2, a first sealing member 3, and a second sealing member 5 as main constituent members.
  • the solar cell string 2 includes a plurality of solar cells 10 (10a to 10c), wiring members 11 (11a and 11b), and a conductive adhesive 12, as shown in FIG. 1(b). Batteries 10 (10a to 10c) are connected in series by wiring members 11 (11a, 11b).
  • the solar cell 10 includes a photoelectric conversion substrate 20, a first collecting electrode 21, and a second collecting electrode 22, as shown in FIGS.
  • the photoelectric conversion substrate 20 is, as shown in FIGS. It is a transparent conductive substrate in which a transparent electrode layer 31 is laminated and a second transparent electrode layer 32 is laminated on the second main surface 36 side. Further, the photoelectric conversion substrate 20 has a first texture structure 37 formed on a first main surface 35 serving as a main surface on the first sealing member 3 side, and a second main surface serving as a main surface on the second sealing member 5 side. A second textured structure 38 is formed on surface 36 .
  • the photoelectric conversion part 30 is a part that has a PN junction and converts light energy into electrical energy. As shown in FIG. 5 , the photoelectric conversion section 30 has a first intrinsic semiconductor layer 41 and a first conductivity type semiconductor layer 42 laminated in this order on a first main surface 45 of a semiconductor substrate 40 , and a second main surface 46 . A second intrinsic semiconductor layer 43 and a second conductivity type semiconductor layer 44 are stacked thereon in this order.
  • the semiconductor substrate 40 is an n-type or p-type semiconductor substrate, specifically, an n-type or p-type crystalline silicon substrate.
  • a single crystal silicon substrate or a polycrystalline silicon substrate can be used as the semiconductor substrate 40 .
  • the semiconductor substrate 40 has pyramid-shaped semiconductor-side texture structures 47 and 48 formed on the surfaces of the first main surface 45 and the second main surface 46, respectively.
  • the first intrinsic semiconductor layer 41 is a silicon thin film that does not substantially contain dopants, and preferably has a dopant concentration of 1/100 or less of the dopant concentration of the first conductivity type semiconductor layer 42 .
  • the first conductivity type semiconductor layer 42 is an n-type or p-type silicon-based thin film layer containing a dopant, and is a p-type silicon layer in this embodiment.
  • the second intrinsic semiconductor layer 43 is a silicon thin film that does not substantially contain dopants, and preferably has a dopant concentration of 1/100 or less of the dopant concentration of the second conductivity type semiconductor layer 44 .
  • the second-conductivity-type semiconductor layer 44 is a silicon layer containing a dopant and having a conductivity type opposite to that of the first-conductivity-type semiconductor layer 42 . That is, when the conductivity type of the semiconductor layer 42 of the first conductivity type is n-type, the conductivity type of the semiconductor layer 44 of the second conductivity type is p-type, and when the conductivity type of the semiconductor layer 42 of the first conductivity type is p-type, , the conductivity type of the second conductivity type semiconductor layer 44 is n-type.
  • the first conductivity type semiconductor layer 42 is a p-type silicon layer, so the second conductivity type semiconductor layer 44 is formed of an n-type silicon layer.
  • the transparent electrode layers 31 and 32 are transparent conductive layers having transparency and conductivity, and are specifically made of a transparent conductive oxide such as indium tin oxide (ITO) or tungsten-doped indium oxide (IWO). It is a transparent conductive oxide layer.
  • a transparent conductive oxide such as indium tin oxide (ITO) or tungsten-doped indium oxide (IWO). It is a transparent conductive oxide layer.
  • the first texture structure 37 is formed by forming the semiconductor layers 41 and 42 and the first transparent electrode layer 31 following the semiconductor-side texture structure 47 of the underlying semiconductor substrate 40 . That is, the first texture structure 37 has pyramid-shaped unevenness, and includes a plurality of protrusions 51 , like the semiconductor-side texture structure 47 of the semiconductor substrate 40 . As shown in FIG. 4, the convex portion 51 has a quadrangular pyramid shape, the cross-sectional area of which gradually decreases from the first transparent electrode layer 31 side toward the top portion 52, and the top portion 52 is sharp. From another point of view, the first texture structure 37 has a concave portion 55 formed by adjacent convex portions 51, 51, as shown in FIG.
  • the concave portion 55 has an inverted square pyramid shape, and the bottom portion 56 is pointed.
  • the depth of the concave portion 55 that is, the height of the convex portion 51 (the distance between the top portion 52 and the bottom portion 56 in the thickness direction) is larger than the thickness of the first collector electrode 21 and is 1 ⁇ m or more and 10 ⁇ m or less, as shown in FIG. Preferably.
  • the second texture structure 38 is formed by forming the semiconductor layers 43 and 44 and the second transparent electrode layer 32 following the semiconductor-side texture structure 48 of the underlying semiconductor substrate 40 . That is, the second texture structure 38 has pyramid-shaped unevenness, and includes a plurality of protrusions 61 , like the semiconductor-side texture structure 48 of the semiconductor substrate 40 . As shown in FIG. 4, the convex portion 61 has a quadrangular pyramid shape, the cross-sectional area of which gradually decreases from the second transparent electrode layer 32 side toward the top portion 62, and the top portion 62 is sharp. From another point of view, the second texture structure 38 has recesses 65 formed by adjacent protrusions 61, 61, as shown in FIG.
  • the recess 65 has an inverted quadrangular pyramid shape with a sharp bottom 66 .
  • the depth of the concave portion 65 that is, the height of the convex portion 61 (the distance between the top portion 62 and the bottom portion 66 in the thickness direction) is, as shown in FIG. Preferably.
  • the first collector electrode 21 forms a pair with the second collector electrode 22 and is an extraction electrode for extracting from the photoelectric conversion substrate 20 electrical energy photoelectrically converted by the photoelectric conversion substrate 20 together with the second collector electrode 22 .
  • the collecting electrodes 21 and 22 are partially formed on both main surfaces 35 and 36 of the photoelectric conversion substrate 20, and are mainly composed of metal electrode layers 70a and 70b.
  • the metal electrode layers 70a and 70b are metal layers having higher conductivity than the transparent electrode layers 31 and 32, and are reflective electrode layers capable of reflecting light.
  • the metal electrode layers 70a and 70b are formed of a plurality of metal particles 71 as shown in FIGS.
  • the thickness of the metal electrode layers 70a and 70b is thinner than the height of the protrusions 51 and 61, preferably 0.1 ⁇ m or more and 10 ⁇ m or less, more preferably 0.2 ⁇ m or more and 5 ⁇ m or less, and 1 ⁇ m or less. is more preferred.
  • the metal particles 71 are nano-sized particles and have a diameter smaller than the height of the projections 51 and 61 .
  • Metal particles 71 preferably have a number average particle diameter of 10 nm or more and less than 100 nm. The number average particle size can be calculated, for example, by checking the particle size of 100 samples with a scanning electron microscope or a transmission electron microscope and calculating the arithmetic mean of the particle sizes of 100 samples.
  • the metal particles 71 can be made of, for example, gold, silver, copper, platinum, aluminum, nickel, palladium, or the like. Silver particles are used as the metal particles 71 of the present embodiment.
  • the metal electrode layers 70a and 70b are preferably formed by an inkjet printing method or a screen printing method, and more preferably formed by an inkjet printing method.
  • the metal electrode layers 70a and 70b of the present embodiment are formed by applying metal ink containing metal particles 71 onto the photoelectric conversion substrate 20, as will be described later.
  • the first collector electrode 21 when the photoelectric conversion substrate 20 is viewed from the first main surface 35 side, the first collector electrode 21 includes a first busbar electrode portion 80a and a first finger electrode portion 81a.
  • the second collector electrode 22 is composed of a second busbar electrode portion 80b and second finger electrode portions 81b when the photoelectric conversion substrate 20 is viewed from the second main surface 36 side. It is
  • the busbar electrode portions 80a and 80b are portions that have width in the horizontal direction and extend in the vertical direction.
  • the finger electrode portions 81a and 81b are portions extending like comb teeth from intermediate portions of the busbar electrode portions 80a and 80b.
  • the finger electrode portions 81a and 81b extend in a direction crossing the extending direction of the busbar electrode portions 80a and 80b, and in this embodiment extend in a direction orthogonal to the extending direction of the busbar electrode portions 80a and 80b. That is, the finger electrode portions 81a and 81b have a width in the vertical direction and extend in the horizontal direction. Finger electrode portions 81 a and 81 b have a width narrower than that of busbar electrode portions 80 a and 80 b and wider than that of protrusions 51 and 61 .
  • the wiring member 11 is a tab wiring that connects adjacent solar cells 10, 10 as shown in FIG.
  • the wiring member 11a has a first connection portion connected to the busbar electrode portion 80a of one of the adjacent solar cells 10a and 10b, and a second connection portion connected to the busbar electrode portion 80b of the other solar cell 10b. has a department.
  • Wiring member 11b has a first connection portion connected to busbar electrode portion 80a of solar cell 10b and a second connection portion connected to busbar electrode portion 80b of solar cell 10c adjacent to solar cell 10b on the opposite side of solar cell 10a. has a department.
  • the conductive adhesive 12 adheres the connecting portion of the wiring member 11 to the busbar electrode portions 80 a and 80 b of the solar cell 10 .
  • the conductive adhesive 12 is not particularly limited as long as it has conductivity and adhesiveness. Solder, for example, can be used as the conductive adhesive 12 .
  • the first sealing member 3 is a member that spreads in a plane and seals the solar cell string 2 together with the second sealing member 5 .
  • the sealing part 100 is composed of a transparent insulating substrate or a transparent insulating sheet having translucency and insulating properties, and for example, a glass substrate or a resin sheet can be used.
  • the adhesive portion 101 is made of a translucent adhesive having translucency and adhesiveness, and is more preferably thermoplastic resin. For example, an EVA sheet can be used as the adhesive portion 101 .
  • the second sealing member 5 spreads in a plane and includes a sealing portion 102 and an adhesive portion 103 .
  • the sealing portion 102 is composed of an insulating substrate or an insulating sheet having insulating properties, and for example, a glass substrate or a resin sheet can be used.
  • the adhesive portion 103 is made of an adhesive material having adhesiveness, and is more preferably made of a thermoplastic resin.
  • an EVA sheet can be used as the adhesive portion 101 .
  • the method of manufacturing the solar cell module 1 of the present embodiment includes, as main steps, a photoelectric conversion substrate forming step, a collecting electrode forming step, a wiring attaching step, and a sealing step.
  • the semiconductor substrate 40 on which the semiconductor-side texture structures 47 and 48 are formed in advance is subjected to plasma CVD on the first main surface 45 of the semiconductor substrate 40.
  • a first intrinsic semiconductor layer 41 and a first conductivity type semiconductor layer 42 are formed, and a second intrinsic semiconductor layer 43 and a second conductivity type semiconductor layer 44 are formed on a second main surface 46 of a semiconductor substrate 40 to form a photoelectric conversion section.
  • 30 is formed (photoelectric conversion portion forming step).
  • the first transparent electrode layer 31 is formed on the first main surface 45 side of the photoelectric conversion body 30, and the second transparent electrode layer 32 is formed on the second main surface 46 side (transparent electrode layer formation). step), and the photoelectric conversion substrate 20 is formed (photoelectric conversion substrate forming step).
  • the texture structure 37 reflecting the texture structure 47 of the semiconductor substrate 40 is formed on the first principal surface 35, and the texture structure 48 of the semiconductor substrate 40 is reflected on the second principal surface 36.
  • a textured structure 38 is formed.
  • a metal ink containing metal particles 71 is applied in a predetermined pattern on the first main surface 35 and the second main surface 36 of the photoelectric conversion substrate 20 (application step), and the metal ink is applied.
  • the photoelectric conversion substrate 20 thus obtained is heated at a heating temperature T1 for a heating time t1 and baked (heating step) to form collecting electrodes 21 and 22 (collecting electrode forming step).
  • the metal electrode layers 70 a and 70 b constituting the collecting electrodes 21 and 22 are formed by filling the bottoms 56 and 66 of the concave portions 55 and 65 of the photoelectric conversion substrate 20 with the metal particles 71 .
  • the metal particles 71 are preferably filled to a height of 1/20 or more and 2/3 or less of the depth of the recesses 55 and 65 from the bottoms 56 and 66 of the recesses 55 and 65, and 1/10 or more and 1/2 or less. is more preferably filled up to a height of Holes are formed in the metal electrode layers 70a and 70b constituting the collecting electrodes 21 and 22 so as to avoid the projections 51 and 61, as shown in FIGS.
  • the top portions 52 and 62 of the convex portions 51 and 61 of the photoelectric conversion substrate 20 are not covered with the metal particles 71, and the vicinity of the top portions 52 and 62 are exposed from the holes of the collector electrodes 21 and 22, and the exposed regions 110 are exposed. is formed.
  • the metal electrode layers 70a and 70b surround the apexes 52 and 62 of the protrusions 51 and 61 when viewed from above as shown in FIG.
  • the metal ink used at this time is obtained by dispersing metal particles 71 in a dispersion liquid.
  • the heating temperature T1 at this time is a temperature at which the dispersion solvent volatilizes or vaporizes and substantially only the metal particles 71 remain as the metal electrode layers 70a and 70b.
  • the heating temperature T1 is preferably 100° C. or higher and 180° C. or lower, and more preferably 150° C. or lower.
  • the heating time t1 is appropriately set together with the heating temperature T1. For example, it is preferably 5 minutes or more and 2 hours or less, and more preferably 20 minutes or more and 1 hour or less.
  • an inorganic solvent such as water or an organic solvent may be used as long as only the metal particles 71 substantially remain after heating at the heating temperature T1.
  • a mixed solvent of hydrocarbon and alcohol can be used as the dispersion solvent.
  • the wiring member 11 is adhered to the busbar electrode portions 80a and 80b of the collecting electrodes 21 and 22 via the conductive adhesive 12, and the solar cells 10 are electrically connected in series or in parallel by the wiring member 11.
  • a solar cell string 2 is formed (wiring connection step).
  • the conductive adhesive 12 covers the collector electrodes 21 and 22 and the exposed regions 110 of the convex portions 51 and 61 in the busbar electrode portions 80a and 80b while being in contact therewith. Exposed regions 110 of portions 51 and 61 are encroaching. That is, the conductive adhesive 12 and the exposed regions 110 of the projections 51 and 61 are engaged with each other.
  • the solar cell string 2 is sandwiched between the sealing members 3 and 5 and sealed (sealing step). After that, post-processing such as wiring is performed in the same manner as in conventional solar cell modules, and the solar cell module 1 is completed. do.
  • the adhesive portions 101 and 103 of the sealing members 3 and 5 are covered while being in contact with the wiring member 11 and the exposed regions 110 of the collector electrodes 21 and 22 and the convex portions 51 and 61 in the finger electrode portions 81a and 81b. , and the exposed regions 110 of the protrusions 51 and 61 are encroaching. That is, the adhesive portions 101 and 103 of the sealing members 3 and 5 and the exposed regions 110 of the convex portions 51 and 61 are engaged with each other.
  • the thickness of the metal electrode layers 70a and 70b is thinner than the height of the protrusions 51 and 61 and partially covers the protrusions 51 and 61. are exposed from the metal electrode layers 70a and 70b. Therefore, as shown in FIG. 7, light can be incident from the top portions 52 and 62, the light receiving area can be increased compared to the conventional art, and the power generation efficiency can be improved.
  • the convex portions 51 and 61 are formed on the transparent electrode layers 31 and 32 laminated on the photoelectric conversion section 30, most of the photoelectric conversion section 30 can receive light. .
  • the metal particles 71 forming the metal electrode layers 70a and 70b have a number average particle diameter of 10 nm or more and less than 100 nm, and It is filled to a height of 1/20 or more and 2/3 or less of the depth of the recesses 55 and 65 . Therefore, the metal particles 71 penetrate deeply into the bottoms 56, 66 of the recesses 55, 65, and the contact resistance can be reduced as compared with the conventional case.
  • the metal electrode layers 70a and 70b surround the tops 52 and 62 of the projections 51 and 61 when the photoelectric conversion substrate 20 is viewed from above.
  • 70a and 70b are continuous in the planar direction. That is, since the conductive paths of the metal electrode layers 70a and 70b are not blocked by the protrusions 51 and 61, electric power can flow stably, and the protrusions 51 and 61 are exposed from the metal electrode layers 70a and 70b. However, reliability as an electrode can be ensured.
  • the wiring member 11 is connected to part of the metal electrode layer 70a (70b) via the conductive adhesive 12, and is exposed from the metal electrode layer 70a (70b).
  • the projected portions 51 ( 61 ) of the photoelectric conversion substrate 20 are covered while being in contact with the conductive adhesive 12 . Therefore, an anchor effect works between the convex portion 51 (61) and the conductive adhesive 12, and the adhesive strength at the interface between the conductive adhesive 12 and the photoelectric conversion substrate 20 can be improved.
  • the solar cell 10 is adhered to the sealing members 3 and 5 with the metal electrode layers 70a and 70b in close contact with the bonding portions 101 and 103 of the sealing members 3 and 5.
  • the convex portions 51 and 61 of the photoelectric conversion substrate 20 exposed from the metal electrode layers 70a and 70b are covered while being in contact with the adhesive portions 101 and 103, respectively. Therefore, an anchor effect is produced between the convex portions 51 and 61 and the adhesive portions 101 and 103, and the adhesive strength between the photoelectric conversion substrate 20 and the sealing members 3 and 5 can be improved.
  • the photoelectric conversion substrate 20 has pyramid-shaped texture structures 37 and 38 with quadrangular pyramid-shaped protrusions 51 and 61, but the present invention is not limited to this.
  • the shape of the protrusions 51 and 61 may be a polygonal pyramid such as a triangular pyramid, a pentagonal pyramid, or a hexagonal pyramid, or may be conical.
  • the photoelectric conversion substrate 20 has the texture structures 37, 38 on both main surfaces 35, 36, but the present invention is not limited to this.
  • the texture structure 37 may be provided only on the main surface 35 on the light receiving side.
  • the solar cell 10 is a crystalline silicon solar cell using the semiconductor substrate 40 made of silicon as a supporting substrate, but the present invention is not limited to this.
  • the solar cell 10 may be another type of solar cell with a collecting electrode 21 on the light receiving side.
  • solar cell 10 may be a PERC type solar cell.
  • each constituent member can be freely replaced or added between the embodiments.
  • first sealing member 3 first sealing member 5 second sealing member 10, 10a, 10b solar cell 11, 11a, 11b wiring member 12 conductive adhesive 20 photoelectric conversion substrate 30 photoelectric conversion part 31 first transparent electrode layer ( transparent conductive oxide layer) 32 Second transparent electrode layer (transparent conductive oxide layer) 35 first main surface 37 first texture structure 38 second texture structure 51, 61 convex portions 52, 62 top portions 55, 65 concave portions 56, 66 bottom portions 70a, 70b metal electrode layer (metal layer) 71 metal particles 101, 103 bonding portion

Abstract

The present invention provides a solar cell, a solar cell module, and a method for manufacturing a solar cell, in which the light-receiving area per unit area is improved compared to the prior art.　The present invention comprises a metal layer laminated on a photoelectric conversion substrate, the photoelectric conversion substrate comprising a texture structure having a plurality of protrusions on a first main surface, the metal layer being thinner than the height of the protrusions and covering part of the protrusions, and the protrusions having apexes that are exposed from the metal layer.

Description

太陽電池、太陽電池モジュール、及び太陽電池の製造方法SOLAR CELL, SOLAR CELL MODULE, AND SOLAR CELL MANUFACTURING METHOD
　本発明は、太陽電池、太陽電池モジュール、及び太陽電池の製造方法に関する。 The present invention relates to a solar cell, a solar cell module, and a method for manufacturing a solar cell.
　従来から太陽電池は、高い発電効率を確保するべく、光電変換基板の表面に凹凸を設けて光電変換基板内に取り込まれた光を光電変換基板内に閉じ込める構造となっている（例えば、特許文献１）。 Conventionally, in order to ensure high power generation efficiency, a solar cell has a structure in which unevenness is provided on the surface of a photoelectric conversion substrate so that light taken into the photoelectric conversion substrate is confined within the photoelectric conversion substrate (see, for example, Patent Documents 1).
　また、両面に電極を有する両面電極型の太陽電池では、受光側の面にも光電変換基板から電気を取り出すための櫛歯状の集電極が形成されている。
　例えば、特許文献１の太陽電池では、表面に微細な凹凸をもつ光電変換基板の受光側の表面に、０．１～０．５μｍの範囲の粒径の銀ペーストを塗布して焼き付けて集電極を形成している。こうすることで、特許文献１では、集電極と光電変換基板の接触抵抗を低減できるとされている。 Further, in a double-sided electrode type solar cell having electrodes on both sides, a comb-like collecting electrode is formed on the light-receiving side surface for extracting electricity from the photoelectric conversion substrate.
For example, in the solar cell of Patent Document 1, silver paste having a particle size in the range of 0.1 to 0.5 μm is applied to the light-receiving side surface of a photoelectric conversion substrate having fine unevenness on the surface, and is baked to form a collecting electrode. forming In this way, Patent Document 1 states that the contact resistance between the collecting electrode and the photoelectric conversion substrate can be reduced.
特開２００３－１３３５６７号公報JP-A-2003-133567
　ところで、更なる発電効率を向上させるためには、光電変換基板への受光面積を大きくすることが必要となる。
　しかしながら、特許文献１の太陽電池は、銀ペーストを表面凹凸の凸部の高さよりも厚く塗布しており、銀ペーストが塗布された部分では光を受光できない。そのため、特許文献１の太陽電池は、更なる受光面積の向上に向けて改良の余地があった。 By the way, in order to further improve power generation efficiency, it is necessary to increase the light receiving area of the photoelectric conversion substrate.
However, in the solar cell of Patent Document 1, the silver paste is applied thicker than the height of the convex portions of the surface unevenness, and light cannot be received in the portions where the silver paste is applied. Therefore, the solar cell of Patent Literature 1 has room for improvement to further improve the light-receiving area.
　そこで、本発明は、従来に比べて単位面積当たりの受光面積を向上した太陽電池、太陽電池モジュール、及び太陽電池の製造方法を提供することを課題とする。 Therefore, it is an object of the present invention to provide a solar cell, a solar cell module, and a method for manufacturing a solar cell with an improved light receiving area per unit area compared to conventional ones.
　上記した課題を解決するための本発明の一つの様相は、光電変換基板上に金属層が積層された太陽電池であって、前記光電変換基板は、第１主面に複数の凸部を有するテクスチャー構造を備えており、前記金属層は、前記凸部の高さよりも薄く、かつ前記凸部の一部を覆っており、前記凸部は、頂部が前記金属層から露出している、太陽電池である。 One aspect of the present invention for solving the above-described problems is a solar cell in which a metal layer is laminated on a photoelectric conversion substrate, the photoelectric conversion substrate having a plurality of protrusions on its first main surface. a textured structure, wherein the metal layer is thinner than the height of the protrusions and covers a part of the protrusions, and the protrusions have tops exposed from the metal layer. Battery.
　本様相によれば、光電変換基板の凸部の頂部が金属層から露出しているので、頂部部分から光を入射させることができ、従来に比べて受光面積を大きくできる。 According to this aspect, since the apex of the convex portion of the photoelectric conversion substrate is exposed from the metal layer, light can be incident from the apex portion, and the light receiving area can be increased compared to the conventional case.
　好ましい様相は、前記光電変換基板は、光電変換部上に透明導電性酸化物層が積層されており、前記透明導電性酸化物層は、前記凸部を構成していることである。 A preferable aspect is that the photoelectric conversion substrate has a transparent conductive oxide layer laminated on the photoelectric conversion part, and the transparent conductive oxide layer constitutes the convex part.
　好ましい様相は、前記テクスチャー構造は、前記複数の凸部に隣接して複数の凹部が形成されており、前記凹部の深さは、１μｍ以上であり、前記金属層は、複数の金属粒子を含み、前記金属粒子は、数平均粒子径が１０ｎｍ以上１００ｎｍ未満であって、かつ前記凹部の底部から前記凹部の深さの１／２０以上２／３以下の高さまで充填されていることである。 In a preferred aspect, the texture structure has a plurality of recesses formed adjacent to the plurality of protrusions, the depth of the recesses is 1 μm or more, and the metal layer includes a plurality of metal particles. The metal particles have a number average particle diameter of 10 nm or more and less than 100 nm, and are filled from the bottom of the recess to a height of 1/20 or more and 2/3 or less of the depth of the recess.
　好ましい様相は、前記金属層は、前記光電変換基板を平面視したときに、前記凸部の頂部を囲んでいることである。 A preferable aspect is that the metal layer surrounds the top of the convex portion when the photoelectric conversion substrate is viewed from above.
　好ましい様相は、配線部材と、導電性接着材を有し、前記配線部材は、前記導電性接着材を介して前記金属層の一部と接続されており、前記金属層から露出した凸部は、前記導電性接着材に接しながら覆われていることである。 A preferred aspect has a wiring member and a conductive adhesive, the wiring member is connected to a part of the metal layer via the conductive adhesive, and the convex portion exposed from the metal layer is , is covered while being in contact with the conductive adhesive.
　本発明の一つの様相は、上記の太陽電池と、第１封止部材と、第２封止部材を有し、前記太陽電池は、前記第１封止部材と前記第２封止部材によって挟まれて封止されており、前記第１封止部材は、接着部を有し、前記太陽電池は、前記金属層が前記接着部と密着して前記第１封止部材に接着されており、前記金属層から露出した凸部は、前記接着部に接しながら覆われている、太陽電池モジュールである。 One aspect of the present invention has the above solar cell, a first sealing member, and a second sealing member, and the solar cell is sandwiched between the first sealing member and the second sealing member. The first sealing member has an adhesive portion, and the solar cell is adhered to the first sealing member with the metal layer in close contact with the adhesive portion, The projecting portion exposed from the metal layer is a solar cell module that is covered while being in contact with the adhesive portion.
　本様相によれば、光電変換基板の凸部と第１封止部材の接着部との間でアンカー効果が働き、従来に比べて光電変換基板と第１封止部材の間の接着強度を向上できる。 According to this aspect, an anchor effect works between the convex portion of the photoelectric conversion substrate and the adhesive portion of the first sealing member, and the adhesive strength between the photoelectric conversion substrate and the first sealing member is improved compared to the conventional art. can.
　本発明の一つの様相は、上記の太陽電池の製造方法であって、数平均粒子径が１０ｎｍ以上１００ｎｍ未満の金属粒子を含む金属インキを前記光電変換基板上に塗布する塗布工程と、前記金属インキが塗布された前記光電変換基板を１００℃以上１８０℃以下の加熱温度で加熱する加熱工程を含む、太陽電池の製造方法である。 One aspect of the present invention is the above-described method for manufacturing a solar cell, comprising: a coating step of coating a metal ink containing metal particles having a number average particle size of 10 nm or more and less than 100 nm on the photoelectric conversion substrate; The method for manufacturing a solar cell includes a heating step of heating the photoelectric conversion substrate coated with ink at a heating temperature of 100° C. or higher and 180° C. or lower.
　本様相によれば、比較的低温で金属層を形成でき、製造コストを低減できる。 According to this aspect, the metal layer can be formed at a relatively low temperature, and the manufacturing cost can be reduced.
　本発明によれば、従来に比べて単位面積当たりの受光面積を向上できる。 According to the present invention, the light-receiving area per unit area can be improved compared to the conventional art.
本発明の第１実施形態の太陽電池モジュールの説明図であり、（ａ）は太陽電池モジュールを模式的に示した斜視図であり、（ｂ）は（ａ）のＡ－Ａ断面図である。なお、理解を容易にするためにハッチングを省略している。BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram of a solar cell module according to a first embodiment of the present invention, where (a) is a schematic perspective view of the solar cell module and (b) is a cross-sectional view taken along the line AA of (a). . Note that hatching is omitted for easy understanding. 図１（ａ）の太陽電池のＢ－Ｂ断面の端面図である。なお、理解を容易にするためにハッチングを省略している。FIG. 2 is an end view of the BB section of the solar cell of FIG. 1(a); Note that hatching is omitted for easy understanding. 図１（ａ）の太陽電池のＣ－Ｃ断面の端面図である。なお、理解を容易にするためにハッチングを省略している。FIG. 2 is an end view of the cross section CC of the solar cell of FIG. 1(a); Note that hatching is omitted for easy understanding. 図１（ａ）の太陽電池の要部の分解斜視図である。Fig. 1(a) is an exploded perspective view of the main part of the solar cell of Fig. 1(a); 図４の光電変換基板の断面図である。なお、理解を容易にするためにハッチングを省略している。FIG. 5 is a cross-sectional view of the photoelectric conversion substrate of FIG. 4; Note that hatching is omitted for easy understanding. 図１（ａ）の太陽電池の説明図であり、（ａ）は表面側からみた平面図であり、（ｂ）が裏面側からみた平面図である。It is explanatory drawing of the solar cell of Fig.1 (a), (a) is the top view seen from the surface side, (b) is the top view seen from the back surface side. 図１の太陽電池モジュールに光を照射したときの太陽電池における光路の説明図であり、太陽電池の要部の断面図である。なお、理解を容易にするためにハッチングを省略し、光路を矢印で示している。FIG. 2 is an explanatory diagram of an optical path in the solar cell when the solar cell module of FIG. 1 is irradiated with light, and is a cross-sectional view of a main part of the solar cell. To facilitate understanding, hatching is omitted and the optical paths are indicated by arrows.
　以下、本発明の実施形態について詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail.
　本発明の第１実施形態の太陽電池モジュール１は、光を電気に変換する光電変換装置であり、少なくとも一方の主面で光を受光するものである。
　太陽電池モジュール１は、図１（ａ）のように、主要構成部材として、太陽電池ストリング２と、第１封止部材３と、第２封止部材５を備えている。 A solar cell module 1 according to the first embodiment of the present invention is a photoelectric conversion device that converts light into electricity, and receives light on at least one main surface.
As shown in FIG. 1(a), the solar cell module 1 includes a solar cell string 2, a first sealing member 3, and a second sealing member 5 as main constituent members.
（太陽電池ストリング２）
　太陽電池ストリング２は、図１（ｂ）のように、複数の太陽電池１０（１０ａ～１０ｃ）と、配線部材１１（１１ａ，１１ｂ）と、導電性接着材１２を備えており、複数の太陽電池１０（１０ａ～１０ｃ）が配線部材１１（１１ａ，１１ｂ）によって直列接続されている。
　太陽電池１０は、図２，図３のように、光電変換基板２０と、第１集電極２１と、第２集電極２２を備えている。 (Solar cell string 2)
The solar cell string 2 includes a plurality of solar cells 10 (10a to 10c), wiring members 11 (11a and 11b), and a conductive adhesive 12, as shown in FIG. 1(b). Batteries 10 (10a to 10c) are connected in series by wiring members 11 (11a, 11b).
The solar cell 10 includes a photoelectric conversion substrate 20, a first collecting electrode 21, and a second collecting electrode 22, as shown in FIGS.
（光電変換基板２０）
　光電変換基板２０は、図２，図３のように、第１主面３５と、第２主面３６を有した板状基板であり、光電変換部３０の第１主面３５側に第１透明電極層３１が積層され、第２主面３６側に第２透明電極層３２が積層された透明導電性基板である。
　また、光電変換基板２０は、第１封止部材３側の主面たる第１主面３５に第１テクスチャー構造３７が形成されており、第２封止部材５側の主面たる第２主面３６に第２テクスチャー構造３８が形成されている。 (Photoelectric conversion substrate 20)
The photoelectric conversion substrate 20 is, as shown in FIGS. It is a transparent conductive substrate in which a transparent electrode layer 31 is laminated and a second transparent electrode layer 32 is laminated on the second main surface 36 side.
Further, the photoelectric conversion substrate 20 has a first texture structure 37 formed on a first main surface 35 serving as a main surface on the first sealing member 3 side, and a second main surface serving as a main surface on the second sealing member 5 side. A second textured structure 38 is formed on surface 36 .
　光電変換部３０は、ＰＮ接合を有し、光エネルギーを電気エネルギーに変換する部位である。
　光電変換部３０は、図５のように、半導体基板４０の第１主面４５上に第１真性半導体層４１、第１導電型半導体層４２がこの順に積層されており、第２主面４６上に第２真性半導体層４３、第２導電型半導体層４４がこの順に積層されている。 The photoelectric conversion part 30 is a part that has a PN junction and converts light energy into electrical energy.
As shown in FIG. 5 , the photoelectric conversion section 30 has a first intrinsic semiconductor layer 41 and a first conductivity type semiconductor layer 42 laminated in this order on a first main surface 45 of a semiconductor substrate 40 , and a second main surface 46 . A second intrinsic semiconductor layer 43 and a second conductivity type semiconductor layer 44 are stacked thereon in this order.
　半導体基板４０は、ｎ型又はｐ型の半導体の基板であり、具体的には、ｎ型又はｐ型の結晶シリコン基板である。半導体基板４０としては、単結晶シリコン基板や多結晶シリコン基板を使用できる。
　半導体基板４０は、第１主面４５及び第２主面４６の表面にピラミッド形状の半導体側テクスチャー構造４７，４８がそれぞれ形成されている。 The semiconductor substrate 40 is an n-type or p-type semiconductor substrate, specifically, an n-type or p-type crystalline silicon substrate. A single crystal silicon substrate or a polycrystalline silicon substrate can be used as the semiconductor substrate 40 .
The semiconductor substrate 40 has pyramid-shaped semiconductor- side texture structures 47 and 48 formed on the surfaces of the first main surface 45 and the second main surface 46, respectively.
　第１真性半導体層４１は、ドーパントを実質的に含まないシリコン薄膜であり、ドーパント濃度が第１導電型半導体層４２のドーパント濃度の１／１００以下であることが好ましい。 The first intrinsic semiconductor layer 41 is a silicon thin film that does not substantially contain dopants, and preferably has a dopant concentration of 1/100 or less of the dopant concentration of the first conductivity type semiconductor layer 42 .
　第１導電型半導体層４２は、ドーパントを含んだｎ型又はｐ型のシリコン系薄膜層であり、本実施形態ではｐ型のシリコン層である。 The first conductivity type semiconductor layer 42 is an n-type or p-type silicon-based thin film layer containing a dopant, and is a p-type silicon layer in this embodiment.
　第２真性半導体層４３は、ドーパントを実質的に含まないシリコン薄膜であり、ドーパント濃度が第２導電型半導体層４４のドーパント濃度の１／１００以下であることが好ましい。 The second intrinsic semiconductor layer 43 is a silicon thin film that does not substantially contain dopants, and preferably has a dopant concentration of 1/100 or less of the dopant concentration of the second conductivity type semiconductor layer 44 .
　第２導電型半導体層４４は、ドーパントを含み、第１導電型半導体層４２の導電型とは逆の導電型を有するシリコン層である。
　すなわち、第１導電型半導体層４２の導電型がｎ型の場合は、第２導電型半導体層４４の導電型はｐ型であり、第１導電型半導体層４２の導電型がｐ型の場合は、第２導電型半導体層４４の導電型はｎ型である。
　上記したように本実施形態では、第１導電型半導体層４２は、ｐ型のシリコン層であるから、第２導電型半導体層４４は、ｎ型のシリコン層で形成されている。 The second-conductivity-type semiconductor layer 44 is a silicon layer containing a dopant and having a conductivity type opposite to that of the first-conductivity-type semiconductor layer 42 .
That is, when the conductivity type of the semiconductor layer 42 of the first conductivity type is n-type, the conductivity type of the semiconductor layer 44 of the second conductivity type is p-type, and when the conductivity type of the semiconductor layer 42 of the first conductivity type is p-type, , the conductivity type of the second conductivity type semiconductor layer 44 is n-type.
As described above, in the present embodiment, the first conductivity type semiconductor layer 42 is a p-type silicon layer, so the second conductivity type semiconductor layer 44 is formed of an n-type silicon layer.
　透明電極層３１，３２は、透明性と導電性を有する透明導電層であり、具体的には、酸化インジウム錫（ＩＴＯ）やタングステンドープ酸化インジウム（ＩＷＯ）などの透明導電性酸化物で構成された透明導電性酸化物層である。 The transparent electrode layers 31 and 32 are transparent conductive layers having transparency and conductivity, and are specifically made of a transparent conductive oxide such as indium tin oxide (ITO) or tungsten-doped indium oxide (IWO). It is a transparent conductive oxide layer.
　第１テクスチャー構造３７は、図５のように、半導体層４１，４２及び第１透明電極層３１が下地の半導体基板４０の半導体側テクスチャー構造４７を追随して形成されたものである。
　すなわち、第１テクスチャー構造３７は、半導体基板４０の半導体側テクスチャー構造４７と同様、ピラミッド型の凹凸を有しており、複数の凸部５１を備えている。
　凸部５１は、図４のように、四角錐状であり、第１透明電極層３１側から頂部５２に向かって漸次断面積が小さくなっており、頂部５２が尖っている。
　また、第１テクスチャー構造３７は、別の観点からみると、図５のように、隣接する凸部５１，５１によって凹部５５が形成されている。
　凹部５５は、逆四角錐状であり、底部５６が尖っている。
　凹部５５の深さ、すなわち、凸部５１の高さ（厚み方向における頂部５２と底部５６の距離）は、図４のように、第１集電極２１の厚みよりも大きく、１μｍ以上１０μｍ以下であることが好ましい。 As shown in FIG. 5, the first texture structure 37 is formed by forming the semiconductor layers 41 and 42 and the first transparent electrode layer 31 following the semiconductor-side texture structure 47 of the underlying semiconductor substrate 40 .
That is, the first texture structure 37 has pyramid-shaped unevenness, and includes a plurality of protrusions 51 , like the semiconductor-side texture structure 47 of the semiconductor substrate 40 .
As shown in FIG. 4, the convex portion 51 has a quadrangular pyramid shape, the cross-sectional area of which gradually decreases from the first transparent electrode layer 31 side toward the top portion 52, and the top portion 52 is sharp.
From another point of view, the first texture structure 37 has a concave portion 55 formed by adjacent convex portions 51, 51, as shown in FIG.
The concave portion 55 has an inverted square pyramid shape, and the bottom portion 56 is pointed.
The depth of the concave portion 55, that is, the height of the convex portion 51 (the distance between the top portion 52 and the bottom portion 56 in the thickness direction) is larger than the thickness of the first collector electrode 21 and is 1 μm or more and 10 μm or less, as shown in FIG. Preferably.
　第２テクスチャー構造３８は、図５のように、半導体層４３，４４及び第２透明電極層３２が下地の半導体基板４０の半導体側テクスチャー構造４８を追随して形成されたものである。
　すなわち、第２テクスチャー構造３８は、半導体基板４０の半導体側テクスチャー構造４８と同様、ピラミッド型の凹凸を有しており、複数の凸部６１を備えている。
　凸部６１は、図４のように、四角錐状であり、第２透明電極層３２側から頂部６２に向かって漸次断面積が小さくなっており、頂部６２が尖っている。
　また、第２テクスチャー構造３８は、別の観点からみると、図５のように、隣接する凸部６１，６１によって凹部６５が形成されている。
　凹部６５は、逆四角錐状であり、底部６６が尖っている。
　凹部６５の深さ、すなわち、凸部６１の高さ（厚み方向における頂部６２と底部６６の距離）は、図４のように、第２集電極２２の厚みよりも大きく、１μｍ以上１０μｍ以下であることが好ましい。 As shown in FIG. 5, the second texture structure 38 is formed by forming the semiconductor layers 43 and 44 and the second transparent electrode layer 32 following the semiconductor-side texture structure 48 of the underlying semiconductor substrate 40 .
That is, the second texture structure 38 has pyramid-shaped unevenness, and includes a plurality of protrusions 61 , like the semiconductor-side texture structure 48 of the semiconductor substrate 40 .
As shown in FIG. 4, the convex portion 61 has a quadrangular pyramid shape, the cross-sectional area of which gradually decreases from the second transparent electrode layer 32 side toward the top portion 62, and the top portion 62 is sharp.
From another point of view, the second texture structure 38 has recesses 65 formed by adjacent protrusions 61, 61, as shown in FIG.
The recess 65 has an inverted quadrangular pyramid shape with a sharp bottom 66 .
The depth of the concave portion 65, that is, the height of the convex portion 61 (the distance between the top portion 62 and the bottom portion 66 in the thickness direction) is, as shown in FIG. Preferably.
（集電極２１，２２）
　第１集電極２１は、第２集電極２２と対をなし、第２集電極２２とともに光電変換基板２０で光電変換された電気エネルギーを光電変換基板２０から取り出す取出電極である。
　集電極２１，２２は、光電変換基板２０の両主面３５，３６上に部分的に形成されたものであり、主に金属電極層７０ａ，７０ｂで構成されている。
　金属電極層７０ａ，７０ｂは、透明電極層３１，３２よりも導電性を有する金属層であり、光を反射可能な反射電極層である。
　金属電極層７０ａ，７０ｂは、図２，図３のように、複数の金属粒子７１によって形成されている。
　金属電極層７０ａ，７０ｂの厚みは、凸部５１，６１の高さよりも薄く、０．１μｍ以上１０μｍ以下であることが好ましく、０．２μｍ以上５μｍ以下であることがより好ましく、１μｍ以下であることがさらに好ましい。
　金属粒子７１は、ナノサイズオーダーの粒子であり、凸部５１，６１の高さに対して直径が小さいものである。
　金属粒子７１は、数平均粒子径が１０ｎｍ以上１００ｎｍ未満であることが好ましい。
　数平均粒子径は、例えば、走査型電子顕微鏡や透過型電子顕微鏡によって１００サンプルの粒子径を確認し、１００サンプルの粒子径を算術平均することで算出できる。
　金属粒子７１は、例えば、金、銀、銅、白金、アルミニウム、ニッケル、パラジウム等で構成することができる。
　本実施形態の金属粒子７１は、銀粒子を使用している。
　金属電極層７０ａ，７０ｂは、インクジェット印刷法やスクリーン印刷法によって形成することが好ましく、インクジェット印刷法によって形成することがより好ましい。
　本実施形態の金属電極層７０ａ，７０ｂは、後述するように、金属粒子７１を含む金属インキを光電変換基板２０上に塗布して形成している。 (collecting electrodes 21, 22)
The first collector electrode 21 forms a pair with the second collector electrode 22 and is an extraction electrode for extracting from the photoelectric conversion substrate 20 electrical energy photoelectrically converted by the photoelectric conversion substrate 20 together with the second collector electrode 22 .
The collecting electrodes 21 and 22 are partially formed on both main surfaces 35 and 36 of the photoelectric conversion substrate 20, and are mainly composed of metal electrode layers 70a and 70b.
The metal electrode layers 70a and 70b are metal layers having higher conductivity than the transparent electrode layers 31 and 32, and are reflective electrode layers capable of reflecting light.
The metal electrode layers 70a and 70b are formed of a plurality of metal particles 71 as shown in FIGS.
The thickness of the metal electrode layers 70a and 70b is thinner than the height of the protrusions 51 and 61, preferably 0.1 μm or more and 10 μm or less, more preferably 0.2 μm or more and 5 μm or less, and 1 μm or less. is more preferred.
The metal particles 71 are nano-sized particles and have a diameter smaller than the height of the projections 51 and 61 .
Metal particles 71 preferably have a number average particle diameter of 10 nm or more and less than 100 nm.
The number average particle size can be calculated, for example, by checking the particle size of 100 samples with a scanning electron microscope or a transmission electron microscope and calculating the arithmetic mean of the particle sizes of 100 samples.
The metal particles 71 can be made of, for example, gold, silver, copper, platinum, aluminum, nickel, palladium, or the like.
Silver particles are used as the metal particles 71 of the present embodiment.
The metal electrode layers 70a and 70b are preferably formed by an inkjet printing method or a screen printing method, and more preferably formed by an inkjet printing method.
The metal electrode layers 70a and 70b of the present embodiment are formed by applying metal ink containing metal particles 71 onto the photoelectric conversion substrate 20, as will be described later.
　また、第１集電極２１は、図６（ａ）のように、第１主面３５側から光電変換基板２０を平面視したときに、第１バスバー電極部８０ａと、第１フィンガー電極部８１ａで構成されている。
　第２集電極２２は、図６（ｂ）のように、第２主面３６側から光電変換基板２０を平面視したときに、第２バスバー電極部８０ｂと、第２フィンガー電極部８１ｂで構成されている。
　バスバー電極部８０ａ，８０ｂは、横方向に幅をもち、縦方向に延びる部位である。
　フィンガー電極部８１ａ，８１ｂは、バスバー電極部８０ａ，８０ｂの中間部から櫛歯状に延びる部位である。
　フィンガー電極部８１ａ，８１ｂは、バスバー電極部８０ａ，８０ｂの延び方向に対する交差方向に延びており、本実施形態では、バスバー電極部８０ａ，８０ｂの延び方向に対する直交方向に延びている。すなわち、フィンガー電極部８１ａ，８１ｂは、縦方向に幅をもち、横方向に延びている。
　フィンガー電極部８１ａ，８１ｂは、幅がバスバー電極部８０ａ，８０ｂの幅よりも狭く、凸部５１，６１の幅よりも広い。 Moreover, as shown in FIG. 6A, when the photoelectric conversion substrate 20 is viewed from the first main surface 35 side, the first collector electrode 21 includes a first busbar electrode portion 80a and a first finger electrode portion 81a. consists of
As shown in FIG. 6B, the second collector electrode 22 is composed of a second busbar electrode portion 80b and second finger electrode portions 81b when the photoelectric conversion substrate 20 is viewed from the second main surface 36 side. It is
The busbar electrode portions 80a and 80b are portions that have width in the horizontal direction and extend in the vertical direction.
The finger electrode portions 81a and 81b are portions extending like comb teeth from intermediate portions of the busbar electrode portions 80a and 80b.
The finger electrode portions 81a and 81b extend in a direction crossing the extending direction of the busbar electrode portions 80a and 80b, and in this embodiment extend in a direction orthogonal to the extending direction of the busbar electrode portions 80a and 80b. That is, the finger electrode portions 81a and 81b have a width in the vertical direction and extend in the horizontal direction.
Finger electrode portions 81 a and 81 b have a width narrower than that of busbar electrode portions 80 a and 80 b and wider than that of protrusions 51 and 61 .
（配線部材１１）
　配線部材１１は、図１のように、隣接する太陽電池１０，１０間を接続するタブ配線である。
　配線部材１１ａは、隣接する太陽電池１０ａ，１０ｂのうち、一方の太陽電池１０ａのバスバー電極部８０ａと接続する第１接続部と、他方の太陽電池１０ｂのバスバー電極部８０ｂと接続する第２接続部を備えている。
　配線部材１１ｂは、太陽電池１０ｂのバスバー電極部８０ａと接続する第１接続部と、太陽電池１０ｂに太陽電池１０ａとは反対側で隣接する太陽電池１０ｃのバスバー電極部８０ｂと接続する第２接続部を備えている。 (Wiring member 11)
The wiring member 11 is a tab wiring that connects adjacent solar cells 10, 10 as shown in FIG.
The wiring member 11a has a first connection portion connected to the busbar electrode portion 80a of one of the adjacent solar cells 10a and 10b, and a second connection portion connected to the busbar electrode portion 80b of the other solar cell 10b. has a department.
Wiring member 11b has a first connection portion connected to busbar electrode portion 80a of solar cell 10b and a second connection portion connected to busbar electrode portion 80b of solar cell 10c adjacent to solar cell 10b on the opposite side of solar cell 10a. has a department.
（導電性接着材１２）
　導電性接着材１２は、太陽電池１０のバスバー電極部８０ａ，８０ｂに配線部材１１の接続部を接着するものである。
　導電性接着材１２は、導電性と接着性を有するものであれば、特に限定されるものではない。導電性接着材１２としては、例えば、はんだなどが使用できる。 (Conductive adhesive 12)
The conductive adhesive 12 adheres the connecting portion of the wiring member 11 to the busbar electrode portions 80 a and 80 b of the solar cell 10 .
The conductive adhesive 12 is not particularly limited as long as it has conductivity and adhesiveness. Solder, for example, can be used as the conductive adhesive 12 .
（封止部材３，５）
　第１封止部材３は、図１のように、面状に広がりをもち、第２封止部材５とともに太陽電池ストリング２を封止する部材であり、封止部１００と、接着部１０１を備えている。
　封止部１００は、透光性及び絶縁性を有した透明絶縁基板又は透明絶縁シートで構成されており、例えば、ガラス基板や樹脂シートが使用できる。
　接着部１０１は、透光性及び接着性を有する透光性接着材で構成されており、熱可塑性樹脂であることがより好ましい。接着部１０１としては、例えば、ＥＶＡシートが使用できる。
　第２封止部材５は、第１封止部材３と同様、面状に広がりをもち、封止部１０２と、接着部１０３を備えている。
　封止部１０２は、絶縁性を有した絶縁基板又は絶縁シートで構成されており、例えば、ガラス基板や樹脂シートが使用できる。
　接着部１０３は、接着性を有する接着材で構成されており、熱可塑性樹脂であることがより好ましい。接着部１０１としては、例えば、ＥＶＡシートが使用できる。 (Sealing members 3 and 5)
As shown in FIG. 1 , the first sealing member 3 is a member that spreads in a plane and seals the solar cell string 2 together with the second sealing member 5 . I have it.
The sealing part 100 is composed of a transparent insulating substrate or a transparent insulating sheet having translucency and insulating properties, and for example, a glass substrate or a resin sheet can be used.
The adhesive portion 101 is made of a translucent adhesive having translucency and adhesiveness, and is more preferably thermoplastic resin. For example, an EVA sheet can be used as the adhesive portion 101 .
Like the first sealing member 3 , the second sealing member 5 spreads in a plane and includes a sealing portion 102 and an adhesive portion 103 .
The sealing portion 102 is composed of an insulating substrate or an insulating sheet having insulating properties, and for example, a glass substrate or a resin sheet can be used.
The adhesive portion 103 is made of an adhesive material having adhesiveness, and is more preferably made of a thermoplastic resin. For example, an EVA sheet can be used as the adhesive portion 101 .
　続いて、第１実施形態の太陽電池モジュール１の製造方法について説明する。 Next, a method for manufacturing the solar cell module 1 of the first embodiment will be described.
　本実施形態の太陽電池モジュール１の製造方法は、主な工程として、光電変換基板形成工程と、集電極形成工程と、配線取付工程と、封止工程を実施するものである。 The method of manufacturing the solar cell module 1 of the present embodiment includes, as main steps, a photoelectric conversion substrate forming step, a collecting electrode forming step, a wiring attaching step, and a sealing step.
　本実施形態の太陽電池モジュール１の製造方法では、まず、あらかじめ半導体側テクスチャー構造４７，４８が形成された半導体基板４０に対して、プラズマＣＶＤ法によって、半導体基板４０の第１主面４５上に第１真性半導体層４１及び第１導電型半導体層４２を形成し、半導体基板４０の第２主面４６上に第２真性半導体層４３及び第２導電型半導体層４４を形成して光電変換部３０を形成する（光電変換部形成工程）。
　続いて、スパッタ法によって、光電変換部３０の第１主面４５側に第１透明電極層３１を形成し、第２主面４６側に第２透明電極層３２を形成し（透明電極層形成工程）、光電変換基板２０を形成する（光電変換基板形成工程）。 In the method for manufacturing the solar cell module 1 of the present embodiment, first, the semiconductor substrate 40 on which the semiconductor- side texture structures 47 and 48 are formed in advance is subjected to plasma CVD on the first main surface 45 of the semiconductor substrate 40. A first intrinsic semiconductor layer 41 and a first conductivity type semiconductor layer 42 are formed, and a second intrinsic semiconductor layer 43 and a second conductivity type semiconductor layer 44 are formed on a second main surface 46 of a semiconductor substrate 40 to form a photoelectric conversion section. 30 is formed (photoelectric conversion portion forming step).
Subsequently, by sputtering, the first transparent electrode layer 31 is formed on the first main surface 45 side of the photoelectric conversion body 30, and the second transparent electrode layer 32 is formed on the second main surface 46 side (transparent electrode layer formation). step), and the photoelectric conversion substrate 20 is formed (photoelectric conversion substrate forming step).
　このとき、光電変換基板２０は、第１主面３５に半導体基板４０のテクスチャー構造４７が反映されたテクスチャー構造３７が形成され、第２主面３６に半導体基板４０のテクスチャー構造４８が反映されたテクスチャー構造３８が形成される。 At this time, in the photoelectric conversion substrate 20, the texture structure 37 reflecting the texture structure 47 of the semiconductor substrate 40 is formed on the first principal surface 35, and the texture structure 48 of the semiconductor substrate 40 is reflected on the second principal surface 36. A textured structure 38 is formed.
　続いて、インクジェット法によって、光電変換基板２０の第１主面３５上及び第２主面３６上に金属粒子７１を含む金属インキを所定のパターンで塗布し（塗布工程）、金属インキが塗布された光電変換基板２０を加熱温度Ｔ１、加熱時間ｔ１で加熱して焼成し（加熱工程）、集電極２１，２２を形成する（集電極形成工程）。 Subsequently, by an inkjet method, a metal ink containing metal particles 71 is applied in a predetermined pattern on the first main surface 35 and the second main surface 36 of the photoelectric conversion substrate 20 (application step), and the metal ink is applied. The photoelectric conversion substrate 20 thus obtained is heated at a heating temperature T1 for a heating time t1 and baked (heating step) to form collecting electrodes 21 and 22 (collecting electrode forming step).
　このとき、集電極２１，２２を構成する金属電極層７０ａ，７０ｂは、金属粒子７１が光電変換基板２０の凹部５５，６５の底部５６，６６に充填されて形成される。
　金属粒子７１は、凹部５５，６５の底部５６，６６から凹部５５，６５の深さの１／２０以上２／３以下の高さまで充填されていることが好ましく、１／１０以上１／２以下の高さまで充填されていることがより好ましい。
　集電極２１，２２を構成する金属電極層７０ａ，７０ｂには、図２～図４のように、凸部５１，６１を避けるように穴部が形成されている。すなわち、光電変換基板２０の凸部５１，６１は、頂部５２，６２が金属粒子７１に覆われておらず、集電極２１，２２の穴部から頂部５２，６２近傍が露出し、露出領域１１０が形成されている。言い換えると、金属電極層７０ａ，７０ｂは、図４のように、平面視したときに、凸部５１，６１の頂部５２，６２を囲んでいる。
　このとき使用される金属インキは、金属粒子７１が分散液に分散されたものである。
　このときの加熱温度Ｔ１は、分散溶媒が揮発又は気化し、金属電極層７０ａ，７０ｂとして実質的に金属粒子７１のみが残る温度である。
　ここでいう「実質的に金属粒子７１のみが残る」とは、全成分の９８％以上が金属粒子７１となって残ることをいう。
　加熱温度Ｔ１は、１００℃以上１８０℃以下であることが好ましく、１５０℃以下であることがより好ましい。
　加熱時間ｔ１は、加熱温度Ｔ１とともに適宜設定されるが、例えば、５分以上２時間以下であることが好ましく、２０分以上１時間以下であることがより好ましい。
　分散溶媒としては、加熱温度Ｔ１による加熱によって実質的に金属粒子７１のみが残るものであれば、水等の無機溶媒でも有機溶媒でもよい。
　分散溶媒としては、例えば、炭化水素とアルコールの混合溶媒が使用できる。 At this time, the metal electrode layers 70 a and 70 b constituting the collecting electrodes 21 and 22 are formed by filling the bottoms 56 and 66 of the concave portions 55 and 65 of the photoelectric conversion substrate 20 with the metal particles 71 .
The metal particles 71 are preferably filled to a height of 1/20 or more and 2/3 or less of the depth of the recesses 55 and 65 from the bottoms 56 and 66 of the recesses 55 and 65, and 1/10 or more and 1/2 or less. is more preferably filled up to a height of
Holes are formed in the metal electrode layers 70a and 70b constituting the collecting electrodes 21 and 22 so as to avoid the projections 51 and 61, as shown in FIGS. That is, the top portions 52 and 62 of the convex portions 51 and 61 of the photoelectric conversion substrate 20 are not covered with the metal particles 71, and the vicinity of the top portions 52 and 62 are exposed from the holes of the collector electrodes 21 and 22, and the exposed regions 110 are exposed. is formed. In other words, the metal electrode layers 70a and 70b surround the apexes 52 and 62 of the protrusions 51 and 61 when viewed from above as shown in FIG.
The metal ink used at this time is obtained by dispersing metal particles 71 in a dispersion liquid.
The heating temperature T1 at this time is a temperature at which the dispersion solvent volatilizes or vaporizes and substantially only the metal particles 71 remain as the metal electrode layers 70a and 70b.
Here, “substantially only the metal particles 71 remain” means that 98% or more of all components remain as the metal particles 71 .
The heating temperature T1 is preferably 100° C. or higher and 180° C. or lower, and more preferably 150° C. or lower.
The heating time t1 is appropriately set together with the heating temperature T1. For example, it is preferably 5 minutes or more and 2 hours or less, and more preferably 20 minutes or more and 1 hour or less.
As the dispersion solvent, an inorganic solvent such as water or an organic solvent may be used as long as only the metal particles 71 substantially remain after heating at the heating temperature T1.
As the dispersion solvent, for example, a mixed solvent of hydrocarbon and alcohol can be used.
　続いて、集電極２１，２２のバスバー電極部８０ａ，８０ｂに導電性接着材１２を介して配線部材１１を接着し、各太陽電池１０を配線部材１１によって電気的に直列又は並列に接続して太陽電池ストリング２を形成する（配線接続工程）。 Subsequently, the wiring member 11 is adhered to the busbar electrode portions 80a and 80b of the collecting electrodes 21 and 22 via the conductive adhesive 12, and the solar cells 10 are electrically connected in series or in parallel by the wiring member 11. A solar cell string 2 is formed (wiring connection step).
　このとき、導電性接着材１２は、図２のように、バスバー電極部８０ａ，８０ｂにおいて、集電極２１，２２と、凸部５１，６１の露出領域１１０に跨って接しながら覆っており、凸部５１，６１の露出領域１１０が食い込んでいる。すなわち、導電性接着材１２と凸部５１，６１の露出領域１１０は、噛み合っている。 At this time, as shown in FIG. 2, the conductive adhesive 12 covers the collector electrodes 21 and 22 and the exposed regions 110 of the convex portions 51 and 61 in the busbar electrode portions 80a and 80b while being in contact therewith. Exposed regions 110 of portions 51 and 61 are encroaching. That is, the conductive adhesive 12 and the exposed regions 110 of the projections 51 and 61 are engaged with each other.
　続いて、太陽電池ストリング２を封止部材３，５で挟んで封止し（封止工程）、その後、従来の太陽電池モジュールと同様、配線等の後処理をして太陽電池モジュール１が完成する。 Subsequently, the solar cell string 2 is sandwiched between the sealing members 3 and 5 and sealed (sealing step). After that, post-processing such as wiring is performed in the same manner as in conventional solar cell modules, and the solar cell module 1 is completed. do.
　このとき、封止部材３，５の接着部１０１，１０３は、フィンガー電極部８１ａ，８１ｂにおいて、集電極２１，２２と凸部５１，６１の露出領域１１０と配線部材１１に跨って接しながら覆っており、凸部５１，６１の露出領域１１０が食い込んでいる。すなわち、封止部材３，５の接着部１０１，１０３と凸部５１，６１の露出領域１１０は、噛み合っている。 At this time, the adhesive portions 101 and 103 of the sealing members 3 and 5 are covered while being in contact with the wiring member 11 and the exposed regions 110 of the collector electrodes 21 and 22 and the convex portions 51 and 61 in the finger electrode portions 81a and 81b. , and the exposed regions 110 of the protrusions 51 and 61 are encroaching. That is, the adhesive portions 101 and 103 of the sealing members 3 and 5 and the exposed regions 110 of the convex portions 51 and 61 are engaged with each other.
　第１実施形態の太陽電池１０によれば、金属電極層７０ａ，７０ｂの厚みが凸部５１，６１の高さよりも薄く、かつ凸部５１，６１の一部を覆っており、光電変換基板２０の凸部５１，６１の頂部５２，６２が金属電極層７０ａ，７０ｂから露出している。そのため、図７のように頂部５２，６２から光を入射させることができ、従来に比べて受光面積を大きくでき、発電効率を向上できる。 According to the solar cell 10 of the first embodiment, the thickness of the metal electrode layers 70a and 70b is thinner than the height of the protrusions 51 and 61 and partially covers the protrusions 51 and 61. are exposed from the metal electrode layers 70a and 70b. Therefore, as shown in FIG. 7, light can be incident from the top portions 52 and 62, the light receiving area can be increased compared to the conventional art, and the power generation efficiency can be improved.
　第１実施形態の太陽電池１０によれば、光電変換部３０上に積層された透明電極層３１，３２に凸部５１，６１が形成されているので、光電変換部３０の大部分で受光できる。 According to the solar cell 10 of the first embodiment, since the convex portions 51 and 61 are formed on the transparent electrode layers 31 and 32 laminated on the photoelectric conversion section 30, most of the photoelectric conversion section 30 can receive light. .
　第１実施形態の太陽電池１０によれば、金属電極層７０ａ，７０ｂを構成する金属粒子７１は、数平均粒子径が１０ｎｍ以上１００ｎｍ未満であって、かつ凹部５５，６５の底部５６，６６から凹部５５，６５の深さの１／２０以上２／３以下の高さまで充填されている。そのため、金属粒子７１が凹部５５，６５の底部５６，６６に深く入りこみ、従来に比べて接触抵抗を低くできる。 According to the solar cell 10 of the first embodiment, the metal particles 71 forming the metal electrode layers 70a and 70b have a number average particle diameter of 10 nm or more and less than 100 nm, and It is filled to a height of 1/20 or more and 2/3 or less of the depth of the recesses 55 and 65 . Therefore, the metal particles 71 penetrate deeply into the bottoms 56, 66 of the recesses 55, 65, and the contact resistance can be reduced as compared with the conventional case.
　第１実施形態の太陽電池１０によれば、金属電極層７０ａ，７０ｂは、光電変換基板２０を平面視したときに、凸部５１，６１の頂部５２，６２を囲んでいるので、金属電極層７０ａ，７０ｂが面方向に連続する。すなわち、金属電極層７０ａ，７０ｂが凸部５１，６１によって導電経路が遮断されていないので、安定して電力を流すことができ、凸部５１，６１が金属電極層７０ａ，７０ｂから露出していても、電極としての信頼性を確保できる。 According to the solar cell 10 of the first embodiment, the metal electrode layers 70a and 70b surround the tops 52 and 62 of the projections 51 and 61 when the photoelectric conversion substrate 20 is viewed from above. 70a and 70b are continuous in the planar direction. That is, since the conductive paths of the metal electrode layers 70a and 70b are not blocked by the protrusions 51 and 61, electric power can flow stably, and the protrusions 51 and 61 are exposed from the metal electrode layers 70a and 70b. However, reliability as an electrode can be ensured.
　第１実施形態の太陽電池１０によれば、配線部材１１は、導電性接着材１２を介して金属電極層７０ａ（７０ｂ）の一部と接続されており、金属電極層７０ａ（７０ｂ）から露出した光電変換基板２０の凸部５１（６１）は、導電性接着材１２に接しながら覆われている。そのため、凸部５１（６１）と導電性接着材１２との間でアンカー効果が働き、導電性接着材１２と光電変換基板２０との界面での接着強度を向上できる。 According to the solar cell 10 of the first embodiment, the wiring member 11 is connected to part of the metal electrode layer 70a (70b) via the conductive adhesive 12, and is exposed from the metal electrode layer 70a (70b). The projected portions 51 ( 61 ) of the photoelectric conversion substrate 20 are covered while being in contact with the conductive adhesive 12 . Therefore, an anchor effect works between the convex portion 51 (61) and the conductive adhesive 12, and the adhesive strength at the interface between the conductive adhesive 12 and the photoelectric conversion substrate 20 can be improved.
　第１実施形態の太陽電池モジュール１によれば、太陽電池１０は、金属電極層７０ａ，７０ｂが封止部材３，５の接着部１０１，１０３と密着して封止部材３，５に接着されており、金属電極層７０ａ，７０ｂから露出した光電変換基板２０の凸部５１，６１は、接着部１０１，１０３に接しながら覆われている。そのため、凸部５１，６１と接着部１０１，１０３との間でアンカー効果が奏され、光電変換基板２０と封止部材３，５との間の接着強度を向上できる。 According to the solar cell module 1 of the first embodiment, the solar cell 10 is adhered to the sealing members 3 and 5 with the metal electrode layers 70a and 70b in close contact with the bonding portions 101 and 103 of the sealing members 3 and 5. The convex portions 51 and 61 of the photoelectric conversion substrate 20 exposed from the metal electrode layers 70a and 70b are covered while being in contact with the adhesive portions 101 and 103, respectively. Therefore, an anchor effect is produced between the convex portions 51 and 61 and the adhesive portions 101 and 103, and the adhesive strength between the photoelectric conversion substrate 20 and the sealing members 3 and 5 can be improved.
　第１実施形態の太陽電池モジュール１の製造方法によれば、数平均粒子径が１０ｎｍ以上１００ｎｍ未満の金属粒子７１を含む金属インキを光電変換基板２０上に塗布する塗布工程と、金属インキが塗布された光電変換基板２０を１００℃以上１８０℃以下の加熱温度で加熱する加熱工程を含む。そのため、従来に比べて、比較的低温で金属電極層７０ａ，７０ｂを形成でき、製造コストを低減できる。 According to the method for manufacturing the solar cell module 1 of the first embodiment, the coating step of coating the photoelectric conversion substrate 20 with the metal ink containing the metal particles 71 having a number average particle size of 10 nm or more and less than 100 nm; a heating step of heating the photoelectric conversion substrate 20 thus formed at a heating temperature of 100° C. or higher and 180° C. or lower. Therefore, the metal electrode layers 70a and 70b can be formed at a relatively low temperature compared with the conventional method, and the manufacturing cost can be reduced.
　上記した実施形態では、光電変換基板２０は、四角錐状の凸部５１，６１をもつピラミッド形状のテクスチャー構造３７，３８が形成されていたが、本発明はこれに限定されるものではない。凸部５１，６１の形状は、三角錐や五角錐、六角錐などの多角推状であってもよいし、円錐状であってもよい。 In the above-described embodiment, the photoelectric conversion substrate 20 has pyramid-shaped texture structures 37 and 38 with quadrangular pyramid-shaped protrusions 51 and 61, but the present invention is not limited to this. The shape of the protrusions 51 and 61 may be a polygonal pyramid such as a triangular pyramid, a pentagonal pyramid, or a hexagonal pyramid, or may be conical.
　上記した実施形態では、光電変換基板２０は、両主面３５，３６にテクスチャー構造３７，３８を設けていたが、本発明はこれに限定されるものではない。受光側の主面３５のみにテクスチャー構造３７を設けてもよい。 In the above-described embodiment, the photoelectric conversion substrate 20 has the texture structures 37, 38 on both main surfaces 35, 36, but the present invention is not limited to this. The texture structure 37 may be provided only on the main surface 35 on the light receiving side.
　上記した実施形態では、太陽電池１０は、シリコン製の半導体基板４０を支持基板とする結晶シリコン太陽電池である場合について説明したが、本発明はこれに限定されるものではない。太陽電池１０は、受光側に集電極２１をもつ他の種類の太陽電池であってもよい。例えば、太陽電池１０は、ＰＥＲＣ型の太陽電池であってもよい。 In the above-described embodiment, the solar cell 10 is a crystalline silicon solar cell using the semiconductor substrate 40 made of silicon as a supporting substrate, but the present invention is not limited to this. The solar cell 10 may be another type of solar cell with a collecting electrode 21 on the light receiving side. For example, solar cell 10 may be a PERC type solar cell.
　上記した実施形態は、本発明の技術的範囲に含まれる限り、各実施形態間で各構成部材を自由に置換や付加できる。 As long as the above-described embodiments are within the technical scope of the present invention, each constituent member can be freely replaced or added between the embodiments.
　　１　太陽電池モジュール
　　３　第１封止部材
　　５　第２封止部材
　１０，１０ａ，１０ｂ　太陽電池
　１１，１１ａ，１１ｂ　配線部材
　１２　導電性接着材
　２０　光電変換基板
　３０　光電変換部
　３１　第１透明電極層（透明導電性酸化物層）
　３２　第２透明電極層（透明導電性酸化物層）
　３５　第１主面
　３７　第１テクスチャー構造
　３８　第２テクスチャー構造
　５１，６１　凸部
　５２，６２　頂部
　５５，６５　凹部
　５６，６６　底部
　７０ａ，７０ｂ　金属電極層（金属層）
　７１　金属粒子
１０１，１０３　接着部 1 solar cell module 3 first sealing member 5 second sealing member 10, 10a, 10b solar cell 11, 11a, 11b wiring member 12 conductive adhesive 20 photoelectric conversion substrate 30 photoelectric conversion part 31 first transparent electrode layer ( transparent conductive oxide layer)
32 Second transparent electrode layer (transparent conductive oxide layer)
35 first main surface 37 first texture structure 38 second texture structure 51, 61 convex portions 52, 62 top portions 55, 65 concave portions 56, 66 bottom portions 70a, 70b metal electrode layer (metal layer)
71 metal particles 101, 103 bonding portion

Claims (7)

  1. 　光電変換基板上に金属層が積層された太陽電池であって、
    　前記光電変換基板は、第１主面に複数の凸部を有するテクスチャー構造を備えており、
    　前記金属層は、前記凸部の高さよりも薄く、かつ前記凸部の一部を覆っており、
    　前記凸部は、頂部が前記金属層から露出している、太陽電池。     A solar cell in which a metal layer is laminated on a photoelectric conversion substrate,
    The photoelectric conversion substrate has a texture structure having a plurality of protrusions on the first main surface,
    The metal layer is thinner than the height of the protrusion and covers a part of the protrusion,
    The solar cell, wherein the convex portion has a top portion exposed from the metal layer.
  2. 　前記光電変換基板は、光電変換部上に透明導電性酸化物層が積層されており、
    　前記透明導電性酸化物層は、前記凸部を構成している、請求項１に記載の太陽電池。     The photoelectric conversion substrate has a transparent conductive oxide layer laminated on the photoelectric conversion part,
    2. The solar cell according to claim 1, wherein said transparent conductive oxide layer constitutes said convex portion.
  3. 　前記テクスチャー構造は、前記複数の凸部に隣接して複数の凹部が形成されており、
    　前記凹部の深さは、１μｍ以上であり、
    　前記金属層は、複数の金属粒子を含み、
    　前記金属粒子は、数平均粒子径が１０ｎｍ以上１００ｎｍ未満であって、かつ前記凹部の底部から前記凹部の深さの１／２０以上２／３以下の高さまで充填されている、請求項１又は２に記載の太陽電池。     The texture structure has a plurality of recesses adjacent to the plurality of protrusions,
    The recess has a depth of 1 μm or more,
    The metal layer includes a plurality of metal particles,
    The metal particles have a number average particle diameter of 10 nm or more and less than 100 nm, and are filled from the bottom of the recess to a height of 1/20 or more and 2/3 or less of the depth of the recess. 2. The solar cell according to 2.
  4. 　前記金属層は、前記光電変換基板を平面視したときに、前記凸部の頂部を囲んでいる、請求項１～３のいずれか１項に記載の太陽電池。 The solar cell according to any one of claims 1 to 3, wherein the metal layer surrounds the top of the projection when the photoelectric conversion substrate is viewed from above.
  5. 　配線部材と、導電性接着材を有し、
    　前記配線部材は、前記導電性接着材を介して前記金属層の一部と接続されており、
    　前記金属層から露出した凸部は、前記導電性接着材に接しながら覆われている、請求項１～４のいずれか１項に記載の太陽電池。     having a wiring member and a conductive adhesive,
    The wiring member is connected to a portion of the metal layer via the conductive adhesive,
    The solar cell according to any one of claims 1 to 4, wherein the convex portion exposed from the metal layer is covered while being in contact with the conductive adhesive.
  6. 　請求項１～５のいずれか１項に記載の太陽電池と、第１封止部材と、第２封止部材を有し、
    　前記太陽電池は、前記第１封止部材と前記第２封止部材によって挟まれて封止されており、
    　前記第１封止部材は、接着部を有し、
    　前記太陽電池は、前記金属層が前記接着部と密着して前記第１封止部材に接着されており、
    　前記金属層から露出した凸部は、前記接着部に接しながら覆われている、太陽電池モジュール。     A solar cell according to any one of claims 1 to 5, a first sealing member, and a second sealing member,
    The solar cell is sandwiched and sealed between the first sealing member and the second sealing member,
    The first sealing member has an adhesive portion,
    In the solar cell, the metal layer is adhered to the first sealing member in close contact with the adhesion portion,
    The solar cell module, wherein the convex portion exposed from the metal layer is covered while being in contact with the adhesive portion.
  7. 　請求項１～５のいずれか１項に記載の太陽電池の製造方法であって、
    　数平均粒子径が１０ｎｍ以上１００ｎｍ未満の金属粒子を含む金属インキを前記光電変換基板上に塗布する塗布工程と、
    　前記金属インキが塗布された前記光電変換基板を１００℃以上１８０℃以下の加熱温度で加熱する加熱工程を含む、太陽電池の製造方法。     A method for manufacturing a solar cell according to any one of claims 1 to 5,
    a coating step of coating the photoelectric conversion substrate with a metal ink containing metal particles having a number average particle size of 10 nm or more and less than 100 nm;
    A method for manufacturing a solar cell, comprising a heating step of heating the photoelectric conversion substrate coated with the metal ink at a heating temperature of 100° C. or higher and 180° C. or lower.
PCT/JP2022/045649 2022-01-31 2022-12-12 Solar cell, solar cell module, and method for manufacturing solar cell WO2023145280A1 (en)

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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007040065A1 (en) * 2005-09-30 2007-04-12 Sanyo Electric Co., Ltd. Solar battery and solar battery module
US20100065117A1 (en) * 2008-09-16 2010-03-18 Jinsung Kim Solar cell and texturing method thereof
JP2013524514A (en) * 2010-03-26 2013-06-17 テトラサン インコーポレイテッド Doping through shielded electrical contacts and passivated dielectric layers in high efficiency crystalline solar cells, and their structure and manufacturing method
JP2014103259A (en) * 2012-11-20 2014-06-05 Mitsubishi Electric Corp Solar cell, solar cell module, and method of manufacturing the same
WO2014083803A1 (en) * 2012-11-29 2014-06-05 三洋電機株式会社 Solar cell
JP2014229877A (en) * 2013-05-27 2014-12-08 株式会社カネカ Solar cell and manufacturing method therefor, and solar cell module
JP2015056461A (en) * 2013-09-11 2015-03-23 三菱電機株式会社 Method for manufacturing solar cell module, and solar cell module
WO2016129686A1 (en) * 2015-02-13 2016-08-18 株式会社カネカ Solar cell, method for manufacturing same, and solar cell module

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007040065A1 (en) * 2005-09-30 2007-04-12 Sanyo Electric Co., Ltd. Solar battery and solar battery module
US20100065117A1 (en) * 2008-09-16 2010-03-18 Jinsung Kim Solar cell and texturing method thereof
JP2013524514A (en) * 2010-03-26 2013-06-17 テトラサン インコーポレイテッド Doping through shielded electrical contacts and passivated dielectric layers in high efficiency crystalline solar cells, and their structure and manufacturing method
JP2014103259A (en) * 2012-11-20 2014-06-05 Mitsubishi Electric Corp Solar cell, solar cell module, and method of manufacturing the same
WO2014083803A1 (en) * 2012-11-29 2014-06-05 三洋電機株式会社 Solar cell
JP2014229877A (en) * 2013-05-27 2014-12-08 株式会社カネカ Solar cell and manufacturing method therefor, and solar cell module
JP2015056461A (en) * 2013-09-11 2015-03-23 三菱電機株式会社 Method for manufacturing solar cell module, and solar cell module
WO2016129686A1 (en) * 2015-02-13 2016-08-18 株式会社カネカ Solar cell, method for manufacturing same, and solar cell module

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