EP2429963A1 - Substrate glass for thin-film solar cell - Google Patents

Substrate glass for thin-film solar cell

Info

Publication number
EP2429963A1
EP2429963A1 EP10718892A EP10718892A EP2429963A1 EP 2429963 A1 EP2429963 A1 EP 2429963A1 EP 10718892 A EP10718892 A EP 10718892A EP 10718892 A EP10718892 A EP 10718892A EP 2429963 A1 EP2429963 A1 EP 2429963A1
Authority
EP
European Patent Office
Prior art keywords
solar cell
substrate glass
cell according
glass
substrate
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn
Application number
EP10718892A
Other languages
German (de)
French (fr)
Inventor
Burkhard Speit
Eveline Rudigier-Voigt
Silke Wolff
Wolfgang Mannstadt
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schott AG
Original Assignee
Schott AG
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 Schott AG filed Critical Schott AG
Publication of EP2429963A1 publication Critical patent/EP2429963A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
    • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
    • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
    • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
    • C03C17/3605—Coatings of the type glass/metal/inorganic compound
    • 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
    • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
    • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
    • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
    • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
    • C03C17/3649—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer made of metals other than silver
    • 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
    • C03C17/00—Surface treatment of glass, not in the form of fibres or filaments, by coating
    • C03C17/34—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions
    • C03C17/36—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal
    • C03C17/3602—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer
    • C03C17/3668—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the multilayer coating having electrical properties
    • C03C17/3678—Surface treatment of glass, not in the form of fibres or filaments, by coating with at least two coatings having different compositions at least one coating being a metal the metal being present as a layer the multilayer coating having electrical properties specially adapted for use in solar cells
    • 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
    • C03C3/11—Glass compositions containing silica with 40% to 90% silica, by weight containing halogen or nitrogen
    • C03C3/112—Glass compositions containing silica with 40% to 90% silica, by weight containing halogen or nitrogen containing fluorine
    • 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
    • C03C4/00—Compositions for glass with special properties
    • C03C4/0092—Compositions for glass with special properties for glass with improved high visible transmittance, e.g. extra-clear 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
    • H01L31/036—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
    • 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
    • H01L31/0248—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
    • H01L31/03925—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 AIIBVI compound materials, e.g. CdTe, CdS
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/04—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices
    • H01L31/06—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers
    • H01L31/072—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PN heterojunction type
    • H01L31/0749—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof adapted as photovoltaic [PV] conversion devices characterised by potential barriers the potential barriers being only of the PN heterojunction type including a AIBIIICVI compound, e.g. CdS/CulnSe2 [CIS] heterojunction 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
    • H01L31/0352—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 shape or by the shapes, relative sizes or disposition of the semiconductor regions
    • H01L31/035272—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 shape or by the shapes, relative sizes or disposition of the semiconductor regions characterised by at least one potential jump barrier or surface barrier
    • H01L31/035281—Shape of the body
    • 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

  • the invention relates to a thin-film solar cell.
  • photoactive semiconductor materials in particular indirect semiconductors, such as silicon-based materials (here, my amorphous or microcrystalline and crystalline silicon or their layers), are direct semiconductors, such as so-called highly absorbent compound semiconductors of groups Il to VI of the Periodic Table of the Elements (for example CdTe ), or the group I to Ml to VI2, such as Cu (lni -x Ga x ) (Sei -y S y ) 2 (CldS) on inexpensive, sufficiently temperature-resistant substrates, for. B. molybdenum coated substrate glasses, deposited in a few micron thick layers.
  • the cost reduction potential lies above all in the low consumption of semi-consumables and the high level of automation in the production process.
  • Solarization-stable aluminosilicate glasses having a total content of CaO, SrO and BaO of from 8 to less than 17% by weight as a substrate for solar collectors are disclosed in document EP 0879 800 A1.
  • the glass substrate in this case has the following composition in wt % to: SiO 2 50 to 80, Al 2 O 3 5 to 15, Na 2 O 1 to 15, K 2 O 1 to 15, MgO 1 to 10, CaO 1 to 10, SrO 1 to 10, BaO 1 to 10, ZrO 2 1 to 10, and is characterized by a so-called "Anneing Point" (temperature at a viscosity of the glass of 10 13 dPas) of greater than 550 0 C from.
  • Substrate glasses for use in thin-film photovoltaics, in particular based on compound semiconductors, are disclosed in the publication DE 100 05 088 C1.
  • the glasses have a B 2 O 3 content of 1 to 8 wt .-% and a total content of alkaline earth oxides (MgO, CaO, SrO and BaO) of 10 to 25 wt .-% to.
  • MgO, CaO, SrO and BaO alkaline earth oxides
  • the object of the invention is to find a comparison with the prior art improved thin-film solar cell.
  • the solar cell according to the invention should also be economical to produce by known methods and have a higher efficiency.
  • the object is achieved by a thin-film solar cell comprising at least one Na 2 O-containing multi-component substrate glass.
  • the Na 2 O-containing multi-component substrate glass must have at least all of the following features:
  • Thin film solar cell is referred to below for simplicity short Sola r cell, and in the dependent claims.
  • Substrate glass in the sense of this application may also comprise a superstrate glass.
  • Na 2 O-containing multicomponent substrate glass in the context of this invention is meant that the substrate glass in addition to Na 2 O further composition components such as B 2 O 3 , BaO, CaO, SrO, ZnO, K 2 O, MgO, SiO 2 and Al 2 O 3 , but also non-oxidic components, for.
  • B. anionic bound components such as F, P, N may contain.
  • Such solar cells according to the invention can be produced by known methods, wherein the process parameters may need to be adjusted.
  • Known method for producing the semiconductor layers on the substrate glass or a previously coated substrate glass are, for example, the sequential process (implementation of metallic layers in chalcogen atmosphere), the so-called co-evaporation (almost simultaneous evaporation of the individual elements or element compounds), as well as liquid coating processes followed by temperature step in chalcogen atmosphere.
  • the inventors have recognized that a B 2 ⁇ 3 content of the substrate glassy; of more than 1 wt .-% negative impact on the efficiency of the solar cell. Boiatomes can probably pass from the substrate glass via evaporation or diffusion into the semiconductor. This probably leads to defects within the semiconductor layer which are electrically active and cause an increased recombination, whereby the performance of the solar cell is reduced.
  • a content of BaO of less than 1% by weight and an amount of one or more of the following substrate glass components CaO, SrO and / or ZnO of less than 3% by weight (total CaO + SrO + ZnO ⁇ 3% by weight). , preferably ⁇ 0.5 wt .-%) has a positive effect on the mobility of the sodium ions in the substrate glass during the production of the solar cell, resulting in an increase in the efficiency of the solar cell.
  • the molar ratio of the substrate glass components (Na 2 O + K 2 O) / (MgO + CaO + SrO + BaO) is greater than 0.95, preferably> 0.95 bi,> 6.5, must be to increase the efficiency of the solar cell according to the invention over a known solar cell.
  • the inventive solar cell comprises a substrate glass containing less than 0.5 wt .-% B 2 O 3, in particular from unavoidable traces, no B 2 O 3.
  • the solar cell according to the invention preferably comprises a substrate glass which contains less than 0.5% by weight of BaO, in particular, except for unavoidable traces, no BaO.
  • the substrate glasses except for unavoidable traces, are free of B 2 O 3 and / or BaO, in particular if less than 1000 ppm B 2 O 3 and / or less than 1000 ppm BaO are contained.
  • the solar cell comprises a substrate glass containing a total of less than 2 wt .-% CaO + SrO + ZnO of the substrate glass components, resulting in a higher Bewegl ability of the alkali ions in the substrate glass during the production of the solar cell and thus leads to a more efficient solar cell.
  • the solar cell comprises a substrate glass containing at least 5 wt .-% Na 2 O, in particular at least 8 wt .-% Na 2 O.
  • the solar cell comprises a substrate glass which contains at most 18% by weight of Na 2 O, and preferably at most 16% by weight of Na 2 O.
  • the molar ratio of the substrate glass components SiO 2 ZAI 2 O 3 is less than 6 and greater than 5.
  • the solar cell has preferably a Aluminosilikatsubstr ⁇ itglas, in particular a Aluminosilikatsubstratglas with a Transformatiorstem- temperature Tg of> 550 0 C, the following composition of components (in mol%) comprising:
  • the solar cell according to the invention preferably has an aluminosilicate substrate glass which comprises the following composition components (in mols / l):
  • the substrate glass may contain further customary components in glass production, such as further refining agents, in the usual amounts, in particular up to 1.5% by weight of sulfate and / or up to 1% by weight of chloride.
  • the solar cell substrate a glass with planter thermal expansion coefficient ⁇ 2 o / oo 3 of greater than 7.5 x 10 -6 / K, in particular of 8.0 x 10 "-6 / K to 9.5 x 10" 6 / K, has, in the temperature range from 20 0 C to 300 0 C ciuf-.
  • the thermal expansion coefficient of the substrate glass it has been shown that it is advantageous to adapt the thermal expansion coefficient of the substrate glass to that of the photoactive semiconductor layer, for example the CIGS layer.
  • the solar cell has a substrate glass having an electrical conductivity of greater than 17 x 10 "12 S / cm at 25 ° C, wherein the electrical conductivity of the substrate glass at 250 0 C by a factor of 10 4 is greater, preferably greater by a factor of 10 5 and particularly preferably greater by a factor of 10 6 , than the electrical conductivity of the substrate glass at 25 ° C.
  • the described substrate glasses are particularly well suited, since ions can be exchanged preferentially in these substrate glasses by chemical means. The sodium ions which are undesirable in these cases can thus easily be replaced by other ions, for example lithium or potassium ions.
  • these substrate glasses are also suitable for special CIGS solar cells in which Na (for example as NaFa) is doped, since they have a have intrinsic Na barrier through the ion-exchanged interface, without having to apply another layer as a barrier layer.
  • the substrate glasses for example, in a potassium salt melt, z. B. in a KN ⁇ 3 melt at 400 0 C to 520 0 C, immersed for a certain time, which determines the thickness of the exchange layer in the substrate substantially. If you exchange z. B. at 450 0 C for 10 hours, so on the surface of the substrate glass, a nearly sodium ion-free surface layer of a surface depth of at least 20 microns formed, with potassium ions on the sodium ion sites.
  • the sodium ions of the substrate glass are at least partially replaced by other cations, in particular by potassium ions, to a surface depth of 20 ⁇ m, so that the sodium ion content in the surface layer is lowered compared to the total matrix content of the substrate glass.
  • the substrate glass of a solar cell according to the invention is preferably coated with at least one molybdenum layer, wherein the molybdenum layer is preferably 0.25 to 3.0 microns and more preferably 0.5 to 1, 5 microns thick.
  • the solar cell is a silicon-based thin film solar cell or a compound semiconductor-based thin film solar cell such as CdTe, CIS or CIGS.
  • the solar cell can be a planar, curved, spherical or cylindrical thin-film solar cell.
  • the solar cell according to the invention is a substantially planar (flat) solar cell or a substantially tubular solar cell, wherein preferably flat substrate glasses or tubular substrate glasses are used.
  • the solar cell according to the invention is subject to no restriction with regard to its shape or to the shape of the substrate glass.
  • the outer diameter of a tubular substrate glass of the solar cell is preferably 5 to 100 mm and the wall thickness of the tubular substrate glass is preferably 0.5 to 10 mm.
  • the solar cell has functional layers.
  • the functional layers of the solar cell preferably consist of conductive and transparent conductive materials, of photosensitive compound semiconductor materials, of buffer materials and / or metallic back contact materials. If at least two solar cells are connected in series, a thin-film photovoltaic module is produced by encapsulation, in particular by encapsulation with SiO 2 , plastics and films, such as EVA (ethylene-vinyl acetate), paint layers or / and by a further substrate glass of environmental influences is protected.
  • the further substrate glass may in this case be the same substrate glass as already included in the solar cell, but it may also be another, for example a substrate glass pretensioned by ion exchange.
  • the solar cell preferably has at least one photoactive semiconductor which is applied to the substrate glass or a previously coated substrate glass at a temperature of at least one second.
  • this temperature is less than the transformation temperature Tg of the substrate glass.
  • the solar cell is a compound semiconductor-based thin film solar cell, as exemplified below.
  • the thin-film solar cells according to the invention based on II-VI or III-VI compound semiconductors, such as CdTe or CIGS of the general formula Cu (I x .xGa x ) (Si- y Sey) 2 have a - in comparison to the prior art - better crystallinity and thus increased open circuit voltage and higher efficiency.
  • These compound semiconductors applied to the substrate glasses in the form of thin layers / layer packages, fulfill essential prerequisites, such as, for example, in CIGS a band gap very well adapted to the solar spectrum by mixing the ternary compounds (1.10 ⁇ E 9 ⁇ 2.0 eV ) and a high absorption of the incident light (absorption coefficient> 2 ⁇ 10 4 cm -1 ) for their use in solar cells.
  • Thin, polycrystalline layers / layer packages of slightly varying Cu (In I- x Ga ⁇ ) (Si -y Sey) 2 compositions can in principle be prepared by a number of methods (eg simultaneous vapor deposition of the elements, sputtering with subsequent reactive gas step , CVD, MOCVD, co-evaporation, electrodeposition or liquid separation with subsequent temperature step in chalcogen atmosphere, etc.) in several stages.
  • Such CIGS layers / layer packages have an intrinsic p-type.
  • the p / n junction in such material systems is then deposited by introducing a thin buffer layer (e.g., a few nanometers thick CdS layer, etc.) and subsequently deposited n-type transparent oxides (TCO) ZnO or ZnO (AI)) realized.
  • a thin buffer layer e.g., a few nanometers thick CdS layer, etc.
  • TCO transparent oxides
  • AI n-type transparent oxides
  • Figure 1 shows an example of the schematic structure of a planar thin-film solar cell of the invention with pn heterojunction based on Cu (I domestic x Ga x) (Si y Sey). 2
  • a substrate glass with the composition of glass 2 and Tg of 632 ° C, s. Table 2 produced by floats and singulated with the help of carbide cutting tools.
  • the substrate glass panes thus obtained were cleaned in a standard industrial process and coated with the following layer system: Substrate glass / back contact (molybdenum via sputtering technology) / absorber (CIGS, the metallic layers being applied by sputtering and subsequently heated in a chalcogen-containing atmosphere by means of a so-called .
  • FIG. 2 essentially shows the structure of FIG. 1, wherein the thin-film solar module is protected from environmental influences by encapsulation of a plurality of series-connected thin-film solar cells.
  • a barrier layer for example SiN
  • an Na-containing intermediate layer such as, for example, NaF via evaporation, between back contact layer and absorber layer, the latter is not shown in FIG 2.
  • the further layers in FIG. 2 correspond to those of FIG. 1.
  • a lamination film for example EVA film
  • a hardened, commercially available cover glass for example a low-iron soda-lime glass
  • Typical lamination temperatures are in the range of 50 to 200 ° C.
  • Figure 3 shows in principle the same layer structure of the compound semiconductor as in Figure 1, however, on the surface of an inner glass tube as substrate glass (tube diameter about 15 to 18 mm), which then in another outer glass tube with a larger diameter (about 25 mm) and a suitable Fill liquid (eg silicone oil) between the inner tube coated with the solar cell and the outer tube are installed.
  • a suitable Fill liquid eg silicone oil
  • the substrate glass is preferably made of an aluminosilicate glass, as it is known for example from the documents DE 196 16 633 C 1 and DE 196 16 679 C 1, provided that it meets the features of claim 1 and its thermal expansion coefficient c ⁇ 2 o / 3 oo to the of the semiconductor is adjusted.
  • a contacting layer here of metallic molybdenum, applied.
  • the actual photoactive semiconductor On top of this is a buffer layer of eg CdS and then a window (here a transparent, conductive layer (TCO) applied through which the sunlight can penetrate to the semiconductor.
  • TCO transparent, conductive layer
  • An essential requirement for a suitable substrate glass is derived from the temperatures prevailing in the coating process.
  • temperatures are required at least above 550 0 C.
  • Higher temperatures, in particular temperatures above 600 ° C. lead to even better results with regard to the deposition rate and the crystallinity of the layers.
  • the substrate glass to be coated is generally positioned very close to a radiation source, in particular embodiments hanging over the evaporation sources used in the coating process, the substrate glass should have the highest possible thermal capacity, ie as a rough orientation the transformation temperature (T 9 ) should According to DIN 52 324 of the glass corresponding to at least above 550 0 C.
  • T 9 the transformation temperature
  • DIN 52 324 of the glass corresponding to at least above 550 0 C.
  • a process temperature below T 9 also prevents the introduction of stresses into the substrate glass and thus into the layer system by rapid cooling, which is usually the case CIGS coating processes is the case.
  • the substrate glass In order to prevent spalling of the coating systems during cooling after the coating process, the substrate glass must continue to the thermal expansion of the back contact (eg., Molybdenum, about 5 x 10 -6 / K), and more BES be adapted to the semiconductor layer deposited thereon (eg about 8.5 ⁇ 10 -4 / K for CIGS).
  • the back contact e.g., Molybdenum, about 5 x 10 -6 / K
  • BES be adapted to the semiconductor layer deposited thereon (eg about 8.5 ⁇ 10 -4 / K for CIGS).
  • the substrate glass has to serve in addition to the property of a carrier material to have an additional functionality: namely the targeted delivery, both temporally and spatially (homogeneously over the coating surface) of sodium.
  • the glass should release sodium ions / atoms at temperatures around T 9 , which presupposes increased mobility of the sodium ions in the glass.
  • a barrier layer may be applied to the glass surface prior to coating with molybdenum (eg, an Al 2 O 3 layer) that completely prevents sodium ion diffusion.
  • Sodium ions must then be added separately in a further process step (eg in the form of NaF 2 ), which increases the process times and costs.
  • a further process step eg in the form of NaF 2
  • sufficient chemical resistance to environmental influences, especially water (moisture, moisture, rain) as well as other aggressive reagents possibly used in the manufacturing process, must be ensured.
  • the layers themselves are protected by encapsulation with SiO 2 , plastic, paint layers or / and also by a cover glass from the environment.
  • Table 1 shows properties of substrate glasses for CIGS thin-film solar cells compared to the prior art, which are suitable for the solar cell according to the invention.
  • boron and barium aluminosilicates katgläser the requirements for use as substrate glass for the thin-film photovoltaics, as for example in the high-temperature manufacturing technology CIGS substrate glass temperatures during the coating of up to 700 0 C.
  • CIGS substrate glass temperatures during the coating of up to 700 0 C.
  • efficiencies of CIGS thin-film solar cells over 2% were achieved absolutely in comparison to the prior art, ie instead of, for example, 12% with a conventional substrate glass, an efficiency of 14% was achieved.
  • Big bubbles i. Blisters that are visible to the naked eye (diameter> 80 ⁇ m) are also counted with the naked eye, in a polished glass cube of 10 cm edge length. The size and number of smaller bubbles are measured / counted on 10 cm x 10 cm x 0.1 cm glass plates with good optical polishing by means of a microscope with 400 to 500 times magnification.
  • the glasses were melted in 4-liter platinum crucibles from conventional raw materials ie carbonates, nitrates, fluorides and oxides of the components.
  • the raw materials were placed over a period of 8 h at melting temperatures of 1580 0 C and then held for 14 h at this temperature. With stirring, the glass melt was then cooled to 1400 0 C within 8 h and then poured into a preheated 500 0 C graphite mold. This mold was placed immediately after the cast in a preheated to 650 0 C cooling furnace cooled at 5 ° C / h to room temperature. Out Afterwards, the glass samples necessary for the measurements were removed from this block.
  • the determination of the conductivity is of particular importance.
  • the dielectric measurements were carried out with the impedance spectrometer alpha-Analyzer from Novocontrol, Limburg, and the associated temperature control unit. During the measurement, a mostly round disc of the glass sample with a diameter of typically 40 mm and a thickness of approximately 0.5 to 2 mm is contacted on both sides with conductive silver. With gilded brass contacts, the sample is clamped from the top and bottom in a sample holder and placed in a cryostat. As a function of frequency and temperature, the electrical resistance and the capacitance of the device can now be measured by means of a bridge balance. With known geometries, the conductivity and the dielectric constant of the material can then be determined.
  • Table 2 Examples of glass compositions in mol%, molar ratios and properties of substrate glasses, which are suitable for the solar cell according to the invention.
  • the glasses can without deformation not only at temperatures of about 100 0 C to 150 0 C over the prior art are used, but turn out to be due to the increased sodium ion mobility as a reliable doping source for the crystallization process by example.
  • This high mobility is responsible for the crystalline growth of the compound semiconductor layers, in particular the CIGS layers and the then achievable phosphorous layers. to voltaic properties of these layers is a prerequisite, given that the sodium ions must reach the crystallization zone before they reach the crystallization zone and must diffuse through a 0.5 to 1 ⁇ m thick molybdenum layer on the substrate glass and / or reach the growing semiconductor layer via the vapor phase as sodium atoms.
  • the positive influence of sodium ions on chalcogen incorporation in the semiconductor crystal has an effect not only on improved crystallite structure and crystal density, but also on crystallite size and orientation.
  • the sodium ion is incorporated in the grain boundaries of the system and can i.a. contribute to a reduction in charge carrier recombination at the grain boundaries. These phenomena inevitably lead to significantly better semiconductor properties, in particular to a reduction of the recombination in the bulk material and thus an increased open circuit voltage. Of course, this manifests itself above all in the efficiency with which the solar spectrum can be converted into electricity.
  • This ion mobility can be favorably influenced in the substrate glasses by a surface treatment in acidic or alkaline solutions, for example in the sense that at higher temperatures an ionic movement starts earlier, or a uniform diffusion of the sodium ions or a more uniform evaporation of sodium given from the surface is present.
  • the solar cell has at least one Na 2 O-containing multi-component substrate glass having the features according to claim 1 and which is not phase-deadened and one Content of ⁇ -OH from 25 to 80 mmol / l possesses.
  • the Na 2 O-containing multi-component substrate glass is less than 1% by weight B 2 O 3 , less than 1% by weight BaO and in Sum less than 3 wt.% CaO + SrO + ZnO contains that the molar ratio of the substrate glass components (Na 2 O + K 2 O) / (MgO + CaO + SrO + BaO) is greater than 0.95, that is the molar ratio Ratio of the substrate glass components SiO2 / Al2O3 is less than 7, and that the substrate glass has a transformation temperature Tg of greater than 550 ° C, in particular greater than 600 0 C.
  • a substrate glass is not phase-separated in the sense of this invention if it has less than 10, preferably less than 5, surface defects in a surface area of 100 ⁇ 100 nm 2 after a conditioning experiment.
  • the conditioning experiment was carried out as follows: At 500 to 600 0 C, a flow of compressed air in the range between 15 to 50 ml / min and a flow of sulfur dioxide gas (SO 2 ) in the range 5 to 25 ml / min, for a period of 5 to 20 minutes, the substrate glass surface to be examined is gassed. Irrespective of the glass type, a crystalline coating forms on the substrate glass.
  • the surface defects per substrate glass surface area are determined microscopically. If less than 10, in particular less than 5, surface defects are present in a surface area of 100 ⁇ 100 nm 2 , the substrate glass is considered not to be phase-separated. All surface defects with a diameter of> 5 nm are counted.
  • the ⁇ -OH content of the substrate glass was determined as follows.
  • the equipment used for the quantitative determination of the water over the OH stretching vibration around 2700 nm is the commercially available Nicolet FTIR spectrometer with attached computer evaluation.
  • the absorption in the wavelength range from 2500 to 6500 nm was measured first and the absorption maximum around 2700 nm was determined.
  • the e value is taken from the work of H. Frank and H. Scholze from the "Glastechnische Berichte" Volume 36, Volume 9 page 350.

Landscapes

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

Abstract

The claimed thin-film solar cell comprises at least one multicomponent substrate glass containing Na2O, said substrate glass containing less than 1 wt.% B2O3, less than 1 wt.% BaO and less than, in total, 3 wt.% CaO + SrO + ZnO. The molar ratio of the substrate glass components (Na2O+K2O)/(MgO+CaO+SrO+BaO) is greater than 0.95, the molar ratio of the substrate glass components SiO2/AI2O3 is less than 7, and the substrate glass has a transformation temperature Tg which is higher than 550 °C, in particular higher than 600 °C.

Description

B E S C H R E I B U N G DESCRIPTION
SUBSTRATGLAS FÜR DÜNNSCHICHTSOLARZELLESUBSTRATE GLASS FOR THIN-HOSE SOLAR CELL
Die Erfindung betrifft eine Dünnschichtsolarzelle.The invention relates to a thin-film solar cell.
Die zukünftige Marktentwicklung der Photovoltaik, insbesondere für netzgobun- dene Photovoltaikanlagen, ist maßgeblich vom Kostenreduktionspotential bei der Herstellung von Solarzellen abhängig. Ein großes Potential wird bei dor Herstellung von Dünnschichtsolarzellen gesehen, da wesentlich weniger photDakti- ves Material für eine effiziente Umwandlung von Sonnenlicht in Elektrizitäi benötigt wird, als bei herkömmlichen kristallinen, siliziumbasierten Solarzellen. Bei Dünnschichtsolarzellen werden photoaktive Halbleitermaterialien, im Spez iellen indirekte Halbleiter, wie siliziumbasierte Materialien (hier unterscheidet mein amorphes bzw. mikrokristallines und kristallines Silizium beziehungsweise deren Schichten), direkte Halbleiter, wie sogenannte hochabsorbierende Verbindungshalbleiter der Gruppe Il bis VI des Periodensystems der Elemente (beispielsweise CdTe), oder der Gruppe I bis Ml bis VI2, wie Cu(lni-xGax)(Sei-ySy)2 (CldS) auf kostengünstigen, ausreichend temperaturbeständigen Substraten, z. B. Molybdän beschichteten Substratgläsern, in wenigen μm-dicken Schichten abgeschieden. Das Kostensenkungspotential liegt dabei vor allem im geringen Halb eiter- materialverbrauch und der hohen Automatisierbarkeit bei der Herstellung. Jedoch bleiben die bisher erreichten Wirkungsgrade von kommerziellen Dürm- schichtsolarzellen noch deutlich hinter denen kristalliner, siltziumbasierter Solarzellen zurück (Dünnschichtsolarzellen: ca. 10 bis 15 % Wirkungsgrad; kristalline siliziumbasierte Solarzellen aus Siliziumwafem: ca. 15 bis 18 % Wirkungsgrad).The future market development of photovoltaics, in particular for grid-connected photovoltaic systems, is largely dependent on the cost reduction potential in the production of solar cells. Great potential is seen in the fabrication of thin-film solar cells because significantly less photodactic material is needed for efficient conversion of sunlight into electricity than conventional crystalline silicon-based solar cells. For thin-film solar cells, photoactive semiconductor materials, in particular indirect semiconductors, such as silicon-based materials (here, my amorphous or microcrystalline and crystalline silicon or their layers), are direct semiconductors, such as so-called highly absorbent compound semiconductors of groups Il to VI of the Periodic Table of the Elements (for example CdTe ), or the group I to Ml to VI2, such as Cu (lni -x Ga x ) (Sei -y S y ) 2 (CldS) on inexpensive, sufficiently temperature-resistant substrates, for. B. molybdenum coated substrate glasses, deposited in a few micron thick layers. The cost reduction potential lies above all in the low consumption of semi-consumables and the high level of automation in the production process. However, the efficiencies achieved so far by commercial thin-film solar cells still lag far behind those of crystalline, siltium-based solar cells (thin-film solar cells: approximately 10 to 15% efficiency, crystalline silicon-based solar cells made of silicon wafers: approximately 15 to 18% efficiency).
Neben Solarzellen, die gefloatete Kalknatrongläser als Substratglas für Dύnn- schichtphotovoltaikanwendungen, umfassen, sind auch Solarzellen mit arideren Substratglasarten bzw. weitere Substratglasarten, die sich für die Photovoltaik eigenen sollen, bekannt.In addition to solar cells, which include floated soda lime glasses as a substrate glass for thin film photovoltaic applications, there are also solar cells with other types Substrate types of glass or other types of substrate glass, which should own for the photovoltaic known.
Aus der Schrift DE 699 16 683 T2 gehen Substratgläser für Bildschirme rr it einem Wärmeausdehnungskoeffizienten von 6,0 x 10"6/K bis 7,4 x 10"6/K im Temperaturbereich von 50 °C bis 350 0C hervor, die auch für Solarzellen geeiςmet sein sollen.From the document DE 699 16 683 T2 substrate glasses for screens rr it with a coefficient of thermal expansion of 6.0 x 10 "6 / K to 7.4 x 10 " 6 / K in the temperature range of 50 ° C to 350 0 C, which also for solar cells should be.
Solarisationsstabile Aluminosilikatgläser mit einem Gesamtgehalt an CaO, SrO und BaO von 8 bis kleiner 17 Gew.-% als Substrat für Sonnenkollektoren gehen aus der Schrift EP 0879 800 A1 hervor.Solarization-stable aluminosilicate glasses having a total content of CaO, SrO and BaO of from 8 to less than 17% by weight as a substrate for solar collectors are disclosed in document EP 0879 800 A1.
Dünnschichtsolarzellen, insbesondere auf Verbundhalbleiterbasis, umfass end ein Glassubstrat mit einem Wärmeausdehnungskoeffizienten von 6 x 10"6 fK bis 10 x 10'6/K gehen aus der Schrift JP 11-135819 A hervor. Das Glassubstrat weist dabei folgende Zusammensetzung in Gew.-% auf: Siθ2 50 bis 80, AI2O3 5 bis 15, Na2O 1 bis 15, K2O 1 bis 15, MgO 1 bis 10, CaO 1 bis 10, SrO 1 bis 10, BaO 1 bis 10, ZrO2 1 bis 10, und zeichnet sich durch einen sogenannten "Anne- ling Point" (Temperatur bei einer Viskosität des Glases von 1013 dPas) vo i größer als 550 0C aus.Thin film solar cells, and in particular compound semiconductor base, umfass end, a glass substrate having a thermal expansion coefficient of 6 x 10 "6 f K to 10 x 10 -6 / K become apparent from the JP 11-135819 A. The glass substrate in this case has the following composition in wt % to: SiO 2 50 to 80, Al 2 O 3 5 to 15, Na 2 O 1 to 15, K 2 O 1 to 15, MgO 1 to 10, CaO 1 to 10, SrO 1 to 10, BaO 1 to 10, ZrO 2 1 to 10, and is characterized by a so-called "Anneing Point" (temperature at a viscosity of the glass of 10 13 dPas) of greater than 550 0 C from.
Substratgläser für die Verwendung in der Dünnschichtphotovoltaik, insbesionde- re auf Verbundhalbleiterbasis, werden in der Schrift DE 100 05 088 C1 ofen- bart. Die Gläser weisen einen B2O3-Gehalt von 1 bis 8 Gew.-% und einen Gesamtgehalt an Erdalkalioxiden (MgO, CaO, SrO und BaO) von 10 bis 25 Gew.-% auf.Substrate glasses for use in thin-film photovoltaics, in particular based on compound semiconductors, are disclosed in the publication DE 100 05 088 C1. The glasses have a B 2 O 3 content of 1 to 8 wt .-% and a total content of alkaline earth oxides (MgO, CaO, SrO and BaO) of 10 to 25 wt .-% to.
Aufgabe der Erfindung ist es, eine gegenüber dem Stand der Technik verbesserte Dünnschichtsolarzelle zu finden. Die erfindungsgemäße Solarzelle soll dabei auch mittels bekannter Verfahren wirtschaftlich herstellbar sein und einen höheren Wirkungsgrad aufweisen. Gelöst wird die Aufgabe durch eine Dünnschichtsolarzelle, die wenigstens ein Na2O-haltiges Mehrkomponentensubstratglas umfasst. Das Na2O-haltige N/Iehr- komponentensubstratglas (Substratglas) muss dabei wenigstens alle der iolgen- den Merkmale aufweisen:The object of the invention is to find a comparison with the prior art improved thin-film solar cell. The solar cell according to the invention should also be economical to produce by known methods and have a higher efficiency. The object is achieved by a thin-film solar cell comprising at least one Na 2 O-containing multi-component substrate glass. The Na 2 O-containing multi-component substrate glass (substrate glass) must have at least all of the following features:
Ein Gehalt der Substratglaskomponenten von weniger als 1 Gew.-% Ei2O3, von weniger als 1 Gew-% BaO und von in Summe weniger als 3 Gew.-% CaO + SrO + ZnO, ein molares Verhältnis der Substratglaskomponenten (Na2O + K2O)/(MgO + CaO + SrO + BaO) von größer als 0,95 (d.h. das Substratglas enthält wenigstens Na2O oder K2O und wenigstens MgO oder CaO oder SrO oder BaO), ein molares Verhältnis der Substratglaskomponenten SiO2/AI2O3 von kleiner als 7 (d.h. das Substratglas enthält SiO2 und AI2O3), eine Transformationstemperatur Tg (Temperatur bei einer Viskosität des Glases von 1014'5 dPas nach DIN 52324) des Substratglases von größer als 550 0C, insbesondere von größer als 600 0C.A content of the substrate glass components of less than 1% by weight of Ei 2 O 3 , of less than 1% by weight of BaO and of in total less than 3% by weight of CaO + SrO + ZnO, a molar ratio of the substrate glass components (Na 2 O + K 2 O) / (MgO + CaO + SrO + BaO) of greater than 0.95 (ie the substrate glass contains at least Na 2 O or K 2 O and at least MgO or CaO or SrO or BaO), a molar ratio of Substrate glass components SiO 2 / Al 2 O 3 of less than 7 (ie, the substrate glass contains SiO 2 and Al 2 O 3 ), a transformation temperature Tg (temperature at a viscosity of the glass of 10 14 ' 5 dPas according to DIN 52324) of the substrate glass of greater as 550 0 C, in particular of greater than 600 0 C.
Dünnschichtsolarzelle wird im folgenden der Einfachheit wegen kurz Solarzelle genannt, auch in den abhängigen Ansprüchen. Substratglas im Sinne dieser Anmeldung kann auch ein Superstratglas umfassen.Thin film solar cell is referred to below for simplicity short Sola r cell, and in the dependent claims. Substrate glass in the sense of this application may also comprise a superstrate glass.
Mit Na2O-haltigem Mehrkomponentensubstratglas im Sinne dieser Erfindung ist gemeint, dass das Substratglas neben Na2O weitere Zusammensetzungskomponenten, wie beispielsweise B2O3, BaO, CaO, SrO, ZnO, K2O, MgO, SiO2 und AI2O3, aber auch nichtoxidische Komponenten, z. B. anionisch gebundene Komponenten wie F, P, N, enthalten kann.By Na 2 O-containing multicomponent substrate glass in the context of this invention is meant that the substrate glass in addition to Na 2 O further composition components such as B 2 O 3 , BaO, CaO, SrO, ZnO, K 2 O, MgO, SiO 2 and Al 2 O 3 , but also non-oxidic components, for. B. anionic bound components such as F, P, N may contain.
Solche erfindungsgemäßen Solarzellen lassen sich mittels bekannter Verfahren herstellen, wobei die Verfahrensparameter ggf. angepasst werden müssen. Bekannte Verfahren zur Herstellung der Halbleiterschichten auf dem Substrutglas bzw. einem zuvor beschichteten Substratglas, sind zum Beispiel, der sequentielle Prozess (Umsetzung von metallischen Schichten in Chalkogenatmosphäre), die sog. Co-Verdampfung (nahezu simultane Verdampfung der einzelnen Elemente oder Elementverbindungen), sowie Flüssigbeschichtungsprozesse mit anschließendem Temperaturschritt in Chalkogenatmosphäre. Überrascheiderweise wurde gefunden, dass insbesondere bei der Abscheidung der Halbteiter- schichten weit höhere Verfahrenstemperaturen eingesetzt werden können als auf Grundlage von herkömmlichen Kalknatronsubstratgläsern, ohne dass sich das Substratglas unvorteilhaft für einen späteren Laminierungsprozess verformt, und die erfindungsgemäßen Solarzellen weisen gegenüber bekannten Solarzellen mit Kalknatronsubstratgläsern einen um über 2 % absolut höheren Wirkungsgrad auf.Such solar cells according to the invention can be produced by known methods, wherein the process parameters may need to be adjusted. Known method for producing the semiconductor layers on the substrate glass or a previously coated substrate glass are, for example, the sequential process (implementation of metallic layers in chalcogen atmosphere), the so-called co-evaporation (almost simultaneous evaporation of the individual elements or element compounds), as well as liquid coating processes followed by temperature step in chalcogen atmosphere. Unfortunately, it has been found that, in particular during the deposition of the half-titer layers, far higher process temperatures can be used than based on conventional soda lime substrate glass without the substrate glass deforming unfavorably for a later lamination process, and the solar cells according to the invention have a conversion over known solar cells with soda lime substrate glass over 2% absolutely higher efficiency.
Die Erfinder haben erkannt, dass sich ein B2θ3-Gehalt des Substratglasej; von über 1 Gew.-% negativ auf den Wirkungsgrad der Solarzelle auswirkt. Boiatome können aus dem Substratglas vermutlich über Abdampfen oder Diffusion in den Halbleiter gelangen. Dies führt innerhalb der Halbleiterschicht vermutlich ;:u Defekten, die elektrisch aktiv sind und eine erhöhte Rekombination bedingen, wodurch die Leistung der Solarzelle herabgesetzt wird.The inventors have recognized that a B 2 θ 3 content of the substrate glassy; of more than 1 wt .-% negative impact on the efficiency of the solar cell. Boiatomes can probably pass from the substrate glass via evaporation or diffusion into the semiconductor. This probably leads to defects within the semiconductor layer which are electrically active and cause an increased recombination, whereby the performance of the solar cell is reduced.
Wohingegen ein Gehalt an BaO von weniger als 1 Gew-% und ein Gehall von einer oder aller der folgenden Substratglaskomponenten CaO, SrO und/oder ZnO von weniger als 3 Gew.-% (Summe CaO + SrO + ZnO < 3 Gew.-%, vorzugsweise < 0,5 Gew.-%) sich positiv auf die Beweglichkeit der Natriumionen im Substratglas während der Herstellung der Solarzelle auswirkt, was zu einer Erhöhung des Wirkungsgrads der Solarzelle führt. Wichtig in diesem Zusammenhang ist hierbei, dass das molare Verhältnis der Substratglaskomponenten (Na2O+K2O)/(MgO+CaO+SrO+BaO) größer als 0,95, bevorzugt > 0,95 bi;> 6,5, sein muss, um den Wirkungsgrad der erfindungsgemäßen Solarzelle gegenüber einer bekannten Solarzelle zu erhöhen. Vorzugsweise umfasst die erfindungsgemäße Solarzelle ein Substratglas, das weniger als 0,5 Gew.-% B2O3, insbesondere bis auf unvermeidliche Spuren kein B2O3 enthält. Weiterhin umfasst vorzugsweise die erfindungsgemäße Solarzelle ein Substratglas, das weniger als 0,5 Gew.-% BaO, insbesondere bis auf unvermeidliche Spuren kein BaO enthält. Für bestimmte Solarzellen ist es von Vorteil, wenn die Substratgläser bis auf unvermeidliche Spuren frei von B2O3 und/oder BaO sind, insbesondere wenn weniger als 1000 ppm B2O3 und/oder weniger als 1000 ppm BaO enthalten sind.In contrast, a content of BaO of less than 1% by weight and an amount of one or more of the following substrate glass components CaO, SrO and / or ZnO of less than 3% by weight (total CaO + SrO + ZnO <3% by weight). , preferably <0.5 wt .-%) has a positive effect on the mobility of the sodium ions in the substrate glass during the production of the solar cell, resulting in an increase in the efficiency of the solar cell. It is important in this context that the molar ratio of the substrate glass components (Na 2 O + K 2 O) / (MgO + CaO + SrO + BaO) is greater than 0.95, preferably> 0.95 bi,> 6.5, must be to increase the efficiency of the solar cell according to the invention over a known solar cell. Preferably, the inventive solar cell comprises a substrate glass containing less than 0.5 wt .-% B 2 O 3, in particular from unavoidable traces, no B 2 O 3. Furthermore, the solar cell according to the invention preferably comprises a substrate glass which contains less than 0.5% by weight of BaO, in particular, except for unavoidable traces, no BaO. For certain solar cells, it is advantageous if the substrate glasses, except for unavoidable traces, are free of B 2 O 3 and / or BaO, in particular if less than 1000 ppm B 2 O 3 and / or less than 1000 ppm BaO are contained.
In einer weiteren, bevorzugten Ausführungsformen der Erfindung umfasst die Solarzelle ein Substratglas, das in Summe weniger als 2 Gew.-% CaO + SrO + ZnO der Substratglaskomponenten enthält, was zu einer höheren Bewegl chkeit der Alkaliionen im Substratglas während der Herstellung der Solarzelle und somit zu einer wirksameren Solarzelle führt.In a further preferred embodiment of the invention, the solar cell comprises a substrate glass containing a total of less than 2 wt .-% CaO + SrO + ZnO of the substrate glass components, resulting in a higher Bewegl ability of the alkali ions in the substrate glass during the production of the solar cell and thus leads to a more efficient solar cell.
Vorzugsweise umfasst die Solarzelle ein Substratglas das mindestens 5 Gew.-% Na2O, insbesondere mindestens 8 Gew.-% Na2O enthält.Preferably, the solar cell comprises a substrate glass containing at least 5 wt .-% Na 2 O, in particular at least 8 wt .-% Na 2 O.
In einer weiteren bevorzugten Ausführungsform umfasst die Solarzelle ein Substratglas, das maximal 18 Gew.-% Na2O, und vorzugsweise maximal 16 Gew.-% Na2O enthält.In a further preferred embodiment, the solar cell comprises a substrate glass which contains at most 18% by weight of Na 2 O, and preferably at most 16% by weight of Na 2 O.
Vorzugsweise ist das molare Verhältnis der Substratglaskomponenten SiO2ZAI2O3 kleiner als 6 und größer als 5.Preferably, the molar ratio of the substrate glass components SiO 2 ZAI 2 O 3 is less than 6 and greater than 5.
Erfindungsgemäß weist die Solarzelle bevorzugt ein Aluminosilikatsubstr∑itglas auf, insbesondere ein Aluminosilikatsubstratglas mit einer Transformatiorstem- peratur Tg > 550 0C, das folgende Zusammensetzungskomponenten (in Mol-%) umfasst:According to the invention the solar cell has preferably a AluminosilikatsubstrΣitglas, in particular a Aluminosilikatsubstratglas with a Transformatiorstem- temperature Tg of> 550 0 C, the following composition of components (in mol%) comprising:
SiO2 63 - 67,5SiO 2 63-67.5
B2O3 O AI2O3 10-12,5B 2 O 3 O Al 2 O 3 10-12.5
Na2O 8,5-15,5Na 2 O 8,5-15,5
K2O 2,5-4,0K 2 O 2.5-4.0
MgO 3,0-9,0MgO 3.0-9.0
BaO 0BaO 0
CaO + SrO + ZnO 0-2,5CaO + SrO + ZnO 0-2.5
TiO2 + ZrO2 0,5-1,5TiO 2 + ZrO 2 0.5-1.5
CeO2 0,02 - 0,5CeO 2 0.02-0.5
As2O3+ Sb2O3 0-0,4As 2 O 3 + Sb 2 O 3 0-0.4
SnO2 0-1,5SnO 2 0-1.5
F 0,05-2,6 wobei folgende molaren Verhältnisse für die Substratglaskomponenten gelten:F 0.05-2.6 where the following molar ratios apply to the substrate glass components:
SiO2/AI2O3 5,0 - 6,8SiO 2 / Al 2 O 3 5.0-6.8
Na2O/K2O 2,1 -6,2Na 2 O / K 2 O 2,1 -6,2
AI2O3ZK2O 2,5 - 5,0Al 2 O 3 ZK 2 O 2.5 - 5.0
AI2O3ZNa2O 0,6-1,5Al 2 O 3 ZNa 2 O 0.6-1.5
(Na2O+K2O)/(MgO+CaO+SrO) 0,95 - 6,5(Na 2 O + K 2 O) / (MgO + CaO + SrO) 0.95-6.5
Weiterhin weist die erfindungsgemäße Solarzelle bevorzugt ein Aluminos likat- substratglas auf, das folgende Zusammensetzungskomponenten (in Mol-'/o) um- fasst:Furthermore, the solar cell according to the invention preferably has an aluminosilicate substrate glass which comprises the following composition components (in mols / l):
SiO2 63 - 67,5SiO 2 63-67.5
B2O3 OB 2 O 3 O
AI2O3 10-12,5Al 2 O 3 10-12.5
Na2O 8,5-17Na 2 O 8,5-17
K2O 2,5-4,0K 2 O 2.5-4.0
MgO 3,0-9,0MgO 3.0-9.0
BaO OBaO O
CaO + SrO + ZnO O - 2,5CaO + SrO + ZnO O - 2.5
MgO + CaO + SrO + BaO größer gleich 3MgO + CaO + SrO + BaO greater than or equal to 3
TiO2 + ZrO2 0-5, insbesondere 0-4, bevorzugt 0,25 - 1 ,5 CeO2 0 - 0,5, insbesondere 0,02 - 0,5TiO 2 + ZrO 2 0-5, in particular 0-4, preferably 0.25-1.5 CeO 2 0 - 0.5, in particular 0.02 - 0.5
As2O3+ Sb2O3 0 - 0,4As 2 O 3 + Sb 2 O 3 0 - 0.4
SnO2 0 - 1 ,5SnO 2 0 - 1, 5
F 0 - 3, insbesondere 0,05 - 2,6 wobei folgende molaren Verhältnisse für die Substratglaskomponenten gelten:F 0-3, in particular 0.05-2.6, the following molar ratios apply to the substrate glass components:
SiO2/AI2O3 > 5SiO 2 / Al 2 O 3 > 5
Na2O/K2O 2,1 - 6,2Na 2 O / K 2 O 2.1-6.2
AI2O3/K2O 2,5 - 5,0Al 2 O 3 / K 2 O 2.5 - 5.0
AI2O3/Na2O 0,6 - 1 ,5Al 2 O 3 / Na 2 O 0.6 - 1.5
(Na2O+K2O)/(MgO+CaO+SrO) > 0,95(Na 2 O + K 2 O) / (MgO + CaO + SrO)> 0.95
Neben diesen bevorzugten Zusammensetzungen kann das Substratglas noch weitere, in der Glasherstellung übliche Komponenten, wie weitere Läutermittel, in den üblichen Mengen aufweisen, insbesondere bis zu 1 ,5 Gew.-% Sulfat und/oder bis zu 1 Gew.-% Chlorid.In addition to these preferred compositions, the substrate glass may contain further customary components in glass production, such as further refining agents, in the usual amounts, in particular up to 1.5% by weight of sulfate and / or up to 1% by weight of chloride.
Weiterhin ist es notwendig, dass die Solarzelle ein Substratglas mit einerr Wärmeausdehnungskoeffizienten α2o/3oo von größer 7,5 x 10'6/K, insbesondere von 8,0 x 10"6/K bis 9,5 x 10"6/K, im Temperaturbereich von 20 0C bis 300 0C ciuf- weist. So hat es sich gezeigt, dass es von Vorteil ist, den Wärmeausdehnungskoeffizienten des Substratglases an den der photoaktiven Halbleiterschicht, beispielsweise der CIGS-Schicht, anzupassen.Furthermore, it is necessary that the solar cell substrate, a glass with einerr thermal expansion coefficient α 2 o / oo 3 of greater than 7.5 x 10 -6 / K, in particular of 8.0 x 10 "-6 / K to 9.5 x 10" 6 / K, has, in the temperature range from 20 0 C to 300 0 C ciuf-. Thus, it has been shown that it is advantageous to adapt the thermal expansion coefficient of the substrate glass to that of the photoactive semiconductor layer, for example the CIGS layer.
Bei einer besonderen Ausführungsform der Erfindung weist die Solarzelle ein Substratglas auf, das eine elektrische Leitfähigkeit von größer 17 x 10"12 S/cm bei 25 °C besitzt, wobei die elektrische Leitfähigkeit des Substratglases bei 250 0C um den Faktor 104 größer, bevorzugt um den Faktor 105 größer und besonders bevorzugt um den Faktor 106 größer ist, als die elektrische Leitfähigkeit des Substratglases bei 25°C. Werden erfindungsgemäß Si-basierte oder CdTe-basierte Dünnschichtsolarzel- len hergestellt, eignen sich die beschriebenen Substratgläser besonders gut, da sich bei diesen Substratgläsern bevorzugt auf chemischen Weg Ionen austauschen lassen. Die in diesen Fällen unerwünschten Natriumionen können so leicht durch andere Ionen, z.B. Lithium- oder Kaliumionen, ersetzt werden Somit eigenen sich diese Substratgläser auch für spezielle CIGS-Solarzellen, bei denen Na (z. B. als NaFa) zudotiert wird, da sie eine intrinsische Na-Sperre durch die ionenausgetauschte Grenzfläche aufweisen, ohne eine weitere Schicht als Barriereschicht aufbringen zu müssen. Dazu werden die Substratgläser beispielsweise in eine Kaliumsalzschmelze, z. B. in eine KNθ3-Schmelze bei 400 0C bis 520 0C, für eine bestimmte Zeit, die im Wesentlichen die Dicke der Austauschschicht im Substrat bestimmt, eingetaucht. Tauscht man z. B. bei 450 0C für 10 Stunden aus, so ist an der Oberfläche des Substratglases eine nahezu natriumionenfreie Oberflächenschicht von einer Oberflächentiefe von mindestens 20 μm entstanden, mit Kaliumionen auf den Natriumionenplätzen. Diese Eigenschaften des lonenaustausches sind auch für den Einsatz bruchfester Abdeckgläser dieser erfindungsgemäßen Solarzellen zu nutzen, wöbe durch den Austausch des kleineren Natriumions durch das größere Kaliumion e ne Druckspannung in der Oberfläche erzeugt wird, die die mechanische Fesiigkeit des Abdeckglases bei unveränderter Transparenz bedeutend verbessert.In a particular embodiment of the invention the solar cell has a substrate glass having an electrical conductivity of greater than 17 x 10 "12 S / cm at 25 ° C, wherein the electrical conductivity of the substrate glass at 250 0 C by a factor of 10 4 is greater, preferably greater by a factor of 10 5 and particularly preferably greater by a factor of 10 6 , than the electrical conductivity of the substrate glass at 25 ° C. If, in accordance with the invention, Si-based or CdTe-based thin-film solar cells are produced, the described substrate glasses are particularly well suited, since ions can be exchanged preferentially in these substrate glasses by chemical means. The sodium ions which are undesirable in these cases can thus easily be replaced by other ions, for example lithium or potassium ions. Thus, these substrate glasses are also suitable for special CIGS solar cells in which Na (for example as NaFa) is doped, since they have a have intrinsic Na barrier through the ion-exchanged interface, without having to apply another layer as a barrier layer. For this purpose, the substrate glasses, for example, in a potassium salt melt, z. B. in a KNθ 3 melt at 400 0 C to 520 0 C, immersed for a certain time, which determines the thickness of the exchange layer in the substrate substantially. If you exchange z. B. at 450 0 C for 10 hours, so on the surface of the substrate glass, a nearly sodium ion-free surface layer of a surface depth of at least 20 microns formed, with potassium ions on the sodium ion sites. These properties of ion exchange are also to be used for the use of break-proof cover glasses of these solar cells according to the invention, wöbe by replacing the smaller sodium ion by the larger potassium ion e ne compressive stress in the surface is produced, which significantly improves the mechanical Fesiigkeit the cover glass with unchanged transparency.
Vorzugsweise sind daher bei den erfindungsgemäßen Solarzellen die Nalrium- ionen des Substratglases bis zu einer Oberflächentiefe von 20 μm wenigstens teilweise durch andere Kationen, insbesondere durch Kaliumionen, ersetzt, so dass der Natriumionengehalt in der Oberflächenschicht gegenüber dem Matriu- mionengesamtgehalt des Substratglases erniedrigt ist.Preferably, therefore, in the solar cells according to the invention, the sodium ions of the substrate glass are at least partially replaced by other cations, in particular by potassium ions, to a surface depth of 20 μm, so that the sodium ion content in the surface layer is lowered compared to the total matrix content of the substrate glass.
Das Substratglas einer erfindungsgemäßen Solarzelle ist vorzugsweise mit wenigstens einer Molybdänschicht beschichtet, wobei die Molybdänschicht bevorzugt 0,25 bis 3,0 μm und besonders bevorzugt 0,5 bis 1 ,5 μm dick ist. Vorzugsweise ist die Solarzelle eine Dünnschichtsolarzelle auf Siliziumbasis o- der eine Dünnschichtsolarzelle auf Verbundhalbleitermaterialbasis, wie beispielsweise CdTe, CIS oder CIGS.The substrate glass of a solar cell according to the invention is preferably coated with at least one molybdenum layer, wherein the molybdenum layer is preferably 0.25 to 3.0 microns and more preferably 0.5 to 1, 5 microns thick. Preferably, the solar cell is a silicon-based thin film solar cell or a compound semiconductor-based thin film solar cell such as CdTe, CIS or CIGS.
Weiterhin hat es sich gezeigt, dass die Solarzelle eine planar, gewölbt, sphärisch oder zylindrisch ausgebildete Dünnschichtsolarzelle sein kann.Furthermore, it has been found that the solar cell can be a planar, curved, spherical or cylindrical thin-film solar cell.
Vorzugsweise ist die erfindungsgemäße Solarzelle eine im wesentlichen planare (flache) Solarzelle oder eine im wesentlichen rohrförmige Solarzelle, wobei vorzugsweise flache Substratgläser oder rohrförmige Substratgläser verwendet werden. Grundsätzlich unterliegt die erfindungsgemäße Solarzelle keiner Beschränkung im Hinblick auf deren Form oder auf die Form des Substratglases. Im Falle einer rohrförmigen Solarzelle ist der Außendurchmesser eines rohrför- migen Substratglases der Solarzelle vorzugsweise 5 bis 100 mm und die Wanddicke des rohrförmigen Substratglases vorzugsweise 0,5 bis 10 mm.Preferably, the solar cell according to the invention is a substantially planar (flat) solar cell or a substantially tubular solar cell, wherein preferably flat substrate glasses or tubular substrate glasses are used. In principle, the solar cell according to the invention is subject to no restriction with regard to its shape or to the shape of the substrate glass. In the case of a tubular solar cell, the outer diameter of a tubular substrate glass of the solar cell is preferably 5 to 100 mm and the wall thickness of the tubular substrate glass is preferably 0.5 to 10 mm.
In einer weiteren bevorzugten Ausgestaltung der Erfindung weist die Solarzelle funktionelle Schichten auf. Die funktionelle Schichten der Solarzelle bestehen dabei vorzugsweise aus leitfähigen und transparent leitfähigen Materialien, aus photosensitiven Verbindungshalbleitermaterialien, aus Puffermaterialien und/oder metallischen Rückkontaktmaterialien. Werden mindestens zwei Solarzellen seriell verschaltet entsteht ein Dünnschicht-Photovoltaik-Modul, das durch Verkapselung, insbesondere durch Verkapselung mit Siθ2, Kunststoffen und Folien, wie z.B. EVA ( Ethylen-Vinyl-Acetat), Lackschichten oder/und durch ein weiteres Substratglas von Umwelteinflüssen geschützt ist. Das weitere Substratglas kann dabei das gleiche Substratglas, wie bereits in der Solarzelle umfasst, sein, es kann aber auch ein anderes, z.B. ein durch lonenaustausch vorgespanntes Substratglas, sein.In a further preferred embodiment of the invention, the solar cell has functional layers. The functional layers of the solar cell preferably consist of conductive and transparent conductive materials, of photosensitive compound semiconductor materials, of buffer materials and / or metallic back contact materials. If at least two solar cells are connected in series, a thin-film photovoltaic module is produced by encapsulation, in particular by encapsulation with SiO 2 , plastics and films, such as EVA (ethylene-vinyl acetate), paint layers or / and by a further substrate glass of environmental influences is protected. The further substrate glass may in this case be the same substrate glass as already included in the solar cell, but it may also be another, for example a substrate glass pretensioned by ion exchange.
Die Solarzelle weist bevorzugt wenigstens einen photoaktiven Halbleiter auf, der auf das Substratglas oder ein zuvor beschichtetes Substratglas bei einer Tem- peratur > 5500C aufgebracht wurde. Vorzugsweise ist diese Temperatur kleiner als die Transformationstemperatur Tg des Substratglases.The solar cell preferably has at least one photoactive semiconductor which is applied to the substrate glass or a previously coated substrate glass at a temperature of at least one second. temperature> 550 0 C was applied. Preferably, this temperature is less than the transformation temperature Tg of the substrate glass.
Vorzugsweise ist die Solarzelle eine auf Verbundhalbleiter-basierte Dünnschichtsolarzelle, wie im Folgenden beispielhaft erläutert wird.Preferably, the solar cell is a compound semiconductor-based thin film solar cell, as exemplified below.
Die erfindungsgemäßen Dünnschichtsolarzellen auf Basis von Il-Vl- oder I-Ill-Vl- Verbundhalbleitem, wie CdTe oder CIGS der allgemeinen Formel Cu(lni. xGax)(Si-ySey)2 weisen eine - im Vergleich zum Stand der Technik - bessere Kri- stallinität auf und damit eine erhöhte Leerlaufspannung und einen höheren Wirkungsgrad.The thin-film solar cells according to the invention based on II-VI or III-VI compound semiconductors, such as CdTe or CIGS of the general formula Cu (I x .xGa x ) (Si- y Sey) 2 have a - in comparison to the prior art - better crystallinity and thus increased open circuit voltage and higher efficiency.
Diese Verbundhalbleiter, in Form von dünnen Schichten/Schichtpaketen auf die Substratgläser aufgebacht, erfüllen wesentliche Voraussetzungen, wie beispielsweise bei CIGS eine an das Sonnenspektrum durch Mischung der ternä- ren Verbindungen sehr gut angepasste Bandlücke (1 ,0 < E9 < 2,0 eV) und eine hohe Absorption des einfallenden Lichtes (Absorptionskoeffizient > 2 x 104 cm"1) für deren Einsatz in Solarzellen.These compound semiconductors, applied to the substrate glasses in the form of thin layers / layer packages, fulfill essential prerequisites, such as, for example, in CIGS a band gap very well adapted to the solar spectrum by mixing the ternary compounds (1.10 <E 9 <2.0 eV ) and a high absorption of the incident light (absorption coefficient> 2 × 10 4 cm -1 ) for their use in solar cells.
Dünne, polykristalline Schichten/Schichtpakete von leicht variierenden Cu(InI- xGaχ)(Si-ySey)2-Kompositionen lassen sich prinzipiell durch eine Reihe von Verfahren (z. B. simultanes Aufdampfen der Elemente, Sputtern mit anschließendem Reaktivgas-Schritt, CVD, MOCVD, Co-Verdampfung, galvanische Abscheidung oder Flüssigabscheidung mit anschließendem Temperaturschritt in Chal- kogenatmosphäre etc.) mehrstufig herstellen. Solchen CIGS- Schichten/Schichtpaketen ist eine intrinsische p-Leitung zu eigen. Der p/n- Übergang in solchen Materialsystemen wird dann über Einbringen einer dünnen Pufferschicht (z. B. eine wenige Nanometer dicke CdS-Schicht o.a.) und nachfolgend abgeschiedenem n-leitenden, transparenten Oxiden (TCO von englisch Transparent Conductive Oxides wie z. B. ZnO oder ZnO(AI)) realisiert. Um parasitäre Absorption zu vermeiden, ist die Pufferschicht sehr dünn ausgebildet, während die TCO-Schicht zusätzlich eine hohe elektrische Leitfähigkeit auswei- sen muss, um eine möglichst verlustfreie Ableitung des Stromes zu gewährleisten.Thin, polycrystalline layers / layer packages of slightly varying Cu (In I- x Gaχ) (Si -y Sey) 2 compositions can in principle be prepared by a number of methods (eg simultaneous vapor deposition of the elements, sputtering with subsequent reactive gas step , CVD, MOCVD, co-evaporation, electrodeposition or liquid separation with subsequent temperature step in chalcogen atmosphere, etc.) in several stages. Such CIGS layers / layer packages have an intrinsic p-type. The p / n junction in such material systems is then deposited by introducing a thin buffer layer (e.g., a few nanometers thick CdS layer, etc.) and subsequently deposited n-type transparent oxides (TCO) ZnO or ZnO (AI)) realized. In order to avoid parasitic absorption, the buffer layer is very thin, while the TCO layer additionally has a high electrical conductivity. must be ensured in order to ensure a loss-free derivation of the current.
Die Wirkungsgrade von Cu(lni.xGax)(Si-ySey)2-ZellenI hergestellt im Pilot- oder Produktionsmaßstab, bewegen sich derzeit zwischen 10 und 15 %. Übliche Modulformate, aufgebaut aus einzelnen Solarzellen über monolithisch integrierte Serienverschaltung, liegen in der Größenordnung von 60 x 120 cm2 und das bei Gewährleistung der Homogenität der Schichten (Dicke, Zusammensetzung) über die gesamte Modulfläche.The efficiencies of Cu (In x Ga x ) (Si- y Se y 2 cells I produced on a pilot or production scale are currently between 10 and 15%. Conventional module formats, constructed from individual solar cells via monolithically integrated series connection, are in the order of magnitude of 60 × 120 cm 2 and this while ensuring the homogeneity of the layers (thickness, composition) over the entire module area.
Figur 1 zeigt beispielhaft den schematischen Aufbau einer erfindungsgemäßen planaren Dünnschichtsolarzelle mit pn-Heteroübergang auf der Basis von Cu(In-I- xGax)(Si-ySey)2.Figure 1 shows an example of the schematic structure of a planar thin-film solar cell of the invention with pn heterojunction based on Cu (I domestic x Ga x) (Si y Sey). 2
In einem Ausführungsbeispiel, wie in Figur 1 dargestellt, wurde ein Substratglas mit der Zusammensetzung von Glas 2 und Tg von 632°C, s. Tabelle 2, mittels floaten hergestellt und mit Hilfe von Hartmetallschneidewerkzeugen vereinzelt. Die so erhaltenen Substratglasscheiben wurden in einem industriellen Standardverfahren gereinigt und mit folgendem Schichtsystem beschichtet: Substratglas / Rückkontakt (Molybdän via Sputter-Technologie) / Absorber (CIGS, wobei die metallischen Schichten mittels sputtem aufgebracht und anschließend in Chal- kogen-haltiger Atmosphäre mittels eines sog. „rapid thermal processing" kurz RTP umgesetzt wurden mit Tanneaiiπg > 55O0C) / Pufferschicht (CdS via chemischer Badabscheidung) / Fensterschicht (i-ZnO/ZnO:AI via Sputter-Technologie). Je nach Ausführungsform - Modul oder Solarzelle - wurde eine integrierte Serienverschaltung über diverse zwischengeschaltete Strukturierungsschritte bzw. ein Frontgrid, über Siebdruck aufgebracht, realisiert. Im Vergleich zu einer Solarzelle auf einem herkömmlichen Kalknatronglassubstrat wurde so ein um mehr als 15% höherer Wirkungsgrad erzielt (Wirkungsgrad Solarzelle mit Kalknatronglassubstrat 15,5%; Wirkunsgrad Solarzelle mit Glas 2 als Substratglas 18%). Der Wirkungsgrad wurde dabei über eine Strom-Spannungs-Kennlinie mittels eines sog. Sonnensimulators bestimmt. Figur 2 zeigt im Wesentlichen den Aufbau von Figur 1 , wobei das Dünnschichtsolarmodul aus mehreren seriell verschalteten Dünnschichtsolarzellen durch Verkapselung vor Umwelteinflüssen geschützt ist. In einer besonderen Ausführungsform kann zwischen dem Substratglas und der Rückkontaktschicht eine Barriereschicht, bspw. SiN über Sputter-Technologie, aufgebracht sein, sowie zwischen Rückkontakt- und Absorberschicht eine Na-haltige Zwischenschicht, wie bspw. NaF über Verdampfung, letztere ist nicht gezeigt in Figur 2. Die weiteren Schichten in Figur 2 entsprechen denen von Figur 1. Für die Verkapselung wurde eine Laminationsfolie, bspw. EVA-Folie, sowie ein gehärtetes kommerziell erhältliches Deckglas, bspw. ein eisenarmes Kalknatronglas, über dem integriert serienverschalteten Modul positioniert und abgelegt und im folgendem in einem thermischen Härtungsschritt laminiert. Typische Laminationstemperaturen liegen im Bereich von 50 bis 200 0C.In one embodiment, as shown in Figure 1, a substrate glass with the composition of glass 2 and Tg of 632 ° C, s. Table 2, produced by floats and singulated with the help of carbide cutting tools. The substrate glass panes thus obtained were cleaned in a standard industrial process and coated with the following layer system: Substrate glass / back contact (molybdenum via sputtering technology) / absorber (CIGS, the metallic layers being applied by sputtering and subsequently heated in a chalcogen-containing atmosphere by means of a so-called . "rapid thermal processing" brief RTP (with T at neaiiπg> 55O 0 C) / buffer layer (CdS via chemical bath deposition) / window layer i-ZnO / ZnO were implemented: AI via sputtering technology) Depending on the design - module or solar cell. An integrated series connection was realized by means of various intermediate structuring steps or a front grid, applied by screen printing In comparison to a solar cell on a conventional soda-lime glass substrate, a more than 15% higher efficiency was achieved (efficiency solar cell with soda-lime glass substrate 15.5%; Efficiency solar cell with glass 2 as Substrate glass 18%). The efficiency was determined via a current-voltage characteristic curve by means of a so-called solar simulator. FIG. 2 essentially shows the structure of FIG. 1, wherein the thin-film solar module is protected from environmental influences by encapsulation of a plurality of series-connected thin-film solar cells. In a particular embodiment, a barrier layer, for example SiN, can be applied by sputtering technology between the substrate glass and the back contact layer, and an Na-containing intermediate layer, such as, for example, NaF via evaporation, between back contact layer and absorber layer, the latter is not shown in FIG 2. The further layers in FIG. 2 correspond to those of FIG. 1. For the encapsulation, a lamination film, for example EVA film, and a hardened, commercially available cover glass, for example a low-iron soda-lime glass, are positioned and deposited over the integrated series-connected module and deposited following in a thermal curing step. Typical lamination temperatures are in the range of 50 to 200 ° C.
Figur 3 zeigt prinzipiell den gleichen Schichtaufbau des Verbindungshalbleiters wie in Figur 1 allerdings auf der Oberfläche eines inneren Glasrohres als Substratglas (Rohrdurchmesser etwa 15 bis 18 mm), die dann in einem weiteren äußeren Glasrohr mit größerem Durchmesser (ca. 25 mm) und einer geeigneten Füllflüssigkeit (z.B. Silikonöl) zwischen dem Innenrohr mit der Solarzelle beschichtet und dem Außenrohr verbaut sind. Zur Effizienzsteigerung kann eine reflektierend weiße Fläche hinter den Rohren im Sonnenschatten notwendig sein.Figure 3 shows in principle the same layer structure of the compound semiconductor as in Figure 1, however, on the surface of an inner glass tube as substrate glass (tube diameter about 15 to 18 mm), which then in another outer glass tube with a larger diameter (about 25 mm) and a suitable Fill liquid (eg silicone oil) between the inner tube coated with the solar cell and the outer tube are installed. To increase efficiency, a reflective white area behind the tubes in the sun's shadow may be necessary.
Das Substratglas besteht vorzugsweise aus einem Aluminosilikatglas, wie es beispielsweise aus den Schriften DE 196 16 633 C 1 und DE 196 16 679 C 1 bekannt ist, sofern es den Merkmalen gemäß Anspruch 1 genügt und dessen Wärmeausdehnungskoeffizient c<2o/3oo an den des Halbleiters angepasst ist. Auf dem Substratglas ist eine Kontaktierungsschicht, hier aus metallischen Molybdän, aufgebracht. Darauf befindet sich der eigentliche photoaktive Halbleiter. Auf diesem ist weiter eine Pufferschicht aus z.B. CdS und darauf ein Fenster (hier eine transparente, leitfähige Schicht (TCO) aufgebracht, durch die das Sonnenlicht bis zum Halbleiter durchdringen kann.The substrate glass is preferably made of an aluminosilicate glass, as it is known for example from the documents DE 196 16 633 C 1 and DE 196 16 679 C 1, provided that it meets the features of claim 1 and its thermal expansion coefficient c < 2 o / 3 oo to the of the semiconductor is adjusted. On the substrate glass, a contacting layer, here of metallic molybdenum, applied. On it is the actual photoactive semiconductor. On top of this is a buffer layer of eg CdS and then a window (here a transparent, conductive layer (TCO) applied through which the sunlight can penetrate to the semiconductor.
Eine wesentliche Anforderung an ein geeignetes Substratglas leitet sich von den beim Beschichtungsverfahren herrschenden Temperaturen ab. In Hinblick auf hohe Abscheideraten bzw. sehr gute kristalline Qualität der Schichten ergibt sich aus dem Phasendiagramm von Cu(lni-xGaχ)(Si-ySey)2, dass Temperaturen mindestens oberhalb von 550 0C erforderlich sind. Höhere Temperaturen, insbesondere Temperaturen über 600 0C, führen zu noch besseren Ergebnissen hinsichtlich der Abscheidrate und der Kristallinität der Schichten. Da das zu beschichtende Substratglas in der Regel sehr nahe an einer Strahlungsquelle positioniert ist, in besonderen Ausführungsformen hängend über den im Beschich- tungsprozess eingesetzten Verdampferquellen, sollte das Substratglas eine möglichst hohe thermische Belastbarkeit besitzen, d.h. als grobe Orientierung sollte die Transformationstemperatur (T9) nach DIN 52 324 des Glases entsprechend mindestens oberhalb 550 0C liegen. Je höher T9, desto geringer ist die Gefahr der Durchbiegung des Substratglases während der Beschichtung bei Temperaturen nahe Tg. Eine Prozesstemperatur unterhalb von T9 verhindert auch das Einbringen von Spannungen in das Substratglas und damit in das Schichtsystem durch ein schnelles Abkühlen, was üblicherweise bei CIGS- Beschichtungsprozessen der Fall ist.An essential requirement for a suitable substrate glass is derived from the temperatures prevailing in the coating process. In view of high deposition rates and very good crystalline quality of the layers can be seen from the phase diagram of Cu (lni Gaχ -x) (Si y Sey) 2, that temperatures are required at least above 550 0 C. Higher temperatures, in particular temperatures above 600 ° C., lead to even better results with regard to the deposition rate and the crystallinity of the layers. Since the substrate glass to be coated is generally positioned very close to a radiation source, in particular embodiments hanging over the evaporation sources used in the coating process, the substrate glass should have the highest possible thermal capacity, ie as a rough orientation the transformation temperature (T 9 ) should According to DIN 52 324 of the glass corresponding to at least above 550 0 C. The higher T 9 , the lower the risk of deflection of the substrate glass during coating at temperatures near Tg. A process temperature below T 9 also prevents the introduction of stresses into the substrate glass and thus into the layer system by rapid cooling, which is usually the case CIGS coating processes is the case.
Nicht nur die Transformationstemperatur (T9), sondern das Viskositätsverhalten bis zur Erweichungstemperatur (Ew) - definitionsgemäß entspricht Ew einer Temperatur des Glases bei einer Glasviskosität von 107|6dPas nach DIN 52 312 - sind zu beachten, wobei eine möglichst große Differenz zwischen T9 und Ew ("langes Glas") die Gefahr der thermischen Verformung des Substrates bei Be- schichtungstemperaturen über 600 0C reduziert.Not only the transformation temperature (T 9 ), but the viscosity behavior up to the softening temperature (Ew) - by definition corresponds to Ew a temperature of the glass at a glass viscosity of 10 7 | 6 dPas according to DIN 52 312 - are to be observed, with the largest possible difference between T 9 and Ew ( "long glass") the risk of thermal deformation of the substrate during loading coating temperatures above 600 0 C reduced.
Um ein Abplatzen der Schichtsysteme beim Abkühlen nach dem Beschich- tungsprozess zu verhindern, muss das Substratglas weiterhin an die thermische Ausdehnung des Rückkontaktes (z. B. Molybdän, ca. 5 x 10~6/K) und noch bes- ser an die darauf abgeschiedene Halbleiterschicht (z. B. ca. 8,5 x 10^/K für CIGS) angepasst sein.In order to prevent spalling of the coating systems during cooling after the coating process, the substrate glass must continue to the thermal expansion of the back contact (eg., Molybdenum, about 5 x 10 -6 / K), and more BES be adapted to the semiconductor layer deposited thereon (eg about 8.5 × 10 -4 / K for CIGS).
Weiterhin ist bekannt, dass Natrium in den Halbleiter eingebaut werden kann und damit den Wirkungsgrad der Solarzelle durch verbesserten Chalkogenein- bau in die Kristallstruktur des Halbleiters erhöht. Damit hat das Substratglas neben der Eigenschaft als Trägermaterial zu dienen, eine zusätzliche Funktionalität aufzuweisen: Nämlich die gezielte Abgabe, sowohl zeitlich als auch räumlich (homogen über die Beschichtungsfläche), von Natrium. Das Glas sollte Natriumionen / -atome bei Temperaturen um T9 abgeben, was eine erhöhte Mobilität der Natriumionen im Glas voraussetzt. Alternativ kann eine Barriereschicht auf die Glasoberfläche vor der Beschichtung mit Molybdän aufgebracht werden (z. B. eine Al2θ3-Schicht), die eine Natriumionendiffusion komplett verhindert. Natriumionen müssen dann in einem weiteren Prozessschritt separat zugegeben werden (z. B. in Form von NaF2), was die Prozesszeiten und -kosten erhöht. Außerdem ist infolge der üblichen Standorte der Solarzellen (im Freien) auf ausreichende chemische Resistenz gegenüber Umwelteinflüssen, insbesondere Wasser (Feuchtigkeit, Nässe, Regen) wie auch gegenüber anderer, möglicherweise im Herstellungsprozess eingesetzter aggressiver Reagenzien, zu achten. Die Schichten selbst werden durch Verkapselung mit SiO2, Kunststoff, Lackschichten oder/und auch durch ein Deckglas von der Umwelt geschützt.Furthermore, it is known that sodium can be incorporated into the semiconductor and thus increases the efficiency of the solar cell by improved chalcogen incorporation into the crystal structure of the semiconductor. Thus, the substrate glass has to serve in addition to the property of a carrier material to have an additional functionality: namely the targeted delivery, both temporally and spatially (homogeneously over the coating surface) of sodium. The glass should release sodium ions / atoms at temperatures around T 9 , which presupposes increased mobility of the sodium ions in the glass. Alternatively, a barrier layer may be applied to the glass surface prior to coating with molybdenum (eg, an Al 2 O 3 layer) that completely prevents sodium ion diffusion. Sodium ions must then be added separately in a further process step (eg in the form of NaF 2 ), which increases the process times and costs. In addition, due to the common locations of the solar cells (outdoors), sufficient chemical resistance to environmental influences, especially water (moisture, moisture, rain) as well as other aggressive reagents possibly used in the manufacturing process, must be ensured. The layers themselves are protected by encapsulation with SiO 2 , plastic, paint layers or / and also by a cover glass from the environment.
Die folgende Tabelle 1 zeigt Eigenschaften von Substratgläsern für CIGS- Dünnschichtsolarzellen im Vergleich zum Stand der Technik, die für die erfindungsgemäße Solarzelle geeignet sind. Tabelle 1The following Table 1 shows properties of substrate glasses for CIGS thin-film solar cells compared to the prior art, which are suitable for the solar cell according to the invention. Table 1
Überraschenderweise erfüllten insbesondere bor- und bariumfreie Alumosili- katgläser die Anforderungen zur Verwendung als Substratglas für die Dünn- schichtphotovoltaik, da beispielsweise in der Hochtemperatur-CIGS- Herstellungstechnologie Substratglastemperaturen während der Beschichtung von bis zu 700 0C erreicht werden. Insbesondere durch die erfindungsgemäßen Eigenschaften der Substratgläser wurden Wirkungsgrade von CIGS- Dünnschichtsolarzellen über 2 % absolut gegenüber dem Stand der Technik erzielt, also anstatt beispielsweise 12 % mit einem üblichen Substratglas wurde nun ein Wirkungsgrad von 14 % erreicht. Surprisingly fulfilled particularly boron and barium aluminosilicates katgläser the requirements for use as substrate glass for the thin-film photovoltaics, as for example in the high-temperature manufacturing technology CIGS substrate glass temperatures during the coating of up to 700 0 C. In particular, due to the properties of the substrate glasses according to the invention, efficiencies of CIGS thin-film solar cells over 2% were achieved absolutely in comparison to the prior art, ie instead of, for example, 12% with a conventional substrate glass, an efficiency of 14% was achieved.
Überraschenderweise wurde auch gefunden, dass diese Gläser beim Schmelzen unter oxidierenden Bedingungen bei Verwendung von Nitraten der Alkali- und/oder der Erdalkalikomponenten, z. B. KNO3, Ca(NO3)2, eine hohe Homogenität bezüglich Blasigkeit aufweisen.Surprisingly, it was also found that these glasses when melting under oxidizing conditions when using nitrates of the alkali and / or alkaline earth components, z. B. KNO 3 , Ca (NO 3 ) 2, have a high homogeneity with respect to blowing.
Große Blasen, d.h. Blasen, die mit dem bloßen Auge sichtbar sind (Durchmesser >80 μm), werden auch mit dem bloßen Auge ausgezählt und zwar in einem polierten Glaswürfel von 10 cm Kantenlänge. Größe und Zahl kleinerer Blasen werden an 10 cm x 10 cm x 0,1 cm großen Glasplatten mit guter optischer Politur mittels eines Mikroskops mit 400 bis 500facher Vergrößerung gemessen/gezählt.Big bubbles, i. Blisters that are visible to the naked eye (diameter> 80 μm) are also counted with the naked eye, in a polished glass cube of 10 cm edge length. The size and number of smaller bubbles are measured / counted on 10 cm x 10 cm x 0.1 cm glass plates with good optical polishing by means of a microscope with 400 to 500 times magnification.
Ausführungsbeispiele sind der folgenden Tabelle 2 zu entnehmen (Zusammensetzung der Gläser in Mol-%).Exemplary embodiments are shown in the following Table 2 (composition of the glasses in mol%).
Die Gläser wurden in 4-Liter Platintiegeln aus herkömmlichen Rohstoffen d.h. aus Carbonaten, Nitraten, Fluoriden und Oxiden der Komponenten erschmolzen. Die Rohstoffe wurden über einen Zeitraum von 8 h bei Schmelztemperaturen von 15800C eingelegt und anschließend 14 h lang auf dieser Temperatur gehalten. Unter Rühren wurde dann die Glasschmelze innerhalb von 8 h auf 14000C abgekühlt und anschließend in eine 5000C vorgeheizte Graphitform gegossen. Diese Gussform wurde unmittelbar nach dem Guss in einen auf 6500C vorgeheizten Kühlofen verbracht, der mit 5°C/h auf Raumtemperatur abkühlte. Aus diesem Block wurden danach die für die Messungen notwendigen Glasproben herauspräpariert.The glasses were melted in 4-liter platinum crucibles from conventional raw materials ie carbonates, nitrates, fluorides and oxides of the components. The raw materials were placed over a period of 8 h at melting temperatures of 1580 0 C and then held for 14 h at this temperature. With stirring, the glass melt was then cooled to 1400 0 C within 8 h and then poured into a preheated 500 0 C graphite mold. This mold was placed immediately after the cast in a preheated to 650 0 C cooling furnace cooled at 5 ° C / h to room temperature. Out Afterwards, the glass samples necessary for the measurements were removed from this block.
Neben den bekannten Methoden zur Bestimmung der typischen Glaseigenschaften kommt hier der Bestimmung der Leitfähigkeit eine besondere Bedeutung zu. Die dielektrischen Messungen wurden mit dem Impedanzspektrometer alpha-Analyser der Firma Novocontrol, Limburg, und der dazugehörenden Temperaturkontrolleinheit durchgeführt. Bei der Messung wird eine meist runde Scheibe der Glasprobe mit einem Durchmesser von typischerweise 40 mm und einer Dicke von ca. 0,5 bis 2 mm beidseitig mit Leitsilber kontaktiert. Mit vergoldeten Messingkontakten wird die Probe von Ober- und Unterseite in einem Probenhalter eingespannt und einem Kryostaten platziert. Als Funktion von Frequenz und Temperatur kann nun der elektrische Widerstand und die Kapazität der Anordnung mit Hilfe eines Brückenabgleichs gemessen werden. Bei bekannten Geometrien lässt sich dann die Leitfähigkeit und die dielektrische Konstante des Materials bestimmen.In addition to the known methods for determining the typical glass properties here, the determination of the conductivity is of particular importance. The dielectric measurements were carried out with the impedance spectrometer alpha-Analyzer from Novocontrol, Limburg, and the associated temperature control unit. During the measurement, a mostly round disc of the glass sample with a diameter of typically 40 mm and a thickness of approximately 0.5 to 2 mm is contacted on both sides with conductive silver. With gilded brass contacts, the sample is clamped from the top and bottom in a sample holder and placed in a cryostat. As a function of frequency and temperature, the electrical resistance and the capacitance of the device can now be measured by means of a bridge balance. With known geometries, the conductivity and the dielectric constant of the material can then be determined.
Tabelle 2: Beispiele für Glaszusammensetzungen in Mol-%, molare Verhältnisse und Eigenschaften von Substratgläsern, die sich für die erfindungsgemäße Solarzelle eignen.Table 2: Examples of glass compositions in mol%, molar ratios and properties of substrate glasses, which are suitable for the solar cell according to the invention.
Die relativ hohe elektrische Leitfähigkeit bei Raumtemperatur (typische Werte von Gläsern liegen zwischen 10'14 bis 10"17 S/cm; 25°C ), die hohe Temperaturabhängigkeit der Leitfähigkeit und die gemessene niedrige Aktivierungsenergie < 1eV aller Beispielgläser sind ein Maß für die hohe Natriumionenbeweglichkeit dieser Substratmaterialien. Aus dem linearen Verhalten der Temperaturabhängigkeit der elektrischen Leitfähigkeit in der Arrhenius-Darstellung (Figur 4. Beispiel 2 = Glas 2; Beispiel 3 = Glas 3) wird zudem ersichtlich, dass nur eine Spezies nämlich Na+ die Leitfähigkeit bestimmt, obwohl auch beträchtliche Mengen an K+ vorhanden sind.The relatively high electrical conductivity at room temperature (typical values of glasses are between 10 '14 to 10 "17 S / cm; 25 ° C), the high temperature dependence of the conductivity and the measured low activation energy <1eV of all sample glasses are a measure of the high From the linear behavior of the temperature dependence of the electrical conductivity in the Arrhenius representation (Figure 4. Example 2 = Glass 2, Example 3 = Glass 3) it is also seen that only one species, Na +, determines the conductivity, although also considerable amounts of K + are present.
Die Gläser können ohne Deformation nicht nur bei Temperaturen von ca. 100 0C bis 150 0C über dem Stand der Technik eingesetzt werden, sondern erweisen sich durch die erhöhte Natriumionenbeweglichkeit auch als zuverlässige Dotierquelle für den Kristallisationsprozess von bspw. l-lll-VI2-Verbindungshalbleitem, wie CIGS, welche damit in einem um 100 0C bis 150 0C höheren Temperaturbereich zu höherer Perfektion wachsen kann.The glasses can without deformation not only at temperatures of about 100 0 C to 150 0 C over the prior art are used, but turn out to be due to the increased sodium ion mobility as a reliable doping source for the crystallization process by example. I-III-VI 2 Compound semiconductors, such as CIGS, which can thus grow in a higher by 100 0 C to 150 0 C temperature range to higher perfection.
Diese hohe Beweglichkeit ist für das kristalline Wachstum der Verbundhalbleiterschichten, insbesondere der CIGS-Schichten und der dann erreichbaren pho- tovoltaischen Eigenschaften dieser Schichten eine Voraussetzung, bedenkt man, dass die Natriumionen bevor sie die Kristallisationszone erreichen durch eine 0,5 bis 1 μm dicke Molybdänschicht auf dem Substratglas diffundieren müssen und/oder über die Dampfphase als Natriumatome zur wachsenden Halbleiterschicht gelangen.This high mobility is responsible for the crystalline growth of the compound semiconductor layers, in particular the CIGS layers and the then achievable phosphorous layers. to voltaic properties of these layers is a prerequisite, given that the sodium ions must reach the crystallization zone before they reach the crystallization zone and must diffuse through a 0.5 to 1 μm thick molybdenum layer on the substrate glass and / or reach the growing semiconductor layer via the vapor phase as sodium atoms.
Der positive Einfluss der Natriumionen auf den Chalkogeneinbau in den Halbleiterkristall wirkt sich nicht nur auf eine verbesserte Kristallitstruktur und Kristalldichte aus, sondern auch auf die Kristallitgröße und -Orientierung. Das Natriumion wird unter anderem auch in den Komgrenzen des Systems eingebaut und kann u.a. dabei zu einer Reduzierung der Ladungsträgerrekombination an den Korngrenzen beitragen. Diese Phänomene führen zwangsläufig zu erheblich besseren Halbleitereigenschaften, insbesondere zu einer Reduktion der Rekombination im Volumenmaterial und damit einer erhöhten Leerlaufspannung. Dies äußert sich natürlich dann vor allem in der Effizienz, mit der das Sonnenspektrum in elektrischen Strom umgewandelt werden kann.The positive influence of sodium ions on chalcogen incorporation in the semiconductor crystal has an effect not only on improved crystallite structure and crystal density, but also on crystallite size and orientation. Among other things, the sodium ion is incorporated in the grain boundaries of the system and can i.a. contribute to a reduction in charge carrier recombination at the grain boundaries. These phenomena inevitably lead to significantly better semiconductor properties, in particular to a reduction of the recombination in the bulk material and thus an increased open circuit voltage. Of course, this manifests itself above all in the efficiency with which the solar spectrum can be converted into electricity.
Diese lonenbeweglichkeit kann in den Substratgläsern weiter bevorzugt durch eine Oberflächenbehandlung in sauren oder alkalischen Lösungen positiv beein- flusst werden, beispielsweise in dem Sinne, dass bei höheren Temperaturen frühzeitiger eine lonenbewegung in Gang kommt, beziehungsweise eine gleichmäßige Diffusion der Natriumionen oder eine gleichmäßigere Abdampfung von Natrium aus der Oberfläche vorhanden gegeben ist.This ion mobility can be favorably influenced in the substrate glasses by a surface treatment in acidic or alkaline solutions, for example in the sense that at higher temperatures an ionic movement starts earlier, or a uniform diffusion of the sodium ions or a more uniform evaporation of sodium given from the surface is present.
Weiterhin hat es sich überraschenderweise gezeigt, dass eine wesentliche Erhöhung des Wirkungsgrades einer Dünnschichtsolarzelle einfach erreicht werden kann, wenn die Solarzelle wenigstens ein Na2θ-haltiges Mehrkomponen- tensubstratglas aufweist, das die Merkmale gemäß Anspruch 1 aufweist und das nicht phasenentmischt ist und das einen Gehalt an ß-OH von 25 bis 80 mMol/l besitzt. Merkmale gemäß Anspruch 1: Dass das Na2O-haltige Mehrkomponen- tensubstratglas weniger als 1 Gew.-% B2O3, weniger als 1 Gew.-% BaO und in Summe weniger als 3 Gew.-% CaO + SrO + ZnO enthält, dass das molare Verhältnis der Substratglaskomponenten (Na2O+K2O)/(MgO+CaO+SrO+BaO) größer als 0,95 ist, dass das molare Verhältnis der Substratglaskomponenten SiO2/AI2O3 kleiner als 7 ist, und dass das Substratglas eine Transformationstemperatur Tg von größer als 550 °C, insbesondere von größer als 600 0C aufweist.Furthermore, it has surprisingly been found that a substantial increase in the efficiency of a thin-film solar cell can be achieved easily if the solar cell has at least one Na 2 O-containing multi-component substrate glass having the features according to claim 1 and which is not phase-deadened and one Content of β-OH from 25 to 80 mmol / l possesses. Features according to claim 1: that the Na 2 O-containing multi-component substrate glass is less than 1% by weight B 2 O 3 , less than 1% by weight BaO and in Sum less than 3 wt.% CaO + SrO + ZnO contains that the molar ratio of the substrate glass components (Na 2 O + K 2 O) / (MgO + CaO + SrO + BaO) is greater than 0.95, that is the molar ratio Ratio of the substrate glass components SiO2 / Al2O3 is less than 7, and that the substrate glass has a transformation temperature Tg of greater than 550 ° C, in particular greater than 600 0 C.
Ein Substratglas ist nicht phasenentmischt im Sinne dieser Erfindung, wenn es weniger als 10, vorzugsweise weniger als 5 Oberflächendefekte in einem Oberflächenbereich von 100 x 100 nm2 nach einem Konditionierungsversuch aufweist. Der Konditionierungsversuch wurde dabei folgendermaßen durchgeführt: Bei 500 bis 6000C, einem Durchfluss von Druckluft im Bereich zwischen 15 bis 50 ml/min und einem Durchfluss von Schwefeldioxidgas (SO2) im Bereich 5 bis 25 ml/min, für eine Dauer von 5 bis 20 Minuten, wird die zu untersuchende Substratglasoberfläche begast. Dabei bildet sich unabhängig von Glastyp ein kristalliner Belag auf dem Substratglas. Nach Abwaschen des kristallinen Belags (z.B. mittels Wasser oder einer sauren oder basischen wässrigen Lösung, so dass die Oberfläche nicht weiter angegriffen wird) werden mikroskopisch die Oberflächendefekte pro Substratglasoberflächefläche bestimmt. Sofern weniger als 10, insbesondere weniger als 5 Oberflächendefekte in einem Oberflächenbereich von 100 x 100 nm2 vorliegen, gilt das Substratglas als nicht phasenentmischt. Gezählt werden dabei alle Oberflächendefekte die einen Durchmesser von > 5 nm aufweisen.A substrate glass is not phase-separated in the sense of this invention if it has less than 10, preferably less than 5, surface defects in a surface area of 100 × 100 nm 2 after a conditioning experiment. The conditioning experiment was carried out as follows: At 500 to 600 0 C, a flow of compressed air in the range between 15 to 50 ml / min and a flow of sulfur dioxide gas (SO 2 ) in the range 5 to 25 ml / min, for a period of 5 to 20 minutes, the substrate glass surface to be examined is gassed. Irrespective of the glass type, a crystalline coating forms on the substrate glass. After washing off the crystalline coating (eg by means of water or an acidic or basic aqueous solution so that the surface is not further attacked), the surface defects per substrate glass surface area are determined microscopically. If less than 10, in particular less than 5, surface defects are present in a surface area of 100 × 100 nm 2 , the substrate glass is considered not to be phase-separated. All surface defects with a diameter of> 5 nm are counted.
Der ß-OH-Gehalt des Substratglases wurde wie folgt bestimmt. Die eingesetzte Apparatur zur quantitativen Bestimmung des Wassers über die OH- Streckschwingung um 2700 nm ist das handelsübliche Nicolet-FTIR- Spektrometer mit angeschlossener Computerauswertung. Es wurde zunächst die Absorption im Wellenlängenbereich von 2500 - 6500 nm gemessen und das Absorptionsmaximum um 2700 nm bestimmt. Der Absorptionskoeffizient α wur- de dann mit der Probendicke d, der Reintransmission T1 und dem Reflektionsfak- tor P berechnet: α = 1/d*lg(1/Tj) [cm"1], wobei Tj = T/P mit der Transmission T. Der Wassergehalt errechnet sich weiter aus c = α /e, wobei e der prakt. Extinktionskoeffizient [l*Mor1*cm"1] und wird für den oben genannten Auswertebereich als konstanter Wert von e = 110 l*Mor1*crrf1 bezogen auf Mol H2O eingesetzt. Der e-Wert ist der Arbeit von H. Frank und H. Scholze aus den „Glastechnischen Berichten" 36. Jahrgang, Heft 9. Seite 350 entnommen. The β-OH content of the substrate glass was determined as follows. The equipment used for the quantitative determination of the water over the OH stretching vibration around 2700 nm is the commercially available Nicolet FTIR spectrometer with attached computer evaluation. The absorption in the wavelength range from 2500 to 6500 nm was measured first and the absorption maximum around 2700 nm was determined. The absorption coefficient α was de is then calculated with the sample thickness d, the net transmission T 1 and the reflection factor P: α = 1 / d * lg (1 / Tj) [cm "1 ], where Tj = T / P with the transmission T. The water content is further calculated from c = α / e, where e is the practical extinction coefficient [l * Mor 1 * cm -1 ] and is used for the abovementioned evaluation range as a constant value of e = 110 l * Mor 1 * crrf 1 based on mol H 2 O used. The e value is taken from the work of H. Frank and H. Scholze from the "Glastechnische Berichte" Volume 36, Volume 9 page 350.

Claims

P A T E N T A N S P R Ü C H E PATENT APPLICATIONS
1. Dünnschichtsolarzelle, umfassend wenigstens ein Na2O-haltiges Mehr- komponentensubstratglas, wobei das Substratglas weniger als 1 Gew.-% B2O3, weniger als 1 Gew.-%A thin-film solar cell comprising at least one multi-component substrate glass containing Na 2 O, wherein the substrate glass is less than 1% by weight B 2 O 3 , less than 1% by weight.
BaO und in Summe weniger als 3 Gew.-% CaO + SrO + ZnO enthäll, wobei das molare Verhältnis der SubstratglaskompcnentenBaO and in total less than 3 wt .-% CaO + SrO + ZnO enthäll, wherein the molar ratio of Substratglaskompcnenten
(Na2O+K2O)/(MgO+CaO+SrO+BaO) größer als 0,95 ist, wobei das molare Verhältnis der Substratglaskomponenten SiC2/AI2O3 kleiner als 7 ist, und wobei das Substratglas eine Transformationstemperatur Tg von größer als(Na 2 O + K 2 O) / (MgO + CaO + SrO + BaO) is greater than 0.95, wherein the molar ratio of the substrate glass components SiC 2 / Al 2 O 3 is less than 7, and wherein the substrate glass has a transformation temperature Tg of greater than
550 0C, insbesondere von größer als 600 0C aufweist.550 0 C, in particular of greater than 600 0 C.
2. Solarzelle nach Anspruch 1 , dadurch gekennzeichnet, dass das Substratglas weniger als 0,5 Gew.-% B2O3, insbesondere bis auf unvermeidliche Spuren kein B2O3 enthält.2. Solar cell according to claim 1, characterized in that the substrate glass contains less than 0.5 wt .-% B 2 O 3 , in particular, except for unavoidable traces no B 2 O 3 .
3. Solarzelle nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass das Substratglas weniger als 0,5 Gew.-% BaO, insbesondere bis auf unvermeidliche Spuren kein BaO enthält.3. Solar cell according to claim 1 or 2, characterized in that the substrate glass contains less than 0.5 wt .-% BaO, in particular, except for unavoidable traces no BaO.
4. Solarzelle nach wenigstens einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass das Substratglas in Summe weniger als 2 Gew.-% CaO + SrC + ZnO enthält.4. Solar cell according to at least one of claims 1 to 3, characterized in that the substrate glass in total contains less than 2 wt .-% CaO + SrC + ZnO.
5. Solarzelle nach wenigstens einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass das Substratglas mindestens 5 Gew.-% Na2O, insbesondere mindestens 8 Gew.-% Na2O enthält.5. Solar cell according to at least one of claims 1 to 4, characterized the substrate glass contains at least 5% by weight of Na 2 O, in particular at least 8% by weight of Na 2 O.
6. Solarzelle nach wenigstens einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass das molare Verhältnis der Substratglaskompcnenten (Na2O+K2O)/(MgO+CaO+SrO+BaO) kleiner als 6,5 ist.6. Solar cell according to at least one of claims 1 to 5, characterized in that the molar ratio of Substratglaskompcnenten (Na 2 O + K 2 O) / (MgO + CaO + SrO + BaO) is less than 6.5.
7. Solarzelle nach wenigstens einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, dass das molare Verhältnis der Substratglaskomponenten SiO2/AI2O3 kleiner als 6 und größer als 5 ist.7. Solar cell according to at least one of claims 1 to 6, characterized in that the molar ratio of the substrate glass components SiO 2 / Al 2 O 3 is less than 6 and greater than 5.
8. Solarzelle nach wenigstens einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, dass das Substratglas einen Wärmeausdehnungskoeffizienten α2o 3oo von größer 7,5 x 10'6/K, insbesondere von 8,0 x 10"6/K bis 9,5 x 10"6/K, im Temperaturbereich von 20 0C bis 300 0C aufweist.8. Solar cell according to at least one of claims 1 to 7, characterized in that the substrate glass has a thermal expansion coefficient α 2 o 3 oo greater than 7.5 x 10 '6 / K, in particular from 8.0 x 10 "6 / K to 9 , 5 x 10 "6 / K, in the temperature range from 20 0 C to 300 0 C.
9. Solarzelle nach wenigstens einem der Ansprüche 1 bis 8, dadurch gekennzeichnet, dass das Substratglas eine elektrische Leitfähigkeit von größer 17 x 10~12 S/cm bei 25 0C aufweist, und die elektrische Leitfähigkeit des Subϊ.tratgla- ses bei 250 0C um den Faktor 104 größer, bevorzugt um den Fal;tor 105 größer und besonders bevorzugt um den Faktor 106 größer ist, als die e- lektrische Leitfähigkeit des Substratglases bei 25 0C.9. Solar cell according to at least one of claims 1 to 8, characterized in that the substrate is glass having an electrical conductivity of greater than 17 x 10 -12 S / cm at 25 0 C, and the electrical conductivity of Subϊ.tratgla- ses at 250 0 C by a factor of 10 4 is greater, preferably by a Fal; 10 tor 5 is greater and more preferably by a factor of 10 6 is greater than the e- lectrical conductivity of the substrate glass at 25 0 C.
10. Solarzelle nach wenigstens einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, dass bei dem Substratglas bis zu einer Oberflächentiefe von 20 μm die Natriumionen wenigstens teilweise durch andere Kationen, insbesondere durch Kaliumionen, ersetzt sind, so dass der Natriumionengehalt in der Oberflächenschicht gegenüber dem Natriumionengesamtgehalt des Substratglases erniedrigt ist.10. Solar cell according to at least one of claims 1 to 9, characterized in that in the substrate glass to a surface depth of 20 microns, the sodium ions at least partially by other cations, in particular by potassium ions, so that the sodium ion content in the surface layer is lowered from the total sodium ion content of the substrate glass.
11. Solarzelle nach wenigstens einem der Ansprüche 1 bis 10, dadurch gekennzeichnet, dass das Substratglas folgende Zusammensetzungskomponenten in MoI- % umfasst:11. Solar cell according to at least one of claims 1 to 10, characterized in that the substrate glass comprises the following composition components in MoI-%:
SiO2 63 - 67,5SiO 2 63-67.5
AI2O3 10-12,5Al 2 O 3 10-12.5
Na2O 8,5-15,5Na 2 O 8,5-15,5
K2O 2,5-4,0K 2 O 2.5-4.0
MgO 3,0-9,0MgO 3.0-9.0
CaO + SrO + ZnO O - 2,5CaO + SrO + ZnO O - 2.5
TiO2 + ZrO2 0,5-1,5TiO 2 + ZrO 2 0.5-1.5
CeO2 0,02 - 0,5CeO 2 0.02-0.5
As2O3+ Sb2O3 O - 0,4As 2 O 3 + Sb 2 O 3 O - 0.4
SnO2 0-1,5SnO 2 0-1.5
F 0,05-2,6 wobei folgende molaren Verhältnisse für die Substratglaskomponen en gelten:F 0.05-2.6 where the following molar ratios apply to the substrate glass components:
SiO2/AI2O3 5,0 - 6,8SiO 2 / Al 2 O 3 5.0-6.8
Na2O/K2O 2,1 -6,2Na 2 O / K 2 O 2,1 -6,2
AI2O3/K2O 2,5-5,0Al 2 O 3 / K 2 O 2.5-5.0
AI2O3ZNa2O 0,6 - 1 ,5 (Na2O+K2O)/(MgO+CaO+SrO) 0,95 - 6,5Al 2 O 3 ZNa 2 O 0.6-1.5 (Na 2 O + K 2 O) / (MgO + CaO + SrO) 0.95-6.5
12. Solarzellen nach wenigstens einem der Ansprüche 1 bis 11, dadurch gekennzeichnet, dass das Substratglas mit wenigstens einer Molybdänschicht beschichtet ist, wobei die Schicht bevorzugt 0,25 bis 3,0 μm und besonders bevorzugt 0,5 bis 1 ,5 μm dick ist.12. Solar cell according to at least one of claims 1 to 11, characterized in that the substrate glass is coated with at least one molybdenum layer, wherein the layer is preferably 0.25 to 3.0 microns and more preferably 0.5 to 1, 5 microns thick.
13. Solarzelle nach wenigstens einem der Ansprüche 1 bis 12, dadurch gekennzeichnet, dass die Solarzelle eine Dünnschichtsolarzelle auf Siliziumbasis oder eine Dünnschichtsolarzelle auf Verbundhalbleitermaterialbasis, wie CdTe, CIS oder CIGS, ist.13. Solar cell according to at least one of claims 1 to 12, characterized in that the solar cell is a thin film solar cell based on silicon or a thin film solar cell based on compound semiconductor, such as CdTe, CIS or CIGS.
14. Solarzelle nach wenigstens einem der Ansprüche 1 bis 13, dadurch gekennzeichnet, dass die Solarzelle eine planar, gewölbt, sphärisch oder zylindrisch ∑iusge- bildete Dünnschichtsolarzelle ist.14. Solar cell according to at least one of claims 1 to 13, characterized in that the solar cell is a planar, curved, spherical or cylindrical Σiusge- formed thin film solar cell.
15. Solarzelle nach wenigstens einem der Ansprüche 1 bis 14, dadurch gekennzeichnet, dass die Solarzelle funktionelle Schichten aufweist, bestehend aus hϊitfähi- gen und transparent leitfähigen Materialien, aus photosensitiven Verbindungshalbleitermaterialien, aus Puffermaterialien und/oder metallischen Rückkontaktmaterialien.15. Solar cell according to at least one of claims 1 to 14, characterized in that the solar cell has functional layers consisting of hϊitfähi- and transparent conductive materials, from photosensitive compound semiconductor materials, from buffer materials and / or metallic back contact materials.
16. Solarzelle nach wenigstens einem der Ansprüche 1 bis 15, dadurch gekennzeichnet, dass mindestens zwei Solarzellen zu einem Photovoltaikmodul seriell verschaltet sind und durch Verkapselung, insbesondere mit SiO2, Kunststoffen, insbesondere EVA (Ethyl-Vinyl-Acetat), Lackschichten oder/und durch ein weiteres Substratglas von Umwelteinflüssen geschützt sind.16. Solar cell according to at least one of claims 1 to 15, characterized in that at least two solar cells are connected in series to form a photovoltaic module and by encapsulation, in particular with SiO 2 , plastics, in particular EVA (ethyl vinyl acetate), paint layers and / or protected by a further substrate glass from environmental influences.
17. Solarzelle nach wenigstens einem der Ansprüche 1 bis 16, dadurch gekennzeichnet, dass die Solarzelle wenigstens einen photoaktiven Halbleiter aufweist, der auf das Substratglas oder auf ein zuvor beschichtetes Substratglas bei einer Temperatur > 5500C aufgebracht wurde.17. Solar cell according to at least one of claims 1 to 16, characterized in that the solar cell has at least one photoactive semiconductor which has been applied to the substrate glass or to a previously coated substrate glass at a temperature> 550 ° C.
18. Solarzelle nach wenigstens einem der Ansprüche 1 bis 17, dadurch gekennzeichnet, dass das Substratglas nicht phasenentmischt ist und einen Gehalt an ß-OH von 25 bis 80 mMol/l aufweist. 18. Solar cell according to at least one of claims 1 to 17, characterized in that the substrate glass is not phase-separated and has a content of ß-OH of 25 to 80 mmol / l.
EP10718892A 2009-05-12 2010-05-05 Substrate glass for thin-film solar cell Withdrawn EP2429963A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102009020955 2009-05-12
DE102009050988A DE102009050988B3 (en) 2009-05-12 2009-10-28 Thin film solar cell
PCT/EP2010/002741 WO2010130358A1 (en) 2009-05-12 2010-05-05 Substrate glass for thin-film solar cell

Publications (1)

Publication Number Publication Date
EP2429963A1 true EP2429963A1 (en) 2012-03-21

Family

ID=42813917

Family Applications (1)

Application Number Title Priority Date Filing Date
EP10718892A Withdrawn EP2429963A1 (en) 2009-05-12 2010-05-05 Substrate glass for thin-film solar cell

Country Status (8)

Country Link
US (1) US20100288351A1 (en)
EP (1) EP2429963A1 (en)
JP (1) JP4944977B2 (en)
KR (1) KR101023801B1 (en)
CN (1) CN101885580A (en)
DE (1) DE102009050988B3 (en)
TW (1) TW201100347A (en)
WO (1) WO2010130358A1 (en)

Families Citing this family (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8975199B2 (en) 2011-08-12 2015-03-10 Corsam Technologies Llc Fusion formable alkali-free intermediate thermal expansion coefficient glass
US8445394B2 (en) 2008-10-06 2013-05-21 Corning Incorporated Intermediate thermal expansion coefficient glass
CN102249542B (en) * 2010-05-18 2015-08-19 肖特玻璃科技(苏州)有限公司 For the alkali aluminosilicate glass of 3D accurate die pressing and thermal flexure
JPWO2012053549A1 (en) * 2010-10-20 2014-02-24 旭硝子株式会社 Glass substrate for Cu-In-Ga-Se solar cell and solar cell using the same
JP2012209346A (en) * 2011-03-29 2012-10-25 Kyocera Corp Photoelectric conversion module
TWM428665U (en) * 2011-04-01 2012-05-11 Ritedia Corp LED plant production device
US8889575B2 (en) * 2011-05-31 2014-11-18 Corning Incorporated Ion exchangeable alkali aluminosilicate glass articles
JPWO2013047246A1 (en) * 2011-09-30 2015-03-26 旭硝子株式会社 CdTe solar cell glass substrate and solar cell using the same
DE102011116062A1 (en) 2011-10-18 2013-04-18 Sintertechnik Gmbh Ceramic product for use as a target
KR101305845B1 (en) * 2011-11-16 2013-09-06 엘지이노텍 주식회사 Solar cell apparatus and method of fabricating the same
KR101338659B1 (en) * 2011-11-29 2013-12-06 엘지이노텍 주식회사 Solar cell and method of fabricating the same
KR101327039B1 (en) 2011-11-29 2013-11-07 엘지이노텍 주식회사 Solar cell and method of fabricating the same
CN103998388B (en) * 2011-12-15 2017-06-13 陶氏环球技术有限责任公司 The method for forming the photoelectric device with stable metal oxide layer
CN104271524A (en) * 2012-05-11 2015-01-07 旭硝子株式会社 Front glass plate for laminated body, and laminated body
CN103474505B (en) * 2012-06-06 2016-07-20 尚越光电科技有限公司 Alkali-metal-doped method in copper-indium-galliun-selenium film solar cell large-scale production
US11352287B2 (en) * 2012-11-28 2022-06-07 Vitro Flat Glass Llc High strain point glass
US20140238481A1 (en) * 2013-02-28 2014-08-28 Corning Incorporated Sodium out-flux for photovoltaic cigs glasses
WO2014150235A1 (en) * 2013-03-15 2014-09-25 The Trustees Of Dartmouth College Multifunctional nanostructured metal-rich metal oxides
WO2014179140A2 (en) 2013-04-29 2014-11-06 Corning Incorporated Photovoltaic module package
EP3007236A4 (en) * 2013-06-05 2017-01-18 Jun, Young-kwon Solar cell and method for manufacturing same
EP2881998A3 (en) * 2013-11-12 2015-07-15 Anton Naebauer PV module with particularly high resistance to degradation from parasitic electrical currents
DE102013114225B4 (en) * 2013-12-17 2017-03-16 Schott Ag Chemically toughenable glass and glass element made therefrom
WO2016057429A1 (en) * 2014-10-06 2016-04-14 California Institute Of Technology Photon and carrier management design for nonplanar thin-film copper indium gallium diselenide photovoltaics
KR102526728B1 (en) * 2016-12-29 2023-04-27 코닝 인코포레이티드 Solarization Resistant Rare Earth Doped Glasses
JP2021024781A (en) * 2019-08-08 2021-02-22 コーニング インコーポレイテッド Chemically-strengthenable glasses for laminates
BR112022010785A2 (en) * 2019-12-03 2022-08-23 Nanoflex Power Corp PROTECTIVE ENCAPSULATION OF SOLAR PLATES
CN113072300B (en) * 2021-04-06 2022-06-07 浙江大学 Organic solar cell ultraviolet radiation resistant layer glass and preparation method thereof

Family Cites Families (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0662247B1 (en) * 1992-09-22 1999-03-10 Siemens Aktiengesellschaft Process for rapidly generating a chalkopyrite semiconductor on a substrate
EP0795522B1 (en) * 1996-03-14 1999-08-18 Asahi Glass Company Ltd. Glass composition for a substrate
JP3800656B2 (en) * 1996-03-14 2006-07-26 旭硝子株式会社 Glass composition for substrate
US5908794A (en) * 1996-03-15 1999-06-01 Asahi Glass Company Ltd. Glass composition for a substrate
DE19616633C1 (en) * 1996-04-26 1997-05-07 Schott Glaswerke Chemically toughenable alumino-silicate glass
DE19616679C1 (en) * 1996-04-26 1997-05-07 Schott Glaswerke Chemically toughened alumino-silicate glass production
US5824127A (en) * 1996-07-19 1998-10-20 Corning Incorporated Arsenic-free glasses
DE19721738C1 (en) * 1997-05-24 1998-11-05 Schott Glas Aluminosilicate glass for flat displays and uses
JPH11135819A (en) * 1997-10-31 1999-05-21 Matsushita Electric Ind Co Ltd Compound thin-film solar cell
US6128024A (en) * 1997-12-18 2000-10-03 Hewlett-Packard Company Polar controller for defining and generating spiral-like shapes
JP4320823B2 (en) * 1998-02-27 2009-08-26 旭硝子株式会社 Substrate glass composition
US6313052B1 (en) * 1998-02-27 2001-11-06 Asahi Glass Company Ltd. Glass for a substrate
TW565539B (en) * 1998-08-11 2003-12-11 Asahi Glass Co Ltd Glass for a substrate
DE10005088C1 (en) * 2000-02-04 2001-03-15 Schott Glas Aluminoborosilicate glass used e.g. as substrate glass in thin layer photovoltaic cells contains oxides of silicon, boron, aluminum, sodium, potassium, calcium, strontium, barium, tin, zirconium, titanium and zinc
US20070215197A1 (en) * 2006-03-18 2007-09-20 Benyamin Buller Elongated photovoltaic cells in casings
US7632701B2 (en) * 2006-05-08 2009-12-15 University Of Central Florida Research Foundation, Inc. Thin film solar cells by selenization sulfurization using diethyl selenium as a selenium precursor
US20080308147A1 (en) * 2007-06-12 2008-12-18 Yiwei Lu Rear electrode structure for use in photovoltaic device such as CIGS/CIS photovoltaic device and method of making same
JP5467490B2 (en) * 2007-08-03 2014-04-09 日本電気硝子株式会社 Method for producing tempered glass substrate and tempered glass substrate
JP5331325B2 (en) * 2007-09-28 2013-10-30 旭ファイバーグラス株式会社 Solar cell module
JP5614607B2 (en) * 2008-08-04 2014-10-29 日本電気硝子株式会社 Tempered glass and method for producing the same
WO2010050591A1 (en) * 2008-10-31 2010-05-06 旭硝子株式会社 Solar cell
JP5610563B2 (en) * 2008-11-13 2014-10-22 日本電気硝子株式会社 Glass substrate for solar cell
JP5825703B2 (en) * 2009-02-03 2015-12-02 日本電気硝子株式会社 Chemically tempered glass

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2010130358A1 *

Also Published As

Publication number Publication date
KR20100122466A (en) 2010-11-22
WO2010130358A1 (en) 2010-11-18
CN101885580A (en) 2010-11-17
US20100288351A1 (en) 2010-11-18
JP4944977B2 (en) 2012-06-06
DE102009050988B3 (en) 2010-11-04
TW201100347A (en) 2011-01-01
KR101023801B1 (en) 2011-03-21
JP2010267965A (en) 2010-11-25

Similar Documents

Publication Publication Date Title
DE102009050988B3 (en) Thin film solar cell
DE102009050987B3 (en) Planar, curved, spherical or cylindrical shaped thin film solar cell comprises sodium oxide-containing multicomponent substrate glass, which consists of barium oxide, calcium oxide, strontium oxide and zinc oxide
EP0715358B1 (en) Process for fabricating a solar cell with a chalcopyrite absorbing layer and solar cell so produced
US10196297B2 (en) Intermediate thermal expansion coefficient glass
DE10005088C1 (en) Aluminoborosilicate glass used e.g. as substrate glass in thin layer photovoltaic cells contains oxides of silicon, boron, aluminum, sodium, potassium, calcium, strontium, barium, tin, zirconium, titanium and zinc
US9530910B2 (en) Fusion formable silica and sodium containing glasses
EP2492247A1 (en) Glass sheet for cu-in-ga-se solar cells, and solar cells using same
US8895463B2 (en) Glass substrate for Cu-In-Ga-Se solar cell and solar cell using same
KR102225583B1 (en) Photovoltaic module package
DE102010023366B4 (en) Use of glasses for photovoltaic applications
WO2011035889A1 (en) Aluminosilicate glass having high thermal stability and low processing temperature
EP1228013A1 (en) Alkaline-earth aluminoborosilicate glass and the uses thereof
DE102009045929A1 (en) Solar cell and method for producing the same
US20130233386A1 (en) Glass substrate for cu-in-ga-se solar cells and solar cell using same
DE112011100358T5 (en) Photovoltaic cell with a substrate glass made of aluminosilicate glass
DE102012211894A1 (en) Use of microporous anionic inorganic framework structures, in particular containing dopant cations, for the production of thin-film solar cells or modules, photovoltaic thin-film solar cells containing microporous anionic inorganic framework structures, and methods for producing such thin-film solar photovoltaic modules
EP2881998A2 (en) PV module with particularly high resistance to degradation from parasitic electrical currents
DE102013018949A1 (en) PV module with particularly high resistance to degradation due to parasitic electrical currents
DE202008018125U1 (en) Improvements to elements that can absorb light

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20111111

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

DAX Request for extension of the european patent (deleted)
17Q First examination report despatched

Effective date: 20130801

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20131212