WO2015053578A1 - Solar cell and manufacturing method therefor - Google Patents

Solar cell and manufacturing method therefor Download PDF

Info

Publication number
WO2015053578A1
WO2015053578A1 PCT/KR2014/009513 KR2014009513W WO2015053578A1 WO 2015053578 A1 WO2015053578 A1 WO 2015053578A1 KR 2014009513 W KR2014009513 W KR 2014009513W WO 2015053578 A1 WO2015053578 A1 WO 2015053578A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
electrode
nanocrystals
nanocrystal
solar cell
Prior art date
Application number
PCT/KR2014/009513
Other languages
French (fr)
Korean (ko)
Inventor
박재근
심태헌
김달호
김지헌
신재우
박주형
Original Assignee
한양대학교 산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from KR1020140018183A external-priority patent/KR101646727B1/en
Application filed by 한양대학교 산학협력단 filed Critical 한양대학교 산학협력단
Priority to US15/028,420 priority Critical patent/US10998515B2/en
Priority to CN201480066817.7A priority patent/CN105981181B/en
Publication of WO2015053578A1 publication Critical patent/WO2015053578A1/en

Links

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
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022408—Electrodes for devices characterised by at least one potential jump barrier or surface barrier
    • H01L31/022425—Electrodes for devices characterised by at least one potential jump barrier or surface barrier for solar cells
    • 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
    • H01L31/0248—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 characterised by their semiconductor bodies
    • H01L31/036—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes
    • H01L31/0384—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including other non-monocrystalline materials, e.g. semiconductor particles embedded in an insulating material
    • H01L31/03845—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 characterised by their semiconductor bodies characterised by their crystalline structure or particular orientation of the crystalline planes including other non-monocrystalline materials, e.g. semiconductor particles embedded in an insulating material comprising semiconductor nanoparticles embedded in a semiconductor matrix
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/20—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation comprising organic-organic junctions, e.g. donor-acceptor junctions
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/80—Constructional details
    • H10K30/87—Light-trapping means
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K30/00—Organic devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation
    • H10K30/50—Photovoltaic [PV] devices
    • 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
    • Y02E10/549—Organic PV cells
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a solar cell and a method for manufacturing the same, and more particularly, to a solar cell and a method for manufacturing the same that can improve photoelectric conversion efficiency.
  • Solar cells are photoelectric conversion elements that convert sunlight into electrical energy. Unlike other energy sources, solar cells are endless and environmentally friendly, and their importance is increasing over time. Conventional solar cells have used a large number of single crystal or polycrystalline silicon solar cells. However, there is a problem that silicon solar cells are expensive to manufacture and cannot be applied to a flexible substrate.
  • the organic solar cell has a basic structure in which an organic photoactive layer is formed between the first and second electrodes spaced apart from each other.
  • An example of such an organic solar cell is shown in Korean Patent Publication No. 10-2010-0106779.
  • the organic solar cell may be manufactured by spin coating, inkjet printing, roll coating, or a doctor blade method. Therefore, the manufacturing process is simple, the manufacturing cost is low, and a large area can be coated, a thin film can be formed even at a low temperature, and almost all kinds of substrates such as glass substrates and plastic substrates can be used. .
  • the organic solar cell may be manufactured in various forms such as plastic molded products such as curved surfaces and spherical surfaces, without limitation, and may be bent or folded, which is convenient to carry. By utilizing such advantages, it is convenient to attach to clothes, bags, etc. of people, or attach to portable electric and electronic products.
  • the polymer blend thin film has a high transparency to light, and can be attached to a glass window of a building or a car window so that the outside can be produced while generating power, and thus the application range may be much larger than that of an opaque silicon solar cell.
  • an organic solar cell In an organic solar cell, light incident through a transparent electrode (ITO) is absorbed into an electron donor in a photoactive layer of a bulk heterojunction formed of an electron donor, an electron acceptor. At this time, excitons, which are electron and hole pairs, are formed and separation occurs at the interface between the electron donor and the electron acceptor. The separated electrons and holes move to the cathode and the anode, respectively, and an exciton and a hole blocking layer are formed to prevent the excitons and holes from moving to the cathode. In addition, after the formation of the interfacial layer that serves to lower the electron injection and energy band before the cathode is formed, the cathode is formed.
  • organic solar cells have low photoelectric conversion efficiencies due to their low absorption rates, making them unsuitable for practical applications.
  • the present invention provides a solar cell capable of improving the photoelectric conversion efficiency and a method of manufacturing the same.
  • the present invention provides a solar cell and a method for manufacturing the same, which can improve photoelectric conversion efficiency by using an internal surface plasmon resonance effect.
  • a solar cell of one embodiment of the present invention includes a first electrode formed on a substrate; A nano crystal layer including a plurality of nano crystals contacted on the first electrode; A hole transport layer formed on the first electrode to cover the plurality of nanocrystals; A photoactive layer formed on the hole transport layer; And a second electrode formed on the photoactive layer.
  • an exciton and hole blocking layer formed between the photoactive layer and the second electrode, and an electron injection and interfacial layer.
  • the exciton and the hole blocking layer are formed using BCP or metal oxide.
  • the electron injection and interfacial layer is formed of at least one of LiF, CsF, Liq, LiCoO 2 , Cs 2 CO 3 .
  • the nanocrystal layer is formed of a material having a reflectivity of light of 50% or more.
  • the nano crystal layer is formed to a thickness of 1nm to 15nm, preferably formed of a thickness of 5nm to 8nm.
  • the nanocrystals have a long axis of 15 nm to 45 nm and a short axis of 8 nm to 17 nm.
  • the nanocrystal has a shorter contact distance with the first electrode than a length of an axis parallel thereto.
  • the nanocrystals have an average diameter of 15 nm to 45 nm, and an average separation distance between adjacent nano crystals is formed of 25 nm to 75 nm.
  • the hole transport layer is formed of at least one of MoO x , V 2 O 5 , VO x , WO 3 , NiO x , Cu 2 O.
  • the photoactive layer comprises an electron donor and an electron acceptor of a bulk heterojunction.
  • a method of manufacturing a solar cell includes forming a first electrode on a substrate; Forming a nanocrystal layer including a plurality of nanocrystals on the first electrode; Forming a hole transporting layer on the first electrode to cover the nanocrystals; Forming a photoactive layer by applying a material mixed with an electron acceptor and an electron donor on the hole transport layer; And forming a second electrode on the photoactive layer.
  • the method may further include performing at least one of plasma treatment and ultraviolet treatment on the substrate before forming the nanocrystal layer.
  • the method may further include forming an exciton and a hole blocking layer, an electron injection, and an interface layer between the photoactive layer and the second electrode.
  • the nano crystal layer is formed to a thickness of 5nm to 8nm.
  • the nanocrystals have a long axis of 15 nm to 45 nm and a short axis of 8 nm to 17 nm.
  • the nanocrystals are formed such that a distance contacting the first electrode is shorter than a length of an axis parallel thereto.
  • the nanocrystals have an average diameter of 15 nm to 45 nm and an average separation distance between adjacent nano crystals of 25 nm to 75 nm.
  • a nanocrystal layer including a plurality of nanocrystals is formed on the first electrode on the substrate by contacting the first electrode.
  • the electric field is amplified by the surface plasmon effect by the plurality of nanocrystals, light is scattered while passing through the nanocrystals, and the amount of light is amplified. Therefore, since the amount of light supplied to the photoactive layer is increased, the light absorption in the photoactive layer can be increased, thereby improving the photoelectric conversion efficiency.
  • FIG. 1 is a cross-sectional view of a solar cell according to an embodiment of the present invention.
  • FIG. 2 is a cross-sectional view of a nanocrystal according to the present invention.
  • 3 is a cross-sectional view for explaining the shape change of the nanocrystals according to the deposition thickness of the nanocrystal layer.
  • FIG. 5 is a process flowchart illustrating a method of manufacturing a solar cell according to an embodiment of the present invention.
  • FIG. 6 is a SEM image showing the shape of the nanocrystals according to the thickness of the nanocrystal layer.
  • Figure 7 is a graph showing the change in the average area, density, separation distance and average diameter of the nanocrystals with the thickness of the nanocrystal layer.
  • FIG. 8 is a TEM image showing the cross-sectional shape of the nanocrystals according to the thickness of the nanocrystal layer.
  • 10 is a graph showing changes in wavelength and external quantum efficiency according to the thickness of the nanocrystal layer.
  • FIG. 11 is a graph showing a change in external quantum efficiency according to the thickness of a nanocrystal layer.
  • FIG. 12 is a graph showing the change of organic solar cell characteristics according to the thickness of the nano-crystal layer.
  • FIGS. 2 to 4 are cross-sectional views and plan views of nanocrystals applied to the present invention.
  • a solar cell includes a substrate 100, a first electrode 200 formed on the substrate 100, and a plurality of nanoparticles formed on the first electrode 200.
  • a second electrode 800 formed on the 700.
  • the second electrode 800 may be formed on the photoactive layer 500 without forming the exciton and hole blocking layers 600, the electron injection, and the interface layer 700. That is, in the solar cell according to the exemplary embodiment, the first electrode 200, the nano crystal layer 300, the hole transport layer 400, the photoactive layer 500, and the first electrode 200 may be formed in at least one region on the substrate 100.
  • the second electrode 800 may be stacked, and the exciton and hole blocking layer 600 and the electron injection and crab layer 700 may be further formed between the photoactive layer 500 and the second electrode 800.
  • the substrate 100 may use a transparent substrate, and may use a transparent substrate having a transmittance of at least 70% or more, preferably 80% or more in the visible light wavelength band.
  • the substrate 100 may use a transparent inorganic substrate such as quartz, glass, or the like, and may be polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polystyrene (PS), polypropylene ( Plastic substrates, such as PP), polyimide (PI), polyethylenesulfonate (PES), polyoxymethylene (POM), AS resin, and ABS resin, can also be used.
  • PET polyethylene terephthalate
  • PEN polyethylene naphthalate
  • PC polycarbonate
  • PS polystyrene
  • PS polypropylene
  • Plastic substrates such as PP
  • PI polyimide
  • PES polyethylenesulfonate
  • POM polyoxymethylene
  • AS resin and ABS resin
  • the first electrode 200 is formed in at least one region on the substrate 100. Since the light passing through the substrate 100 reaches the photoactive layer 500, the first electrode 200 may be formed of a material having high transparency.
  • the first electrode 200 may be formed of, for example, indium tin oxide (ITO), gold, silver, florin doped tin oxide (FTO), ZnO-Ga 2 O 3 , ZnO-Al 2 O 3 , SnO 2 -Sb 2 O 3, etc. can be formed by using.
  • ITO indium tin oxide
  • FTO florin doped tin oxide
  • ZnO-Ga 2 O 3 ZnO-Al 2 O 3
  • SnO 2 -Sb 2 O 3, etc. can be formed by using.
  • the material is not limited to these materials and a transparent conductive material may be used as the first electrode 200.
  • the nano crystal layer 300 includes a plurality of nano crystals 310 and is formed on the first electrode 200. That is, the plurality of nanocrystals 310 are formed in contact on the surface of the first electrode 200.
  • the nanocrystals 310 may be formed of a material having high reflectivity for light, for example, may be formed of a material having a reflectivity of light of 50% or more.
  • the reflectivity with respect to light means the ratio of the amount of light incident to the metal and the amount of reflected light.
  • Such highly reflective materials are, for example, silver, gold, aluminum, copper, nickel, iron, titanium or alloys thereof, calcium / aluminum alloys, magnesium / silver alloys, aluminum / lithium alloys, and the like. It is not.
  • the intensity of the electric field on the surface is amplified by the surface plasma resonance by the nanocrystals 310, thereby increasing the light absorption in the photoactive layer 500, thereby improving the photoelectric conversion efficiency.
  • the nanocrystals 310 are formed of a highly reflective metal, light is scattered between the nanocrystals 310 while passing through the nanocrystals 310, thereby increasing the amount of light. Since the amount of light increases while passing through the nanocrystal 310, light absorption in the photoactive layer 500 may be increased, thereby improving photoelectric conversion efficiency. That is, the amount of light supplied to the photoactive layer 500 may be increased by surface plasmon resonance and light scattering by the plurality of nanocrystals 310 formed on the first electrode 200, thereby absorbing light of the photoactive layer 500. Can be increased, thereby improving the photoelectric conversion efficiency.
  • the nanocrystal layer 300 including the plurality of nanocrystals 310 according to the present invention will be described in detail later.
  • the hole transport layer 400 includes a nanocrystal layer 300 including a plurality of nanocrystals 310 and is formed on the first electrode 200. That is, the hole transport layer 400 is formed on the first electrode 200 to cover the plurality of nanocrystals 310.
  • the hole transport layer 400 allows holes separated from the photoactive layer 500 to reach the first electrode 200. Therefore, the hole moving layer 400 may be formed using a material capable of smoothly moving holes.
  • the hole transport layer 400 may include PEDOT (poly (3,4-ethylenedioxythiophene)), PSS (poly (styrenesulfonate)), polyaniline, phthalocyanine, pentacene, polydiphenylacetylene, poly ( t-butyl) diphenylacetylene, poly (trifluoromethyl) diphenylacetylene, Cu-PC (copper phthalocyanine) poly (bistrifluoromethyl) acetylene, polybis (T-butyldiphenyl) acetylene, poly (trimethyl Silyl) diphenylacetylene, poly (carbazole) diphenylacetylene, polydiacetylene, polyphenylacetylene, polypyridineacetylene, polymethoxyphenylacetylene, polymethylphenylacetylene, poly (t-butyl) phenylacetylene, polynitrophenylacetylene Conductive polymers such as
  • the hole transport layer 400 may be formed using the PEDOT-PSS mixture.
  • the hole transport layer 400 may be formed of at least one of an oxide-based material, for example, MoO x , V 2 O 5 , VO x , WO 3 , NiO x , Cu 2 O.
  • the photoactive layer 500 is formed on the hole transport layer 400, and a material in which the electron donor and the electron acceptor are blended may be formed by spin coating or the like.
  • Light incident from the outside through the first electrode 200 is amplified by the plurality of nanocrystals 310 and absorbed by the electron donor formed in the photoactive layer 500.
  • the unabsorbed light is reflected by the second electrode 800 and is again absorbed by the electron donor.
  • the light that is not reabsorbed may be rereflected by the nanocrystals 310 to be reabsorbed by the photoactive layer 500. Therefore, since light incident from the outside is amplified and reflected by the nanocrystals 310, the light absorption rate of the photoactive layer 500 is increased.
  • the electron donor examples include P3HT (poly (3-hexylthiophene)), polysiloxane carbazole, polyaniline, polyethylene oxide, (poly (1-methoxy-4- (0-dispersed 1) -2,5-phenylene- Vinylene), polyindole, polycarbazole, polypyridazine, polyiso thianaphthalene, polyphenylene sulfide, polyvinylpyridine, polythiophene, polyfluorene, polypyridine, derivatives thereof and the like
  • P3HT poly (3-hexylthiophene)
  • polysiloxane carbazole polyaniline
  • polyethylene oxide polyethylene oxide
  • polyindole polycarbazole
  • polypyridazine polyiso thianaphthalene
  • polyphenylene sulfide polyvinylpyridine, poly
  • a mixture of ([6,6] -phenyl-C61 butyric acid methyl ester) can be used, wherein P3HT and PCBM can be mixed in a weight ratio (wt%) of 1: 0.1 to 2: 1.
  • 500 spraying for example , Spin coating, dipping, printing, doctor blading, sputtering or the like can be formed.
  • the exciton and hole blocking layer 600 may be formed on the photoactive layer 500 to prevent holes separated from the photoactive layer 500 and excitons not separated from moving to the second electrode 800 to be recombined again.
  • the exciton and hole blocking layer 600 may be formed using a material having a high highest Occupied Molecular Orbital (HOMO) energy level, such as, for example, bathocuproine (BCP).
  • HOMO Occupied Molecular Orbital
  • BCP bathocuproine
  • the exciton and the hole blocking layer 600 may be formed using a metal oxide, for example, at least one of TiO x , ZnO, Al 2 O 3 , and CaO. .
  • the electron injection and interfacial layer 700 allows electrons separated from the exciton to be well injected into the second electrode 800, and also the photoactive layer 500 or the exciton and hole blocking layer 600 and the second electrode 800. It can improve the interfacial property of and can form using an alkali metal compound.
  • the exciton and hole blocking layer 600 may be formed using LiF, CsF, Liq, LiCoO 2 , Cs 2 CO 3, or the like.
  • the second electrode 800 is formed on the electron injection and interfacial layer 700.
  • the second electrode 800 is incident through the first electrode 200, but uses a material having high reflectivity and low resistance to reabsorb light that is not absorbed by the photoactive layer 500 in the photoactive layer 500. Can be formed.
  • a material having a lower work function than that of the first electrode 200 may be used.
  • FIG. 2 is a cross-sectional conceptual view of a nanocrystal according to the present invention
  • Figure 3 is a cross-sectional conceptual view for explaining the shape change of the nano-crystal according to the deposition thickness of the nano-crystal layer
  • Figure 4 is a plan view and a cross-sectional conceptual view of the nano-crystal. .
  • the nanocrystal layer 300 may be formed to a thickness of 1 nm to 15 nm for the surface plasmon effect by the nano crystal 310. That is, the nanocrystal layer 300 may be formed by, for example, a thermal evaporation method.
  • the nanocrystal layer 300 may have a thickness or a set thickness measured using a thickness meter as 1 nm to 15 nm. Can be formed.
  • the thickness meter is provided inside the chamber including the crystal sensor, and the thickness may be checked by vibration of the sensor according to the deposition thickness. In addition, the thickness may be confirmed through optical analysis such as SEM and TEM.
  • the thickness of the nano crystal layer 300 may be set using the supplied DC power, deposition time and deposition rate.
  • the nanocrystal 310 has a length in one direction, that is, a length of a long axis (a), as shown in FIG. 2. 6 nm to 160 nm, and the length in the other direction orthogonal to one direction, that is, the length of the short axis b, may be formed to 5 nm to 30 nm. In other words, when the nanocrystal layer 300 is formed to a predetermined thickness and the nanocrystal 310 is measured, the nanocrystal 310 may be larger than the thickness of the nanocrystal layer 300.
  • the long axis (a) is shown in the horizontal direction and the short axis (b) is shown in the longitudinal direction
  • the relatively long direction may be a long axis (a)
  • the short direction may be a short axis (b).
  • the nanocrystals 310 may be provided in a spherical shape with the same length of the long axis a and the short axis b, or may be provided in an elliptical shape where the long axis a is longer than the short axis b.
  • the nanocrystal layer 300 is preferably formed in a thickness of 5nm to 8nm, the nanocrystal 310 at this time is the length of the long axis (a) is 15nm to 45nm, the length of the short axis (b) 8 nm to 17 nm. That is, as the thickness of the nanocrystal layer 300 increases, the size of the nanocrystal 310 may increase.
  • the nanocrystal layer 300 is formed to a thickness of 5 nm to 8 nm, and the nano crystal 310 has a length of 15 nm to 45 nm in the major axis a and a length of 8 nm to 17 in the minor axis b. When formed in nm, it is preferable because of the low optical loss and high external quantum efficiency.
  • the nano crystal layer 300 has a dot-shaped nano crystal 310 is formed, and as the deposition thickness increases, the nano crystal 310 increases in shape as the island shape becomes larger as the nano crystal 310 increases.
  • the lower layer forms a layer. That is, as shown in FIG. 3 (a), a dot-shaped nanocrystal 310 is formed on the first electrode 200, and as the deposition thickness increases, the first as shown in FIG. 3 (b).
  • the contact area with the electrode 200 increases to increase the size of the nanocrystal 310, and as shown in FIG. 3C, the contact area with the first electrode 200 has a long axis of the nanocrystal 310. It will have an island shape larger than its length. In this case, when the size of the nanocrystal 310 is larger, the nanocrystals 310 are combined to form a layer.
  • the nano crystal 310 When the nanocrystal layer 300 is formed to a thickness of 1 nm to 15 nm, the nano crystal 310 has an average diameter (D) of 7 nm to 160 nm, and an average separation between adjacent nano crystals 310.
  • the distance C may be formed to be 20 nm to 180 nm, and the density of the nanocrystals 310 may be formed to be 25 to 1800.
  • the nano-crista layer 300 is formed to a thickness of 5 nm to 8 nm
  • the nano crystal 310 has an average diameter D of 15 nm to 45 nm, and an average between adjacent nano crystals 310 is formed.
  • the separation distance C may be formed to be 25 nm to 75 nm, and the density of the nanocrystals 310 may be formed to be 170 to 1100.
  • the average diameter D of the nanocrystals 310 may be larger than the contact distance d of the first electrode 200 of the nanocrystals 310 as shown in FIG. 4. Since the nanocrystal 310 is in contact with the first electrode 200, the contact distance with the first electrode 200 is greater than zero. That is, the contact distance d of the nanocrystals 310 with the first electrode 200 may be greater than zero and smaller than the average diameter D of the nanocrystals 310. However, when the contact distance (d) of the nanocrystals 310 is larger than the average diameter (D), the nanocrystals 310 are formed in an island shape as shown in FIG. It is not preferable because the quantum efficiency is lowered.
  • the nanocrystal layer 300 including the plurality of nanocrystals 310 is formed by contacting the first electrode 200 on the first electrode 200. do.
  • the electric field is amplified by the surface plasmon effect by the plurality of nanocrystals 310 and supplied to the photoactive layer 500, and the amount of light is amplified by the light scattering by the plurality of nanocrystals 310 having high light reflectivity and the photoactive layer. Supplied to 500. Therefore, light absorption in the photoactive layer 500 can be increased, thereby improving photoelectric conversion efficiency. That is, compared to the case where the nanocrystals 310 are not formed, an external quantum efficiency of about 30% can be improved.
  • FIG. 5 is a flowchart illustrating a method of manufacturing a solar cell according to an embodiment of the present invention.
  • a photoactive layer material and a hole transport layer material are prepared (S110).
  • the electron donor and the electron acceptor may be mixed in a predetermined solvent in a predetermined solvent.
  • P3HT and PCBM are mixed in a weight ratio of 1: 0.1 to 2: 1, and a mixture thereof is mixed in 1,2 dichlorobenzene in 1 to 5 weight ratios and then blended for a minimum of 72 hours.
  • the photoactive layer material can be prepared.
  • the solvent may be used in addition to 2-chlorobenzene chlorobenzene, benzene, chloroform and THF.
  • PEDOT-PSS and Isopropyl Alcohol (IPA) may be blended in a weight ratio of 1: 2 for at least 24 hours to prepare a hole transporting layer material.
  • a first electrode is formed on the substrate (S120).
  • the substrate may use a transparent substrate having a transmittance of at least 70% or more, preferably 80% or more, in the visible light wavelength band.
  • the first electrode may be formed by forming a transparent conductive material such as ITO on a substrate and then patterning the same.
  • the substrate may be cleaned using acetone or the like. Washing can be performed, for example for 10 to 100 minutes, and can be dried for 5 to 15 hours at the temperature of 50 to 100 degreeC after washing
  • cleaning On the other hand, in addition to acetone, isopropyl alcohol and pure water (DI) may be used to clean the substrate.
  • DI isopropyl alcohol and pure water
  • an oxygen plasma treatment may be performed on the substrate, followed by ultraviolet treatment having a wavelength of 365 nm (S130).
  • ultraviolet treatment having a wavelength of 365 nm (S130).
  • Plasma treatment is performed to smooth the surface roughness of the first electrode and to increase the work function of the first electrode.
  • ultraviolet treatment is performed in order to remove the organic substance which remains on the surface of a 1st electrode after a washing process.
  • a nanocrystal layer including a plurality of nanocrystals is formed on the substrate on which the first electrode is formed (S140).
  • the nanocrystal layer may be formed using a metal having high reflectivity including silver (Ag).
  • the nanocrystal layer can be formed by a thermal deposition method in a vacuum state.
  • the nanocrystal layer may be formed at a deposition rate of, for example, 0.1 to 2.0 kV / sec depending on the deposition thickness, the deposition time, and the like.
  • the nanocrystal layer may be formed by various methods other than the vaporization method, and may be formed using a sputter, an E-beam, a coating method, or the like.
  • the nanocrystal layer thus formed may be formed, for example, in a thickness of 1 nm to 15 nm, and preferably in a thickness of 5 nm to 8 nm. That is, the nanocrystal layer may be formed with a thickness or a set thickness measured by a thickness meter or optical analysis as 1 nm to 15 nm, preferably 5 nm to 8 nm. In this case, the nanocrystals may have a length of 6 nm to 160 nm in the major axis (a) and a length of 5 nm to 30 nm in the minor axis (b).
  • the length of the major axis a may be 15 nm to 45 nm, and the length of the minor axis b may be 8 nm to 17 nm.
  • the nanocrystals have an average diameter (D) of 7 nm to 160 nm, preferably 15 nm to 45 nm, and the average separation distance (C) between adjacent nanocrystals 310 is 20 nm to 180 nm, Preferably it is formed from 25 nm to 75 nm, the density may be formed from 25 to 1800, preferably 170 to 1100.
  • an electron transport layer is formed on the first electrode to cover the plurality of nanocrystals (150).
  • the hole transport layer is spin-coated the PEDOT-PSS and the IPA blended material of the hole transport layer material at, for example, 60 rpm to 300 seconds at 1000 rpm to 3000 rpm for 10 minutes to 100 minutes in a nitrogen atmosphere of 100 ° C to 150 ° C. It can be formed by annealing. That is, the time and rotation speed of the spin coating, the annealing temperature and the time may be adjusted according to the thickness of the hole transport layer.
  • a photoactive layer is formed on the hole transport layer (S160).
  • the photoactive layer was spin-coated the photoactive layer material containing P3HT and PCBM in 2-chlorobenzene at 500 rpm to 2000 rpm for 60 seconds to 300 seconds, followed by annealing for 10 to 100 minutes in a nitrogen atmosphere at 100 ° C to 150 ° C. Can be formed. That is, the time and rotation speed of the spin coating, the annealing temperature and the time can be adjusted according to the thickness of the photoactive layer.
  • BCP bathoproine
  • LiF lithium fluoride
  • P3HT and PCBM were mixed at a weight ratio of 2: 1, then mixed with 1,2 dichlorobenzene at 2wt% and blended for 72 hours to prepare a photoactive layer material.
  • PEDOT-PSS and IPA were blended at a weight ratio of 1: 2 for 24 hours to prepare a hole transport layer material.
  • a first electrode was formed on the transparent substrate using ITO, and silver (Ag) was deposited on the first electrode to form a nanocrystal layer including a plurality of nanocrystals.
  • the nano-crystal layer was formed at a deposition rate of 0.3 ⁇ / sec, and formed on the plurality of substrates each with a thickness of 3 nm to 15 nm.
  • the hole transport layer material material blended with PEDOT-PSS and IPA to cover a plurality of nanocrystals was spin coated at 2000 rpm for 60 seconds and annealed for 10 minutes in a nitrogen atmosphere of 140 ° C. to form a hole transport layer.
  • the photoactive layer material containing P3HT and PCBM mixed in 1,2 dichlorobenzene was spin coated at 1000 rpm for 60 seconds and then annealed for about 10 minutes in a nitrogen atmosphere at 125 ° C. to form a photoactive layer.
  • BCP bathoproine
  • LiF is deposited to a thickness of 0.5 nm to form an electron injection and an interfacial layer
  • aluminum (Al) is 80 nm thick.
  • FIG. 6 is an SEM image showing the shape of the nanocrystals according to the thickness of the nanocrystal layer.
  • Figure 7 is a graph of the change in the average area, density, separation distance and average diameter of the nanocrystals according to the thickness of the nanocrystal layer.
  • the nanocrystals grow from a dot shape according to the thickness of the nanocrystal layer from 3 nm to 8 nm, and from 9 nm or more, the size of the nano crystals increases to grow into island shapes and adjacent to each other. It can be seen that the nanocrystals grow in contact with each other.
  • the average area (A), the separation distance (C), and the average diameter (D) of the nanocrystals increase, and the density (B) decreases. .
  • the average diameter of the nanocrystals increases, so that the average area and the separation distance of the nanocrystals on the first electrode increase, and the density between the nanocrystals decreases.
  • the average area, density, distance and average diameter of the nanocrystals according to the thickness of the nanocrystal layer are shown in [Table 1].
  • the distance between the nanocrystals is calculated from an equation obtained by multiplying the distance L from the center of one nanocrystal by the unit cell minus the average radius r of the nanocrystals by 2.
  • the distance (L) from the center of one nanocrystal to the unit cell may be expressed as the distance from the end of the unit cell to the center of the nanocrystal, assuming that the nanocrystal is present in one unit cell.
  • the area may be defined as a value obtained by dividing the area of the first electrode on which the plurality of nanocrystals is formed by the number of nanocrystals.
  • the average area (nm 2 ) of the nanocrystals is calculated from the sum of the area of the nanocrystals divided by the number of nanocrystals, as shown in [Equation 2], and the density (cm ⁇ 2 ) of the nanocrystals is [ As shown in Equation 3, the number of nanocrystals may be calculated from a value divided by the total area. And, the average diameter of the nanocrystals can be calculated from the average area of the nanocrystals as shown in [Equation 4].
  • 8 is a TEM image showing the cross-sectional shape of the nanocrystals according to the thickness of the nanocrystal layer, the length and ratio of the major and minor axis of the nanocrystals according to the thickness of the nanocrystal at this time is shown in [Table 2]. 8 shows the length and distance of the major axis according to the thickness of the nanocrystal layer.
  • the nanocrystals when the nanocrystal layer is formed to a thickness of 3 nm, the nanocrystals have long and short axes of 8 nm and 7 nm, respectively, as shown in FIG. 8 (b). Likewise, when the nanocrystal layer is formed to a thickness of 5 nm, the nanocrystals have long and short axes of 18 nm and 10 nm, respectively. In addition, as shown in FIG. 8C, when the nanocrystal layer is formed to a thickness of 7 nm, the nanocrystals have long and short axes of 38 nm and 14 nm, respectively. As shown in FIGS.
  • the nanocrystal layer when the nanocrystal layer is formed to a thickness of 10 nm, 12 nm, and 15 nm, the nanocrystals have long axes of 63 nm, respectively. , 77 nm and 154 nm and short axes are formed at 22 nm, 24 nm and 25 nm, respectively.
  • the differential aspect ratio of the nanocrystals is shown.
  • the differential aspect race can be expressed as the average value of the radius of the minor axis relative to the average value of the major axis.
  • FIG. 9 is a graph showing optical loss according to the thickness of the nanocrystal layer. As shown, the optical loss decreases as the thickness of the nanocrystal layer increases to 8 nm, and the optical loss increases from 9 nm or more. In particular, it can be seen that the optical loss is the smallest when the thickness of the nanocrystal layer is 5 nm to 8 nm. Therefore, it can be seen that the light absorption is the largest when the thickness of the nanocrystal layer is 5 nm to 8 nm, and therefore the photoelectric conversion efficiency is the largest.
  • FIG. 10 is a graph illustrating an external quantum efficiency (EQE) according to the thickness of the nanocrystal layer.
  • EQE external quantum efficiency
  • the external quantum efficiency according to the size and distance of the nanocrystal is divided by the external quantum efficiency of the solar cell in which the nanocrystal is not formed.
  • the nanocrystal layer is formed with a thickness of 4 nm, 5 nm, 6 nm, 7 nm, and 8 nm, respectively, the external quantum efficiency is 10%, 30%, 15 compared with the case where the nano crystal layer is not formed. It can be seen that the%, 20%, 30% increase.
  • the external quantum efficiency is the same as or less than that when the nano crystal layer is not formed. Since the density of nanocrystals is higher than 5 nm, the external quantum efficiency is low due to the increase of reflectivity, and the thickness of 9 nm or more does not produce surface plasmon effect, that is, it is not an oblate shape. It is gradually formed in the form of a layer and exhibits low external quantum efficiency due to increased reflectivity.
  • FIG. 12 shows the degree of (a) photoelectric conversion efficiency, (b) current density, (c) fill factor, (d) open voltage, (e) shunt resistance, and (f) series resistance, depending on the thickness of the nanocrystal layer. It is a graph. Depending on the thickness of the nanocrystal layer, nanocrystals of different diameters and shapes are formed, and the nanocrystals thus formed exhibit surface plasmon phenomena due to separation distance, density, area, diameter, shape, and dielectric constant and refractive index of the material around the nanocrystals. Will be raised.
  • the current density characteristics of the nanocrystal layer was the largest increase in the thickness of 6nm, the diameter of the nanocrystal is 28nm, the shape is oblate (oblate).
  • the dielectric constant difference exists between the first electrode ITO and the hole transport layer PEDOT: PSS.
  • the current density increased by 31.04%, and as shown in FIGS. 12 (c) and 12 (d), the filling rate and the opening voltage were almost unchanged.
  • the photoelectric conversion efficiency (PCE) of FIG. 12 (a) increased by 32.02% at 6 nm (28 nm in diameter / 42 nm apart), and the thickness of the nano crystal layer was 5-10 nm than that without applying nano crystals.
  • the thickness of the nanocrystal layer is 3 to 4 nm, the current density and the photoelectric conversion efficiency are reduced, so that the optimum diameter, density, and shape should be achieved, but the surface plasmon phenomenon occurs. Increase to increase efficiency.

Landscapes

  • Engineering & Computer Science (AREA)
  • Electromagnetism (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Sustainable Development (AREA)
  • Sustainable Energy (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Nanotechnology (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Photovoltaic Devices (AREA)

Abstract

The present invention provides a solar cell and a manufacturing method therefor, the solar cell comprising: a first electrode formed on a substrate; a nano-crystal layer in contact with and formed on the first electrode, the nano-crystal layer comprising a plurality of nano-crystals; a hole transfer layer formed on the first electrode so as to cover the plurality of nano-crystals; an optical active layer formed on the hole transfer layer; and a second electrode formed on the optical active layer.

Description

태양 전지 및 그 제조 방법Solar cell and its manufacturing method
본 발명은 태양 전지 및 그 제조 방법에 관한 것으로, 특히 광전 변환 효율을 향상시킬 수 있는 태양 전지 및 그 제조 방법에 관한 것이다.TECHNICAL FIELD The present invention relates to a solar cell and a method for manufacturing the same, and more particularly, to a solar cell and a method for manufacturing the same that can improve photoelectric conversion efficiency.
태양 전지는 태양 광을 전기 에너지로 변환하는 광전 변환 소자이다. 태양 전지는 다른 에너지원과는 달리 무한하고 환경친화적이므로 시간이 갈수록 그 중요성이 더해가고 있다. 종래의 태양 전지는 단결정 또는 다결정의 실리콘 태양 전지가 많이 이용되었다. 그러나, 실리콘 태양 전지는 제조 비용이 많이 들고 플렉서블 기판에는 적용할 수 없는 등의 문제점이 있다.Solar cells are photoelectric conversion elements that convert sunlight into electrical energy. Unlike other energy sources, solar cells are endless and environmentally friendly, and their importance is increasing over time. Conventional solar cells have used a large number of single crystal or polycrystalline silicon solar cells. However, there is a problem that silicon solar cells are expensive to manufacture and cannot be applied to a flexible substrate.
실리콘 태양 전지의 문제점을 해결하기 위하여 최근에는 유기물 태양 전지에 대한 연구가 활발하게 진행되고 있다. 유기물 태양 전지는 서로 이격된 제 1 및 제 2 전극 사이에 유기물 광활성층이 형성된 기본 구조를 갖는다. 이러한 유기물 태양 전지의 예가 한국공개특허 제10-2010-0106779호에 제시되어 있다. 유기물 태양 전지는 스핀 코팅, 잉크젯 프린팅, 롤 코팅 또는 닥터 블레이드 방법 등으로 제조할 수 있다. 따라서, 제조 공정이 간단하여 제조 비용이 적으며, 넓은 면적을 코팅할 수 있고, 낮은 온도에서도 박막을 형성할 수 있으며, 유리 기판을 비롯하여 플라스틱 기판 등 거의 모든 종류의 기판을 이용할 수 있는 장점이 있다. 또한, 유기물 태양 전지는 기판의 형태에 제한 없이 곡면, 구면 등 플라스틱 성형품과 같은 다양한 형태로 제작할 수 있고, 구부리거나 접을 수도 있어서 휴대하기 편리하다. 이와 같은 장점을 활용하면 사람의 옷, 가방 등에 부착하거나 휴대용 전기전자 제품에 부착하여 이용하기 편리하다. 또한, 고분자 블렌드 박막은 광에 대한 투명도가 높아서 건물의 유리창 또는 자동차의 유리창 등에 부착하여 밖을 볼 수 있게 하면서도 전력을 생산할 수 있어 불투명한 실리콘 태양 전지보다 응용 범위가 훨씬 클 수 있다.Recently, researches on organic solar cells have been actively conducted to solve the problems of silicon solar cells. The organic solar cell has a basic structure in which an organic photoactive layer is formed between the first and second electrodes spaced apart from each other. An example of such an organic solar cell is shown in Korean Patent Publication No. 10-2010-0106779. The organic solar cell may be manufactured by spin coating, inkjet printing, roll coating, or a doctor blade method. Therefore, the manufacturing process is simple, the manufacturing cost is low, and a large area can be coated, a thin film can be formed even at a low temperature, and almost all kinds of substrates such as glass substrates and plastic substrates can be used. . In addition, the organic solar cell may be manufactured in various forms such as plastic molded products such as curved surfaces and spherical surfaces, without limitation, and may be bent or folded, which is convenient to carry. By utilizing such advantages, it is convenient to attach to clothes, bags, etc. of people, or attach to portable electric and electronic products. In addition, the polymer blend thin film has a high transparency to light, and can be attached to a glass window of a building or a car window so that the outside can be produced while generating power, and thus the application range may be much larger than that of an opaque silicon solar cell.
유기물 태양 전지는 투명 전극(ITO)을 통해 입사된 광이 전자 공여체, 전자 수용체로 형성된 벌크 헤테로 접합의 광활성층 내 전자 공여체로 흡수된다. 이때, 전자와 정공쌍인 엑시톤이 형성되고 전자 공여체와 전자 수용체의 계면에서 분리가 일어나게 된다. 분리된 전자와 정공은 각각 음극 및 양극으로 이동하는데, 엑시톤 및 정공이 음극으로 이동하는 것을 방지하기 위해 엑시톤 및 정공 블록킹층이 형성된다. 또한, 음극이 형성되기 이전에 전자 주입 및 에너지 밴드를 낮춰주는 역할을 하는 계면층이 형성된 후 음극이 형성된다. 그런데, 종래의 유기물 태양 전지는 입사된 광이 대부분 전자 공여체에 흡수되지만, 입사된 광의 60% 밖에 흡수를 하지 못하는 단점이 있어 광 흡수율 증가가 필요하다. 따라서, 많은 장점에도 불구하고 유기물 태양 전지는 낮은 흡수율로 인해 광전 변환 효율이 낮아 실용적 응용에는 적합하지 않다.In an organic solar cell, light incident through a transparent electrode (ITO) is absorbed into an electron donor in a photoactive layer of a bulk heterojunction formed of an electron donor, an electron acceptor. At this time, excitons, which are electron and hole pairs, are formed and separation occurs at the interface between the electron donor and the electron acceptor. The separated electrons and holes move to the cathode and the anode, respectively, and an exciton and a hole blocking layer are formed to prevent the excitons and holes from moving to the cathode. In addition, after the formation of the interfacial layer that serves to lower the electron injection and energy band before the cathode is formed, the cathode is formed. By the way, in the conventional organic solar cell, the incident light is mostly absorbed by the electron donor, but only 60% of the incident light is absorbed. Thus, despite many advantages, organic solar cells have low photoelectric conversion efficiencies due to their low absorption rates, making them unsuitable for practical applications.
본 발명은 광전 변환 효율을 향상시킬 수 있는 태양 전지 및 그 제조 방법을 제공한다.The present invention provides a solar cell capable of improving the photoelectric conversion efficiency and a method of manufacturing the same.
본 발명은 내부의 표면 플라즈몬 공진(surface plasmon resonance) 효과를 이용하여 광전 변환 효율을 향상시킬 수 있는 태양 전지 및 그 제조 방법을 제공한다.The present invention provides a solar cell and a method for manufacturing the same, which can improve photoelectric conversion efficiency by using an internal surface plasmon resonance effect.
본 발명의 일 형태에 따른 태양 전지는 기판 상에 형성된 제 1 전극; 상기 제 1 전극 상에 접촉 형성된 복수의 나노 크리스탈을 포함하는 나노 크리스탈층; 상기 복수의 나노 크리스탈을 덮도록 상기 제 1 전극 상에 형성된 정공 이동층; 상기 정공 이동층 상에 형성된 광활성층; 및 상기 광활성층 상에 형성된 제 2 전극을 포함한다.A solar cell of one embodiment of the present invention includes a first electrode formed on a substrate; A nano crystal layer including a plurality of nano crystals contacted on the first electrode; A hole transport layer formed on the first electrode to cover the plurality of nanocrystals; A photoactive layer formed on the hole transport layer; And a second electrode formed on the photoactive layer.
상기 광활성층과 상기 제 2 전극 사이에 형성된 엑시톤 및 정공 블록킹층과, 전자 주입 및 계면층을 더 포함한다.And an exciton and hole blocking layer formed between the photoactive layer and the second electrode, and an electron injection and interfacial layer.
상기 엑시톤 및 정공 블록킹층은 BCP 또는 금속 산화물을 이용하여 형성한다.The exciton and the hole blocking layer are formed using BCP or metal oxide.
상기 전자 주입 및 계면층은 LiF, CsF, Liq, LiCoO2, Cs2CO3 중 적어도 어느 하나로 형성된다.The electron injection and interfacial layer is formed of at least one of LiF, CsF, Liq, LiCoO 2 , Cs 2 CO 3 .
상기 나노 크리스탈층은 광에 대한 반사도가 50% 이상인 물질로 형성된다.The nanocrystal layer is formed of a material having a reflectivity of light of 50% or more.
상기 나노 크리스탈층은 1㎚ 내지 15㎚의 두께로 형성되고, 바람직하게는 5㎚ 내지 8㎚의 두께로 형성된다.The nano crystal layer is formed to a thickness of 1nm to 15nm, preferably formed of a thickness of 5nm to 8nm.
상기 나노 크리스탈은 장축의 길이가 15㎚ 내지 45㎚로 형성되고, 단축의 길이가 8㎚ 내지 17㎚로 형성된다.The nanocrystals have a long axis of 15 nm to 45 nm and a short axis of 8 nm to 17 nm.
상기 나노 크리스탈은 상기 제 1 전극과 접촉되는 거리가 이와 평행한 축의 길이보다 짧다.The nanocrystal has a shorter contact distance with the first electrode than a length of an axis parallel thereto.
상기 나노 크리스탈은 평균 직경이 15㎚ 내지 45㎚로 형성되고, 인접한 나노 크리스탈 사이의 평균 이격 거리가 25㎚ 내지 75㎚로 형성된다.The nanocrystals have an average diameter of 15 nm to 45 nm, and an average separation distance between adjacent nano crystals is formed of 25 nm to 75 nm.
상기 정공 이동층은 MoOx, V2O5, VOx, WO3, NiOx, Cu2O 중 적어도 어느 하나로 형성된다.The hole transport layer is formed of at least one of MoO x , V 2 O 5 , VO x , WO 3 , NiO x , Cu 2 O.
상기 광활성층은 벌크 헤테로 접합의 전자 공여체와 전자 수용체를 포함한다.The photoactive layer comprises an electron donor and an electron acceptor of a bulk heterojunction.
본 발명의 다른 형태에 따른 태양 전지의 제조 방법은 기판 상에 제 1 전극을 형성하는 단계; 상기 제 1 전극 상에 복수의 나노 크리스탈을 포함하는 나노 크리스탈층을 형성하는 단계; 상기 나노 크리스탈을 덮도록 상기 제 1 전극 상에 정공 이동층을 형성하는 단계; 상기 정공 이동층 상에 전자 수용체와 전자 공여체가 혼합된 물질을 도포하여 광활성층을 형성하는 단계; 및 상기 광활성층 상에 제 2 전극을 형성하는 단계를 포함한다.According to another aspect of the present invention, a method of manufacturing a solar cell includes forming a first electrode on a substrate; Forming a nanocrystal layer including a plurality of nanocrystals on the first electrode; Forming a hole transporting layer on the first electrode to cover the nanocrystals; Forming a photoactive layer by applying a material mixed with an electron acceptor and an electron donor on the hole transport layer; And forming a second electrode on the photoactive layer.
상기 나노 크리스탈층을 형성하기 이전에 상기 기판에 플라즈마 처리 및 자외선 처리의 적어도 어느 하나를 실시하는 단계를 더 포함한다.The method may further include performing at least one of plasma treatment and ultraviolet treatment on the substrate before forming the nanocrystal layer.
상기 광활성층과 상기 제 2 전극 사이에 엑시톤 및 정공 블록킹층과, 전자 주입 및 계면층을 더 형성하는 단계를 더 포함한다.The method may further include forming an exciton and a hole blocking layer, an electron injection, and an interface layer between the photoactive layer and the second electrode.
상기 나노 크리스탈층은 5㎚ 내지 8㎚의 두께로 형성한다.The nano crystal layer is formed to a thickness of 5nm to 8nm.
상기 나노 크리스탈은 장축의 길이를 15㎚ 내지 45㎚로 형성하고, 단축의 길이를 8㎚ 내지 17㎚로 형성한다.The nanocrystals have a long axis of 15 nm to 45 nm and a short axis of 8 nm to 17 nm.
상기 나노 크리스탈은 상기 제 1 전극과 접촉되는 거리가 이와 평행한 축의 길이보다 짧도록 형성한다.The nanocrystals are formed such that a distance contacting the first electrode is shorter than a length of an axis parallel thereto.
상기 나노 크리스탈은 평균 직경을 15㎚ 내지 45㎚로 형성하고, 인접한 나노 크리스탈 사이의 평균 이격 거리를 25㎚ 내지 75㎚로 형성한다.The nanocrystals have an average diameter of 15 nm to 45 nm and an average separation distance between adjacent nano crystals of 25 nm to 75 nm.
본 발명의 실시 예들에 따른 태양 전지는 기판 상의 제 1 전극 상에 제 1 전극과 접촉되어 복수의 나노 크리스탈을 포함하는 나노 크리스탈층이 형성된다. 복수의 나노 크리스탈에 의한 표면 플라즈몬 효과에 의해 전계가 증폭되고, 나노 크리스탈을 통과하면서 광이 산란되어 광량이 증폭된다. 따라서, 광활성층에 공급되는 광량이 증가하게 되므로 광활성층에서의 광 흡수를 증가시킬 수 있고, 그에 따라 광전 변환 효율을 향상시킬 수 있다.In the solar cell according to the embodiments of the present invention, a nanocrystal layer including a plurality of nanocrystals is formed on the first electrode on the substrate by contacting the first electrode. The electric field is amplified by the surface plasmon effect by the plurality of nanocrystals, light is scattered while passing through the nanocrystals, and the amount of light is amplified. Therefore, since the amount of light supplied to the photoactive layer is increased, the light absorption in the photoactive layer can be increased, thereby improving the photoelectric conversion efficiency.
도 1은 본 발명의 일 실시 예에 따른 태양 전지의 단면도.1 is a cross-sectional view of a solar cell according to an embodiment of the present invention.
도 2는 본 발명에 따른 나노 크리스탈의 단면도.2 is a cross-sectional view of a nanocrystal according to the present invention.
도 3은 나노 크리스탈층의 증착 두께에 따른 나노 크리스탈의 형상 변화를 설명하기 위한 단면도.3 is a cross-sectional view for explaining the shape change of the nanocrystals according to the deposition thickness of the nanocrystal layer.
도 4는 나노 크리스탈의 평면도 및 그에 따른 단면도.4 is a plan view and cross-sectional view of the nanocrystals.
도 5는 본 발명의 일 실시 예에 따른 태양 전지의 제조 방법을 설명하기 위한 공정 흐름도.5 is a process flowchart illustrating a method of manufacturing a solar cell according to an embodiment of the present invention.
도 6은 나노 크리스탈층의 두께에 따른 나노 크리스탈의 형상을 도시한 SEM 이미지.6 is a SEM image showing the shape of the nanocrystals according to the thickness of the nanocrystal layer.
도 7은 나노 크리스탈층의 두께에 따른 나노 크리스탈의 평균 면적, 밀도, 이격 거리 및 평균 직경의 변화를 도시한 그래프.Figure 7 is a graph showing the change in the average area, density, separation distance and average diameter of the nanocrystals with the thickness of the nanocrystal layer.
도 8은 나노 크리스탈층의 두께에 따른 나노 크리스탈의 단면 형상을 도시한 TEM 이미지.8 is a TEM image showing the cross-sectional shape of the nanocrystals according to the thickness of the nanocrystal layer.
도 9는 나노 크리스탈층의 두께에 따른 광학 손실의 변화를 도시한 그래프.9 is a graph showing the change in optical loss with the thickness of the nanocrystal layer.
도 10은 나노 크리스탈층의 두께에 따른 파장과 외부 양자 효율의 변화를 도시한 그래프.10 is a graph showing changes in wavelength and external quantum efficiency according to the thickness of the nanocrystal layer.
도 11은 나노 크리스탈층의 두께에 따른 외부 양자 효율의 변화를 도시한 그래프.11 is a graph showing a change in external quantum efficiency according to the thickness of a nanocrystal layer.
도 12는 나노 크리스탈층의 두께에 따른 유기물 태양전지 특성 변화를 도시한 그래프.12 is a graph showing the change of organic solar cell characteristics according to the thickness of the nano-crystal layer.
이하, 첨부된 도면을 참조하여 본 발명의 실시 예를 상세히 설명하기로 한다. 그러나, 본 발명은 이하에서 개시되는 실시 예에 한정되는 것이 아니라 서로 다른 다양한 형태로 구현될 것이며, 단지 본 실시 예들은 본 발명의 개시가 완전하도록 하며, 통상의 지식을 가진 자에게 발명의 범주를 완전하게 알려주기 위해 제공되는 것이다.Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention and to those skilled in the art. It is provided for complete information.
도 1은 본 발명의 일 실시 예에 따른 태양 전지의 단면도이고, 도 2 내지 도 4는 본 발명에 적용되는 나노 크리스탈의 단면 및 평면도이다.1 is a cross-sectional view of a solar cell according to an exemplary embodiment of the present invention, and FIGS. 2 to 4 are cross-sectional views and plan views of nanocrystals applied to the present invention.
도 1을 참조하면, 본 발명의 일 실시 예에 따른 태양 전지는 기판(100)과, 기판(100) 상에 형성된 제 1 전극(200)과, 제 1 전극(200) 상에 형성된 복수의 나노 크리스탈(310)을 포함하는 나노 크리스탈층(300)과, 나노 크리스탈층(300)을 포함한 제 1 전극(200) 상에 형성된 정공 이동층(400)과, 정공 이동층(400) 상에 형성된 광활성층(500)과, 광활성층(500) 상에 형성된 엑시톤 및 정공 블록킹층(600)과, 엑시톤 및 정공 블록킹층(600) 상에 형성된 전자 주입 및 계면층(700)과, 전자 주입 및 계면층(700) 상에 형성된 제 2 전극(800)를 포함한다. 여기서, 엑시톤 및 정공 블록킹층(600)과 전자 주입 및 계면층(700)을 형성하지 않고 광활성층(500) 상에 제 2 전극(800)을 형성할 수도 있다. 즉, 본 발명의 일 실시 예에 따른 태양 전지는 기판(100) 상의 적어도 일 영역에서 제 1 전극(200), 나노 크리스탈층(300), 정공 이동층(400), 광활성층(500) 및 제 2 전극(800)이 적층 형성될 수 있고, 광활성층(500)과 제 2 전극(800) 사이에 엑시톤 및 정공 블록킹층(600) 및 전자 주입 및 게면층(700)이 더 형성될 수도 있다.Referring to FIG. 1, a solar cell according to an exemplary embodiment of the present invention includes a substrate 100, a first electrode 200 formed on the substrate 100, and a plurality of nanoparticles formed on the first electrode 200. The nano crystal layer 300 including the crystal 310, the hole transport layer 400 formed on the first electrode 200 including the nano crystal layer 300, and the photoactive layer formed on the hole transport layer 400. The layer 500, the exciton and hole blocking layer 600 formed on the photoactive layer 500, the electron injection and interface layer 700 formed on the exciton and hole blocking layer 600, and the electron injection and interface layer. And a second electrode 800 formed on the 700. Here, the second electrode 800 may be formed on the photoactive layer 500 without forming the exciton and hole blocking layers 600, the electron injection, and the interface layer 700. That is, in the solar cell according to the exemplary embodiment, the first electrode 200, the nano crystal layer 300, the hole transport layer 400, the photoactive layer 500, and the first electrode 200 may be formed in at least one region on the substrate 100. The second electrode 800 may be stacked, and the exciton and hole blocking layer 600 and the electron injection and crab layer 700 may be further formed between the photoactive layer 500 and the second electrode 800.
기판(100)은 투명 기판을 이용할 수 있는데, 가시광선 파장대에서 적어도 70% 이상, 바람직하게는 80% 이상의 투과율을 갖는 투명 기판을 이용할 수 있다. 예를 들어, 기판(100)은 석영, 유리 등과 같은 투명 무기 기판을 이용할 수 있고, 폴리에틸렌테레프탈레이트(PET), 폴리에틸렌나프탈레이트(PEN), 폴리카보네이트(PC), 폴리스티렌(PS), 폴리프로필렌(PP), 폴리이미드(PI), 폴리에틸렌설포네이트(PES), 폴리옥시메틸렌(POM), AS 수지, ABS 수지 등의 플라스틱 기판을 이용할 수도 있다.The substrate 100 may use a transparent substrate, and may use a transparent substrate having a transmittance of at least 70% or more, preferably 80% or more in the visible light wavelength band. For example, the substrate 100 may use a transparent inorganic substrate such as quartz, glass, or the like, and may be polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polystyrene (PS), polypropylene ( Plastic substrates, such as PP), polyimide (PI), polyethylenesulfonate (PES), polyoxymethylene (POM), AS resin, and ABS resin, can also be used.
제 1 전극(200)은 기판(100) 상의 적어도 일 영역에 형성된다. 제 1 전극(200)은 기판(100)을 통과한 광이 광활성층(500)에 도달하는 경로가 되므로 높은 투명도를 갖는 물질로 형성하는 것이 바람직하다. 이를 위해 제 1 전극(200)은 예를 들어 인듐틴옥사이드(ITO), 금, 은, 플로린 도핑된 틴 옥사이드(FTO), ZnO-Ga2O3, ZnO-Al2O3, SnO2-Sb2O3 등을 이용하여 형성할 수 있다. 그러나, 이들 재질로 한정되지 않고 투명 도전성 물질은 제 1 전극(200)으로 이용될 수 있다.The first electrode 200 is formed in at least one region on the substrate 100. Since the light passing through the substrate 100 reaches the photoactive layer 500, the first electrode 200 may be formed of a material having high transparency. For this purpose, the first electrode 200 may be formed of, for example, indium tin oxide (ITO), gold, silver, florin doped tin oxide (FTO), ZnO-Ga 2 O 3 , ZnO-Al 2 O 3 , SnO 2 -Sb 2 O 3, etc. can be formed by using. However, the material is not limited to these materials and a transparent conductive material may be used as the first electrode 200.
나노 크리스탈층(300)은 복수의 나노 크리스탈(310)을 포함하여 제 1 전극(200) 상에 형성된다. 즉, 복수의 나노 크리스탈(310)은 제 1 전극(200)의 표면 상에 접촉 형성된다. 이러한 나노 크리스탈(310)은 광에 대한 반사도가 높은 물질로 형성될 수 있는데, 예를 들어 광에 대한 반사도가 50% 이상인 물질로 형성될 수 있다. 여기서, 광에 대한 반사도란 금속을 향해 입사되는 광의 양과 반사되는 광의 양을 비율을 의미한다. 이렇게 광에 대한 반사도 높은 물질은 예를 들면, 은, 금, 알루미늄, 구리, 니켈, 철, 티타늄 또는 그들의 합금, 칼슘/알루미늄 합금, 마그네슘/은 합금, 알루미늄/리튬 합금 등이 있으며, 이에 한정되는 것은 아니다. 복수의 나노 크리스탈(310)이 형성됨으로써 나노 크리스탈(310)에 의한 표면 플라즈몬 공명(surface plasmon resonance)이 발생된다. 표면 플라즈몬 공명은 음의 유전 함수(dielectric function, ε'<0)를 갖는 금속, 즉 나노 크리스탈(310)과 양의 유전 함수(ε'>0)를 갖는 매체, 즉 제 1 전극(200)의 계면을 따라 전파하는 전도대(conduction band) 전자들의 집단적인 진동(collective oscillation) 현상이다. 이러한 나노 크리스탈(310)에 의한 표면 플라즈마 공명에 의해 표면에서의 전계의 세기가 증폭되고, 그에 따라 광활성층(500)에서의 광 흡수를 증가시킬 수 있어 광전 변환 효율을 향상시킬 수 있다. 또한, 반사도가 높은 금속으로 나노 크리스탈(310)이 형성됨으로써 광이 나노 크리스탈(310) 사이를 통과하면서 나노 크리스탈(310) 사이에서 산란하게 되고, 그에 따라 광량이 증가하게 된다. 나노 크리스탈(310)을 통과하면서 광량이 증가하기 때문에 광활성층(500)에서의 광 흡수를 증가시킬 수 있고, 그에 따라 광전 변환 효율을 향상시킬 수 있다. 즉, 제 1 전극(200) 상부에 형성된 복수의 나노 크리스탈(310)에 의한 표면 플라즈몬 공진 및 광 산란에 의해 광활성층(500)에 공급되는 광량을 증가시킬 수 있어 광활성층(500)의 광 흡수를 증가시킬 수 있고, 그에 따라 광전 변환 효율을 향상시킬 수 있다. 본 발명에 따른 복수의 나노 크리스탈(310)을 포함하는 나노 크리스탈층(300)에 대해서는 이후 상세히 설명한다.The nano crystal layer 300 includes a plurality of nano crystals 310 and is formed on the first electrode 200. That is, the plurality of nanocrystals 310 are formed in contact on the surface of the first electrode 200. The nanocrystals 310 may be formed of a material having high reflectivity for light, for example, may be formed of a material having a reflectivity of light of 50% or more. Here, the reflectivity with respect to light means the ratio of the amount of light incident to the metal and the amount of reflected light. Such highly reflective materials are, for example, silver, gold, aluminum, copper, nickel, iron, titanium or alloys thereof, calcium / aluminum alloys, magnesium / silver alloys, aluminum / lithium alloys, and the like. It is not. As the plurality of nanocrystals 310 are formed, surface plasmon resonance caused by the nanocrystals 310 is generated. The surface plasmon resonance of the metal having the negative dielectric function ε '<0, i.e., the medium having the nanocrystal 310 and the positive dielectric function ε'> 0, i.e., the first electrode 200 It is a collective oscillation phenomenon of conduction band electrons propagating along the interface. The intensity of the electric field on the surface is amplified by the surface plasma resonance by the nanocrystals 310, thereby increasing the light absorption in the photoactive layer 500, thereby improving the photoelectric conversion efficiency. In addition, since the nanocrystals 310 are formed of a highly reflective metal, light is scattered between the nanocrystals 310 while passing through the nanocrystals 310, thereby increasing the amount of light. Since the amount of light increases while passing through the nanocrystal 310, light absorption in the photoactive layer 500 may be increased, thereby improving photoelectric conversion efficiency. That is, the amount of light supplied to the photoactive layer 500 may be increased by surface plasmon resonance and light scattering by the plurality of nanocrystals 310 formed on the first electrode 200, thereby absorbing light of the photoactive layer 500. Can be increased, thereby improving the photoelectric conversion efficiency. The nanocrystal layer 300 including the plurality of nanocrystals 310 according to the present invention will be described in detail later.
정공 이동층(400)은 복수의 나노 크리스탈(310)을 포함하는 나노 크리스탈층(300)을 포함하여 제 1 전극(200) 상부에 형성된다. 즉, 정공 이동층(400)은 복수의 나노 크리스탈(310)을 덮도록 제 1 전극(200) 상부에 형성된다. 정공 이동층(400)은 광활성층(500)에서 분리된 정공이 제 1 전극(200)에 도달되도록 한다. 따라서, 정공 이동층(400)은 정공의 이동을 원활하게 할 수 있는 물질을 이용하여 형성할 수 있다. 예를 들어, 정공 이동층(400)은 PEDOT(폴리(3,4-에틸렌디옥시티오펜)), PSS(폴리(스티렌설포네이트)), 폴리아닐린, 프탈로시아닌, 펜타센, 폴리디페닐아세틸렌, 폴리(t-부틸)디페닐아세틸렌, 폴리(트리플루오로메틸)디페닐아세틸렌, Cu-PC(커퍼 프탈로시아닌) 폴리(비스트리플루오로메틸)아세틸렌, 폴리비스(T-부틸디페닐)아세틸렌, 폴리(트리메틸실릴)디페닐아세틸렌, 폴리(카르바졸)디페닐아세틸렌, 폴리디아세틸렌, 폴리페닐아세틸렌, 폴리피리딘아세틸렌, 폴리메톡시페닐아세틸렌, 폴리메틸페닐아세틸렌, 폴리(t-부틸)페닐아세틸렌, 폴리니트로페닐아세틸렌, 폴리(트리플루오로메틸)페닐아세틸렌, 폴리(트리메틸실릴)페닐아세틸렌 및 이들의 유도체와 같은 전도성 고분자 등이 하나 또는 둘 이상의 조합으로 사용될 수 있다. 바람직하게, PEDOT-PSS 혼합물을 이용하여 정공 이동층(400)을 형성할 수 있다. 또한, 정공 이동층(400)은 산화물 계열의 물질, 예를 들어 MoOx, V2O5, VOx, WO3, NiOx, Cu2O의 적어도 어느 하나로 형성할 수 있다.The hole transport layer 400 includes a nanocrystal layer 300 including a plurality of nanocrystals 310 and is formed on the first electrode 200. That is, the hole transport layer 400 is formed on the first electrode 200 to cover the plurality of nanocrystals 310. The hole transport layer 400 allows holes separated from the photoactive layer 500 to reach the first electrode 200. Therefore, the hole moving layer 400 may be formed using a material capable of smoothly moving holes. For example, the hole transport layer 400 may include PEDOT (poly (3,4-ethylenedioxythiophene)), PSS (poly (styrenesulfonate)), polyaniline, phthalocyanine, pentacene, polydiphenylacetylene, poly ( t-butyl) diphenylacetylene, poly (trifluoromethyl) diphenylacetylene, Cu-PC (copper phthalocyanine) poly (bistrifluoromethyl) acetylene, polybis (T-butyldiphenyl) acetylene, poly (trimethyl Silyl) diphenylacetylene, poly (carbazole) diphenylacetylene, polydiacetylene, polyphenylacetylene, polypyridineacetylene, polymethoxyphenylacetylene, polymethylphenylacetylene, poly (t-butyl) phenylacetylene, polynitrophenylacetylene Conductive polymers such as poly (trifluoromethyl) phenylacetylene, poly (trimethylsilyl) phenylacetylene and derivatives thereof and the like can be used in one or two or more combinations. Preferably, the hole transport layer 400 may be formed using the PEDOT-PSS mixture. In addition, the hole transport layer 400 may be formed of at least one of an oxide-based material, for example, MoO x , V 2 O 5 , VO x , WO 3 , NiO x , Cu 2 O.
광활성층(500)은 정공 이동층(400) 상에 형성되며, 전자 공여체와 전자 수용체가 블렌딩된 물질이 스핀 코팅 등의 방법으로 형성될 수 있다. 외부에서 제 1 전극(200)을 통해 입사된 광은 복수의 나노 크리스탈(310)에 의해 증폭되어 광활성층(500)에 형성된 전자 공여체에 의해 흡수된다. 또한, 흡수되지 않은 광은 제 2 전극(800)에서 반사되어 다시 전자 공여체에 의해 재흡수된다. 이때, 재흡수되지 않은 광은 나노 크리스탈(310)에 의해 재반사되어 광활성층(500)에 재흡수될 수 있다. 따라서, 외부에서 입사되는 광이 나노 크리스탈(310)에 의해 증폭 및 반사되므로 광활성층(500)에서의 광흡수율이 증가하게 된다. 전자 공여체로서는 P3HT(폴리(3-헥실티오펜)), 폴리실록산 카르바졸, 폴리아닐린, 폴리에틸렌 옥사이드, (폴리(1-메톡시-4-(0-디스퍼스레드1)-2,5-페닐렌-비닐렌), 폴리인돌, 폴리카르바졸, 폴리피리디아진, 폴리이소 티아나프탈렌, 폴리페닐렌 설파이드, 폴리비닐피리딘, 폴리티오펜, 폴리플루오렌, 폴리피리딘, 그리고 이들의 유도체 등을 포함하는 전도성 고분자의 어느 하나 또는 2종 이상의 물질을 혼합하여 이용할 수 있다. 또한, 전자 수용체로서는 플러렌 또는 플러렌 유도체를 이용할 수 있다. 바람직하게 광활성층(500)은 전자 공여체로서 P3HT와 전자 수용체로서 플러렌 유도체인 PCBM([6,6]-phenyl-C61 butyric acid methyl ester)의 혼합물을 이용할 수 있다. 여기서, P3HT와 PCBM은 1:0.1 내지 2:1의 중량비(wt%)로 혼합될 수 있다. 이러한 광활성층(500)은 예를 들어 스프레잉, 스핀 코팅, 딥핑, 프린팅, 닥터블레이딩, 스퍼터링 등의 방법을 이용하여 형성할 수 있다.The photoactive layer 500 is formed on the hole transport layer 400, and a material in which the electron donor and the electron acceptor are blended may be formed by spin coating or the like. Light incident from the outside through the first electrode 200 is amplified by the plurality of nanocrystals 310 and absorbed by the electron donor formed in the photoactive layer 500. In addition, the unabsorbed light is reflected by the second electrode 800 and is again absorbed by the electron donor. In this case, the light that is not reabsorbed may be rereflected by the nanocrystals 310 to be reabsorbed by the photoactive layer 500. Therefore, since light incident from the outside is amplified and reflected by the nanocrystals 310, the light absorption rate of the photoactive layer 500 is increased. Examples of the electron donor include P3HT (poly (3-hexylthiophene)), polysiloxane carbazole, polyaniline, polyethylene oxide, (poly (1-methoxy-4- (0-dispersed 1) -2,5-phenylene- Vinylene), polyindole, polycarbazole, polypyridazine, polyiso thianaphthalene, polyphenylene sulfide, polyvinylpyridine, polythiophene, polyfluorene, polypyridine, derivatives thereof and the like One or two or more substances of the polymer may be mixed and used, and fullerene or fullerene derivative may be used as the electron acceptor, and preferably, the photoactive layer 500 may include P3HT as an electron donor and PCBM as a fullerene derivative as the electron acceptor. A mixture of ([6,6] -phenyl-C61 butyric acid methyl ester) can be used, wherein P3HT and PCBM can be mixed in a weight ratio (wt%) of 1: 0.1 to 2: 1. 500 spraying for example , Spin coating, dipping, printing, doctor blading, sputtering or the like can be formed.
엑시톤 및 정공 블록킹층(600)은 광활성층(500) 상에 형성되어 광활성층(500)에서 분리된 정공과 분리되지 않은 엑시톤들이 제 2 전극(800)으로 이동하여 다시 재결합하는 것을 방지한다. 이러한 엑시톤 및 정공 블로킹층(600)은 예를 들어 BCP(bathocuproine)와 같이 HOMO(highest Occupied Molecular Orbital) 에너지 준위가 높은 물질을 이용하여 형성할 수 있다. 또한, 엑시톤 및 정공 블록킹층(600)은 금속 산화물(metal oxide)을 이용하여 형성할 수도 있는데, 예를 들어 TiOx, ZnO, Al2O3, CaO의 적어도 어느 하나를 이용하여 형성할 수도 있다. The exciton and hole blocking layer 600 may be formed on the photoactive layer 500 to prevent holes separated from the photoactive layer 500 and excitons not separated from moving to the second electrode 800 to be recombined again. The exciton and hole blocking layer 600 may be formed using a material having a high highest Occupied Molecular Orbital (HOMO) energy level, such as, for example, bathocuproine (BCP). In addition, the exciton and the hole blocking layer 600 may be formed using a metal oxide, for example, at least one of TiO x , ZnO, Al 2 O 3 , and CaO. .
전자 주입 및 계면층(700)은 엑시톤에서 분리된 전자들이 제 2 전극(800)으로 잘 주입하게 하며, 또한 광활성층(500) 또는 엑시톤 및 정공 블로킹층(600)과 제 2 전극(800)과의 계면 특성을 향상시키며, 알칼리 금속 화합물을 이용하여 형성할 수 있다. 예를 들어, 엑시톤 및 정공 블록킹층(600)은 LiF, CsF, Liq, LiCoO2, Cs2CO3 등을 이용하여 형성할 수 있다.The electron injection and interfacial layer 700 allows electrons separated from the exciton to be well injected into the second electrode 800, and also the photoactive layer 500 or the exciton and hole blocking layer 600 and the second electrode 800. It can improve the interfacial property of and can form using an alkali metal compound. For example, the exciton and hole blocking layer 600 may be formed using LiF, CsF, Liq, LiCoO 2 , Cs 2 CO 3, or the like.
제 2 전극(800)은 전자 주입 및 계면층(700) 상에 형성된다. 제 2 전극(800)은 제 1 전극(200)을 통해 입사되었으나, 광활성층(500)에서 흡수되지 못한 광을 광활성층(500)에서 재흡수되도록 하기 위해 반사도가 높고 저항이 적은 물질을 이용하여 형성할 수 있다. 이러한 제 2 전극(800) 물질로는 제 1 전극(200)의 물질보다는 낮은 일함수의 물질을 이용할 수 있는데, 예를 들어 마그네슘, 칼슘, 나트륨, 칼륨, 티타늄, 인듐, 이트륨, 리튬, 알루미늄, 은, 주석 및 납과 같은 금속, 또는 이들의 합금을 포함할 수 있다.The second electrode 800 is formed on the electron injection and interfacial layer 700. The second electrode 800 is incident through the first electrode 200, but uses a material having high reflectivity and low resistance to reabsorb light that is not absorbed by the photoactive layer 500 in the photoactive layer 500. Can be formed. As the material of the second electrode 800, a material having a lower work function than that of the first electrode 200 may be used. For example, magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, aluminum, Metals such as silver, tin and lead, or alloys thereof.
도 2 내지 도 4를 이용하여 본 발명에 따른 나노 크리스탈에 대해 상세하게 설명한다. 도 2는 본 발명에 따른 나노 크리스탈의 단면 개념도이고, 도 3은 나노 크리스탈층의 증착 두께에 따른 나노 크리스탈의 형상 변화를 설명하기 위한 단면 개념도이며, 도 4는 나노 크리스탈의 평면 개념도 및 단면 개념도이다.2 to 4 will be described in detail with respect to the nano-crystal according to the present invention. 2 is a cross-sectional conceptual view of a nanocrystal according to the present invention, Figure 3 is a cross-sectional conceptual view for explaining the shape change of the nano-crystal according to the deposition thickness of the nano-crystal layer, Figure 4 is a plan view and a cross-sectional conceptual view of the nano-crystal. .
도 2 내지 도 4를 참조하면, 나노 크리스탈(310)에 의한 표면 플라즈몬 효과를 위해 나노 크리스탈층(300)은 1㎚∼15㎚의 두께로 형성될 수 있다. 즉, 나노 크리스탈층(300)은 예를 들어 열 증착(thermal evaporation) 방법으로 형성할 수 있는데, 두께 측정기를 이용하여 측정된 두께 또는 설정된 두께를 1㎚∼15㎚로 하여 나노 크리스탈층(300)을 형성할 수 있다. 두께 측정기는 크리스탈 센서를 포함하여 챔버 내부에 마련되며, 증착 두께에 따른 센서의 진동에 의해 두께를 확인할 수 있다. 또한, SEM, TEM 등의 광학적 분석을 통해 두께를 확인할 수도 있다. 한편, 나노 크리스탈층(300)의 두께는 공급되는 DC 파워, 증착 시간 및 증착 속도 등을 이용하여 설정할 수 있다. 그런데, 이러한 두께로 나노 크리스탈층(300)을 형성한 후 나노 크리스탈(310)의 사이즈를 측정하면 나노 크리스탈(310)은 도 2에 도시된 바와 같이 일 방향의 길이, 즉 장축(a)의 길이가 6㎚∼160㎚로 형성되고, 일 방향과 직교하는 타 방향의 길이, 즉 단축(b)의 길이가 5㎚∼30㎚으로 형성될 수 있다. 즉, 나노 크리스탈층(300)을 소정 두께로 형성한 후 나노 크리스탈(310)을 측정하면 나노 크리스탈(310)이 나노 크리스탈층(300)의 두께보다 크게 형성될 수 있다. 이때, 장축(a)은 가로 방향으로 도시되고 단축(b)은 세로 방향으로 도시되었으나, 상대적으로 긴 방향이 장축(a)이 되고 짧은 방향이 단축(b)이 될 수 있다. 즉, 나노 크리스탈(310)은 장축(a)과 단축(b)의 길이가 같은 구 형상으로 마련될 수도 있고, 장축(a)이 단축(b)보다 긴 타원형으로 마련될 수도 있다. 한편, 나노 크리스탈층(300)은 바람직하게 5㎚∼8㎚의 두께로 형성되고, 이때의 나노 크리스탈(310)은 장축(a)의 길이가 15㎚∼45㎚, 단축(b)의 길이가 8㎚∼17㎚로 형성될 수 있다. 즉, 나노 크리스탈층(300)의 두께가 두꺼울수록 나노 크리스탈(310)의 사이즈가 커질 수 있다. 그러나, 나노 크리스탈층(300)이 5㎚∼8㎚의 두께로 형성되고, 나노 크리스탈(310)은 장축(a)의 길이가 15㎚∼45㎚, 단축(b)의 길이가 8㎚∼17㎚로 형성될 때 광학 손실(optical loss)이 적고 외부 양자 효율(external quantum efficiency)이 높으므로 바람직하다.2 to 4, the nanocrystal layer 300 may be formed to a thickness of 1 nm to 15 nm for the surface plasmon effect by the nano crystal 310. That is, the nanocrystal layer 300 may be formed by, for example, a thermal evaporation method. The nanocrystal layer 300 may have a thickness or a set thickness measured using a thickness meter as 1 nm to 15 nm. Can be formed. The thickness meter is provided inside the chamber including the crystal sensor, and the thickness may be checked by vibration of the sensor according to the deposition thickness. In addition, the thickness may be confirmed through optical analysis such as SEM and TEM. On the other hand, the thickness of the nano crystal layer 300 may be set using the supplied DC power, deposition time and deposition rate. However, when the nanocrystal layer 300 is formed to such a thickness and the size of the nanocrystal 310 is measured, the nanocrystal 310 has a length in one direction, that is, a length of a long axis (a), as shown in FIG. 2. 6 nm to 160 nm, and the length in the other direction orthogonal to one direction, that is, the length of the short axis b, may be formed to 5 nm to 30 nm. In other words, when the nanocrystal layer 300 is formed to a predetermined thickness and the nanocrystal 310 is measured, the nanocrystal 310 may be larger than the thickness of the nanocrystal layer 300. At this time, the long axis (a) is shown in the horizontal direction and the short axis (b) is shown in the longitudinal direction, the relatively long direction may be a long axis (a) and the short direction may be a short axis (b). That is, the nanocrystals 310 may be provided in a spherical shape with the same length of the long axis a and the short axis b, or may be provided in an elliptical shape where the long axis a is longer than the short axis b. On the other hand, the nanocrystal layer 300 is preferably formed in a thickness of 5nm to 8nm, the nanocrystal 310 at this time is the length of the long axis (a) is 15nm to 45nm, the length of the short axis (b) 8 nm to 17 nm. That is, as the thickness of the nanocrystal layer 300 increases, the size of the nanocrystal 310 may increase. However, the nanocrystal layer 300 is formed to a thickness of 5 nm to 8 nm, and the nano crystal 310 has a length of 15 nm to 45 nm in the major axis a and a length of 8 nm to 17 in the minor axis b. When formed in nm, it is preferable because of the low optical loss and high external quantum efficiency.
또한, 나노 크리스탈층(300)은 점(dot) 모양의 나노 크리스탈(310)이 형성되고, 증착 두께가 증가할수록 나노 크리스탈(310)이 커지면서 섬(island) 모양으로 형상이 변화되면서 두께가 더 증가하면 층(layer)을 형성하게 된다. 즉, 도 3(a)에 도시된 바와 같이 제 1 전극(200) 상에 점 모양의 나노 크리스탈(310)이 형성되고, 증착 두께가 증가함에 따라 도 3(b)에 도시된 바와 같이 제 1 전극(200)과의 접촉 면적이 증가하여 나노 크리스탈(310)의 사이즈가 증가하고, 도 3(c)에 도시된 바와 같이 제 1 전극(200)과의 접촉 면적이 나노 크리스탈(310)의 장축의 길이보다 큰 섬 모양을 갖게 된다. 여기서, 나노 크리스탈(310)의 사이즈가 더 커지면 나노 크리스탈(310)이 결합되면서 층(layer)을 이루게 된다.In addition, the nano crystal layer 300 has a dot-shaped nano crystal 310 is formed, and as the deposition thickness increases, the nano crystal 310 increases in shape as the island shape becomes larger as the nano crystal 310 increases. The lower layer forms a layer. That is, as shown in FIG. 3 (a), a dot-shaped nanocrystal 310 is formed on the first electrode 200, and as the deposition thickness increases, the first as shown in FIG. 3 (b). The contact area with the electrode 200 increases to increase the size of the nanocrystal 310, and as shown in FIG. 3C, the contact area with the first electrode 200 has a long axis of the nanocrystal 310. It will have an island shape larger than its length. In this case, when the size of the nanocrystal 310 is larger, the nanocrystals 310 are combined to form a layer.
그리고, 나노 크리스탈층(300)이 1㎚∼15㎚의 두께로 형성되면 나노 크리스탈(310)은 평균 직경(D)이 7㎚∼160㎚로 형성되고, 인접한 나노 크리스탈(310) 사이의 평균 이격 거리(C)는 20㎚∼180㎚로 형성되며, 나노 크리스탈(310)의 밀도는 25∼1800으로 형성될 수 있다. 바람직하게, 나노 크리스타층(300)이 5㎚∼8㎚의 두께로 형성되면 나노 크리스탈(310)은 평균 직경(D)이 15㎚∼45㎚로 형성되고, 인접한 나노 크리스탈(310) 사이의 평균 이격 거리(C)는 25㎚∼75㎚로 형성되며, 나노 크리스탈(310)의 밀도는 170∼1100으로 형성될 수 있다. 여기서, 나노 크리스탈(310)의 평균 직경(D)은 도 4에 도시된 바와 같이 나노 크리스탈(310)의 제 1 전극(200)의 접촉 거리(d)보다 클 수 있다. 나노 크리스탈(310)은 제 1 전극(200) 상에 접촉 형성되기 때문에 제 1 전극(200)과의 접촉 거리가 0보다 크다. 즉, 나노 크리스탈(310)의 제 1 전극(200)과의 접촉 거리(d)는 0보다 크고 나노 크리스탈(310)의 평균 직경(D)보다 작을 수 있다. 그런데, 나노 크리스탈(310)의 접촉 거리(d)가 평균 직경(D)보다 크면 나노 크리스탈(310)이 도 3(c)에 도시된 바와 같이 섬 모양으로 형성되고, 이 경우 광학 손실이 크고 외부 양자 효율이 낮아지므로 바람직하지 않다.When the nanocrystal layer 300 is formed to a thickness of 1 nm to 15 nm, the nano crystal 310 has an average diameter (D) of 7 nm to 160 nm, and an average separation between adjacent nano crystals 310. The distance C may be formed to be 20 nm to 180 nm, and the density of the nanocrystals 310 may be formed to be 25 to 1800. Preferably, when the nano-crista layer 300 is formed to a thickness of 5 nm to 8 nm, the nano crystal 310 has an average diameter D of 15 nm to 45 nm, and an average between adjacent nano crystals 310 is formed. The separation distance C may be formed to be 25 nm to 75 nm, and the density of the nanocrystals 310 may be formed to be 170 to 1100. Here, the average diameter D of the nanocrystals 310 may be larger than the contact distance d of the first electrode 200 of the nanocrystals 310 as shown in FIG. 4. Since the nanocrystal 310 is in contact with the first electrode 200, the contact distance with the first electrode 200 is greater than zero. That is, the contact distance d of the nanocrystals 310 with the first electrode 200 may be greater than zero and smaller than the average diameter D of the nanocrystals 310. However, when the contact distance (d) of the nanocrystals 310 is larger than the average diameter (D), the nanocrystals 310 are formed in an island shape as shown in FIG. It is not preferable because the quantum efficiency is lowered.
상술한 바와 같은, 본 발명의 실시 예들에 따른 태양 전지는 제 1 전극(200) 상에 제 1 전극(200)과 접촉되어 복수의 나노 크리스탈(310)을 포함하는 나노 크리스탈층(300)이 형성된다. 복수의 나노 크리스탈(310)에 의한 표면 플라즈몬 효과에 의해 전계가 증폭되어 광활성층(500)에 공급되고, 광 반사도가 높은 복수의 나노 크리스탈(310)에 의한 광 산란에 의해 광량이 증폭되어 광활성층(500)에 공급된다. 따라서, 광활성층(500)에서의 광 흡수를 증가시킬 수 있고, 그에 따라 광전 변환 효율을 향상시킬 수 있다. 즉, 나노 크리스탈(310)이 형성되지 않는 경우에 비해 30% 정도의 외부 양자 효율 향상시킬 수 있다.As described above, in the solar cell according to the embodiments of the present invention, the nanocrystal layer 300 including the plurality of nanocrystals 310 is formed by contacting the first electrode 200 on the first electrode 200. do. The electric field is amplified by the surface plasmon effect by the plurality of nanocrystals 310 and supplied to the photoactive layer 500, and the amount of light is amplified by the light scattering by the plurality of nanocrystals 310 having high light reflectivity and the photoactive layer. Supplied to 500. Therefore, light absorption in the photoactive layer 500 can be increased, thereby improving photoelectric conversion efficiency. That is, compared to the case where the nanocrystals 310 are not formed, an external quantum efficiency of about 30% can be improved.
도 5는 본 발명의 일 실시 예에 따른 태양 전지의 제조 방법을 설명하기 위한 공정 흐름도이다.5 is a flowchart illustrating a method of manufacturing a solar cell according to an embodiment of the present invention.
도 5를 참조하면, 광활성층 재료 및 정공 이동층 재료를 준비한다(S110). 광 활성층 재료를 준비하기 위해 전자 공여체와 전자 수용체를 소정의 비율로 소정의 용매에 혼합할 수 있다. 예를 들어, P3HT와 PCBM를 1:0.1∼2:1의 중량비로 혼합하고, 이들의 혼합물을 1∼5 중량비로 1,2 디클로로벤젠(1,2 dichlorobenzene)에 혼합한 후 최소 72시간 동안 블렌딩하여 광활성층 재료를 준비할 수 있다. 여기서, 용매는 2-클로로벤젠 이외에 클로로벤젠, 벤젠, 클로로폼 및 THF 등을 이용할 수 있다. 또한, 정공 이동층 재료를 준비하기 위해 예를 들어 PEDOT-PSS와 이소프로필 알콜(Isopropyl Alcohol; IPA)을 1:2의 중량비로 최소 24시간 동안 블렌딩할 수 있다.Referring to FIG. 5, a photoactive layer material and a hole transport layer material are prepared (S110). In order to prepare the photoactive layer material, the electron donor and the electron acceptor may be mixed in a predetermined solvent in a predetermined solvent. For example, P3HT and PCBM are mixed in a weight ratio of 1: 0.1 to 2: 1, and a mixture thereof is mixed in 1,2 dichlorobenzene in 1 to 5 weight ratios and then blended for a minimum of 72 hours. The photoactive layer material can be prepared. Here, the solvent may be used in addition to 2-chlorobenzene chlorobenzene, benzene, chloroform and THF. In addition, for example, PEDOT-PSS and Isopropyl Alcohol (IPA) may be blended in a weight ratio of 1: 2 for at least 24 hours to prepare a hole transporting layer material.
이어서, 기판 상에 제 1 전극을 형성한다(S120). 기판은 가시광선 파장대에서 적어도 70% 이상, 바람직하게는 80% 이상의 투과율을 갖는 투명 기판을 이용할 수 있다. 또한, 제 1 전극은 ITO 등의 투명 도전성 물질을 기판 상에 형성한 후 패터닝하여 형성할 수 있다. 그리고, 제 1 전극을 형성한 후 아세톤 등을 이용하여 기판을 세정할 수 있다. 세정은 예를 들어 10분∼100분 정도 실시할 수 있고, 세정 후 50℃∼100℃의 온도에서 5시간∼15시간 정도 건조시킬 수 있다. 한편, 아세톤 이외에 이소프로필 알콜, 순수(DI)를 이용하여 기판을 세정할 수도 있다.Subsequently, a first electrode is formed on the substrate (S120). The substrate may use a transparent substrate having a transmittance of at least 70% or more, preferably 80% or more, in the visible light wavelength band. In addition, the first electrode may be formed by forming a transparent conductive material such as ITO on a substrate and then patterning the same. After forming the first electrode, the substrate may be cleaned using acetone or the like. Washing can be performed, for example for 10 to 100 minutes, and can be dried for 5 to 15 hours at the temperature of 50 to 100 degreeC after washing | cleaning. On the other hand, in addition to acetone, isopropyl alcohol and pure water (DI) may be used to clean the substrate.
이어서, 기판 상에 산소 플라즈마 처리를 실시한 후 365㎚ 파장의 자외선 처리를 실시할 수 있다(S130). 이때, 플라즈마 처리 및 자외선 처리는 어느 하나만을 실시할 수도 있다. 플라즈마 처리는 제 1 전극의 표면 거칠기(surface roughness)를 완만하게 만들고, 제 1 전극의 일함수를 증가시키기 위해 실시한다. 또한, 자외선 처리는 세정 공정 후에도 제 1 전극 표면에 잔류하는 유기물을 제거하기 위해 실시한다.Subsequently, an oxygen plasma treatment may be performed on the substrate, followed by ultraviolet treatment having a wavelength of 365 nm (S130). At this time, only one of the plasma treatment and the ultraviolet treatment may be performed. Plasma treatment is performed to smooth the surface roughness of the first electrode and to increase the work function of the first electrode. In addition, ultraviolet treatment is performed in order to remove the organic substance which remains on the surface of a 1st electrode after a washing process.
이어서, 제 1 전극이 형성된 기판 상에 복수의 나노 크리스탈을 포함하는 나노 크리스탈층을 형성한다(S140). 나노 크리스탈층은 은(Ag)을 포함하여 반사도가 높은 금속을 이용하여 형성할 수 있다. 또한, 나노 크리스탈층은 진공 상태에서 열증착 방법으로 형성할 수 있다. 이때, 나노 크리스탈층은 증착 두께, 증착 시간 등에 따라 예를 들어 0.1∼2.0Å/sec의 증착 속도로 형성할 수 있다. 한편, 기화 방법 이외에 다양한 방법으로 나노 크리스탈층을 형성할 수 있는데, 스퍼터, E-빔, 코팅 방법 등을 이용하여 형성할 수도 있다. 이렇게 형성된 나노 크리스탈층은 예를 들어 1㎚∼15㎚의 두께로 형성할 수 있고, 바람직하게는 5㎚∼8㎚의 두께로 형성할 수 있다. 즉, 나노 크리스탈층은 두께 측정기 또는 광학적 분석을 통해 측정된 두께 또는 설정된 두께를 1㎚∼15㎚, 바람직하게는 5㎚∼8㎚로 하여 형성할 수 있다. 이때, 나노 크리스탈은 장축(a)의 길이가 6㎚∼160㎚로 형성되고, 단축(b)의 길이가 5㎚∼30㎚으로 형성될 수 있다. 바람직하게는 장축(a)의 길이가 15㎚∼45㎚, 단축(b)의 길이가 8㎚∼17㎚로 형성될 수 있다. 또한, 나노 크리스탈은 평균 직경(D)이 7㎚∼160㎚, 바람직하게는 15㎚∼45㎚로 형성되고, 인접한 나노 크리스탈(310) 사이의 평균 이격 거리(C)는 20㎚∼180㎚, 바람직하게는 25㎚∼75㎚로 형성되며, 밀도는 25∼1800, 바람직하게는 170∼1100으로 형성될 수 있다.Subsequently, a nanocrystal layer including a plurality of nanocrystals is formed on the substrate on which the first electrode is formed (S140). The nanocrystal layer may be formed using a metal having high reflectivity including silver (Ag). In addition, the nanocrystal layer can be formed by a thermal deposition method in a vacuum state. In this case, the nanocrystal layer may be formed at a deposition rate of, for example, 0.1 to 2.0 kV / sec depending on the deposition thickness, the deposition time, and the like. Meanwhile, the nanocrystal layer may be formed by various methods other than the vaporization method, and may be formed using a sputter, an E-beam, a coating method, or the like. The nanocrystal layer thus formed may be formed, for example, in a thickness of 1 nm to 15 nm, and preferably in a thickness of 5 nm to 8 nm. That is, the nanocrystal layer may be formed with a thickness or a set thickness measured by a thickness meter or optical analysis as 1 nm to 15 nm, preferably 5 nm to 8 nm. In this case, the nanocrystals may have a length of 6 nm to 160 nm in the major axis (a) and a length of 5 nm to 30 nm in the minor axis (b). Preferably, the length of the major axis a may be 15 nm to 45 nm, and the length of the minor axis b may be 8 nm to 17 nm. Further, the nanocrystals have an average diameter (D) of 7 nm to 160 nm, preferably 15 nm to 45 nm, and the average separation distance (C) between adjacent nanocrystals 310 is 20 nm to 180 nm, Preferably it is formed from 25 nm to 75 nm, the density may be formed from 25 to 1800, preferably 170 to 1100.
이어서, 복수의 나노 크리스탈을 덮도록 제 1 전극 상에 정동 이동층을 형성한다(150). 정공 이동층은 PEDOT-PSS와 IPA가 블렌딩된 상기 정공 이동층 재료 물질을 예를 들어 60초∼300초 동안 1000rpm∼3000rpm으로 스핀 코팅하고 100℃∼150℃의 질소 분위기에서 10분∼100분 동안 어닐링하여 형성할 수 있다. 즉, 정공 이동층의 두께에 따라 스핀 코팅의 시간 및 회전수, 어닐링 온도 및 시간을 조절할 수 있다. Subsequently, an electron transport layer is formed on the first electrode to cover the plurality of nanocrystals (150). The hole transport layer is spin-coated the PEDOT-PSS and the IPA blended material of the hole transport layer material at, for example, 60 rpm to 300 seconds at 1000 rpm to 3000 rpm for 10 minutes to 100 minutes in a nitrogen atmosphere of 100 ° C to 150 ° C. It can be formed by annealing. That is, the time and rotation speed of the spin coating, the annealing temperature and the time may be adjusted according to the thickness of the hole transport layer.
이어서, 정공 이동층 상에 광활성층을 형성한다(S160). 광활성층은 P3HT 및 PCBM을 2-클로로벤젠에 혼합한 상기 광활성층 재료를 60초∼300초 동안 500rpm∼2000rpm으로 스핀 코팅한 후 100℃∼150℃의 질소 분위기에서 10분∼100분 동안 어닐링하여 형성할 수 있다. 즉, 광활성층의 두께에 따라 스핀 코팅의 시간 및 회전수, 어닐링 온도 및 시간을 조절할 수 있다. Subsequently, a photoactive layer is formed on the hole transport layer (S160). The photoactive layer was spin-coated the photoactive layer material containing P3HT and PCBM in 2-chlorobenzene at 500 rpm to 2000 rpm for 60 seconds to 300 seconds, followed by annealing for 10 to 100 minutes in a nitrogen atmosphere at 100 ° C to 150 ° C. Can be formed. That is, the time and rotation speed of the spin coating, the annealing temperature and the time can be adjusted according to the thickness of the photoactive layer.
이어서, 광활성층 상에 증착기를 사용하여 BCP(bathocuproine)를 6㎚ 정도의 두께로 증착하여 엑시톤 및 정공 블록킹층을 형성하고(S170), 엑시톤 및 정공 블록킹층 상에 플루오르화 리튬(LiF)을 0.5㎚ 정도의 두께로 증착하여 전자 주입 및 계면층을 형성한 후(S180) 알루미늄(Al)을 80㎚ 정도의 두께로 증착하여 제 2 전극을 형성한다(S190).Subsequently, BCP (bathocuproine) is deposited on the photoactive layer to a thickness of about 6 nm to form an exciton and a hole blocking layer (S170), and lithium fluoride (LiF) is 0.5 on the exciton and the hole blocking layer. After the deposition to a thickness of about ㎚ to form an electron injection and the interface layer (S180) and aluminum (Al) is deposited to a thickness of about 80nm to form a second electrode (S190).
실시 예Example
P3HT 및 PCBM을 2:1의 중량비로 혼합한 후 2wt%로 1,2 디클로로벤젠에 혼합하고 72시간 동안 블렌딩하여 광활성층 재료를 준비하였다. 또한, PEDOT-PSS와 IPA을 1:2의 중량비로 24시간 동안 블렌딩하여 정공 이동층 재료를 준비하였다.P3HT and PCBM were mixed at a weight ratio of 2: 1, then mixed with 1,2 dichlorobenzene at 2wt% and blended for 72 hours to prepare a photoactive layer material. In addition, PEDOT-PSS and IPA were blended at a weight ratio of 1: 2 for 24 hours to prepare a hole transport layer material.
그리고, 투명 기판 상에 ITO를 이용하여 제 1 전극을 형성하고, 제 1 전극 상에 은(Ag)을 증착시켜 복수의 나노 크리스탈을 포함하는 나노 크리스탈층을 형성하였다. 이때, 나노 크리스탈층은 0.3Å/sec의 증착 속도로 형성하였으며, 복수의 기판 상에 3㎚로부터 15㎚의 두께로 각각 형성하였다. 이어서, 복수의 나노 크리스탈을 덮도록 PEDOT-PSS와 IPA가 블렌딩된 상기 정공 이동층 재료 물질을 60초간 2000rpm으로 스핀 코팅하고 140℃의 질소 분위기에서 10분 동안 어닐링하여 정공 이동층을 형성하였다. 이어서, P3HT 및 PCBM을 1,2 디클로로벤젠에 혼합한 상기 광활성층 재료를 60초간 1000rpm으로 스핀 코팅한 후 125℃의 질소 분위기에서 약 10분 동안 어닐링하여 광활성층을 형성하였다. 이어서, BCP(bathocuproine)를 6㎚의 두께로 증착하여 엑시톤 및 정공 블록킹층을 형성하고, LiF를 0.5㎚의 두께로 증착하여 전자 주입 및 계면층을 형성한 후 알루미늄(Al)을 80㎚의 두께로 증착하여 제 2 전극을 형성하였다.A first electrode was formed on the transparent substrate using ITO, and silver (Ag) was deposited on the first electrode to form a nanocrystal layer including a plurality of nanocrystals. At this time, the nano-crystal layer was formed at a deposition rate of 0.3 Å / sec, and formed on the plurality of substrates each with a thickness of 3 nm to 15 nm. Subsequently, the hole transport layer material material blended with PEDOT-PSS and IPA to cover a plurality of nanocrystals was spin coated at 2000 rpm for 60 seconds and annealed for 10 minutes in a nitrogen atmosphere of 140 ° C. to form a hole transport layer. Subsequently, the photoactive layer material containing P3HT and PCBM mixed in 1,2 dichlorobenzene was spin coated at 1000 rpm for 60 seconds and then annealed for about 10 minutes in a nitrogen atmosphere at 125 ° C. to form a photoactive layer. Subsequently, BCP (bathocuproine) is deposited to a thickness of 6 nm to form an exciton and a hole blocking layer, LiF is deposited to a thickness of 0.5 nm to form an electron injection and an interfacial layer, and then aluminum (Al) is 80 nm thick. Was deposited to form a second electrode.
도 6은 나노 크리스탈층의 두께에 따른 나노 크리스탈의 형상을 도시한 SEM 이미지이다. 또한, 도 7은 나노 크리스탈층의 두께에 따른 나노 크리스탈의 평균 면적, 밀도, 이격 거리 및 평균 직경의 변화 그래프이다.6 is an SEM image showing the shape of the nanocrystals according to the thickness of the nanocrystal layer. In addition, Figure 7 is a graph of the change in the average area, density, separation distance and average diameter of the nanocrystals according to the thickness of the nanocrystal layer.
도 6에 도시된 바와 같이 3㎚로부터 8㎚까지의 나노 크리스탈층의 두께에 따라 나노 크리스탈은 점(dot) 모양으로부터 성장하며, 9㎚ 이상부터는 나노 크리스탈의 사이즈가 증가하여 섬 모양으로 성장하고 인접한 나노 크리스탈이 접촉되어 성장하는 것을 알 수 있다. 또한, 도 7에 도시된 바와 같이 나노 크리스탈층의 두께 증가에 따라 나노 크리스탈의 평균 면적(A), 이격 거리(C) 및 평균 직경(D)이 커지고, 밀도(B)는 줄어드는 것을 알 수 있다. 즉, 나노 크리스탈층의 두께 증가에 따라 나노 크리스탈의 평균 직경이 커지고, 그에 따라 나노 크리스탈의 제 1 전극 상에서의 평균 면적 및 이격 거리가 증가하게 되며, 나노 크리스탈 사이의 밀도는 줄어들게 된다. 나노 크리스탈층의 두께에 따른 나노 크리스탈의 평균 면적, 밀도, 거리 및 평균 직경은 [표 1]과 같다.As shown in FIG. 6, the nanocrystals grow from a dot shape according to the thickness of the nanocrystal layer from 3 nm to 8 nm, and from 9 nm or more, the size of the nano crystals increases to grow into island shapes and adjacent to each other. It can be seen that the nanocrystals grow in contact with each other. In addition, as shown in FIG. 7, as the thickness of the nanocrystal layer increases, the average area (A), the separation distance (C), and the average diameter (D) of the nanocrystals increase, and the density (B) decreases. . That is, as the thickness of the nanocrystal layer increases, the average diameter of the nanocrystals increases, so that the average area and the separation distance of the nanocrystals on the first electrode increase, and the density between the nanocrystals decreases. The average area, density, distance and average diameter of the nanocrystals according to the thickness of the nanocrystal layer are shown in [Table 1].
표 1
나노 크리스탈층두께(㎚) 평균 면적(A) 밀도(B) 이격 거리(㎚)(C) 평균 직경(㎚)(D)
1 50 1685 25 7
2 80 1886 24 8
3 174 1787 21 8
4 262 1633 22 13
5 386 1091 27 18
6 867 460 42 28
7 1552 235 60 38
8 1750 180 68 43
9 3099 104 90 57
10 4787 92 95 63
11 4208 82 101 63
12 6516 75 106 77
13 11226 49 131 89
14 13776 42 142 104
15 18361 27 177 154
Table 1
Nano Crystal Layer Thickness (nm) Average area (A) Density (B) Distance (nm) (C) Average diameter (nm) (D)
One 50 1685 25 7
2 80 1886 24 8
3 174 1787 21 8
4 262 1633 22 13
5 386 1091 27 18
6 867 460 42 28
7 1552 235 60 38
8 1750 180 68 43
9 3099 104 90 57
10 4787 92 95 63
11 4208 82 101 63
12 6516 75 106 77
13 11226 49 131 89
14 13776 42 142 104
15 18361 27 177 154
나노 크리스탈 사이의 거리는 [수학식 1]에 나타낸 바와 같이 일 나노 크리스탈의 중심으로부터 단위 셀까지의 거리(L)에서 나노 크리스탈의 평균 반지름(r)을 뺀 값에 2를 곱한 식으로부터 산출된다. 여기서, 일 나노 크리스탈의 중심으로부터 단위 셀까지의 거리(L)는 하나의 단위 셀 내에 나노 크리스탈이 존재한다고 가정하였을 때 단위 셀의 끝에서부터 나노 크리스탈의 중심까지의 거리로 나타낼 수 있고, 단위 셀의 면적은 복수의 나노 크리스탈이 형성된 제 1 전극의 면적을 나노 크리스탈의 수로 나눈 값으로 정의될 수 있다.As shown in [Equation 1], the distance between the nanocrystals is calculated from an equation obtained by multiplying the distance L from the center of one nanocrystal by the unit cell minus the average radius r of the nanocrystals by 2. Here, the distance (L) from the center of one nanocrystal to the unit cell may be expressed as the distance from the end of the unit cell to the center of the nanocrystal, assuming that the nanocrystal is present in one unit cell. The area may be defined as a value obtained by dividing the area of the first electrode on which the plurality of nanocrystals is formed by the number of nanocrystals.
수학식 1
Figure PCTKR2014009513-appb-M000001
 Equation 1
Figure PCTKR2014009513-appb-M000001
또한, 나노 크리스탈의 평균 면적(㎚2)은 [수학식 2]에 나타낸 바와 같이 나노 크리스탈의 면적의 합을 나노 크리스탈의 갯수로 나눈 값으로부터 산출되고, 나노 크리스탈의 밀도(㎝-2)은 [수학식 3]에 나타낸 바와 같이 나노 크리스탈의 갯수를 전체 면적으로 나눈 값으로부터 산출될 수 있다. 그리고, 나노 크리스탈의 평균 직경은 [수학식 4]에 나타낸 바와 같이 나노 크리스탈의 평균 면적으로부터 산출될 수 있다.In addition, the average area (nm 2 ) of the nanocrystals is calculated from the sum of the area of the nanocrystals divided by the number of nanocrystals, as shown in [Equation 2], and the density (cm −2 ) of the nanocrystals is [ As shown in Equation 3, the number of nanocrystals may be calculated from a value divided by the total area. And, the average diameter of the nanocrystals can be calculated from the average area of the nanocrystals as shown in [Equation 4].
수학식 2
Figure PCTKR2014009513-appb-M000002
 Equation 2
Figure PCTKR2014009513-appb-M000002
수학식 3
Figure PCTKR2014009513-appb-M000003
 Equation 3
Figure PCTKR2014009513-appb-M000003
수학식 4
Figure PCTKR2014009513-appb-M000004
 Equation 4
Figure PCTKR2014009513-appb-M000004
도 8은 나노 크리스탈층의 두께에 따른 나노 크리스탈의 단면 형상을 도시한 TEM 이미지이고, 이때의 나노 크리스탈의 두께에 따른 나노 크리스탈의 장축 및 단축의 길이와 그 비율을 [표 2]에 나타내었다. 도 8에는 나노 크리스탈층의 두께에 따른 장축의 길이 및 거리를 표시하였다.8 is a TEM image showing the cross-sectional shape of the nanocrystals according to the thickness of the nanocrystal layer, the length and ratio of the major and minor axis of the nanocrystals according to the thickness of the nanocrystal at this time is shown in [Table 2]. 8 shows the length and distance of the major axis according to the thickness of the nanocrystal layer.
도 8(a)에 도시된 바와 같이 나노 크리스탈층을 3㎚의 두께로 형성하는 경우 나노 크리스탈은 장축 및 단축이 각각 8㎚ 및 7㎚의 길이로 형성되고, 도 8(b)에 도시된 바와 같이 나노 크리스탈층을 5㎚의 두께로 형성하는 경우 나노 크리스탈은 장축 및 단축이 각각 18㎚ 및 10㎚의 길이로 형성된다. 또한, 도 8(c)에 도시된 바와 같이 나노 크리스탈층을 7㎚의 두께로 형성하는 경우 나노 크리스탈은 장축 및 단축이 각각 38㎚ 및 14㎚의 길이로 형성된다. 그리고, 도 8(d), 도 8(e) 및 도 8(f)에 도시된 바와 같이 나노 크리스탈층을 10㎚, 12㎚ 및 15㎚의 두께로 형성하는 경우 나노 크리스탈은 장축이 각각 63㎚, 77㎚ 및 154㎚로 형성되고 단축이 각각 22㎚, 24㎚ 및 25㎚로 형성된다. 또한, 나노 크리스탈의 디퍼런셜 애스펙트 레이쇼(Different aspect ratio)를 나타내었다. 디퍼런셜 애스펙트 레이쇼는 장축의 평균값에 대한 단축의 반지름의 평균값으로 표시될 수 있다.As shown in FIG. 8 (a), when the nanocrystal layer is formed to a thickness of 3 nm, the nanocrystals have long and short axes of 8 nm and 7 nm, respectively, as shown in FIG. 8 (b). Likewise, when the nanocrystal layer is formed to a thickness of 5 nm, the nanocrystals have long and short axes of 18 nm and 10 nm, respectively. In addition, as shown in FIG. 8C, when the nanocrystal layer is formed to a thickness of 7 nm, the nanocrystals have long and short axes of 38 nm and 14 nm, respectively. As shown in FIGS. 8 (d), 8 (e), and 8 (f), when the nanocrystal layer is formed to a thickness of 10 nm, 12 nm, and 15 nm, the nanocrystals have long axes of 63 nm, respectively. , 77 nm and 154 nm and short axes are formed at 22 nm, 24 nm and 25 nm, respectively. In addition, the differential aspect ratio of the nanocrystals is shown. The differential aspect race can be expressed as the average value of the radius of the minor axis relative to the average value of the major axis.
표 2
열증착 두께(㎚) 나노 크리스탈 사이즈 Different aspect ratio(a/b)(diameter/radius)
단축(b)(㎚)/ average(nm)Diameter 장축(a)(㎚)Diameter
3 5∼9/7 8 8/4㎚
5 8∼12/10 18 18/5㎚
7 13∼15/14 38 38/7㎚
10 20∼24/22 63 63/11㎚
12 22∼26/24 77 77/12㎚
15 23∼27/25 154 154/12.5㎚
TABLE 2
Thermal Deposition Thickness (nm) Nano crystal size Different aspect ratio (a / b) (diameter / radius)
Single axis (b) (nm) / average (nm) Diameter Long axis (a) (nm)
3 5-9 / 7 8 8/4 nm
5 8 to 12/10 18 18/5 nm
7 13-15 / 14 38 38/7 nm
10 20-24 / 22 63 63/11 nm
12 22-26 / 24 77 77 / 12nm
15 23-27 / 25 154 154 / 12.5 nm
도 9는 나노 크리스탈층의 두께에 따른 광학 손실(optical loss)를 도시한 그래프이다. 도시된 바와 같이 나노 크리스탈층의 두께가 8㎚까지 증가할수록 광학 손실은 줄어들고, 9㎚ 이상부터는 광학 손실이 증가하는 것을 알 수 있다. 특히, 나노 크리스탈층의 두께가 5㎚∼8㎚에서 광학 손실이 가장 적은 것을 알 수 있다. 따라서, 나노 크리스탈층의 두께가 5㎚∼8㎚에서 광 흡수율이 가장 크고, 그에 따라 광전 변환 효율이 가장 큰 것을 알 수 있다.FIG. 9 is a graph showing optical loss according to the thickness of the nanocrystal layer. As shown, the optical loss decreases as the thickness of the nanocrystal layer increases to 8 nm, and the optical loss increases from 9 nm or more. In particular, it can be seen that the optical loss is the smallest when the thickness of the nanocrystal layer is 5 nm to 8 nm. Therefore, it can be seen that the light absorption is the largest when the thickness of the nanocrystal layer is 5 nm to 8 nm, and therefore the photoelectric conversion efficiency is the largest.
도 10은 나노 크리스탈층의 두께에 따른 외부 양자 효율(external quantum efficiency; EQE)을 도시한 그래프이다. 도시된 바와 같이 나노 크리스탈층을 3㎚∼8㎚의 두께로 형성하는 경우 나노 크리스탈층을 형성하지 않는 경우에 비해 외부 양자 효율을 향상시킬 수 있다. 즉, 나노 크리스탈층을 형성하지 않는 일반적인 유기 태양 전지의 경우 광활성층에서 흡수가 가장 많이 되는 500㎚의 파장에서 최고의 외부 양자 효율을 나타내지만, 나노 크리스탈이 형성된 경우 460㎚∼480㎚에서 최고의 외부 양자 효율을 나타낸다.FIG. 10 is a graph illustrating an external quantum efficiency (EQE) according to the thickness of the nanocrystal layer. As illustrated, when the nanocrystal layer is formed to a thickness of 3 nm to 8 nm, external quantum efficiency may be improved as compared with the case where the nano crystal layer is not formed. That is, in the case of a general organic solar cell that does not form a nanocrystal layer, the highest external quantum efficiency is shown at a wavelength of 500 nm where the photoactive layer absorbs the most. It shows efficiency.
또한, 도 11은 나노 크리스탈의 크기 및 거리에 따른 외부 양자 효율의 정도를 도시한 그래프이다. 즉, 나노 크리스탈의 크기 및 거리에 따른 외부 양자 효율을 나노 크리스탈이 형성되지 않은 태양 전지의 외부 양자 효율로 나눈 값을 표시한 것이다. 도시된 바와 같이 나노 크리스탈층이 4㎚, 5㎚, 6㎚, 7㎚ 및 8㎚의 두께로 각각 형성되는 경우 나노 크리스탈층이 형성되지 않은 경우에 비해 외부 양자 효율이 10%, 30%, 15%, 20%, 30% 정도 증가하는 것을 알 수 있다. 그러나, 나노 크리스탈층이 5㎚ 이하의 두께로 형성되는 경우와 11㎚ 이상의 두께로 형성되는 경우 나노 크리스탈층이 형성되지 않은 경우와 같거나 그보다 낮은 외부 양자 효율을 보인다. 이는 5㎚ 이하의 두께에서는 나노 크리스탈의 밀도가 높기 때문에 반사도의 증가에 의해서 외부 양자 효율이 낮게 나타나며 9㎚ 이상의 두께에서는 표면 플라즈몬 효과가 생성되지 않는 형태의 모양, 즉 오블레이트(oblate) 모양이 아닌 점점 층의 형태로 형성되어 반사도 증가에 의해 낮은 외부 양자 효율을 나타낸다.11 is a graph showing the degree of external quantum efficiency according to the size and distance of the nanocrystal. That is, the external quantum efficiency according to the size and distance of the nanocrystal is divided by the external quantum efficiency of the solar cell in which the nanocrystal is not formed. As shown, when the nanocrystal layer is formed with a thickness of 4 nm, 5 nm, 6 nm, 7 nm, and 8 nm, respectively, the external quantum efficiency is 10%, 30%, 15 compared with the case where the nano crystal layer is not formed. It can be seen that the%, 20%, 30% increase. However, when the nanocrystal layer is formed with a thickness of 5 nm or less and when formed with a thickness of 11 nm or more, the external quantum efficiency is the same as or less than that when the nano crystal layer is not formed. Since the density of nanocrystals is higher than 5 nm, the external quantum efficiency is low due to the increase of reflectivity, and the thickness of 9 nm or more does not produce surface plasmon effect, that is, it is not an oblate shape. It is gradually formed in the form of a layer and exhibits low external quantum efficiency due to increased reflectivity.
도 12는 나노크리스탈층의 두께에 따른 (a) 광전 변환 효율, (b) 전류 밀도, (c) 충진율, (d) 개방 전압, (e) 션트 저항, (f) 시리즈 저항의 정도를 도시한 그래프이다. 나노 크리스탈층의 두께에 따라 서로 다른 직경 및 모양의 나노 크리스탈이 형성되고, 이렇게 형성된 나노 크리스탈은 이격 거리, 밀도, 면적, 직경, 모양 및 나노 크리스탈 주위 물질의 유전율 및 굴절률 등으로 인하여 표면 플라즈몬 현상을 일으키게 된다. 도 12(b)에서 알 수 있듯이 전류 밀도 특성은 나노 크리스탈층의 두께가 6㎚에서 가장 큰 증가가 일어났고, 이때의 나노 크리스탈의 직경은 28㎚, 모양은 오블레이트(oblate)이다. 또한, 유전율 차이는 제 1 전극인 ITO와 정공 이동층인 PEDOT:PSS 사이에 존재한다. 이러한 조건에서 전류 밀도는 31.04% 증가하였으며, 도 12(c) 및 도 12(d)에서 알 수 있듯이 충진율 및 개방 전압은 거의 변하지 않았다. 도 12(a)의 광전 변환 효율(PCE)은 6㎚(직경 28㎚/이격거리 42㎚)에서 32.02% 증가하였고, 나노 크리스탈층의 두께가 5∼10㎚까지는 나노 크리스탈을 적용하지 않은 경우보다 증가하였으나, 나노 크리스탈층의 두께가 3∼4㎚의 경우 전류 밀도 및 광전 변환 효율이 감소한 것으로 보아 최적의 직경, 밀도 및 모양이 되어야지만 표면 플라즈몬 현상이 일어나게 되고, 이것이 유기물 태양 전지의 전류 밀도를 증가시켜 효율을 증가시킨다는 것을 나타낸다.12 shows the degree of (a) photoelectric conversion efficiency, (b) current density, (c) fill factor, (d) open voltage, (e) shunt resistance, and (f) series resistance, depending on the thickness of the nanocrystal layer. It is a graph. Depending on the thickness of the nanocrystal layer, nanocrystals of different diameters and shapes are formed, and the nanocrystals thus formed exhibit surface plasmon phenomena due to separation distance, density, area, diameter, shape, and dielectric constant and refractive index of the material around the nanocrystals. Will be raised. As can be seen in Figure 12 (b) the current density characteristics of the nanocrystal layer was the largest increase in the thickness of 6nm, the diameter of the nanocrystal is 28nm, the shape is oblate (oblate). In addition, the dielectric constant difference exists between the first electrode ITO and the hole transport layer PEDOT: PSS. Under these conditions, the current density increased by 31.04%, and as shown in FIGS. 12 (c) and 12 (d), the filling rate and the opening voltage were almost unchanged. The photoelectric conversion efficiency (PCE) of FIG. 12 (a) increased by 32.02% at 6 nm (28 nm in diameter / 42 nm apart), and the thickness of the nano crystal layer was 5-10 nm than that without applying nano crystals. However, when the thickness of the nanocrystal layer is 3 to 4 nm, the current density and the photoelectric conversion efficiency are reduced, so that the optimum diameter, density, and shape should be achieved, but the surface plasmon phenomenon occurs. Increase to increase efficiency.
본 발명의 기술적 사상은 상기 실시 예에 따라 구체적으로 기술되었으나, 상기 실시 예는 그 설명을 위한 것이며, 그 제한을 위한 것이 아님을 주지해야 한다. 또한, 본 발명의 기술분야에서 당업자는 본 발명의 기술 사상의 범위 내에서 다양한 실시 예가 가능함을 이해할 수 있을 것이다.Although the technical spirit of the present invention has been described in detail according to the above embodiment, it should be noted that the above embodiment is for the purpose of description and not for the purpose of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

Claims (19)

  1. 기판 상에 형성된 제 1 전극;A first electrode formed on the substrate;
    상기 제 1 전극 상에 접촉 형성된 복수의 나노 크리스탈을 포함하는 나노 크리스탈층;A nano crystal layer including a plurality of nano crystals contacted on the first electrode;
    상기 복수의 나노 크리스탈을 덮도록 상기 제 1 전극 상에 형성된 정공 이동층;A hole transport layer formed on the first electrode to cover the plurality of nanocrystals;
    상기 정공 이동층 상에 형성된 광활성층; 및A photoactive layer formed on the hole transport layer; And
    상기 광활성층 상에 형성된 제 2 전극을 포함하는 태양 전지.A solar cell comprising a second electrode formed on the photoactive layer.
  2. 청구항 1에 있어서, 상기 광활성층과 상기 제 2 전극 사이에 형성된 엑시톤 및 정공 블록킹층과, 전자 주입 및 계면층을 더 포함하는 태양 전지.The solar cell of claim 1, further comprising an exciton and a hole blocking layer formed between the photoactive layer and the second electrode, and an electron injection and interfacial layer.
  3. 청구항 2에 있어서, 상기 엑시톤 및 정공 블록킹층은 BCP 또는 금속 산화물을 이용하여 형성하는 태양 전지.The solar cell of claim 2, wherein the exciton and the hole blocking layer are formed using BCP or a metal oxide.
  4. 청구항 2에 있어서, 상기 전자 주입 및 계면층은 LiF, CsF, Liq, LiCoO2, Cs2CO3 중 적어도 어느 하나로 형성되는 태양 전지.The solar cell of claim 2, wherein the electron injection and interfacial layer is formed of at least one of LiF, CsF, Liq, LiCoO 2 , and Cs 2 CO 3 .
  5. 청구항 1 또는 청구항 2에 있어서, 상기 나노 크리스탈층은 광에 대한 반사도가 50% 이상인 물질로 형성되는 태양 전지.The solar cell of claim 1 or 2, wherein the nanocrystal layer is formed of a material having a reflectivity of light of 50% or more.
  6. 청구항 5에 있어서, 상기 나노 크리스탈층은 1㎚ 내지 15㎚의 두께로 형성되는 태양 전지.The solar cell of claim 5, wherein the nanocrystal layer is formed to a thickness of 1 nm to 15 nm.
  7. 청구항 6에 있어서, 상기 나노 크리스탈층은 5㎚ 내지 8㎚의 두께로 형성되는 태양 전지.The solar cell of claim 6, wherein the nanocrystal layer is formed to a thickness of 5 nm to 8 nm.
  8. 청구항 5에 있어서, 상기 나노 크리스탈은 장축의 길이가 15㎚ 내지 45㎚로 형성되고, 단축의 길이가 8㎚ 내지 17㎚로 형성되는 태양 전지.The solar cell of claim 5, wherein the nanocrystal has a long axis of 15 nm to 45 nm and a short axis of 8 nm to 17 nm.
  9. 청구항 8에 있어서, 상기 나노 크리스탈은 상기 제 1 전극과 접촉되는 거리가 이와 평행한 축의 길이보다 짧은 태양 전지.The solar cell of claim 8, wherein the nanocrystal is shorter in contact with the first electrode than a length of an axis parallel thereto.
  10. 청구항 5에 있어서, 상기 나노 크리스탈은 평균 직경이 15㎚ 내지 45㎚로 형성되고, 인접한 나노 크리스탈 사이의 평균 이격 거리가 25㎚ 내지 75㎚로 형성되는 태양 전지.The solar cell of claim 5, wherein the nanocrystals have an average diameter of 15 nm to 45 nm, and an average separation distance between adjacent nanocrystals is 25 nm to 75 nm.
  11. 청구항 1 또는 2에 있어서, 상기 정공 이동층은 MoOx, V2O5, VOx, WO3, NiOx, Cu2O 중 적어도 어느 하나로 형성되는 태양 전지.The solar cell of claim 1 or 2, wherein the hole transport layer is formed of at least one of MoO x , V 2 O 5 , VO x , WO 3 , NiO x , and Cu 2 O.
  12. 청구항 1 또는 청구항 2에 있어서, 상기 광활성층은 벌크 헤테로 접합의 전자 공여체와 전자 수용체를 포함하는 태양 전지.The solar cell of claim 1 or 2, wherein the photoactive layer comprises an electron donor and an electron acceptor of a bulk heterojunction.
  13. 기판 상에 제 1 전극을 형성하는 단계;Forming a first electrode on the substrate;
    상기 제 1 전극 상에 복수의 나노 크리스탈을 포함하는 나노 크리스탈층을 형성하는 단계;Forming a nanocrystal layer including a plurality of nanocrystals on the first electrode;
    상기 나노 크리스탈을 덮도록 상기 제 1 전극 상에 정공 이동층을 형성하는 단계;Forming a hole transporting layer on the first electrode to cover the nanocrystals;
    상기 정공 이동층 상에 전자 수용체와 전자 공여체가 혼합된 물질을 도포하여 광활성층을 형성하는 단계; 및Forming a photoactive layer by applying a material mixed with an electron acceptor and an electron donor on the hole transport layer; And
    상기 광활성층 상에 제 2 전극을 형성하는 단계를 포함하는 태양 전지의 제조 방법.Forming a second electrode on the photoactive layer.
  14. 청구항 13에 있어서, 상기 나노 크리스탈층을 형성하기 이전에 상기 기판에 플라즈마 처리 및 자외선 처리의 적어도 어느 하나를 실시하는 단계를 더 포함하는 태양 전지의 제조 방법.The method of claim 13, further comprising: performing at least one of plasma treatment and ultraviolet treatment on the substrate before forming the nanocrystal layer.
  15. 청구항 13 또는 청구항 14에 있어서, 상기 광활성층과 상기 제 2 전극 사이에 엑시톤 및 정공 블록킹층과, 전자 주입 및 계면층을 더 형성하는 단계를 더 포함하는 태양 전지.The solar cell of claim 13, further comprising forming an exciton and a hole blocking layer, an electron injection, and an interfacial layer between the photoactive layer and the second electrode.
  16. 청구항 15에 있어서, 상기 나노 크리스탈층은 5㎚ 내지 8㎚의 두께로 형성하는 태양 전지의 제조 방법.The method of claim 15, wherein the nanocrystal layer is formed to a thickness of 5 nm to 8 nm.
  17. 청구항 16에 있어서, 상기 나노 크리스탈은 장축의 길이를 15㎚ 내지 45㎚로 형성하고, 단축의 길이를 8㎚ 내지 17㎚로 형성하는 태양 전지의 제조 방법.The method of claim 16, wherein the nanocrystals have a major axis length of 15 nm to 45 nm and a minor axis length of 8 nm to 17 nm.
  18. 청구항 17에 있어서, 상기 나노 크리스탈은 상기 제 1 전극과 접촉되는 거리가 이와 평행한 축의 길이보다 짧도록 형성하는 태양 전지의 제조 방법.The method of claim 17, wherein the nanocrystal is formed such that a distance in contact with the first electrode is shorter than a length of an axis parallel thereto.
  19. 청구항 18에 있어서, 상기 나노 크리스탈은 평균 직경을 15㎚ 내지 45㎚로 형성하고, 인접한 나노 크리스탈 사이의 평균 이격 거리를 25㎚ 내지 75㎚로 형성하는 태양 전지의 제조 방법.The method of claim 18, wherein the nanocrystals have an average diameter of 15 nm to 45 nm, and an average separation distance between adjacent nanocrystals of 25 nm to 75 nm.
PCT/KR2014/009513 2013-10-10 2014-10-10 Solar cell and manufacturing method therefor WO2015053578A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US15/028,420 US10998515B2 (en) 2013-10-10 2014-10-10 Solar cell and manufacturing method therefor
CN201480066817.7A CN105981181B (en) 2013-10-10 2014-10-10 Solar cell and its manufacture method

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
KR10-2013-0120520 2013-10-10
KR20130120520 2013-10-10
KR1020140018183A KR101646727B1 (en) 2013-10-10 2014-02-18 Solar cell and method of manufacturing the same
KR10-2014-0018183 2014-02-18

Publications (1)

Publication Number Publication Date
WO2015053578A1 true WO2015053578A1 (en) 2015-04-16

Family

ID=52813340

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2014/009513 WO2015053578A1 (en) 2013-10-10 2014-10-10 Solar cell and manufacturing method therefor

Country Status (1)

Country Link
WO (1) WO2015053578A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017045987A (en) * 2015-08-26 2017-03-02 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． Organic photoelectric element and image sensor

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100043861A1 (en) * 2001-09-06 2010-02-25 The Trustees Of Princeton University Organic photovoltaic devices
KR20110108154A (en) * 2010-03-26 2011-10-05 광주과학기술원 Tandem solar cell and method for fabricating the same
US20110297216A1 (en) * 2010-06-07 2011-12-08 Postech Academy-Industry Foundation Organic solar cell and method of manufacturing the same
US20130008509A1 (en) * 2011-07-08 2013-01-10 University Of Florida Research Foundation, Inc. Inverted polymer solar cell using a double interlayer
US20130213477A1 (en) * 2010-09-29 2013-08-22 Jx Nippon Oil & Energy Corporation Photoelectric conversion element

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100043861A1 (en) * 2001-09-06 2010-02-25 The Trustees Of Princeton University Organic photovoltaic devices
KR20110108154A (en) * 2010-03-26 2011-10-05 광주과학기술원 Tandem solar cell and method for fabricating the same
US20110297216A1 (en) * 2010-06-07 2011-12-08 Postech Academy-Industry Foundation Organic solar cell and method of manufacturing the same
US20130213477A1 (en) * 2010-09-29 2013-08-22 Jx Nippon Oil & Energy Corporation Photoelectric conversion element
US20130008509A1 (en) * 2011-07-08 2013-01-10 University Of Florida Research Foundation, Inc. Inverted polymer solar cell using a double interlayer

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2017045987A (en) * 2015-08-26 2017-03-02 三星電子株式会社Ｓａｍｓｕｎｇ Ｅｌｅｃｔｒｏｎｉｃｓ Ｃｏ．，Ｌｔｄ． Organic photoelectric element and image sensor
CN106486599A (en) * 2015-08-26 2017-03-08 三星电子株式会社 Organic optoelectronic device and imageing sensor

Similar Documents

Publication Publication Date Title
KR101312269B1 (en) Polymer solar cell and preparation method thereof
US9184317B2 (en) Electrode containing a polymer and an additive
US9296848B2 (en) Polymer material, solar cell using the same, and solar photovoltaic generation system
KR101082910B1 (en) Organic Solar Cells with Fused Ring Compounds
WO2015115864A1 (en) Organic solar cell comprising nano-bump structure and manufacturing method therefor
WO2011074411A1 (en) Organic photoelectric conversion element
JP5515598B2 (en) Method for producing organic photoelectric conversion element and organic photoelectric conversion element
CN102664238B (en) Organic solar batteries and manufacture method thereof
WO2010107261A2 (en) Solar cell and a production method therefor
KR20090028987A (en) Photovoltaic device and preparing method thereof
WO2016209005A1 (en) Perovskite-based solar cell using graphene as conductive transparent electrode
JP5444743B2 (en) Organic photoelectric conversion element
WO2010110590A2 (en) Solar cell, and method for producing same
JP2012099592A (en) Organic photoelectric conversion element, solar cell and method for manufacturing the same
US10998515B2 (en) Solar cell and manufacturing method therefor
TWI568044B (en) Active layer, organic photovoltaic cell comprising the same and manufacturing method thereof
KR101047396B1 (en) Organic solar cell and its manufacturing method
JP5304448B2 (en) Organic photoelectric conversion element
Yuksel et al. Improvement of photovoltaic performance and stability of AnE-PV: PCBM based organic solar cells using solution processed inverted geometry
WO2015053578A1 (en) Solar cell and manufacturing method therefor
JP2014150081A (en) Organic power generation element
JP5691449B2 (en) Organic photoelectric conversion element, solar cell using the same, and optical sensor array
Lin et al. Enhancing conversion efficiency of inverted organic solar cells using Ag nanoparticles and long wavelength absorbing tin (II) phthalocyanine
JP6010649B2 (en) Solar cell module and manufacturing method thereof
WO2010110567A2 (en) Solar cell, and method for manufacturing same

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14851715

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 15028420

Country of ref document: US

122 Ep: pct application non-entry in european phase

Ref document number: 14851715

Country of ref document: EP

Kind code of ref document: A1