WO2013111749A1 - Substrat de verre pour cellules solaires à base de cu-in-ga-se et cellule solaire utilisant ledit substrat de verre - Google Patents

Substrat de verre pour cellules solaires à base de cu-in-ga-se et cellule solaire utilisant ledit substrat de verre Download PDF

Info

Publication number
WO2013111749A1
WO2013111749A1 PCT/JP2013/051196 JP2013051196W WO2013111749A1 WO 2013111749 A1 WO2013111749 A1 WO 2013111749A1 JP 2013051196 W JP2013051196 W JP 2013051196W WO 2013111749 A1 WO2013111749 A1 WO 2013111749A1
Authority
WO
WIPO (PCT)
Prior art keywords
glass substrate
glass
ratio
solar cell
substrate surface
Prior art date
Application number
PCT/JP2013/051196
Other languages
English (en)
Japanese (ja)
Inventor
裕 黒岩
中島　哲也
雄一 山本
朋美 安部
健 岡東
玲大 臼井
剛 富澤
Original Assignee
旭硝子株式会社
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
Application filed by 旭硝子株式会社 filed Critical 旭硝子株式会社
Priority to KR1020147019768A priority Critical patent/KR20140127805A/ko
Priority to JP2013555273A priority patent/JP6003904B2/ja
Priority to CN201380006811.6A priority patent/CN104080749A/zh
Publication of WO2013111749A1 publication Critical patent/WO2013111749A1/fr

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
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/042—PV modules or arrays of single PV cells
    • H01L31/048—Encapsulation of modules
    • H01L31/0488—Double glass encapsulation, e.g. photovoltaic cells arranged between front and rear glass sheets
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C23/00—Other surface treatment of glass not in the form of fibres or filaments
    • C03C23/008—Other surface treatment of glass not in the form of fibres or filaments comprising a lixiviation step
    • C—CHEMISTRY; METALLURGY
    • C03—GLASS; MINERAL OR SLAG WOOL
    • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00—Glass compositions
    • C03C3/04—Glass compositions containing silica
    • C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
    • C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
    • C03C3/085—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal
    • C03C3/087—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal containing calcium oxide, e.g. common sheet or container glass
    • 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
    • H01L31/0256—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 the material
    • H01L31/0264—Inorganic materials
    • H01L31/032—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312
    • H01L31/0322—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312 comprising only AIBIIICVI chalcopyrite compounds, e.g. Cu In Se2, Cu Ga Se2, Cu In Ga Se2
    • 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
    • H01L31/0392—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 thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate
    • H01L31/03923—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 thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate including AIBIIICVI compound materials, e.g. CIS, CIGS
    • 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
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • 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
    • Y02E10/541—CuInSe2 material PV cells

Definitions

  • This invention relates to the glass substrate for solar cells in which the photoelectric converting layer is formed between the glass plates, and a solar cell using the same.
  • the glass plate typically includes a glass substrate and a cover glass, and at least a photoelectric conversion layer mainly composed of a group 11, group 13, or group 16 element is interposed between the glass substrate and the cover glass.
  • the present invention relates to a glass substrate for a Cu—In—Ga—Se solar cell partially formed by a selenization method and a solar cell using the same.
  • Group 11-13, 11-16 compound semiconductors having a chalcopyrite crystal structure and cubic or hexagonal 12-16 group compound semiconductors have a large absorption coefficient for light in the visible to near-infrared wavelength range. have. Therefore, it is expected as a material for high-efficiency thin film solar cells.
  • Typical examples include Cu (In, Ga) Se 2 (hereinafter also referred to as “CIGS” or “Cu—In—Ga—Se”) and CdTe.
  • CIGS thin film solar cells are inexpensive and have a thermal expansion coefficient close to that of CIGS compound semiconductors, soda lime glass is used as a substrate to obtain solar cells.
  • Patent Document 1 a glass material that can withstand a high heat treatment temperature has been proposed.
  • a CIGS photoelectric conversion layer (hereinafter also referred to as “CIGS layer”) is formed on the glass substrate.
  • CIGS layer A CIGS photoelectric conversion layer
  • Patent Document 1 proposes a glass composition having a relatively high annealing point, but the invention described in Patent Document 1 does not necessarily have high power generation efficiency.
  • the present inventors have found that the power generation efficiency can be increased by increasing the alkali of the glass substrate within a predetermined range, but there is a problem that an increase in the alkali causes a decrease in the glass transition temperature (Tg).
  • the glass substrate used in the CIGS solar cell has a problem that it is difficult to achieve both high power generation efficiency and high glass transition temperature.
  • An object of the present invention is to provide a glass substrate for a Cu—In—Ga—Se solar cell that achieves both particularly high power generation efficiency and high glass transition temperature.
  • the gist of the present invention is as follows. (1) The average total amount (atomic%) of Ca, Sr, and Ba at a depth of 10 to 40 nm from the surface of the glass substrate, and the total amount (atom) of Ca, Sr, and Ba at a depth of 5000 nm from the glass substrate surface. %) Is 0.7 or less, The content of Na 2 O measured by fluorescent X-ray from the glass substrate surface and the (mass%), the content of Na 2 O measured by fluorescent X-ray from the surface removal of the glass 5000nm from the glass substrate surface and the (mass%), The ratio of 0.4 to 1.1, The ratio before and after the heat treatment at 600 ° C.
  • the glass transition temperature is 580 ° C. or higher, and the average thermal expansion coefficient is 70 ⁇ 10 ⁇ 7 to 100 ⁇ 10 ⁇ 7 ° C.
  • a glass substrate for Cu—In—Ga—Se solar cells produced by a selenization method.
  • Atomic ratio The average amount (atomic%) of Ca, Sr and Ba at a depth of 10 to 40 nm from the glass substrate surface, and the total amount of Ca, Sr and Ba at a depth of 5000 nm from the glass substrate surface ( Atomic ratio) is 0.5 or less, The content of Na 2 O measured by fluorescent X-ray from the glass substrate surface and the (mass%), the content of Na 2 O measured by fluorescent X-ray from the surface removal of the glass 5000nm from the glass substrate surface and the (mass%) , The ratio of 0.5 to 0.87, The ratio before and after the heat treatment at 600 ° C.
  • a glass substrate for a Cu—In—Ga—Se solar cell wherein at least the glass substrate of the glass substrate and the cover glass is produced by the selenization method according to any one of (1) to (3) above. Is a solar cell.
  • the glass substrate for a Cu—In—Ga—Se solar cell of the present invention can achieve both high power generation efficiency and high glass transition temperature.
  • CIGS solar cell glass substrate of the present invention a low-cost and high-efficiency solar cell can be provided.
  • FIG. 1 is a cross-sectional view schematically showing an example of an embodiment of the solar cell of the present invention.
  • FIG. 2A shows a solar battery cell produced on a glass substrate for evaluation in the examples.
  • FIG. 2B shows a cross-sectional view along the line A-A ′ of the solar battery cell shown in FIG. 2A.
  • FIG. 3 shows a CIGS solar cell for evaluation on a glass substrate for evaluation in which eight solar cells shown in FIG. 2A are arranged.
  • the glass substrate for a Cu—In—Ga—Se solar cell of the present invention has an average total amount (atomic%) of Ca, Sr and Ba at a depth of 10 to 40 nm from the surface of the glass substrate (hereinafter referred to as “glass substrate surface layer”).
  • the total amount (atomic%) of Ca, Sr and Ba at a depth of 5000 nm from the surface of the glass substrate (hereinafter also referred to as “amount of Ca + Sr + Ba in the glass substrate”) (Hereinafter also referred to as “the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside”) is 0.7 or less, and the Na 2 O content (mass%) measured by fluorescent X-ray from the glass substrate surface (hereinafter, “ content of Na 2 O of the glass substrate surface (% by mass) "and also referred to) and, the content of Na 2 O measured by fluorescent X-ray from the surface removal of the glass 5000nm from the glass substrate surface (quality %) (Hereinafter, “the content of Na 2 O of the glass substrate (wt%)" and also referred to), the ratio (hereinafter, also referred to as "the content of Na 2 O ratio between the inside and the glass substrate surface”) of 0 The ratio of the average Na amount (atomic%) between 10 and 40 nm in depth from the
  • glass substrate surface layer For 1 hour in an N 2 atmosphere (hereinafter referred to as “glass substrate surface layer”)
  • the ratio before and after heat treatment of Na is 1.1 or more, and when the depth from the surface of the glass substrate is 5000 nm or more, 50% to 72% of SiO 2 and Al 2 O are expressed in terms of mass percentage based on the following oxides.
  • MgO to 0 to 10% CaO to 0.1 to 11%, SrO to 0 to 13%, BaO to 0 to 11%, Na 2 O to 1 to 11%, and K 2 O to 2-21%, ZrO 2 0-10.5%, MgO + CaO + SrO + BaO 4-25%, CaO + SrO + BaO 2-23%, Na 2 O + K 2 O 8-22%, Na 2 O / (CaO + SrO + BaO) ⁇ 1.2, glass transition temperature 580 ° C.
  • the glass substrate for a Cu—In—Ga—Se solar cell is preferably a glass substrate for a Cu—In—Ga—Se solar cell manufactured by a selenization method.
  • Cu—In—Ga—Se produced by a selenization method refers to a film in which at least a part of a CIGS layer that is a photoelectric conversion layer of a solar cell is formed by a selenization method.
  • the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside is 0.7 or less, preferably 0.5 or less, more preferably 0.35 or less, and further preferably 0.3 or less. Especially preferably, it is 0.25 or less.
  • the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside can be compared as a relative ratio between the amount of Ca + Sr + Ba on the glass substrate surface layer and the amount of Ca + Sr + Ba inside the glass substrate. That is, when the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside is 0.7 or less, the amount of Ca + Sr + Ba in the glass substrate surface layer is smaller than the amount of Ca + Sr + Ba inside the glass substrate, specifically, Ca, Sr It means that the atoms of Ba and Ba are missing from the vicinity of the surface of the glass substrate.
  • the glass substrate for solar cell of the present invention has a Na 2 O content ratio of 0.4 to 1.1 between the glass substrate surface and the inside. If the Na 2 O content ratio is less than 0.4, the ratio before and after heat treatment of Na on the surface of the glass substrate described later becomes too small, which is not preferable. Preferably it is 0.5 or more, More preferably, it is 0.6 or more. When the Na 2 O content ratio is greater than 1.1, the amount of Ca, Sr, and Ba atoms desorbed from the vicinity of the glass substrate surface is small. Is not preferable because it becomes smaller.
  • the Na 2 O content ratio is preferably 0.9 or less, more preferably 0.87 or less, and even more preferably 0.84 or less. When the Na 2 O content ratio is smaller than 1.1, it means that Na atoms are missing from the vicinity of the glass substrate surface (detached state).
  • the content of Na 2 O on the surface of the glass substrate refers to the calibration curve method of the fluorescent X-ray method using a standard sample for quantification measured from the glass substrate surface with fluorescent X-rays (tube voltage 50 kV 50 mA).
  • the Na 2 O content inside the glass substrate is the Na 2 O content (mass%) measured by fluorescent X-rays (tube voltage 50 kV 50 mA) from the surface from which the glass of 5000 nm has been removed from the glass substrate surface. There is a value obtained by measuring the average content in the range from the surface from which the glass was removed to about 3000 nm.
  • the content of Na 2 O of the glass substrate surface by taking the content of Na 2 O of the glass substrate, the ratio of the degree of loss of Na to a depth of about 3000nm from the glass substrate surface To do.
  • a heat treatment step in a solar cell manufacturing step generally, about 100 to 600 ° C. in an oxygen-free atmosphere containing selenium and sulfur.
  • the present inventors have found that the power generation efficiency of the solar cell is improved when at least a part of CIGS, which is the photoelectric conversion layer of the solar cell, is formed by a selenization method under a heat treatment condition of 5 minutes or more). .
  • the state in which Na and Ca, Sr, and Ba atoms or Ca, Sr, and Ba atoms are missing from the vicinity of the glass substrate surface is the first half of the heat treatment in the solar cell manufacturing process manufactured by the selenization method, specifically, This means that in the process of selenization / sulfurization with hydrogen selenide and hydrogen sulfide while heating the precursor film of In—CuGa alloy, Na diffusion is reduced at the initial stage of the selenization / sulfurization reaction. .
  • the latter half of the heat treatment step in the solar cell manufacturing process generally, about 500 to 600 ° C.
  • the present inventors have found that the amount of Na diffusion from the vicinity of the surface of the glass substrate to the photoelectric conversion layer increases and the power generation efficiency is improved.
  • the present inventors have found that when the amount of Na diffusion is small in the initial stage of the selenization / sulfurization reaction and the amount of Na diffusion is secured in the latter half of the heat treatment step, CIGS It has been found that the crystal quality of is improved. The improvement in crystal quality can be confirmed by an increase in free carrier density in CIGS.
  • a sample with increased free carriers is confirmed as an increase in open circuit voltage (Voc) and fill factor (FF), which will be described later, as the cell characteristics of the solar cell, and as a result, the power generation efficiency is improved.
  • the increase in FF is mainly due to the increase in free carrier density, which increases the electrical conductivity of the CIGS film and decreases the series resistance (Rser).
  • the series resistance (Rser) is a resistance component when a current flows through the element, and the lower the better.
  • the amount of Ca + Sr + Ba or the amount of Na (atomic%) on the surface of the glass substrate is defined as “average total amount of Ca, Sr and Ba (atomic%) at a depth of 10 to 40 nm from the glass substrate surface” or “ The average Na content (atomic%) between 10 to 40 nm in depth from the glass substrate surface is defined as the Ca, Sr and Ba atoms in this region are separated and the vicinity of the glass substrate surface. This is because the diffusion of Na into the surface layer of the glass substrate after the heat treatment becomes significant when the ratio of Na before and after the heat treatment is large. In addition, the range of 0 to less than 10 nm was excluded from the measurement target in consideration of the influence of the composition variation due to the outside air.
  • the Na 2 O content indicates how much Na is in a range from the glass substrate surface to about 3000 nm as an initial state of the substrate, and strongly affects the initial stage of the heat treatment process.
  • the ratio before and after the heat treatment of Na on the surface of the glass substrate is appropriate, so two indexes are introduced for the amount of Na near the glass substrate surface. ing.
  • the “Na 2 O content inside the glass substrate” was defined by the Na 2 O content measured by fluorescent X-ray from the surface from which the glass from the glass substrate surface to 5000 nm was removed, which was deeper than the depth of 5000 nm This is because there is almost no detachment of Na atoms.
  • each raw material component is used so that the composition of the glass substrate falls within the range specified in the present invention, and the dissolution / clarification step and the molding step are carried out in the same manner as in the case of producing a conventional glass substrate for a solar cell.
  • the SO 2 treatment according to the present invention is performed in the cooling step.
  • the composition (each raw material component) of the glass substrate for CIGS solar cell of the present invention and the SO 2 treatment according to the present invention will be described in detail later.
  • the ratio before and after the heat treatment of Na on the glass substrate surface layer is required to be 1.1 or more, preferably 1.2 or more, preferably 1.5 or more. It is more preferable that Thereby, during the heat treatment in the CIGS solar cell manufacturing process, the amount of Na diffusion from the glass substrate to the photoelectric conversion layer of CIGS is increased, and when used in a CIGS solar cell, the present inventors show that the power generation efficiency of the solar cell is increased. Etc. found.
  • the ratio of Na on the surface of the glass substrate before and after the heat treatment is more preferably 1.8 or more, further preferably 2.0 or more, and particularly preferably 2.4 or more.
  • the amount of Na in the surface layer of the glass substrate after the heat treatment is preferably 0.3 atomic% or more. This is because if it is less than 0.3 atomic%, it does not sufficiently diffuse into the photoelectric conversion layer and power generation efficiency may not be sufficiently obtained. More preferably, it is 0.5 atomic% or more, More preferably, it is 1.0 atomic% or more, Most preferably, it is 2.5 atomic% or more.
  • the upper limit of the before-and-after heat treatment ratio of Na on the surface of the glass substrate is 5.
  • the ratio before and after the heat treatment of Na on the glass substrate surface is greater than 5, the amount of Na on the surface of the glass substrate before the heat treatment decreases, and as a result, the amount of Na diffusion from the glass substrate to the photoelectric conversion layer of CIGS decreases. May decrease.
  • the ratio before and after the heat treatment of Na on the surface of the glass substrate is preferably 4.5 or less, more preferably 4 or less.
  • the ratio of Na before and after the heat treatment of the glass substrate surface layer is defined by the conditions of heat treatment at 600 ° C. for 1 hour in an N 2 atmosphere for the following reason. If the diffusion of Na to the surface of the glass substrate under the condition of heat treatment at 600 ° C. for 1 hour in an N 2 atmosphere is sufficient, even if the conditions of the heat treatment step in the solar cell manufacturing process slightly change, the power generation efficiency is positively affected. This has been confirmed by the present inventors.
  • the composition of the glass substrate is specified in the present invention, and the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside is 0.7 or less, preferably 0.5 or less, more preferably 0.35 or less, and still more preferably 0. .3 or less, particularly preferably 0.25 or less, and the Na 2 O content ratio between the glass substrate surface and the inside is 0.4 to 1.1, preferably 0.5 to 0.87.
  • the ratio is preferably 0.6 to 0.84, the ratio before and after the heat treatment of Na on the surface of the glass substrate is easily 1.1 or more, preferably 1.5 or more, more preferably 1.8 or more, and still more preferably 2. It can be 0 or more, particularly preferably 2.4 or more.
  • the glass transition temperature (Tg) of the glass substrate for CIGS solar cell of the present invention is 580 ° C. or higher.
  • the glass transition temperature of the glass substrate for CIGS solar cell of the present invention is higher than the glass transition temperature of soda lime glass.
  • the glass transition point temperature (Tg) of the glass substrate for CIGS solar cell of the present invention is preferably 600 ° C. or higher, more preferably 610 ° C. or higher, to ensure the formation of the photoelectric conversion layer at a high temperature, 620 More preferably, it is at least 630 ° C, particularly preferably at least 630 ° C.
  • the upper limit of the glass transition temperature is 750 ° C.
  • the glass transition temperature is more preferably 700 ° C. or lower, and further preferably 680 ° C. or lower.
  • the average thermal expansion coefficient at 50 to 350 ° C. of the glass substrate for CIGS solar cell of the present invention is 70 ⁇ 10 ⁇ 7 to 100 ⁇ 10 ⁇ 7 / ° C. If the average coefficient of thermal expansion is less than 70 ⁇ 10 ⁇ 7 / ° C. or more than 100 ⁇ 10 ⁇ 7 / ° C., the difference in thermal expansion from the CIGS layer becomes too large, and defects such as peeling tend to occur. Furthermore, when assembling a solar cell (specifically, when a glass substrate having a CIGS photoelectric conversion layer and a cover glass are heated and bonded together), the glass substrate may be easily deformed.
  • the average thermal expansion coefficient is preferably 95 ⁇ 10 ⁇ 7 / ° C. or less, more preferably 90 ⁇ 10 ⁇ 7 / ° C. or less.
  • the average thermal expansion coefficient is preferably 73 ⁇ 10 ⁇ 7 / ° C. or higher, more preferably 75 ⁇ 10 ⁇ 7 / ° C. or higher, and further preferably 80 ⁇ 10 ⁇ 7 / ° C. or higher.
  • SiO 2 is a component that forms a glass skeleton, and if its content is less than 50%, the heat resistance and chemical durability of the glass may decrease, and the average thermal expansion coefficient may increase.
  • the content is preferably 52% or more, more preferably 54% or more, still more preferably 56% or more, and particularly preferably 58% or more.
  • the high-temperature viscosity of the glass may increase, which may cause a problem of deterioration in solubility.
  • the content is preferably 70% or less, more preferably 68% or less, still more preferably 67% or less, and particularly preferably 66% or less.
  • Al 2 O 3 increases the glass transition temperature, improves the weather resistance (solarization), heat resistance and chemical durability, and increases the Young's modulus. If the content is less than 1%, the glass transition temperature may be lowered. Moreover, there exists a possibility that an average thermal expansion coefficient may increase.
  • the content is preferably 2% or more, more preferably 3% or more, further preferably 4% or more, and particularly preferably 5% or more.
  • the content is preferably 14% or less, more preferably 13% or less, still more preferably 12% or less, and particularly preferably 11.5% or less.
  • B 2 O 3 may be contained up to 2% in order to improve the solubility.
  • the content exceeds 2%, the glass transition temperature decreases or the average thermal expansion coefficient decreases, which is not preferable for the process of forming the CIGS layer.
  • the content is more preferably 1% or less.
  • the content is particularly preferably 0.5% or less.
  • B 2 O 3 is not substantially contained.
  • substantially does not contain means that it is not contained other than inevitable impurities mixed from raw materials or the like, that is, it is not intentionally contained. Moreover, the same thing shall mean about another component.
  • MgO may be contained because it has the effect of reducing the viscosity at the time of melting the glass and promoting the melting.
  • the content is preferably 0.5% or more, more preferably 1% or more, still more preferably 2% or more, and particularly preferably 3% or more.
  • the content thereof is preferably 9.5% or less, more preferably 9.0% or less, still more preferably 8.5% or less, and particularly preferably 8.0% or less.
  • CaO has the effect of lowering the viscosity at the time of melting the glass and promoting the melting, so it can be contained at 0.1% or more.
  • the content is preferably 0.5% or more, more preferably 1% or more, still more preferably 2% or more, and particularly preferably 3% or more. However, if the content exceeds 11%, the average thermal expansion coefficient of the glass may increase. In addition, the power generation efficiency may be reduced, that is, the amount of Na diffusion described later may be reduced.
  • the content is preferably 10% or less, more preferably 9% or less, still more preferably 8% or less, and particularly preferably 7% or less.
  • SrO can be contained because it has the effect of reducing the viscosity at the time of melting the glass and promoting the melting. However, if the SrO content exceeds 13%, the power generation efficiency decreases, that is, the amount of Na diffusion described later decreases, and the average thermal expansion coefficient of the glass substrate may increase.
  • the content is preferably 11% or less, more preferably 9% or less, further preferably 7% or less, and particularly preferably 5% or less. Moreover, the content is preferably 0.5% or more, more preferably 1% or more.
  • BaO can be contained because it has the effect of lowering the viscosity at the time of melting the glass and promoting the melting. However, if the BaO content exceeds 11%, the power generation efficiency decreases, that is, the amount of Na diffusion described later decreases, and the average thermal expansion coefficient of the glass substrate may increase. The specific gravity also increases. The content is preferably 7% or less, more preferably 3% or less, and still more preferably 0.5% or less. Particularly preferably, BaO is substantially not contained.
  • ZrO 2 may be contained because it has the effect of lowering the viscosity at the time of melting the glass, promoting the melting, and increasing the Tg.
  • 0.5% or more of ZrO 2 is contained.
  • the content is more preferably 1% or more, still more preferably 1.5% or more, and particularly preferably 2% or more.
  • the power generation efficiency is lowered, that is, the amount of Na diffusion described later is lowered, the devitrification temperature is increased, and the average thermal expansion coefficient of the glass substrate may be increased.
  • the content is preferably 9% or less, more preferably 7% or less, further preferably 5% or less, and particularly preferably 4% or less.
  • MgO, CaO, SrO and BaO are contained in a total amount (MgO + CaO + SrO + BaO) in an amount of 4 to 25% from the viewpoint of reducing the viscosity at the time of melting the glass and promoting the melting. However, if the total amount is more than 25%, the average thermal expansion coefficient increases, and the devitrification temperature may increase.
  • the total amount is preferably 6% or more, and more preferably 9% or more. Further, the total amount is preferably 21% or less, more preferably 20% or less, further preferably 18% or less, and particularly preferably 15% or less.
  • CaO, SrO and BaO are contained in a total amount of 2% or more from the point that the ratio of Ca + Sr + Ba between the surface layer of the glass substrate after SO 2 treatment and the inside is 0.7 or less.
  • CaO, SrO and BaO are contained in a total amount of preferably 2.5% or more, more preferably 3% or more, still more preferably 3.5% or more, and particularly preferably 4% or more. If the total amount of CaO, SrO and BaO is less than 2%, a large amount of MgO must be added to lower the viscosity during glass melting and increase the glass transition temperature, which may increase the devitrification temperature. There is. However, if the total amount exceeds 23%, the amount of Na diffusion after the heat treatment may decrease.
  • the total amount is preferably 19% or less, more preferably 15% or less, further preferably 12% or less, and particularly preferably 10% or less.
  • the total amount of SrO and BaO is preferably 16% or less, more preferably 8% or less, further preferably 6% or less, and particularly preferably 4% or less.
  • Na 2 O is a component that contributes to improving the power generation efficiency of CIGS solar cells, and is an essential component. Further, since it has the effect of lowering the viscosity at the glass melting temperature and facilitating melting, it is contained in an amount of 1 to 11%. Na diffuses into the CIGS photoelectric conversion layer formed on the glass to increase power generation efficiency, but if its content is less than 1%, the amount of Na diffusion into the CIGS photoelectric conversion layer on the glass substrate becomes insufficient. The power generation efficiency may be insufficient.
  • the content is preferably 2% or more, more preferably 2.5% or more, further preferably 3% or more, and particularly preferably 3.5% or more.
  • the content is preferably 10% or less, more preferably 9% or less, and even more preferably 8% or less.
  • the content is particularly preferably less than 7%.
  • K 2 O Since K 2 O has the same effect as Na 2 O, it is contained in an amount of 2 to 21%. However, if the content is more than 21%, the power generation efficiency is lowered, that is, the diffusion of Na is inhibited, the amount of Na diffusion described later is reduced, the glass transition temperature is lowered, and the average thermal expansion coefficient is May grow. It is preferably 3% or more, more preferably 4% or more, still more preferably 5% or more, and particularly preferably 6% or more. The content is preferably 16% or less, more preferably 12% or less, still more preferably 10% or less, and particularly preferably 8% or less.
  • Na 2 O and K 2 O The total content of Na 2 O and K 2 O (Na 2 O + K 2) for sufficiently reducing the viscosity at the glass melting temperature and for improving the power generation efficiency of the CIGS solar cell. O) is 8 to 22%.
  • the total amount is preferably 9% or more, more preferably 10% or more, still more preferably 11% or more, and particularly preferably 12% or more.
  • the total amount is more than 22%, Tg is too low and the average thermal expansion coefficient may be too high.
  • the total amount is preferably 20% or less, more preferably 17% or less, still more preferably 16% or less, and particularly preferably 15% or less.
  • Na 2 O / (CaO + SrO + BaO) When Na 2 O / (CaO + SrO + BaO) exceeds 1.2, the precipitation reaction of Na 2 SO 4 proceeds during the SO 2 treatment, while CaSO 4 , SrSO 4 , BaSO 4. As a result, the separation of Ca, Sr, and Ba on the surface of the glass substrate hardly occurs.
  • Na 2 O / (CaO + SrO + BaO) is preferably 1.0 or less, more preferably 0.9 or less, and still more preferably 0.8 or less.
  • the lower limit of Na 2 O / (CaO + SrO + BaO) is preferably 0.1.
  • Na 2 O / (CaO + SrO + BaO) is smaller than 0.1, the amount of Na 2 O becomes too small and the battery efficiency may be lowered.
  • Na 2 O / (CaO + SrO + BaO) is more preferably 0.2 or more, further preferably 0.3 or more, and still more preferably 0.5 or more.
  • the glass substrate for a CIGS solar cell of the present invention has a matrix composition essentially expressed in terms of mass percentage based on the following oxides: 50 to 72% of SiO 2 , 1 to 15% of Al 2 O 3 and 0 to MgO. 10%, CaO 0.1-11%, SrO 0-13%, BaO 0-11%, Na 2 O 1-11%, K 2 O 2-21%, ZrO 2 0-10 0.5%, MgO + CaO + SrO + BaO 4-25%, CaO + SrO + BaO 2-23%, Na 2 O + K 2 O 8-22%, Na 2 O / (CaO + SrO + BaO) ⁇ 1.2.
  • ZrO 2 is 0.5 to 9%
  • CaO + SrO + BaO is 2.5 to 19%
  • SrO + BaO is 0 to 16%
  • CaO + SrO + BaO is 3 to 15%
  • a combination of 0 to 8% of SrO + BaO is preferable.
  • the glass substrate for CIGS solar cell of the present invention consists essentially of the above mother composition, but may contain other components typically within 5% in total within the range not impairing the object of the present invention.
  • B 2 O 3 , ZnO, Li 2 O, WO 3 , Nb 2 O 5 , V 2 O 5 , Bi 2 O 3 for the purpose of improving weather resistance, solubility, devitrification, ultraviolet shielding, etc.
  • MoO 3 may contain P 2 O 5 or the like.
  • these raw materials are added to the matrix composition raw material so that the glass contains SO 3 , F, Cl and / or SnO 2 in a total amount of 2% or less. May be.
  • ZrO 2 , Y 2 O 3 , La 2 O 3 , TiO 2 and / or SnO 2 may be contained in the glass in a total amount of 5% or less.
  • Y 2 O 3 , La 2 O 3 and TiO 2 contribute to the improvement of the Young's modulus of the glass.
  • the glass may contain a colorant such as Fe 2 O 3 in the glass.
  • the total content of such colorants is preferably 1% or less.
  • the glass substrate for a CIGS solar cell of the present invention considering the environmental burden, it is preferred that free of As 2 O 3 and Sb 2 O 3 substantially. In consideration of stable float forming, it is preferable that ZnO is not substantially contained.
  • the glass substrate for CIGS solar cell of the present invention is not limited to being formed by the float method, and may be manufactured by forming by the fusion method.
  • the glass substrate for CIGS solar cell of the present invention is used so that each raw material component of the glass substrate has the above composition, and similarly to the case of manufacturing the conventional glass substrate for solar cell, the dissolution / clarification step and the molding step are performed. It is obtained by performing the SO 2 treatment shown below in the subsequent slow cooling step.
  • the composition of the glass substrate is within the range specified in the present invention, and by performing the following SO 2 treatment, the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside is 0.7 or less, and the glass substrate surface A CIGS solar cell glass substrate having a Na 2 O content ratio of 0.4 to 1.1 with respect to the inside and a Na before and after heat treatment ratio of the glass substrate surface layer of 1.1 or more is obtained.
  • the conventional glass substrate manufacturing method in order to prevent glass surface scratches during glass conveyance in the slow cooling step, it is known to form a protective film by sulfate by blowing SO 2 gas.
  • the conventional SO 2 gas spraying conditions are the minimum required sulfate in consideration of the prevention of yellow coloration when the silver electrode for the display substrate is provided, the ease of washing the sulfate film, the prevention of corrosion of the equipment, etc. It was preferred to provide a membrane, that is, to perform the SO 2 treatment as mild as possible.
  • the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside is 0.7 or less, and the Na 2 O content ratio between the glass substrate surface and the inside is 0.4 to 1.1.
  • the glass composition is in the composition range specified in the present application, the glass surface temperature is 500 to 700 ° C., the SO 2 concentration is 0.01 to 5 (volume)%, and the treatment is performed so that the ratio before and after the heat treatment of Na in the surface layer is 1.1 or more. It is preferable to perform the SO 2 treatment under conditions of time 1 to 10 minutes.
  • the glass substrate for CIGS solar cells of the present invention is an alkali glass substrate containing alkali metal oxides (Na 2 O and K 2 O), SO 3 can be effectively used as a fining agent, Suitable for the float method and fusion method (down draw method) as the molding method.
  • alkali metal oxides Na 2 O and K 2 O
  • a float method capable of easily and stably forming a large-area glass substrate with the enlargement of the solar cell is used. preferable.
  • molten glass obtained by melting raw materials is formed into a plate shape.
  • raw materials are prepared so that the obtained glass substrate has the above composition, the raw materials are continuously charged into a melting furnace, and heated to about 1450 to 1700 ° C. to obtain molten glass.
  • the molten glass is formed into a ribbon-like glass plate by applying, for example, a float process.
  • the washing method is not particularly limited, and examples include washing with water, washing with a detergent, and rubbing with a brush or the like while spraying a slurry containing cerium oxide.
  • an acidic detergent such as hydrochloric acid or sulfuric acid.
  • the glass substrate surface after washing is free from dirt and irregularities on the glass substrate surface due to deposits such as cerium oxide. If there are irregularities, irregularities on the surface of the film, film thickness deviations, pinholes in the film, and the like may occur during film formation of the electrode film and its underlying layer, and power generation efficiency may be reduced.
  • the unevenness is preferably 20 nm or less with a height difference.
  • the amount (atomic%) of Na and / or the Na 2 O content ratio in the surface layer of the glass substrate is uniform throughout the entire glass substrate for CIGS solar cells. If the amount of Na on the surface of the glass substrate and / or the Na 2 O content ratio is not uniform, a portion with low power generation efficiency will be produced, and this portion will affect the power generation efficiency of the solar cell. This is because there is a risk of losing.
  • the glass substrate for CIGS solar cell of the present invention is also suitable as a glass substrate for CIGS solar cell and a cover glass.
  • the thickness of the glass substrate is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1.5 mm or less.
  • a method for applying a CIGS photoelectric conversion layer to a glass substrate it is preferable that at least a part of the CIGS layer which is a photoelectric conversion layer is prepared by a selenization method.
  • the heating temperature when forming the photoelectric conversion layer can be set to 500 to 650 ° C.
  • the cover glass or the like is not particularly limited.
  • Other examples of the composition of the cover glass include soda lime glass.
  • the thickness of the cover glass is preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1.5 mm or less.
  • the method for assembling the cover glass on the glass substrate having the photoelectric conversion layer is not particularly limited. By using the glass substrate for CIGS solar cell of the present invention, when assembled by heating, the heating temperature can be 500 to 650 ° C.
  • the CIGS solar cell glass substrate of the present invention is used in combination with a CIGS solar cell glass substrate and a cover glass because the thermal expansion and the like during solar cell assembly do not occur because the average thermal expansion coefficients are equivalent.
  • the solar cell according to the present invention has a glass substrate, a cover glass, and a photoelectric conversion layer disposed between the glass substrate and the cover glass. Then, at least a part of the photoelectric conversion layer is a Cu—In—Ga—Se photoelectric conversion layer formed by a selenization method, and at least the glass substrate of the glass substrate and the cover glass is formed of the present invention.
  • This is a glass substrate for a Cu—In—Ga—Se solar cell.
  • FIG. 1 is a cross-sectional view schematically showing an example of an embodiment of a solar cell according to the present invention.
  • a solar cell (CIGS solar cell) 1 includes a glass substrate 5, a cover glass 19, and a CIGS layer 9 between the glass substrate 5 and the cover glass 19. It is preferable that the glass substrate 5 consists of the glass substrate for CIGS solar cells of this invention demonstrated above.
  • the solar cell 1 has the back electrode layer of Mo film which is the plus electrode 7 on the glass substrate 5, and has the photoelectric converting layer which is the CIGS layer 9 on it.
  • the composition of the CIGS layer can be exemplified by Cu (In 1-X Ga x ) Se 2 .
  • x represents the composition ratio of In and Ga, and 0 ⁇ x ⁇ 1.
  • a transparent conductive film 13 of ZnO or ITO is provided via a CdS (cadmium sulfide) or ZnS (zinc sulfide) layer as the buffer layer 11, and a negative electrode 15 is further provided thereon.
  • An extraction electrode such as an Al electrode (aluminum electrode) is provided.
  • An antireflection film may be provided at a necessary place between these layers.
  • an antireflection film 17 is provided between the transparent conductive film 13 and the negative electrode 15.
  • a cover glass 19 may be provided on the minus electrode 15, and if necessary, the minus electrode and the cover glass are sealed with resin or bonded with a transparent resin for adhesion.
  • the cover glass the glass substrate for CIGS solar cell of the present invention may be used.
  • the end portion of the photoelectric conversion layer or the end portion of the solar cell may be sealed.
  • a material for sealing the same material as the glass substrate for CIGS solar cells of this invention, other glass, resin, etc. are mentioned, for example.
  • the raw materials of each component were prepared so as to have the compositions of Examples 1 to 50 shown in Tables 1 to 6, and sulfate was added to 0.4 parts by mass of the raw material in terms of SO 3 with respect to 100 parts by mass of the glass. It melt
  • the average thermal expansion coefficient of the glass substrate thus obtained (unit: ⁇ 10 -7 / ° C), glass transition temperature (Tg) (unit: ° C), Na 2 O content ratio between the glass substrate surface and the inside, glass
  • Tg glass transition temperature
  • Na 2 O content ratio between the glass substrate surface and the inside glass
  • the ratio of Ca + Sr + Ba between the substrate surface layer and the inside and the ratio before and after heat treatment of Na on the glass substrate surface layer were measured and are shown in Tables 1 to 5 below.
  • the power generation efficiency (unit:%), series resistance (Rser, unit: ⁇ ), and free carrier density (unit: 10 15 / cm 3 ) of the obtained glass substrate were evaluated and shown in Tables 1 to 5 below. It was.
  • the measurement method and evaluation method of each physical property are shown below.
  • Tg is a value measured using a differential thermal dilatometer (TMA), and was determined according to JIS R3103-3 (FY2001).
  • Ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside The amount (atomic%) of Ca, Sr, and Ba at depths of 10, 20, 30, 40, and 5000 nm from the surface of the glass substrate was measured with an X-ray photoelectron spectrometer (ESCA5500, manufactured by ULVAC-PHI). Grinding from the glass substrate surface to 10 to 40 nm is sputter-etched with a C 60 ion beam, and grinding from the glass substrate surface to 5000 nm is ground to 4000 nm with a cerium oxide water slurry and then sputter-etched with a C 60 ion beam. did.
  • ESA5500 X-ray photoelectron spectrometer
  • Ratio before and after heat treatment of Na on glass substrate surface The amount of Na (atomic%) at a depth of 10, 20, 30, and 40 nm from the surface of the glass substrate was measured with an X-ray photoelectron spectrometer (manufactured by ULVAC-PHI, ESCA5500). For grinding from the surface of the glass substrate to 10 to 40 nm, sputter etching was performed with a C 60 ion beam.
  • the glass substrate is heated to 600 ° C. at 10 ° C./min in an N 2 atmosphere (simulating anoxic state) in an electric furnace, held at 600 ° C. for 60 minutes, and then cooled to 2 ° C./min to room temperature. Slowly cooled.
  • the amount of Na (atomic%) at depths of 10, 20, 30, and 40 nm from the surface of the glass substrate was measured by the method described above.
  • the ratio of before and after heat treatment at 600 ° C. for 1 hour in an N 2 atmosphere with an average amount of Na (atomic%) between a depth of 10 to 40 nm from the glass substrate surface was determined.
  • the obtained glass plate was processed into a size of 3 cm ⁇ 3 cm and a thickness of 1.1 mm to obtain a glass substrate.
  • membrane was formed into a film as the plus electrode 7a with the sputtering device. Film formation was performed at room temperature to obtain a Mo film having a thickness of 500 nm.
  • a CuGa alloy layer is formed with a CuGa alloy target using a sputtering apparatus, and then an In layer is formed using an In target, whereby an In—CuGa precursor film is formed. A film was formed. Film formation was performed at room temperature.
  • Precursor film was mixed with argon and hydrogen selenide using RTA (Rapid Thermal Annealing) apparatus (hydrogen selenide is 5% by volume with respect to argon, hereinafter referred to as “hydrogen selenide atmosphere”) and hydrogen sulfide mixed atmosphere ( Hydrogen sulfide was heat-treated at 5 vol% with respect to argon, hereinafter referred to as “hydrogen sulfide atmosphere”).
  • RTA Rapid Thermal Annealing
  • Hydrogen sulfide was heat-treated at 5 vol% with respect to argon, hereinafter referred to as “hydrogen sulfide atmosphere”).
  • holding was performed at 500 ° C. for 10 minutes in a hydrogen selenide atmosphere, and Cu, In, and Ga were reacted with Se.
  • the CIGS layer 9a was obtained by growing the CIGS crystal by holding at 580 ° C. for 30 minutes as the second stage.
  • the thickness of the obtained CIGS layer 9a was 2 ⁇ m.
  • a CdS layer was formed as the buffer layer 11a on the CIGS layer 9a by a CBD (Chemical Bath Deposition) method. Specifically, first, cadmium sulfate having a concentration of 0.01M, thiourea having a concentration of 1.0M, ammonia having a concentration of 15M, and pure water were mixed in a beaker. Next, the CIGS layer was immersed in the above mixed solution, and the beaker and the beaker were placed in a constant temperature bath whose water temperature was set to 70 ° C. in advance, to form a 50 to 80 nm CdS layer.
  • CBD Chemical Bath Deposition
  • a transparent conductive film 13a was formed on the CdS layer by a sputtering apparatus by the following method. First, a ZnO layer was formed using a ZnO target, and then an AZO layer was formed using an AZO target (ZnO target containing 1.5 wt% Al 2 O 3 ). Each layer was formed at room temperature to obtain a transparent conductive film 13a having a two-layer structure having a thickness of 480 nm. On the AZO layer of the transparent conductive film 13a, an aluminum film having a thickness of 1 ⁇ m was formed as a U-shaped negative electrode 15a by EB vapor deposition (U-shaped electrode length (vertical 8 mm, horizontal 4 mm), electrode width 0. 5 mm).
  • FIGS. 2A and 2B are views of one solar battery cell as viewed from above, and FIG. 2B is a cross-sectional view taken along line AA ′ in FIG. 2A.
  • One cell has a width of 0.6 cm and a length of 1 cm, and the area excluding the negative electrode 15a is 0.51 cm 2.
  • a total of eight cells are placed on one glass substrate 5a. Obtained.
  • a CIGS solar cell for evaluation (evaluation glass substrate 5a on which the above eight cells were produced) was installed in a solar simulator (YSS-T80A, manufactured by Yamashita Denso Co., Ltd.) and added to the positive electrode 7a previously coated with an InGa solvent.
  • a terminal (not shown) was connected to the voltage generator at the lower end of the U-shape of the negative electrode 15a.
  • the temperature in the solar simulator was controlled at a constant temperature of 25 ° C. with a temperature controller. Pseudo sunlight was irradiated, and after 10 seconds, the voltage was changed from -1 V to +1 V at an interval of 0.015 V, and the current values of each of the eight cells were measured.
  • the power generation efficiency was calculated from the current and voltage characteristics at the time of irradiation according to equation (1).
  • Table 1 shows the value of the most efficient cell among the eight cells as the value of the power generation efficiency of each glass substrate.
  • the illuminance of the light source used for the test was 0.1 W / cm 2 .
  • Power generation efficiency [%] Voc [V] ⁇ Jsc [A / cm 2 ] ⁇ FF [Dimensionless] ⁇ 100 / Illuminance [W / cm 2 ] of the light source used in the test Equation (1)
  • the power generation efficiency is obtained by multiplying the open circuit voltage (Voc), the short circuit current density (Jsc), and the fill factor (FF).
  • the open circuit voltage (Voc) is an output when the terminal is opened, and the short circuit current (Isc) is a current when the terminal is short circuited.
  • the short circuit current density (Jsc) is Isc divided by the cell area excluding the negative electrode.
  • the point that gives the maximum output is called the maximum output point, the voltage at that point is called the maximum voltage value (Vmax), and the current is called the maximum current value (Imax).
  • Vmax the voltage at that point
  • Imax the current
  • a value obtained by dividing the product of the maximum voltage value (Vmax) and the maximum current value (Imax) by the product of the open circuit voltage (Voc) and the short circuit current (Isc) is obtained as a fill factor (FF). Using the above values, the power generation efficiency was determined.
  • Series resistance (Rser) is a resistance component when a current flows through the element, and is a gradient of the current with respect to the voltage when the voltage is equal to the open circuit voltage (Voc) during light irradiation. Using this relationship, series resistance was obtained.
  • the carrier density of the CIGS solar cell was determined by the DLCP (Drive Level Capacitance Profiling) method described in Document 1 below.
  • DLCP Drive Level Capacitance Profiling
  • the measurement frequency is 11 KHz
  • Vac + Vcd 0 [mV]
  • the measured value was taken as the carrier density.
  • CIGS solar cells are known to change in carrier density due to light soaking, in order to remove carriers due to light soaking, hold them at 50 ° C. for 30 minutes or more in an analysis chamber before measurement.
  • the carrier density of the CIGS solar cell was measured at 20K to 300K while increasing the temperature by 10K. On the low temperature side of about 150K or less, the carrier density of free carriers is measured. As the carrier density is further increased from about 150 K, the carrier density rapidly increases due to the rise due to deep level defects. Therefore, the free carrier density is a measured value at 100 K before the carrier density measured by a deep level defect is increased.
  • Reference 1 Heath, Jennifer T., J. David Cohen, William N. Shafarman. "Bulk and MetaStable Defects in CuIn (1-x) Ga (x) Se2 Thin Films Using Drive Level Capacitance Profiling.” J. of Applied Physics 95.3 (2004).
  • the residual amount of SO 3 in the glass was 100 to 500 ppm.
  • the glass substrates of the examples have a ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside of 0.7 or less.
  • the ratio of Na 2 O content between the substrate surface and the inside is 0.4 to 1.1
  • the ratio of Na before and after the heat treatment of the glass substrate surface layer is 1.1 or more
  • the glass transition temperature Tg is high. High efficiency and low series resistance. Accordingly, both high power generation efficiency and high glass transition temperature can be achieved.
  • the glass substrate of the Example (Example 3) has a high free carrier density, and it was confirmed that the crystal quality was improved.
  • the glass substrates of the examples (Examples 1 to 5, 7 to 29, 46 to 48) have an average coefficient of thermal expansion of 70 ⁇ 10 ⁇ 7 to 100 ⁇ 10 ⁇ 7 / ° C.
  • the solar cell of the present invention is used.
  • the glass substrate is hardly deformed and stable power generation efficiency is easily obtained.
  • the glass substrates of the comparative examples (Examples 30 to 32) have a high Na 2 O content of 13.1%, the Tg is lower than 580 ° C., and the substrate is deformed during the CIGS film formation. May cause trouble.
  • the glass substrate of the comparative examples (Examples 33 and 34) has an Na 2 O amount of 0.5% and is small, the SO 2 treatment is performed, but the Na amount after the heat treatment of the glass substrate surface layer is 0.3 atom. The power generation efficiency was low.
  • a glass substrate of a comparative example not the SO 2 treatment (Examples 6, 35 to 43), although the composition of the raw materials are within the scope of the present invention, SO 2 Since no treatment is performed, the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside is as large as 0.90 to 1.00, and the ratio before and after the heat treatment of Na on the glass substrate surface layer is as small as 0.78 to 1.00. Power generation efficiency is difficult to obtain.
  • the glass substrate of the comparative example (Example 6) had a low free carrier density, and an improvement in crystal quality could not be confirmed.
  • the glass substrate of the comparative example (Example 44) has a large Na 2 O / (CaO + SrO + BaO) of 1.62 and is not treated with SO 2, so the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside is as large as 0.97. Since the ratio of Na before and after the heat treatment of the glass substrate surface layer is as small as 0.67, it is difficult to obtain power generation efficiency. Further, since the content of Na 2 O is as large as 13.1%, Tg becomes lower than 580 ° C., and the substrate may be deformed during the CIGS film formation, which may hinder battery manufacture.
  • the glass substrate of the comparative example (Example 45) is not subjected to SO 2 treatment, the ratio before and after heat treatment of Na on the surface of the glass substrate is as small as 0.66, and the amount of Na 2 O is as small as 0.5%. Power generation efficiency is also low.
  • the ratio of Ca + Sr + Ba between the glass substrate surface layer and the inside is 0.7 or less, and Na 2 O between the glass substrate surface and the inside is obtained.
  • the content ratio was 0.4 to 1.1, the ratio of Na before and after the heat treatment of the glass substrate surface layer was 1.1 or more, the glass transition temperature Tg was high, and the power generation efficiency was also high.
  • the glass substrate of Example (47, 48) also had low series resistance. Accordingly, both high power generation efficiency and high glass transition temperature can be achieved. Further, the glass substrates of the examples (Examples 47 and 48) had a high free carrier density, and it was confirmed that the crystal quality was improved.
  • the glass substrates of the comparative examples have a large Ca + Sr + Ba ratio of 0.96 or more between the surface of the glass substrate and the inside, and are not subjected to SO 2 treatment, so that the power generation efficiency is low.
  • the glass substrate for a Cu—In—Ga—Se solar cell produced by the selenization method of the present invention is suitable as a glass substrate for CIGS solar cell produced by the selenization method and a cover glass. It can also be used for substrates and cover glasses. Further, by using the glass substrate for a Cu—In—Ga—Se solar cell manufactured by the selenization method of the present invention, a solar cell with high power generation efficiency can be provided.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Computer Hardware Design (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • Physics & Mathematics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Glass Compositions (AREA)
  • Surface Treatment Of Glass (AREA)
  • Photovoltaic Devices (AREA)

Abstract

La présente invention concerne un substrat de verre pour cellules solaires CIGS produit par un procédé de sélénisation. Le taux de Ca + Sr + Ba dans la couche de surface du substrat de verre par rapport à celui dans la partie interne est inférieur ou égal à 0,7. Le taux de la teneur en Na2O dans la surface du substrat de verre par rapport à celle dans la partie interne se situe dans la plage allant de 0,4 à 1,1. Le taux de Na dans la couche de surface du substrat de verre avant un traitement thermique par rapport à celui après le traitement thermique est supérieur ou égal à 1,1. À une profondeur supérieure ou égale à 5 000 nm à partir de la surface du substrat de verre, le substrat de verre contient, en pourcentage en masse sur la base des oxydes ci-dessous, de 50 à 72 % de SiO2, de 1 à 15 % d'Al2O3, de 0 à 10 % de MgO, de 0,1 à 11 % de CaO, de 0 à 13 % de SrO, de 0 à 11 % de BaO, de 1 à 11 % de Na2O, de 2 à 21 % de K2O, de 0 à 10,5 % de ZrO2, de 4 à 25 % de MgO + CaO + SrO + BaO, de 2 à 23 % de CaO + SrO + BaO et de 8 à 22 % de Na2O + K2O tout en respectant la relation Na2O/(CaO + SrO + BaO) ≤ 1,2. Le substrat de verre pour cellules solaires CIGS présente une température de transition vitreuse supérieure ou égale à 580 °C et un coefficient moyen de dilatation thermique situé dans la plage allant de 70 × 10-7/°C à 100 × 10 -7/°C. Le substrat de verre est apte à obtenir un bon équilibre entre un rendement de production d'énergie élevé et une température de transition vitreuse élevée.
PCT/JP2013/051196 2012-01-25 2013-01-22 Substrat de verre pour cellules solaires à base de cu-in-ga-se et cellule solaire utilisant ledit substrat de verre WO2013111749A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
KR1020147019768A KR20140127805A (ko) 2012-01-25 2013-01-22 Ｃｕ―Ｉｎ―Ｇａ―Ｓｅ 태양 전지용 유리 기판 및 그것을 사용한 태양 전지
JP2013555273A JP6003904B2 (ja) 2012-01-25 2013-01-22 Ｃｕ−Ｉｎ−Ｇａ−Ｓｅ太陽電池用ガラス基板及びそれを用いた太陽電池
CN201380006811.6A CN104080749A (zh) 2012-01-25 2013-01-22 Cu-In-Ga-Se太阳能电池用玻璃基板及使用该玻璃基板的太阳能电池

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012-012875 2012-01-25
JP2012012875 2012-01-25

Publications (1)

Publication Number Publication Date
WO2013111749A1 true WO2013111749A1 (fr) 2013-08-01

Family

ID=48873469

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/051196 WO2013111749A1 (fr) 2012-01-25 2013-01-22 Substrat de verre pour cellules solaires à base de cu-in-ga-se et cellule solaire utilisant ledit substrat de verre

Country Status (5)

Country Link
JP (1) JP6003904B2 (fr)
KR (1) KR20140127805A (fr)
CN (1) CN104080749A (fr)
TW (1) TW201342634A (fr)
WO (1) WO2013111749A1 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014136667A (ja) * 2013-01-18 2014-07-28 Nippon Electric Glass Co Ltd 保護膜付きガラス基材
WO2015194569A1 (fr) * 2014-06-20 2015-12-23 旭硝子株式会社 Plaque de verre et procédé de fabrication correspondant
JP2016000683A (ja) * 2014-05-21 2016-01-07 旭硝子株式会社 ガラス板
WO2016043287A1 (fr) * 2014-09-19 2016-03-24 旭硝子株式会社 Substrat en verre, son procédé de fabrication, et cellule solaire cigs
JP2016147792A (ja) * 2015-02-13 2016-08-18 旭硝子株式会社 ガラス基板
WO2017047366A1 (fr) * 2015-09-18 2017-03-23 旭硝子株式会社 Substrat de verre pour cellules solaires, et cellule solaire
US10683231B2 (en) 2015-03-26 2020-06-16 Pilkington Group Limited Glasses

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011068225A1 (fr) * 2009-12-04 2011-06-09 旭硝子株式会社 Plaque de verre et son procédé de fabrication
JP2011121838A (ja) * 2009-12-14 2011-06-23 Nippon Electric Glass Co Ltd ガラス基板
WO2012014854A1 (fr) * 2010-07-26 2012-02-02 旭硝子株式会社 SUBSTRAT EN VERRE POUR UNE BATTERIE SOLAIRE Cu-In-Ga-Se ET UTILISATION DE CETTE BATTERIE SOLAIRE

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11135819A (ja) * 1997-10-31 1999-05-21 Matsushita Electric Ind Co Ltd 化合物薄膜太陽電池
CN101679105B (zh) * 2007-06-07 2015-06-17 日本电气硝子株式会社 强化玻璃基板及其制造方法
EP2346085A1 (fr) * 2008-10-31 2011-07-20 Asahi Glass Company Limited Pile solaire

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2011068225A1 (fr) * 2009-12-04 2011-06-09 旭硝子株式会社 Plaque de verre et son procédé de fabrication
JP2011121838A (ja) * 2009-12-14 2011-06-23 Nippon Electric Glass Co Ltd ガラス基板
WO2012014854A1 (fr) * 2010-07-26 2012-02-02 旭硝子株式会社 SUBSTRAT EN VERRE POUR UNE BATTERIE SOLAIRE Cu-In-Ga-Se ET UTILISATION DE CETTE BATTERIE SOLAIRE

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2014136667A (ja) * 2013-01-18 2014-07-28 Nippon Electric Glass Co Ltd 保護膜付きガラス基材
JP2016000683A (ja) * 2014-05-21 2016-01-07 旭硝子株式会社 ガラス板
JP2016121069A (ja) * 2014-05-21 2016-07-07 旭硝子株式会社 ガラス板
WO2015194569A1 (fr) * 2014-06-20 2015-12-23 旭硝子株式会社 Plaque de verre et procédé de fabrication correspondant
CN106573830A (zh) * 2014-06-20 2017-04-19 旭硝子株式会社 玻璃板及其制造方法
WO2016043287A1 (fr) * 2014-09-19 2016-03-24 旭硝子株式会社 Substrat en verre, son procédé de fabrication, et cellule solaire cigs
JPWO2016043287A1 (ja) * 2014-09-19 2017-06-29 旭硝子株式会社 ガラス基板、その製造方法及びｃｉｇｓ太陽電池
JP2016147792A (ja) * 2015-02-13 2016-08-18 旭硝子株式会社 ガラス基板
US10683231B2 (en) 2015-03-26 2020-06-16 Pilkington Group Limited Glasses
WO2017047366A1 (fr) * 2015-09-18 2017-03-23 旭硝子株式会社 Substrat de verre pour cellules solaires, et cellule solaire
JPWO2017047366A1 (ja) * 2015-09-18 2018-07-05 旭硝子株式会社 太陽電池用ガラス基板及び太陽電池

Also Published As

Publication number Publication date
JPWO2013111749A1 (ja) 2015-05-11
TW201342634A (zh) 2013-10-16
KR20140127805A (ko) 2014-11-04
CN104080749A (zh) 2014-10-01
JP6003904B2 (ja) 2016-10-05

Similar Documents

Publication Publication Date Title
JP6004048B2 (ja) Ｃｕ−Ｉｎ−Ｇａ−Ｓｅ太陽電池用ガラス基板及びそれを用いた太陽電池
JP6003904B2 (ja) Ｃｕ−Ｉｎ−Ｇａ−Ｓｅ太陽電池用ガラス基板及びそれを用いた太陽電池
WO2011049146A1 (fr) Feuille de verre pour cellules solaires à base de cu-in-ga-se, et cellules solaires utilisant cette feuille de verre
US20130233386A1 (en) Glass substrate for cu-in-ga-se solar cells and solar cell using same
JP6048490B2 (ja) Ｃｕ−Ｉｎ−Ｇａ−Ｓｅ太陽電池用ガラス基板およびそれを用いた太陽電池
JPWO2012102346A1 (ja) Ｃｕ−Ｉｎ−Ｇａ−Ｓｅ太陽電池用ガラス基板およびそれを用いた太陽電池
KR20130110099A (ko) 태양 전지의 제조 방법 및 태양 전지
JP6210136B2 (ja) ガラス基板
JP6156553B2 (ja) Ｃｉｇｓ太陽電池用ガラス基板及びｃｉｇｓ太陽電池
JP6249033B2 (ja) ガラス板
JP6128128B2 (ja) 太陽電池用ガラス基板およびそれを用いた太陽電池
WO2014189003A1 (fr) Substrat de verre et cellule solaire au cigs
WO2014024850A1 (fr) SUBSTRAT DE VERRE POUR CELLULE SOLAIRE Cu-In-Ga-Se, ET CELLULE SOLAIRE METTANT EN ŒUVRE CELUI-CI
JP2016171158A (ja) Ｃｕ−Ｉｎ−Ｇａ−Ｓｅ太陽電池

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: 13741026

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2013555273

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 20147019768

Country of ref document: KR

Kind code of ref document: A

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13741026

Country of ref document: EP

Kind code of ref document: A1