WO2009122938A1 - Substrat pour cellule solaire à couche mince, son procédé de fabrication, et cellule solaire à couche mince l’utilisant - Google Patents

Substrat pour cellule solaire à couche mince, son procédé de fabrication, et cellule solaire à couche mince l’utilisant Download PDF

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WO2009122938A1
WO2009122938A1 PCT/JP2009/055623 JP2009055623W WO2009122938A1 WO 2009122938 A1 WO2009122938 A1 WO 2009122938A1 JP 2009055623 W JP2009055623 W JP 2009055623W WO 2009122938 A1 WO2009122938 A1 WO 2009122938A1
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titanium oxide
substrate
oxide film
film
solar cell
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Japanese (ja)
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村田正義
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Murata Masayoshi
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
    • C23C16/40—Oxides
    • C23C16/407—Oxides of zinc, germanium, cadmium, indium, tin, thallium or bismuth
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
    • C23C16/40—Oxides
    • C23C16/405—Oxides of refractory metals or yttrium
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022466—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0224—Electrodes
    • H01L31/022466—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers
    • H01L31/022483—Electrodes made of transparent conductive layers, e.g. TCO, ITO layers composed of zinc oxide [ZnO]
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • H01L31/1884—Manufacture of transparent electrodes, e.g. TCO, ITO
    • 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

Definitions

  • the present invention relates to a thin film solar cell substrate, a method for producing the same, and a thin film solar cell using the same.
  • Transparent electrodes used in thin film solar cells such as amorphous silicon solar cells and tandem thin film silicon solar cells (a combination of amorphous silicon cells and microcrystalline silicon cells) have electrical properties that have high conductivity, and Optical characteristics are required to have high transparency and light confinement effect (uneven structure of the film). Furthermore, it is required not to change color when exposed to plasma, that is, to have excellent plasma resistance.
  • the plasma resistance is low, for example, when a photoelectric conversion layer for a thin film silicon solar cell is manufactured by a plasma CVD method, the film surface of the transparent electrode is reduced by the plasma and changed to black. As a result, the incident light is absorbed in the blackened portion, the amount of light incident on the photoelectric conversion layer is reduced, and power generation efficiency is reduced.
  • a transparent electrode mainly composed of tin oxide (SnO 2) manufactured by a thermal CVD method described in Patent Document 1 Japanese Patent Laid-Open No. 2003-81633
  • Patent Document 1 Japanese Patent Laid-Open No. 2003-81633
  • ZnO zinc oxide
  • the thermal CVD method requires a high-temperature process of 550 to 650 ° C. to manufacture a transparent electrode mainly composed of tin oxide (SnO 2). Therefore, when tempered glass is used for the substrate, the tempered glass is tempered by the high temperature process, and is usually transformed into glass. Therefore, when tempered glass cannot be used for a substrate and a large area glass substrate is used, it is necessary to increase the glass thickness (weight increase) in order to ensure the strength of the glass substrate. As a result, the weight increases by 4 to 5 times compared to the case where tempered glass is used for the substrate, which is not only inconvenient but also increases in manufacturing cost.
  • Patent Document 2 Patent No. 3215128
  • Patent Document 3 Japanese Patent Laid-Open No. 2000-150928
  • Patent Document 4 Japanese Unexamined Patent Application Publication No. 2005-311292
  • Japanese Patent Application Laid-Open No. 2001-015787 Japanese Patent Application Laid-Open No. 2001-015787.
  • Patent Document 2 Japanese Patent No. 3215128 describes a method for producing a transparent electrode containing zinc oxide (ZnO) as a main component by sputtering. This method is characterized in that sputtering is performed using a ZnO target doped with Al at a sputtering gas pressure of 2 Pa or more and a substrate temperature of 250 ° C. or more.
  • the transparent electrode mainly composed of zinc oxide (ZnO) produced by this method has a columnar or granular agglomerate having a size of 0.1 to 10 ⁇ m and a void of 0.1 to 10 ⁇ m on the film surface.
  • a ZnO thin film doped with Al in which the light transmittance of the film depends on the light incident angle.
  • columnar or granular agglomerates having a size of 0.1 to 10 ⁇ m form voids of 0.1 to 10 ⁇ m on the film surface. Therefore, it is not suitable for a transparent electrode for a thin film silicon solar cell. That is, when a p-type semiconductor film (thickness is, for example, 5 to 20 nm) constituting a photoelectric conversion layer is formed on the transparent electrode film having the voids, A p-type semiconductor film is not formed.
  • the quality of the obtained p-type semiconductor film is affected by the structure of the void portion. As a result, there is a problem that it is difficult to manufacture a p-type semiconductor film formed on the surface of the transparent electrode film with high quality and good reproducibility.
  • Patent Document 3 Japanese Patent Application Laid-Open No. 2000-150928
  • an aluminum film is formed on a light-transmitting substrate by a sputtering method, the aluminum film is partially etched away, and the surface thereof is roughened.
  • the aluminum film is oxidized or nitrided by heating in a nitrogen atmosphere to change into a crystallized aluminum oxide or aluminum nitride aluminum compound film, and transparent conductive material made of zinc oxide or tin oxide is formed by sputtering.
  • a method for forming a transparent electrode substrate by forming a conductive film is described. This method has the following characteristics.
  • a transparent electrode substrate formed by forming a transparent conductive film on a light-transmitting substrate by a sputtering method an uneven aluminum compound film is provided between the light-transmitting substrate and the transparent conductive film. It is characterized by. Further, in a method of forming a transparent electrode substrate formed by forming a transparent conductive film on a light-transmitting substrate by a sputtering method, a step of forming an aluminum film on the light-transmitting substrate, and etching the formed aluminum film And a step of changing the aluminum film into an aluminum compound film, and a step of forming a transparent conductive film on the aluminum compound film by a sputtering method.
  • the manufacturing process has four steps, that is, the step of forming an aluminum film on the translucent substrate, the step of etching the formed aluminum film to make it uneven, and the aluminum film as an aluminum compound film.
  • the process is complicated and includes a process of forming a transparent conductive film on the aluminum compound film by sputtering. This means that when applied to a practical production line, the introduction cost of the apparatus constituting the manufacturing process increases and the running cost increases. In general, it is known that as the number of manufacturing processes increases, the yield of products decreases. As a result, there is a problem that the cause of the increase in production cost is held.
  • Patent Document 4 Japanese Patent Laid-Open No. 2005-311292 describes a method using a low-pressure thermal CVD method (or a method called MOCVD method, Metal-Organic Chemical Vapor Deposition).
  • MOCVD method Metal-Organic Chemical Vapor Deposition
  • light-transmitting fine particles silicon: SiO2, titanium oxide: TiO2, aluminum oxide: Al2O3, zirconium oxide: ZrO2, indium tin oxide: ITO, or magnesium fluoride: MgF2
  • the ZnO film is formed on the light-transmitting fine particles by low-pressure thermal CVD. This method has the following characteristics.
  • a thin film solar cell substrate comprising a light-transmitting insulating substrate and a transparent electrode layer containing at least zinc oxide deposited on the light-transmitting insulating substrate, the light-transmitting insulating substrate being the transparent electrode layer
  • the side interface has fine surface irregularities having a root mean square roughness of 5 to 50 nm, and the convex portions are composed of phases.
  • the transparent electrode layer has a thickness of 1 ⁇ m or more.
  • the translucent insulating substrate is a laminate of a translucent substrate having a smooth surface and a translucent underlayer, and the translucent underlayer has an average particle diameter of 10 nm or more and less than 100 nm. It contains a light-sensitive fine particle and a light-transmitting binder.
  • the transparent insulating substrate is deposited at a temperature of 150 ° C. or more and containing at least zinc oxide.
  • a translucent underlayer composed of a translucent binder and translucent fine particles is disposed on a glass substrate, and the translucent layer A transparent electrode layer is laminated on the base layer.
  • a translucent binder containing a solvent such as silicon oxide, aluminum oxide, titanium oxide, and zirconium oxide
  • translucent fine particles are formed on a translucent insulating substrate. It is necessary to apply a dipping method, a spin coating method, a spray method, or the like and immediately dry the coated thin film after the coating operation is completed.
  • the problem of whether the adhesive force between the translucent underlayer composed of a translucent binder containing a solvent and translucent fine particles and the translucent substrate is sufficiently strong, and high temperature (150 ° C. And the like) whether the adhesive strength does not decrease when exposed to the above. Furthermore, there is a problem of whether long-term stability is good.
  • the solvent is removed from the translucent binder containing the solvent and the translucent fine particles in the heating and drying step of the coated thin film, voids are formed in the portion where the solvent is present, and the porous film is generally porous. It becomes a state. This porous state becomes an impurity generation source in the manufacturing process of the power generation film by the plasma CVD method. As a result, there may be a problem that it is difficult to manufacture a solar cell with high power generation efficiency.
  • Patent Document 5 Japanese Patent Laid-Open No. 2001-015787 uses a substrate with a transparent conductive film having a surface uneven structure, which can be formed at high speed by a sputtering method, and has high productivity, and a manufacturing method, and the substrate with a transparent conductive film.
  • a solar cell is described.
  • the point of idea is that titanium oxide and zinc oxide are laminated on a substrate by sputtering, and has the following characteristics. That is, it is a method for producing a substrate with a transparent conductive film in which a transparent conductive film mainly composed of zinc oxide is laminated on a film mainly composed of titanium oxide formed on the substrate.
  • the present invention is characterized in that it is a substrate with a transparent conductive film in which a transparent conductive film mainly composed of zinc oxide is laminated in contact with a film mainly composed of titanium oxide formed on the substrate. Moreover, it is a solar cell in which a photoelectric conversion layer and an electrode layer are formed in this order on a transparent conductive film containing zinc oxide as a main component of the substrate with the transparent conductive film. Moreover, the base
  • substrate with a transparent conductive film of the said patent document 5 is produced as follows, for example.
  • a TiO2 film having a thickness of 0.5 to 200 nm is formed on a glass substrate by an oxidation reactive sputtering method using a Ti target, and then a conductive oxide target mainly composed of zinc oxide is formed.
  • the zinc oxide transparent conductive film is formed in contact with the TiO 2 film by sputtering in argon gas.
  • Patent Document 5 Japanese Patent Laid-Open No. 2001-015787 shows the following in general.
  • A From the viewpoint of obtaining a solar cell with high conversion efficiency, the titanium oxide film is a transparent film having high light transmittance.
  • a TiO2 film or another component for example, SiO2, A film doped with Al2O3, Fe2O3 is mentioned.
  • the film thickness is preferably 0.5 to 200 nm, particularly 1 to 10 nm.
  • the form of the titanium oxide film may be either a continuous film or a discontinuous film.
  • As the oxide target for forming the titanium oxide film TiO2 or TiO2-x is used.
  • TiO2 is not conductive, it is limited to a high frequency (RF) sputtering method, and in the case of TiO2-x. Is conductive, so that either direct current sputtering or radio frequency (RF) sputtering may be used.
  • the substrate temperature when the titanium oxide film is formed by sputtering is preferably 0 to 600 ° C. In particular, a temperature of 20 to 400 ° C. is preferable.
  • B Regarding the zinc oxide film, it is preferable that the surface uneven state has an arithmetic average roughness defined by JIS B0601 of 15 to 150 nm.
  • examples of the zinc oxide-based transparent conductive film include films in which ZnO is doped with another component (for example, one or more selected from the group consisting of B, Al, Ga, In, Si, and Ti) as a dopant. Yes.
  • another component for example, one or more selected from the group consisting of B, Al, Ga, In, Si, and Ti.
  • Al or Ga is preferable.
  • the dopant content is preferably such that the total amount of dopant relative to the total amount of dopant and zinc (ZnO) is 0.01 to 10 atomic%.
  • the film thickness of the zinc oxide-based transparent conductive film is preferably 100 to 3000 nm. In particular, 100 to 1000 nm is preferable. When it is thinner than 100 nm, the uneven structure is difficult to appear. On the other hand, if it is thicker than 3000 nm, it takes time to form a film, which is not practical, and the amount of light absorption increases, resulting in a large loss of light energy.
  • a zinc oxide type transparent conductive film it is preferable that it is a continuous film (film
  • the substrate temperature when forming the zinc oxide-based transparent conductive film is preferably 0 to 600 ° C. In particular, a temperature of 20 to 400 ° C. is preferable.
  • the sputtering pressure at the time of sputtering the zinc oxide-based transparent conductive film is not particularly limited, and is generally preferably 0.01 to 1.4 Pa at which stable discharge is possible.
  • a substrate such as a substrate on which a film (for example, a silicon oxide film) for preventing diffusion of an alkali component in a glass substrate is formed may be used.
  • This method has the following effects.
  • the titanium oxide film is a substantially flat film without a particularly large uneven structure.
  • the titanium oxide film affects the crystal growth of the zinc oxide-based transparent conductive film laminated on and in contact with the titanium oxide film, and as a result, a zinc oxide crystal having a large crystal grain in which the crystal growth is promoted grows. Due to the crystal grains, the surface of the zinc oxide-based transparent conductive film becomes uneven.
  • the zinc oxide-based transparent conductive film has a roof-like uneven shape, is suitable as an incident side electrode of a solar cell, and has a high light confinement effect.
  • the roof has a relatively gentle slope, when an amorphous silicon layer is laminated on the transparent conductive film, there are very few portions where the amorphous silicon layer is not formed, and it is a continuous suitable as a solar cell. It becomes an amorphous silicon layer.
  • the titanium oxide film also has an effect of preventing diffusion of alkali and moisture from the substrate glass, and can prevent deterioration of the zinc oxide-based transparent conductive film. As a result, the reliability of the solar cell using the substrate on which the titanium oxide film and the transparent conductive film are stacked is improved.
  • Patent Document 5 Japanese Patent Laid-Open No. 2001-015787
  • the target material is expensive and the use efficiency of the target material in the sputtering method is low.
  • the manufacturing cost of the solar cell substrate manufactured using the method is high.
  • Patent Document 5 Japanese Patent Application Laid-Open No. 2001-015787 describes a method for forming a titanium oxide film and a method for forming a transparent conductive film mainly composed of zinc oxide using a sputtering method.
  • a method or apparatus other than the sputtering method is mentioned. That is, there is no mention of a method or apparatus that may have a lower manufacturing cost than the sputtering method. Further, there is no mention of controlling the characteristics of titanium oxide in the film thickness direction.
  • JP 2003-81633 A Japanese Patent No. 3215128 JP2000-150928A JP 2005-311292 A JP 2001-015787 A
  • a transparent electrode mainly composed of tin oxide (SnO2) by a thermal CVD method has been put into practical use, but there is a problem that it is difficult to reduce the manufacturing cost.
  • Recently, in the thin film solar cell industry there has been a strong demand for an innovative reduction in production cost by adopting a large area substrate with a substrate size of the 8th generation (2.2 mx 2.6 m).
  • the conventional thermal CVD method is difficult to cope with the 8th generation substrate because it involves technical difficulties peculiar to high temperature processes (increased glass substrate thickness, glass breakage due to non-use of tempered glass, etc.). There is a problem that there is.
  • Patent Documents 2 to 5 which are expected as new methods and apparatuses in place of the transparent electrode manufacturing method and manufacturing apparatus mainly composed of tin oxide (SnO2) by the thermal CVD method.
  • SnO2 tin oxide
  • the present invention has been made in view of the above problems, and can be easily formed into a large area, and is a low-cost raw material such as an organometallic material such as trimethyl zinc, triethyl zinc, diethyl zinc, etc.
  • An object is to create a new method and apparatus using high-frequency plasma CVD technology that can be used as a raw material, and to provide a technology related thereto.
  • a thin film solar cell substrate in which an amorphous titanium oxide film, a crystalline titanium oxide film, and a crystalline zinc oxide film are laminated on a transparent insulating substrate, a manufacturing method thereof, and a thin film solar cell using the same The purpose is to provide.
  • a substrate for a thin film solar cell includes a light-transmitting insulating substrate (2) and at least a titanium oxide film layer deposited on the light-transmitting insulating substrate ( 3a) and a thin film solar cell substrate (1a) comprising a transparent electrode layer including a zinc oxide film layer (5), wherein the titanium oxide film layer (3a) is formed of an amorphous titanium oxide film layer (4a) and a crystal. It has a two-layer structure composed of a quality titanium oxide film layer (4b).
  • a substrate for a thin-film solar cell includes a translucent insulating substrate (2) and at least titanium oxide deposited on the translucent insulating substrate.
  • a thin film solar cell substrate (1b) comprising a transparent electrode layer including a film layer (3b) and a zinc oxide film layer (5), wherein the titanium oxide film layer (3b) is an amorphous titanium oxide film layer (4a).
  • a substrate for a thin-film solar cell includes a translucent insulating substrate (2) and at least titanium oxide deposited on the translucent insulating substrate.
  • a thin film solar cell substrate (1c) comprising a transparent electrode layer including a film layer (3c) and a zinc oxide film layer (5), wherein the titanium oxide film layer (3c) comprises amorphous titanium oxide and microcrystalline oxide It has a two-layer structure composed of a mixed phase titanium oxide film layer (4c) mixed with titanium and a crystalline titanium oxide film layer (4b).
  • the thin film solar cell substrate according to the fourth aspect of the present invention is characterized in that the zinc oxide film layer (5) has crystallinity.
  • a thin film solar cell substrate has a thickness of the amorphous titanium oxide film layer (4a) of 1 nm to 150 nm and the crystalline material.
  • the titanium oxide film layer (4b) has a thickness of 5 nm to 250 nm.
  • the substrate for a thin film solar cell according to the sixth aspect of the present invention is the thickness of the mixed phase titanium oxide film layer (4c) in which the amorphous titanium oxide and the microcrystalline titanium oxide are mixed. Is 10 nm to 100 nm.
  • a method for manufacturing a thin-film solar cell substrate according to a seventh aspect of the present invention is a method for manufacturing the thin-film solar cell substrate (1a, 1b, 1c),
  • the amorphous titanium oxide film layer (4a), the crystalline titanium oxide film layer (4b) and the zinc oxide film layer (5) are all manufactured using a high-frequency plasma CVD apparatus.
  • a method for manufacturing a thin-film solar cell substrate according to an eighth aspect of the present invention includes the amorphous titanium oxide film layer (4a) and the crystalline titanium oxide film layer (4b). ) Is manufactured using a high-frequency plasma CVD apparatus, and the zinc oxide film layer (5) is manufactured using a sputtering apparatus.
  • a method for manufacturing a thin film solar cell substrate relates to the amorphous titanium oxide film layer (4a) and the crystalline titanium oxide film layer (4b).
  • ) Is manufactured at a temperature of 250 to 450 ° C. of the translucent insulating substrate (2), and the zinc oxide film layer (5) is manufactured at a temperature of 150 to 450 ° C. of the translucent insulating substrate (2). It is characterized by being.
  • the amorphous titanium oxide film layer has a temperature 250 of the translucent insulating substrate (2).
  • the crystalline titanium oxide film layer (4b) is manufactured at a temperature of 250 to 450 ° C. of the translucent insulating substrate (2), and the zinc oxide film layer (5) is the translucent film.
  • the insulating insulating substrate (2) is manufactured at a temperature of 150 to 450 ° C.
  • a method for manufacturing a thin film solar cell substrate according to an eleventh aspect of the present invention includes the amorphous titanium oxide film layer (4a) and the crystalline titanium oxide film layer (4b). ) Using a high-frequency plasma CVD method, at least a mixed gas of titanium tetraisopropoxide and oxygen is used as a raw material, and the temperature of the translucent insulating substrate (2) is 250 to 450 ° C. It is characterized by being.
  • a method for manufacturing a thin film solar cell substrate according to a twelfth aspect of the present invention includes the amorphous titanium oxide film layer (4a) and the crystalline titanium oxide film layer (4b). ),
  • the temperature of the translucent insulating substrate (2) is set to 250 ° C. to 450 ° C., and at least a mixed gas of titanium tetraisopropoxide and oxygen is used as a raw material.
  • the amorphous titanium oxide film layer (4a) formed at the initial deposition stage is used as a barrier layer for impurities from the translucent insulating substrate (2), and the amorphous titanium oxide film layer A crystalline titanium oxide film layer (4b) formed using (4a) as a base is used as a base layer in forming the zinc oxide film layer (5).
  • a thin film solar cell according to a thirteenth aspect of the present invention is characterized in that at least amorphous silicon or microcrystalline silicon is contained in the photoelectric conversion layers (7, 13). .
  • a thin film solar cell in which amorphous titanium oxide, crystalline titanium oxide, and crystalline zinc oxide with a large crystal grain size doped with Ga or Al are laminated on a light-transmitting insulating substrate.
  • a substrate can be manufactured.
  • this thin film solar cell substrate as a transparent electrode of an amorphous silicon solar cell and a tandem solar cell, it is possible to manufacture a solar cell having high photoelectric conversion efficiency.
  • the manufacturing cost of the thin film solar cell can be innovatively reduced.
  • 1 is a structural diagram schematically showing a cross section of a thin-film solar cell substrate according to a first embodiment of the present invention.
  • 1 is an apparatus configuration diagram schematically showing a high-frequency plasma CVD apparatus for manufacturing a titanium oxide (TiO 2) film according to a first embodiment of the present invention.
  • 1 is an apparatus configuration diagram schematically showing a high-frequency plasma CVD apparatus for manufacturing a zinc oxide (ZnO) film according to a first embodiment of the present invention.
  • the substrate temperature is a low temperature range (room temperature to 250 ° C.), and the film formation time is the same as that when the substrate is glass.
  • Explanatory drawing which shows the relationship between the thickness of a film and film quality.
  • the substrate temperature is in the middle temperature range (250 to 350 ° C.), and the film formation time is the same as that in the case where the substrate is glass.
  • Explanatory drawing which shows the relationship between the thickness of a film and film quality.
  • the substrate temperature is in a high temperature range (350 to 450 ° C.) and the film is formed with the film formation time in the case where the substrate is glass.
  • Explanatory drawing which shows the relationship between the thickness of a film and film quality.
  • the substrate temperature is in a high temperature range (350 to 450 ° C.) and the base is amorphous titanium oxide or amorphous oxide.
  • Explanatory drawing which shows the relationship between the mixed phase of titanium and microcrystalline titanium oxide, or the film formation time in crystalline titanium oxide, the thickness of the film formed, and film quality.
  • Explanatory drawing which shows the relationship between thickness and film quality.
  • FIG. 5 is a structural diagram schematically showing a cross section of a thin film solar cell substrate according to a second embodiment of the present invention.
  • FIG. 5 is a structural diagram schematically showing a cross section of a thin-film solar cell substrate according to a third embodiment of the present invention.
  • 1a Substrate for thin film solar cell according to the first embodiment of the present invention, 2 ... Translucent insulating substrate, 4a ... amorphous titanium oxide layer, 4b ... crystalline titanium oxide layer, 4c: mixed phase titanium oxide film of amorphous titanium oxide and crystalline titanium oxide, 5 ... crystalline zinc oxide (ZnO) film layer, 100 ... Vacuum container, 101 ... Ungrounded first electrode, 103 ... a second electrode grounded; 120a: raw material for titanium oxide film, 120b ... Raw material of zinc oxide film, 120c ... doping material of zinc oxide film, 135: Transmitter, 138a, 138b... First and second power amplifiers, 139a, 139b... First and second matching units.
  • FIG. 1 is a structural view schematically showing a cross section of a thin film solar cell substrate according to a first embodiment of the present invention.
  • FIG. 2 is an apparatus configuration diagram showing an outline of a high-frequency plasma CVD apparatus for producing a titanium oxide (TiO 2) film according to the first embodiment of the present invention.
  • FIG. 3 is an apparatus configuration diagram showing an outline of a high-frequency plasma CVD apparatus for manufacturing a zinc oxide (ZnO) film according to the first embodiment of the present invention.
  • FIG. 1 is a structural view schematically showing a cross section of a thin film solar cell substrate according to a first embodiment of the present invention.
  • FIG. 2 is an apparatus configuration diagram showing an outline of a high-frequency plasma CVD apparatus for producing a titanium oxide (TiO 2) film according to the first embodiment of the present invention.
  • FIG. 3 is an apparatus configuration diagram showing an outline of a high-frequency plasma CVD apparatus for manufacturing a zinc oxide (ZnO) film according to the first embodiment of the present invention.
  • FIG. 4 shows the film formation time when the substrate temperature is low (room temperature to 250 ° C.) and the substrate is glass when manufacturing the titanium oxide film by the high-frequency plasma CVD apparatus according to the first embodiment of the present invention. It is explanatory drawing which shows the relationship between the thickness of the film
  • FIG. 5 shows the film formation time when the substrate temperature is in the intermediate temperature range (250 to 350 ° C.) and the substrate is glass when the titanium oxide film is manufactured by the high-frequency plasma CVD apparatus according to the first embodiment of the present invention. It is explanatory drawing which shows the relationship between the thickness of the film
  • FIG. 6 shows the film formation time in the case where the substrate temperature is high (350 to 450 ° C.) and the substrate is glass when the titanium oxide film is manufactured by the high-frequency plasma CVD apparatus according to the first embodiment of the present invention. It is explanatory drawing which shows the relationship between the thickness of the film
  • FIG. 7 shows a substrate temperature in the high temperature region (350 to 450 ° C.) when the titanium oxide film is manufactured by the high-frequency plasma CVD apparatus according to the first embodiment of the present invention, and the base is amorphous titanium oxide.
  • FIG. 8 shows the film formation time and the manufacturing time when the substrate temperature is about 200 to 400 ° C. and the base is crystalline titanium oxide when the zinc oxide film is manufactured by the high-frequency plasma CVD apparatus according to the first embodiment of the present invention.
  • FIG. 9 is an explanatory diagram of application of the thin film solar cell substrate according to the first embodiment of the present invention to the manufacture of an amorphous silicon solar cell.
  • FIG. 10 is an explanatory diagram of application of the thin film solar cell substrate according to the first embodiment of the present invention to manufacture of a tandem thin film solar cell.
  • a thin film solar cell substrate 1a according to the first embodiment of the present invention includes a translucent insulating substrate 2 and a titanium oxide layer 3a (described later from an amorphous titanium oxide layer 4a and a crystalline titanium oxide layer 4b). And a crystalline zinc oxide (ZnO) film layer 5.
  • reference numeral 2 denotes a translucent insulating substrate, for example, a glass substrate having a thickness of 4 to 5 mm.
  • Reference numeral 3a denotes a titanium oxide layer, which is composed of two layers, an amorphous titanium oxide layer 4a and a crystalline titanium oxide layer 4b.
  • the amorphous titanium oxide layer 4a and the crystalline titanium oxide layer 4b are made of titanium tetraisopropoxide: Titanium-Tetra-Iso-Propoxide (here, TTIP) using argon gas or hydrogen gas as a carrier gas. ) And oxygen as a main raw material, and is formed by a high-frequency plasma CVD apparatus.
  • Reference numeral 5 denotes a crystalline zinc oxide (ZnO) film layer.
  • this crystalline zinc oxide (ZnO) film layer uses argon gas or hydrogen gas as a carrier gas, and uses trimethylzinc (CH 3 ) 3 Zn or triethylzinc (C 2 H 5 ) 3 Zn and oxygen.
  • the mixed gas is used as a main raw material to form a film by a high frequency plasma CVD apparatus.
  • the crystalline zinc oxide (ZnO) film layer 5 may be formed by using a sputtering apparatus.
  • trimethylgallium (CH 3 ) 3 Ga, triethylgallium (C 2 H 5 ) 3 Ga, Trimethylaluminum (CH 3 ) 3 Al, triethylaluminum (C 2 H 5 ) 3 Al, or the like is used.
  • symbol 100 is a vacuum vessel.
  • the vacuum vessel 100 is provided with a pair of electrodes for converting a source gas to be described later into plasma, that is, a non-grounded first electrode 101 and a grounded second electrode 103 containing a substrate heater 102 (not shown).
  • Reference numeral 101 denotes a first electrode, which is fixed to the vacuum vessel 100 via an insulator support member 104 and a gas mixing box 105 (not shown).
  • the first electrode 101 has a rectangular flat plate shape, and is disposed to face a second electrode 103 described later.
  • the specific size is, for example, an external dimension of length 1.5 mx width 0.3 mx thickness 20 mm.
  • the first electrode 101 and the gas mixer 105 have gas shower holes 106 and 107 through which the source gas is ejected, respectively.
  • the holes 106 and 107 have a diameter of about 0.4 to 1 mm, for example, a diameter of about 0.7 mm, and a large number of holes 106 and 107 are set.
  • the gas shower hole 107 has a function of rectification for uniformly supplying oxygen gas, which will be described later, between the pair of electrodes 101 and 103 through the gas shower hole 106.
  • the gas shower hole 106 is a rectifier for uniformly supplying a mixed gas of a carrier gas and titanium tetraisopropoxide (hereinafter referred to as TTIP), which will be described later, and the oxygen gas between the pair of electrodes 101 and 103. It has the function of.
  • Reference numeral 103 denotes a second electrode which includes a substrate heater 102 (not shown), and the temperature of the substrate 108 placed thereon can be set to an arbitrary temperature within a range of 100 to 450 ° C.
  • the second electrode 103 can include a pipe through which a refrigerant is passed to control the surface temperature of the second electrode 103.
  • the second electrode 103 has a rectangular flat plate shape and is disposed to face the first electrode 101.
  • the specific size is, for example, an external dimension of length 1.6 mx width 0.4 mx thickness 150 mm.
  • Reference numeral 109 denotes a raw material gas temperature adjusting device, which is a gas for maintaining the temperature of a raw material gas described later, that is, a mixed gas of carrier gas and TTIP, by 10 to 30 ° C. higher than a set value of a TTIP temperature adjusting device 122a described later.
  • the temperature of the mixing box 105 and the first electrode 101 is maintained at 90 ° C.
  • first and second feeding points 110 a and 110 b are arranged on the first electrode 101.
  • the first and second feeding points 110a and 110b are connection points between a power supply system, which will be described later, and the first electrode 101, and power is supplied from these positions.
  • the first and second feeding points 110a and 110b are in a positional relationship facing each other, and are set at the ends of the electrodes and have a relationship as opposing points on the propagation of the high-frequency power wave.
  • Third and fourth feeding points 111 a and 111 b are arranged on the second electrode 103.
  • the third and fourth feeding points 111a and 111b are connection points between a power supply system described later and the electrode 103, and power is supplied from the positions.
  • the third and fourth feeding points 111a and 111b are in a positional relationship facing each other, and are set at the ends of the electrodes and have a relationship as opposing points in the propagation of the high-frequency power wave.
  • the distance between the first and second electrodes 101 and 103 can be arbitrarily set in advance when a substrate lifter 112 described later is operated up and down, and is set to a range of 5 mm to 40 mm, for example, 25 mm.
  • reference numeral 112 denotes a substrate lifter, which receives the substrate 108 on the second electrode 103 from a substrate carry-in / out gate 118 (not shown), up to a position where the distance between the first and second electrodes is maintained at a predetermined value.
  • the first and second electrodes 101 and 103 move to a position where the distance is 25 mm.
  • the vertical position of the substrate lifter 112 can be arbitrarily set, and the distance between the first and second electrodes is set in a range of 5 mm to 40 mm, for example.
  • a bellows 113 is used to keep the vacuum vessel 100 airtight when the substrate lifter 112 moves up and down.
  • connection conductor 115a and the third connection conductor 116a, and the second connection conductor 115b and the fourth connection conductor 116b have a spring characteristic so that they are pressed against each other when they are in contact with each other. is doing.
  • the first connection conductor 115a and the third connection conductor 116a, and the second connection conductor 115b and the fourth connection conductor 116b are set so as to ensure a conductive state with good reproducibility.
  • Reference numeral 108 denotes a substrate, which is disposed on the second electrode 103 using a substrate lifter 112 and a substrate carry-in / out gate 118 (not shown). Then, it is heated to a predetermined temperature by a substrate heater 102 (not shown).
  • the substrate 108 is made of glass having a size of 1.5 mx 0.25 mx 4 mm in thickness.
  • the gas mixing box 105 is configured such that a mixed gas of carrier gas and TTIP supplied from a first source gas supply pipe 126 a to be described later via a source gas supply unit 132 passes through the gas shower hole 106. It has a function of supplying uniformly between the pair of electrodes 101 and 103.
  • the source gas supply unit 132 is made of an insulating material (not shown) and is electrically insulated. Further, it has a function of uniformly supplying oxygen gas supplied from a second source gas supply pipe 130 described later between the pair of electrodes 101 and 103 through the gas shower holes 107 and 106.
  • the second source gas supply pipe 130 is made of an insulating material (not shown) and is electrically insulated.
  • the supplied source gas such as TTIP and oxygen is turned into plasma between the pair of electrodes 101 and 103 and then discharged to the outside of the vacuum vessel 100 by the exhaust pipes 119a and 119b and a vacuum pump (not shown).
  • reference numeral 120a denotes TTIP, which is a raw material for the titanium oxide film.
  • Reference numeral 121a denotes a TTIP container, which is used in combination with a TTIP temperature adjusting device 122a described later.
  • Reference numeral 122a denotes a TTIP temperature adjusting device, which maintains the temperature of the TTIP container 121a at an arbitrary temperature in the range of 65 to 90 ° C, for example, 70 ° C. Then, a part of TTIP inside the container 121a is gasified. Further, when mixed with a carrier gas described later, the gas phase portion of the container 121a is saturated by the carrier gas and gasified TTIP.
  • Reference numeral 123a is a carrier gas supply source of TTIP, and for example, a cylinder such as hydrogen gas or argon gas is used.
  • Reference numeral 124a is a TTIP carrier gas flow meter, which can control a required gas flow rate.
  • Reference numeral 125a denotes a TTIP carrier gas supply pipe for supplying the carrier gas from the TTIP carrier gas supply source 123a to the TTIP container 121a.
  • Reference numeral 126 a is a titanium oxide source gas supply pipe, which supplies a mixed gas of TTIP gas and carrier gas generated in the TTIP container 121 a to the gas mixing box 105 via the source gas supply unit 132.
  • Reference numeral 131a denotes a gas flow rate adjusting device that can control the flow rate of the mixed gas of the TTIP gas and the carrier gas to a required flow rate.
  • the gas flow rate adjusting device 131a adjusts the flow rate of the carrier gas saturated with the generated organic metal as a result of bubbling the liquid organic metal in the container 121a with the carrier gas.
  • the pressure of the carrier gas flowing into the TTIP container 121a is set to 1 atm, for example, and is monitored by a pressure sensor (not shown).
  • the pressure of the carrier gas saturated with the organic metal flowing out of the TTIP container 121a is monitored by a pressure sensor (not shown).
  • Reference numeral 127a denotes a heater, which is 10 to 30 ° C. higher than the TTIP temperature adjusting device 122a, for example, 90 ° C. so that the mixed gas of the TTIP gas and the carrier gas flowing inside the titanium oxide source gas supply pipe 126a does not condense.
  • Reference numeral 133a denotes a flow path opening / closing valve.
  • the raw material gas flowing in the raw material gas supply pipe 126a is supplied to the gas mixing box 105 via the raw material gas supply unit 132 on the downstream side.
  • the flow path opening / closing valve 133a is closed, the source gas flowing inside the source gas supply pipe 126a is discharged toward an exhaust line (not shown).
  • the raw material (TTIP) 120a of the titanium oxide film the raw material (TTIP) 120a of the titanium oxide film, the TTIP container 121a, the TTIP temperature adjustment device 122a, the TTIP carrier gas supply source 123a, the TTIP carrier gas flow meter 124a, the gas flow rate adjustment device 131a, and the oxidation
  • a titanium oxide film material (TTIP) supply device An organometallic material supply device including the titanium source gas supply pipe 126a and the like is referred to as a titanium oxide film material (TTIP) supply device.
  • reference numeral 128 denotes an oxygen gas supply source, for example, an oxygen cylinder.
  • Reference numeral 129 is an oxygen gas flow meter which can control a required gas flow rate.
  • Reference numeral 130 denotes an oxygen gas supply pipe for supplying the gas from the oxygen gas supply source 128 to the gas mixing box 105.
  • the gas supply device including the oxygen gas supply source 128, the oxygen gas flow meter 129, and the oxygen gas supply pipe 130 is referred to as an oxygen gas supply device.
  • the pressure in the vacuum vessel 100 is monitored by a pressure gauge (not shown).
  • the pressure in the vacuum vessel 100 is adjusted by adjusting the flow meters 124a, 131a and 129 to a predetermined value, and by automatically adjusting the exhaust amount of a vacuum pump (not shown) to a predetermined value. Set to the required pressure.
  • the pressure is about 0.01 Torr to 10 Torr (1.33 Pa to 1330 Pa). Can be adjusted.
  • the vacuum ultimate pressure of the vacuum vessel 1 is about 2 to 3E-7 Torr (2.66 to 3.99E-5 Pa).
  • reference numeral 135 denotes a transmitter, which generates a sine wave signal of a high frequency band, for example, 13.56 MHz.
  • Reference numeral 136 denotes a signal distributor which branches the signal from the transmitter 136 into two.
  • Reference numeral 137 denotes a phase adjusting device that adjusts the phase of the sine wave signal. Note that the phase adjustment device 137 used here has a function capable of advancing or delaying the phase within a range of ⁇ 180 degrees, for example.
  • Reference numerals 138a and 138b respectively have a function of amplifying an input signal by the first and second power amplifiers. The output of this apparatus can be arbitrarily adjusted in the range of several hundred W to 10 KW.
  • W 11 (t) Asin ( ⁇ t + ⁇ 1 )
  • W 12 (t) Asin ( ⁇ t + ⁇ 2 )
  • A an amplitude
  • ⁇ an angular frequency
  • t time
  • ⁇ 1 and ⁇ 2 initial phases.
  • reference numerals 139a and 139b denote first and second matching units, respectively, and the outputs of the first and second amplifiers 138a and 138b are efficiently used for the plasma generated between the pair of electrodes 101 and 103. Adjust the output impedance to be transmitted. That is, the first matching device 139a adjusts the output impedance of the first amplifier 138a and the impedance of the plasma generated between the pair of electrodes 101 and 103 that are the loads. The second matching unit 139b adjusts and matches the output impedance of the second amplifier 138b and the impedance of the plasma generated between the pair of electrodes 101 and 103 serving as the load.
  • Reference numeral 140a denotes a first coaxial cable, together with a first connection conductor 115a and a third connection conductor 116a, through a first current introduction terminal 141a, a third coaxial cable 142a, and a first core wire 143a, which will be described later.
  • the output of the first amplifier 138a is supplied to the first and third feeding points 110a and 111a.
  • Reference numeral 141a denotes a first current introduction terminal attached to the wall of the vacuum vessel 100, which keeps the vacuum vessel airtight and connects the first coaxial cable 140a and the third coaxial cable 142a.
  • Reference numeral 140b denotes a second coaxial cable, together with a second connection conductor 115b and a fourth connection conductor 116b, through a second current introduction terminal 141b, a fourth coaxial cable 142b, and a second core wire 143b, which will be described later.
  • the output of the second amplifier 138b is supplied to the second and fourth feeding points 110b and 111b.
  • Reference numeral 141b denotes a second current introduction terminal attached to the wall of the vacuum vessel 100, which keeps the vacuum vessel airtight and connects the second coaxial cable 140b and the fourth coaxial cable 142b.
  • the first amplifier 138a is accompanied by a monitor of an output value (traveling wave) (not shown) and a monitor of a reflected wave that returns from the downstream side. Further, an isolator for protecting the electric circuit of the main body of the first power amplifier 138a by the reflected wave is attached.
  • the impedance is adjusted as follows. That is, the reactance (L and C) of the first matching unit 139a is adjusted while observing the traveling wave Pf and reflected wave Pr detectors attached to the first amplifier 138a. While adjusting the reactance (L and C) of the first matching unit 139a, a condition is selected in which the reflected wave Pr becomes the minimum value.
  • the output of the first amplifier 138a is set to a required value, and the reflected wave Pr becomes the minimum value while adjusting the reactance (L and C) of the first matching device 139a again with the output.
  • the adjustment of the matching unit that is, the condition under which the reflected wave Pr becomes the minimum value does not change unless the plasma generation condition is changed, and therefore does not require much time.
  • the function of the second amplifier 138b will be supplementarily described.
  • the second amplifier 138b is attached with a monitor of an output value (traveling wave) (not shown) and a monitor of a reflected wave that is reflected and returned from the downstream side. Further, an isolator for protecting the electric circuit of the second power amplifier 138b main body due to the reflected wave is attached.
  • the impedance is adjusted as follows. That is, the reactance (L and C) of the second matching unit 139b is adjusted while observing the traveling wave Pf and reflected wave Pr detectors attached to the second amplifier 138b. While adjusting the reactance (L and C) of the second matching unit 139b, a condition is selected in which the reflected wave Pr becomes a minimum value.
  • the output of the second amplifier 138b is set to a required value, and the reflected wave Pr becomes the minimum value while adjusting the reactance (L and C) of the second matching device 139b again with the output.
  • the adjustment of the matching unit that is, the condition under which the reflected wave Pr becomes the minimum value does not change unless the plasma generation condition is changed, and therefore does not require much time.
  • reference numeral 120b denotes a raw material for the zinc oxide film, for example, trimethyl zinc (CH 3 ) 3 Zn, triethyl zinc (C 2 H 5 ) 3 Zn, or diethyl zinc (C 2 H 5 ) 2 Zn. .
  • trimethyl zinc (CH 3 ) 3 Zn is used.
  • Reference numeral 121b denotes a raw material container for the zinc oxide film, which is used in combination with the raw material temperature control device 122b.
  • the temperature adjusting device 122b maintains the temperature of the container 121b at an arbitrary temperature in the range of 55 to 80 ° C., for example, 65 ° C.
  • Reference numeral 123b is a carrier gas supply source of the raw material for the zinc oxide film, and for example, a cylinder such as hydrogen gas or argon gas is used.
  • Reference numeral 124b is a carrier gas flow meter mixed in the raw material of the zinc oxide film, and the required gas flow rate can be controlled.
  • Reference numeral 125b denotes a carrier gas supply pipe for the raw material of the zinc oxide film, which supplies the carrier gas from the carrier gas supply source 123b to the raw material container 121b for the zinc oxide film.
  • Reference numeral 126b denotes a zinc oxide film raw material supply pipe, which supplies the mixed gas of the zinc oxide film raw material and the carrier gas generated in the container 121b to the gas mixing box 105 via the raw material gas supply unit 132.
  • Reference numeral 127b denotes a heater, which is 10 to 30 ° C. higher than the temperature adjustment device 122b so that the mixed gas of the zinc oxide film source gas and the carrier gas flowing inside the zinc oxide film source supply pipe 126b does not condense. Hold at 90 ° C.
  • Reference numeral 131b denotes a gas flow rate adjusting device that can control the flow rate of the mixed gas of the raw material gas of the zinc oxide film and the carrier gas to a required flow rate.
  • the pressure of the carrier gas flowing into the container 121b is set to 1 atm, for example, and is monitored by a pressure sensor (not shown).
  • the pressure of the carrier gas saturated with the organic metal flowing out from the container 121b is monitored by a pressure sensor (not shown).
  • a valve (not shown) installed in the carrier gas first supply pipe 125b and a control device (not shown) are automatically operated. Thus, backflow of the organic metal is prevented.
  • the zinc oxide film raw material 120b, the zinc oxide film raw material container 121b, the temperature adjusting device 122b, the zinc oxide film raw material carrier gas supply source 123b, and the zinc oxide film raw material carrier gas supply pipe 124b An organometallic material supply device including the gas flow rate adjusting device 131b and the zinc oxide film material supply pipe 126b is referred to as a zinc oxide film material supply device.
  • reference numeral 120c denotes a doping material for a zinc oxide film.
  • a doping material for a zinc oxide film For example, trimethylgallium (CH 3 ) 3 Ga, triethylgallium (C 2 H 5 ) 3 Ga, trimethylaluminum (CH 3 ) 3 Al, and triethylaluminum ( C 2 H 5 ) 3 Al.
  • trimethylgallium (CH 3 ) 3 Ga is used.
  • Reference numeral 121c denotes a container for the doping material, which is used in combination with the temperature adjusting device 122c for the material. The temperature adjusting device 122c maintains the temperature of the container 121c at an arbitrary temperature within the range of 60 to 90 ° C., for example, 70 ° C.
  • Reference numeral 123c denotes a carrier gas supply source of a doping material.
  • a carrier gas supply source for example, a cylinder such as hydrogen gas or argon gas is used.
  • Reference numeral 124c is a carrier gas flow meter, which can control a required gas flow rate.
  • Reference numeral 125c is a doping material carrier gas supply pipe for supplying the carrier gas from the carrier gas supply source 123c to the doping material container 121c.
  • Reference numeral 126c is a supply pipe for a mixed gas of a doping material and a carrier gas, and the mixed gas of an oxidizing doping material gas and a carrier gas generated in the container 121c.
  • the gas is supplied to the gas mixing box 105 via the source gas supply unit 132.
  • Reference numeral 127c is a heater, and is maintained at 10 to 30 ° C., for example, 90 ° C. higher than the temperature adjusting device 122c so that the mixed gas of the doping material gas and the carrier gas flowing inside the doping material gas supply pipe 126c does not condense.
  • Reference numeral 131c denotes a gas flow rate adjusting device that can control the flow rate of the mixed gas of the doping material gas and the carrier gas to a required flow rate.
  • the pressure of the carrier gas flowing into the container 121c is set to 1 atm, for example, and is monitored by a pressure sensor (not shown).
  • the pressure of the carrier gas saturated with the organic metal flowing out from the container 121c is monitored by a pressure sensor (not shown).
  • a valve (not shown) installed in the carrier gas first supply pipe 125c and a control device (not shown) are automatically operated. Thus, backflow of the organic metal is prevented.
  • An organometallic material supply device including the gas supply pipe 126c is referred to as a zinc oxide film doping material supply device.
  • Reference numeral 133b denotes a flow path opening / closing valve, and when opened, the organic metal source gas and doping gas flowing in the source gas supply pipes 126b and 126c are passed through the source gas supply unit 132 on the downstream side. Supply to the mixing box 105. When the flow path opening / closing valve 133b is closed, the organometallic source gas flowing in the source gas supply pipes 126b and 126c is discharged toward an exhaust line (not shown).
  • the pressure in the vacuum vessel 100 is monitored by a pressure gauge (not shown).
  • the pressure in the vacuum vessel 100 is adjusted to a predetermined value by adjusting the flow meters 124b, 131b, 124c, 131c, and 129, and the exhaust amount of a vacuum pump (not shown) is automatically set to a predetermined value. By adjusting, the required pressure is set.
  • the pressure is 0.01 Torr to 10 Torr (1. 33 Pa to 1330 Pa).
  • the vacuum ultimate pressure of the vacuum vessel 1 is about 2 to 3E-7 Torr (2.66 to 3.99E-5 Pa).
  • the method described here is a preliminary film formation test (preliminary production) required for grasping the film forming conditions of each of the amorphous titanium oxide film, the crystalline titanium oxide film, and the crystalline zinc oxide film and the film forming speed under those conditions.
  • glass having a size of 1.5 mx 0.25 mx 4 mm in thickness is previously placed on the second electrode 103 as a substrate 108 using a substrate lifter 112 and a substrate carry-in / out gate 118 (not shown).
  • the substrate heater 102 sets the temperature of the substrate 108 in a range of 50 to 450 ° C., for example, 200 ° C.
  • the vacuum pump which is not illustrated is operated and the impurity gas etc. in the vacuum vessel 1 are removed.
  • the pressure in the vacuum vessel 100 is set in the range of 0.01 Torr to 1 Torr (1.33 Pa to 133 Pa), for example, 0.05 Torr (6.65 Pa) by the pressure adjusting device.
  • the temperature of the TTIP container 121a and the titanium oxide film material (TTIP) 120a is set to 70 to 90 ° C., for example, 70 ° C. by the temperature adjusting device 122a, and argon gas supplied from the TTIP carrier gas supply source 123a is used.
  • 400 sccm is set to 300 to 800 sccm with the flowmeter 124a of the carrier gas of TTIP.
  • the flow rate of the gas flow rate adjusting device 131a is set to 800 sccm. Then, in the TTIP container 121a, the TTIP raw material is bubbled with the argon gas as the carrier gas and vaporized. The vaporized mixed gas of TTIP raw material and argon gas is supplied to the flow path opening / closing valve 133a via the gas flow rate adjusting device 131a. Further, the temperature of the gas mixing box 105 and the first electrode 101 is previously set to 80 to 100 ° C., for example, 90 ° C. by the source gas temperature adjusting device 109.
  • the flow rate of the flow meter 129 of the oxygen gas supply device is set to 300 to 800 sccm, for example, 400 sccm. Then, oxygen at a flow rate of 400 sccm is supplied from the oxygen gas supply pipe 130 to the gas mixer 105.
  • a sine wave having a frequency of 13.56 MHz, for example, is generated from the transmitter 135, and the signal is divided into two by a distributor 136, one of which is a first power amplifier via a phase adjustment device 137.
  • the first and third feeding points 110a and 111a are amplified using the first impedance matching unit 139a, the first coaxial cable 140a, the first current introduction terminal 141a, the first core wire 143a, and the like.
  • the other signal is amplified by the second power amplifier 138b, and the second impedance matching unit 139b, the second coaxial cable 140b, the second current introduction terminal 141b, the second core wire 143b, and the like are used. 2 and the fourth feeding points 110b and 111b.
  • the outputs of the first and second power amplifiers 138a and 138b are set in the range of 0.5 to 2 kW, for example, 1.5 kW.
  • the intensity of the plasma between the pair of electrodes generated by the two supplied electric powers is proportional to the power intensity distribution shown below. That is, the power W 11 (t) expressed by the following equation is expressed between the first and third feeding points 110a and 111a, and is expressed by the following equation between the second and fourth feeding points 110b and 111b. Electric power W 12 (t) is supplied.
  • W 11 (t) Asin ( ⁇ t + ⁇ 1 )
  • W 12 (t) Asin ( ⁇ t + ⁇ 2 )
  • A an amplitude
  • ⁇ an angular frequency
  • t time
  • ⁇ 1 and ⁇ 2 are initial phases.
  • the power intensity between the pair of electrodes has a distribution of I (x, t) expressed by the following equation.
  • I (x, t) ⁇ cos 2 ⁇ 2 ⁇ (x ⁇ L0 / 2) / ⁇ / 2 ⁇
  • ⁇ is the wavelength of power
  • L0 the length of the electrode
  • ⁇ ⁇ 1 ⁇ 2 .
  • the reflected wave of the supplied power is prevented from returning to the upstream side of the respective impedance matching units 139a and 139b.
  • the flow path opening / closing valve 133a is opened.
  • the mixed gas of the carrier gas and the TTIP gas supplied from the upstream side is supplied to the gas mixing box 105 through the source gas supply unit 132.
  • a mixed gas of carrier gas and TTIP gas supplied from the titanium oxide film raw material (TTIP) supply device for example, 800 sccm
  • oxygen gas supplied from the oxygen gas supply device for example, 400 sccm
  • plasma of a mixed gas of carrier gas, TTIP gas, and oxygen is generated between the pair of electrodes 101 and 103.
  • the mixed gas of carrier gas, TTIP gas, and oxygen is plasmized, oxygen radicals and radicals including titanium are generated by plasma chemical reaction.
  • Various radicals in the plasma diffuse from a higher concentration to a lower concentration due to a diffusion phenomenon.
  • an amorphous titanium oxide film, a microcrystalline titanium oxide film, or a crystalline titanium oxide film is deposited on the glass substrate.
  • the substrate temperature is set to 10 to 30 minutes, for example, with the substrate temperature, the flow rate of the carrier gas, and the flow rate of oxygen gas as parameters. Then, a titanium oxide film is formed. After the film formation, the substrate 108 is taken out from the vacuum vessel 100, and the film quality and film thickness of the formed titanium oxide film are evaluated. For the evaluation of the film quality, laser Raman spectroscopy, scanning electron microscope (SEM), high resolution transmission electron microscope (TEM), secondary ion mass spectrometry (SIMS), or the like is used. The film thickness is measured with a scanning electron microscope (SEM), a step meter, or a spectroscopic ellipsometer.
  • SEM scanning electron microscope
  • TEM high resolution transmission electron microscope
  • SIMS secondary ion mass spectrometry
  • the substrate 108 is made of glass and the temperature of the substrate 108 is set in the range of 100 to 250 ° C., all films formed on the glass substrate 108 are non-coated.
  • the result is a crystalline titanium oxide. That is, the film forming speed depends on the high frequency power, the flow rate of the TTIP raw material, the flow rate of the carrier gas, and the pressure, but the film quality of the formed titanium oxide film is amorphous as shown in FIG. become.
  • the horizontal axis represents the film formation time
  • the vertical axis represents the film thickness and film quality, so that the titanium oxide film obtained when the substrate is glass and the substrate temperature is 100 to 250 ° C.
  • the film formation rate of amorphous titanium oxide is as follows under the above test conditions, that is, the flow rate of the mixed gas of the carrier gas and the TTIP raw material is 800 sccm, the flow rate of oxygen gas is 400 sccm, the pressure is 0.05 Torr (6.65 Pa), and the high frequency power is 1 In the case of .5 KW, about 10 nm / min is obtained.
  • the film forming speed can be improved by increasing the high-frequency power and the raw material gas.
  • the film formed on the glass substrate 108 is As shown in FIG. 5, amorphous titanium oxide is used up to a film thickness of several tens of nm at the initial stage of film formation. Amorphous titanium oxide is amorphous over the amorphous titanium oxide in a film thickness of several tens of nm. Titanium oxide in a mixed phase of quality and microcrystal is formed. A crystalline titanium oxide film is formed on the mixed phase titanium oxide.
  • amorphous titanium oxide is used up to a film thickness of several tens of nm at the initial stage of film formation.
  • Amorphous titanium oxide is amorphous over the amorphous titanium oxide in a film thickness of several tens of nm. Titanium oxide in a mixed phase of quality and microcrystal is formed. A crystalline titanium oxide film is formed on the mixed phase titanium oxide.
  • the horizontal axis represents the film formation time and the vertical axis represents the film thickness and film quality, so that the titanium oxide film obtained when the substrate is glass and the substrate temperature is 250 to 380 ° C. as the film formation conditions.
  • the characteristics are shown.
  • the film formation rate of crystalline titanium oxide is as follows under the above test conditions, that is, a flow rate of 800 sccm of a mixed gas of carrier gas and TTIP raw material, a flow rate of 400 sccm of oxygen gas, a pressure of 0.05 Torr (6.65 Pa), and a high frequency power of 1. In the case of 5 KW, about 10 nm / min is obtained.
  • the film forming speed can be improved by increasing the high-frequency power and the raw material gas.
  • the film formed on the glass substrate 108 As shown in FIG. 6, in the initial film thickness of 3 to 10 nm, a mixed phase of amorphous and microcrystalline titanium oxide is formed, on which crystalline titanium oxide is formed. Is formed.
  • the horizontal axis represents the film formation time and the vertical axis represents the film thickness and film quality, so that the titanium oxide film obtained when the substrate is glass and the substrate temperature is 380 to 450 ° C. as the film formation conditions. The characteristics are shown.
  • the film formation rate of crystalline titanium oxide is as follows under the above test conditions, that is, a flow rate of 800 sccm of a mixed gas of carrier gas and TTIP raw material, a flow rate of 400 sccm of oxygen gas, a pressure of 0.05 Torr (6.65 Pa), and a high frequency power of 1. In the case of 5 KW, about 20 nm / min is obtained. In addition, the film forming speed can be improved by increasing the high-frequency power and the raw material gas.
  • the substrate 108 is made of glass, on which amorphous titanium oxide having a film thickness of several nm to 50 nm, or amorphous and microcrystalline 7 is formed by forming the mixed phase titanium oxide or crystalline titanium oxide, and setting the temperature condition of the substrate 108 in the range of 350 to 450 ° C. to form titanium oxide.
  • a crystalline titanium oxide film is obtained.
  • the horizontal axis indicates the film forming time
  • the vertical axis indicates the film thickness and film quality.
  • the base is an amorphous titanium oxide film, a microcrystalline titanium oxide film, or a crystalline oxide.
  • the characteristics of the titanium oxide film obtained when the substrate temperature is 350 to 450 ° C. with a titanium film are shown.
  • the film formation rate of crystalline titanium oxide is as follows under the above test conditions, that is, the flow rate of the mixed gas of the carrier gas and the TTIP raw material is 800 sccm, the flow rate of oxygen gas is 400 sccm, the pressure is 0.05 Torr (6.65 Pa), and the high-frequency power is 1 KW. In the case, about 20 nm / min is obtained.
  • the film forming speed can be improved by increasing the high-frequency power and the raw material gas.
  • a glass substrate having a size of 1.5 mx 0.25 mx 4 mm in thickness, on which a crystalline titanium oxide film is formed on the surface of the substrate in advance, is used as a substrate 108 using a substrate lifter 112 and a substrate carry-in / out gate 118 (not shown). And placed on the second electrode 103. Then, the temperature of the substrate 108 is set in the range of 200 to 450 ° C., for example, 300 ° C. by the substrate heater 102 (not shown). And the vacuum pump which is not illustrated is operated and the impurity gas etc. in the vacuum vessel 1 are removed. Further, the pressure in the vacuum vessel 100 is set in the range of 0.01 Torr to 1 Torr (1.33 Pa to 133 Pa), for example, 0.05 Torr (6.65 Pa) by the pressure adjusting device.
  • the flow path opening / closing valve 133b is closed in advance, and the mixed gas of the source gas and the doping gas supplied from the upstream zinc oxide film source supply device and the zinc oxide film doping material supply device is exhausted.
  • the temperature of the container 121b and the zinc oxide film material 120b of the zinc oxide film material supply apparatus is set to an arbitrary temperature in the range of 55 to 80 ° C., for example, 65 ° C.
  • the hydrogen gas supplied from the source 123b is set to 300 to 800 sccm, for example, 400 sccm by the carrier gas flow meter 124b.
  • the flow rate of the gas flow rate adjusting device 131b is set to 800 sccm. Then, in the container 121b, the zinc oxide raw material is bubbled by the carrier gas hydrogen gas and vaporized. The vaporized mixed gas of raw material and hydrogen gas is supplied to the flow path opening / closing valve 133b via the gas flow rate adjusting device 131b. Further, the temperature of the gas mixing box 105 and the first electrode 101 is previously set to 80 to 100 ° C., for example, 90 ° C. by the source gas temperature adjusting device 109.
  • the temperature of the container 121c and the doping material 120c of the doping material supply device for the zinc oxide film is set to an arbitrary temperature in the range of 60 to 90 ° C., for example, 80 ° C., in a state where the exhaust gas can be exhausted to the exhaust line.
  • the hydrogen gas supplied from the carrier gas supply source 123c is set to 20 to 80 sccm, for example, 35 sccm by the carrier gas flow meter 124c.
  • the flow rate of the gas flow rate adjusting device 131c is set to 70 sccm.
  • the doping material is bubbled by the hydrogen gas as the carrier gas and is vaporized.
  • the vaporized mixed gas of doping material and hydrogen gas is supplied to the flow path opening / closing valve 133b via the gas flow rate adjusting device 131c. Then, the flow rate of the flow meter 129 of the oxygen gas supply device is set to 300 to 800 sccm, for example, 400 sccm. Then, oxygen at a flow rate of 400 sccm is supplied from the oxygen gas supply pipe 130 to the gas mixer 105.
  • a sine wave having a frequency of 13.56 MHz, for example, is generated from the transmitter 135, and the signal is divided into two by a distributor 136, one of which is passed through a phase adjustment device 137.
  • the first and third power feedings are amplified by the first power amplifier 138a and using the first impedance matching unit 139a, the first coaxial cable 140a, the first current introduction terminal 141a, the first core wire 143a, and the like.
  • the points 110a and 111a are supplied.
  • the other signal is amplified by the second power amplifier 138b, and the second impedance matching unit 139b, the second coaxial cable 140b, the second current introduction terminal 141b, the second core wire 143b, and the like are used.
  • the outputs of the first and second power amplifiers 138a and 138b are set in the range of 0.5 to 2 kW, for example, 1.5 kW.
  • the intensity of the plasma between the pair of electrodes generated by the two supplied electric powers is proportional to the power intensity distribution shown below. That is, the power W 11 (t) expressed by the following equation is expressed between the first and third feeding points 110a and 111a, and is expressed by the following equation between the second and fourth feeding points 110b and 111b. Electric power W 12 (t) is supplied.
  • W 11 (t) Asin ( ⁇ t + ⁇ 1 )
  • W 12 (t) Asin ( ⁇ t + ⁇ 2 )
  • A an amplitude
  • ⁇ an angular frequency
  • t time
  • ⁇ 1 and ⁇ 2 are initial phases.
  • the power intensity between the pair of electrodes has a distribution of I (x, t) expressed by the following equation.
  • I (x, t) ⁇ cos 2 ⁇ 2 ⁇ (x ⁇ L0 / 2) / ⁇ / 2 ⁇
  • ⁇ is the wavelength of power
  • L0 the length of the electrode
  • ⁇ ⁇ 1 ⁇ 2 .
  • the reflected wave of the supplied power is prevented from returning to the upstream side of the respective impedance matching units 139a and 139b.
  • the flow path opening / closing valve 133b is opened. Then, the mixed gas of the carrier gas and the zinc oxide source gas supplied from the zinc oxide film source supply device is set to 800 sccm, for example.
  • the flow rates of the carrier gas and the doping gas supplied from the doping material supply device for the zinc oxide film are set to 70 sccm, for example.
  • the flow rate of the oxygen gas supplied from the oxygen gas supply device is set to 400 sccm, for example. As a result, the above flow rate, for example 1270 sccm, flows out from the gas shower 106 between the pair of electrodes 101 and 103.
  • plasma of a mixed gas of a carrier gas, a zinc oxide raw material, a doping material, and oxygen is generated between the pair of electrodes 101 and 103.
  • a mixed gas of a carrier gas, a zinc oxide raw material, a doping material, and oxygen is plasmized, various radicals including oxygen radicals and zinc radicals are generated by plasma chemical reaction.
  • Various radicals in the plasma diffuse from a higher concentration to a lower concentration due to a diffusion phenomenon.
  • a Ga-doped crystalline zinc oxide film is deposited on a glass substrate on which titanium oxide is formed as an underlayer.
  • the substrate 108 is taken out from the vacuum vessel 100, and the film quality and film thickness of the formed zinc oxide film are evaluated.
  • laser Raman spectroscopy, scanning electron microscope (SEM), high resolution transmission electron microscope (TEM), secondary ion mass spectrometry (SIMS), or the like is used.
  • Conductivity is measured using a conductivity meter.
  • a measuring instrument defined in JIS B0601 is used for the surface roughness.
  • the film thickness is measured with a scanning electron microscope (SEM), a step meter, or a spectroscopic ellipsometer.
  • the substrate 108 is a glass plate on which a titanium oxide film having a thickness of 20 nm or more is formed, and the temperature of the substrate 108 is set in a range of 200 to 400 ° C.
  • the film forming speed depends on the high-frequency power, the flow rate of the raw material, the flow rate of the carrier gas, and the pressure, but the film quality of the zinc oxide film to be formed becomes crystalline as shown in FIG. .
  • the horizontal axis indicates the film forming time
  • the vertical axis indicates the film thickness and film quality.
  • the base is a crystalline titanium oxide film and the substrate temperature is 200 to 400 ° C.
  • membrane obtained is shown. Further, the unevenness of the surface of the zinc oxide film to be formed is about 20 to 140 nm in terms of arithmetic average roughness defined by JIS B0601.
  • the film formation rate of the crystalline zinc oxide is the same as in the above test conditions, that is, the flow rate of the mixed gas of the carrier gas and the zinc oxide raw material is 800 sccm, the flow rate of the oxygen gas is 400 sccm, the flow rate of the mixed gas of the carrier gas and the doping gas is 70 sccm, and the pressure In the case of 0.05 Torr (6.65 Pa) and high frequency power of 1.5 kW, about 50 nm / min is obtained.
  • the film forming speed can be improved by increasing the high-frequency power and the raw material gas.
  • the specific resistance of crystalline zinc oxide is 5 to 14 ⁇ 10 ⁇ 4 ⁇ ⁇ cm under the above test conditions. Note that the conductivity of the zinc oxide film depends on how the doping material is supplied, so it is necessary to optimize the conditions.
  • a film forming test (manufacturing process) of the thin film solar cell substrate 1a according to the first embodiment of the present invention will be described.
  • a thin film solar cell substrate 1a according to the first embodiment of the present invention shown in FIG. 1 is manufactured based on the result of the preliminary film forming test (preliminary film forming step). The procedure will be described below.
  • an amorphous titanium oxide layer 4a and a crystalline titanium oxide layer 4b are stacked on a glass substrate 2, and a crystalline oxide layer is formed on the crystalline titanium oxide layer 4b. It has a structure in which the zinc layer 5 is laminated.
  • the film thickness is set in the range of 10 to 50 nm, for example, 20 nm.
  • the crystalline titanium oxide layer 4b has a thickness in the range of 20 to 200 nm as an underlayer for providing an effect of promoting crystal growth of the crystalline zinc oxide 5 laminated on the film. For example, it is set to 100 nm.
  • the crystalline zinc oxide layer 5 has a characteristic necessary as a substrate for a thin film solar cell, that is, a film having an uneven structure, a high conductivity and a high light transmittance.
  • the thickness is set in the range of 200 to 2000 nm, for example, 800 nm. If the thickness is less than about 200 nm, the crystal grain size of the zinc oxide film to be formed is not sufficient. It may not be. On the other hand, when the film thickness exceeds about 2000 nm, the film forming time becomes longer and the cost is increased, and there is a problem that the light transmittance is lowered.
  • the amorphous titanium oxide layer 4a having a thickness of 20 nm is formed using a high-frequency plasma CVD apparatus for manufacturing a titanium oxide (TiO 2) film according to the first embodiment of the present invention shown in FIG. .
  • a high-frequency plasma CVD apparatus for manufacturing a titanium oxide (TiO 2) film according to the first embodiment of the present invention shown in FIG. .
  • the results of the preliminary film forming shown in FIGS. 4 and 6 are referred to.
  • a substrate 108 glass having a size of 1.5 mx 0.25 mx 4 mm in thickness is placed on the second electrode 103 using a substrate lifter 112 and a substrate carry-in / out gate 118 (not shown).
  • the interval between the pair of electrodes 101 and 103 is set to 25 mm.
  • the substrate heater 102 sets the temperature of the substrate 108 in a range of 50 to 450 ° C., for example, 200 ° C.
  • the vacuum pump which is not illustrated is operated and the impurity gas etc. in the vacuum vessel 1 are removed.
  • the pressure in the vacuum vessel 100 is set to a range of 0.01 Torr to 1 Torr (1.33 Pa to 133 Pa), for example, 0.05 Torr (6.65 Pa) by the pressure adjusting device.
  • the amorphous titanium oxide layer 4a is formed in the same manner as in the case of forming the amorphous titanium oxide layer in the preliminary film forming test (preliminary film forming step).
  • the flow rate of the mixed gas of the carrier gas and the TTIP raw material is set to 800 sccm
  • the flow rate of the oxygen gas is set to 400 sccm
  • the high-frequency power is 1.5 kW.
  • the film formation time is 2 minutes.
  • the amorphous titanium oxide layer to be formed generally follows the characteristics shown in FIG.
  • the film forming speed in the preliminary film forming test is 10 nm / min
  • an amorphous titanium oxide layer 4 a having a film thickness of 20 nm is formed on the glass substrate 108.
  • the crystalline titanium oxide layer 4a is formed in the same manner as in the case of forming the crystalline titanium oxide layer in the preliminary film forming test (preliminary film forming step).
  • the substrate temperature is set to 390 ° C.
  • the flow rate of the mixed gas of the carrier gas and the TTIP material is set to 800 sccm
  • the flow rate of the oxygen gas is set to 400 sccm
  • the high frequency power is 1.5 kW.
  • the film forming time is 5 minutes.
  • the amorphous titanium oxide layer to be formed generally follows the characteristics shown in FIG.
  • the film-forming speed of the crystalline titanium oxide layer in the preliminary film-forming test is 20 nm / min, so that the upper surface of the amorphous titanium oxide layer 4a formed on the glass substrate 108 is Then, a crystalline titanium oxide layer 4b having a thickness of 100 nm is formed.
  • the crystalline zinc oxide layer 5 is formed in the same manner as in the case of forming the crystalline zinc oxide layer in the preliminary film forming test (preliminary film forming step).
  • the substrate temperature is set to 350 ° C.
  • the flow rate of the mixed gas of the carrier gas and the raw material is set to 800 sccm
  • the flow rate of the oxygen gas is set to 400 sccm
  • the flow rate of the mixed gas of the carrier gas and the doping material gas is set to 70 sccm. .5KW.
  • the film formation time is 16 minutes.
  • the formed crystalline zinc oxide layer generally follows the characteristics shown in FIG.
  • the film forming speed of the crystalline zinc oxide layer in the preliminary film forming test is 50 nm / min.
  • the amorphous titanium oxide layer 4a laminated on the glass substrate 108 and the crystalline A 800 nm-thick Ga-doped crystalline zinc oxide layer 5 is formed on the titanium oxide layer 4b.
  • the pressure in the vacuum vessel 100 is returned to atmospheric pressure, and an amorphous titanium oxide layer 4a, a crystalline titanium oxide layer 4b, and a Ga-doped crystalline zinc oxide are used using a substrate carry-in / out gate 118 (not shown).
  • the glass substrate 108 on which the layer 5 is laminated is taken out. As a result, a required thin film solar cell substrate 1a is obtained.
  • the substrate size of the first electrode 101 is 1.5 mx width 0.3 mx 20 mm in thickness
  • the substrate size is limited to the glass substrate of 1.5 mx 0.25 mx 4 mm in thickness.
  • the width of the substrate size can be increased by increasing the number of the pair of electrodes including the first and second electrodes 101 and 103.
  • the obtained thin film solar cell substrate 1a is an amorphous silicon solar cell or a tandem thin film solar cell (a thin film solar cell in which an amorphous silicon power generation layer and a microcrystalline silicon power generation layer are stacked in order from the light incident side). Applied. The application will be described below. In addition, the manufacturing method of an amorphous silicon solar cell or a tandem-type thin film solar cell is publicly known. In application to amorphous silicon solar cell production, as shown in FIG.
  • the thin film solar cell substrate 1 a that is, the amorphous titanium oxide layer 4 a sequentially laminated on the glass substrate 2, and crystalline titanium oxide
  • An amorphous p layer 6 having a film thickness of 7 to 15 nm, for example, 10 nm, and a film thickness are formed on a substrate composed of the layer 4b and the Ga-doped crystalline zinc oxide layer 5 by a plasma CVD method at a film forming temperature of 170 to 250 ° C.
  • An amorphous i layer 7 having a thickness of 150 to 400 nm, for example, 300 nm, and an amorphous n layer 8 having a thickness of 5 to 30 nm, for example, 20 nm are stacked.
  • a Ga-doped ZnO layer 9 having a film thickness of 10 to 100 nm, for example, 15 nm, and an Ag back electrode 10 having a film thickness of 100 to 300 nm, for example, 200 nm are laminated at a film formation temperature of 200 to 300 ° C. by sputtering.
  • a film formation temperature of 200 to 300 ° C. by sputtering.
  • the amorphous titanium oxide layer 4a sequentially laminated on the thin film solar cell substrate 1a, that is, the glass substrate 2, and the crystalline oxidation
  • An amorphous p layer 6 having a film thickness of 7 to 15 nm, for example, 10 nm, and a film are formed on a substrate composed of the titanium layer 4b and the Ga-doped crystalline zinc oxide layer 5 by a plasma CVD method at a film forming temperature of 170 to 250 ° C.
  • An amorphous i layer 7 having a thickness of 150 to 400 nm, for example, 300 nm, and an amorphous n layer 8 having a thickness of 5 to 30 nm, for example, 20 nm are stacked.
  • a microcrystalline n layer 14 having a thickness of 5 to 30 nm, for example, 20 nm is stacked.
  • a Ga-doped ZnO layer 9 having a film thickness of 20 to 100 nm, for example, 40 nm, and an Ag back electrode 10 having a film thickness of 100 to 300 nm, for example, 200 nm are stacked at a film forming temperature of 200 to 300 ° C. by sputtering.
  • a tandem-type thin film solar cell having a good performance with a stabilized power generation efficiency of 13 to 14.5%.
  • FIG. 11 is a structural diagram schematically showing a cross section of a thin-film solar cell substrate according to the second embodiment of the present invention.
  • reference numeral 2 denotes a translucent insulating substrate, for example, a glass substrate having a thickness of 4 to 5 mm.
  • Reference numeral 3b denotes a titanium oxide layer, which is an amorphous titanium oxide layer 4a and a titanium oxide film in which amorphous titanium oxide and crystalline titanium oxide are mixed (here, amorphous titanium oxide and crystalline titanium oxide). (Referred to as a mixed phase titanium oxide film) and a crystalline titanium oxide layer 4b.
  • Amorphous titanium oxide layer 4a, crystalline titanium oxide layer 4b, amorphous titanium oxide, and mixed phase titanium oxide 4c of crystalline titanium oxide are all formed by the above-described high-frequency plasma CVD apparatus shown in FIG. Is done.
  • Reference numeral 5 denotes a crystalline zinc oxide (ZnO) film layer. This crystalline zinc oxide (ZnO) film layer is formed by the above-described high-frequency plasma CVD apparatus shown in FIG. In addition, the crystalline zinc oxide (ZnO) film layer 5 may be formed by using a sputtering apparatus.
  • a thin film solar cell substrate 1b shown in FIG. 11 includes an amorphous titanium oxide layer 4a, a mixed phase titanium oxide 4c of amorphous titanium oxide and crystalline titanium oxide, and a crystalline titanium oxide layer on a glass substrate 2. 4b is laminated, and the crystalline zinc oxide layer 5 is laminated on the crystalline titanium oxide layer 4b.
  • the film thickness is set in the range of 10 to 50 nm, for example, 40 nm. To do. Further, the film thickness of the mixed phase titanium oxide 4c of amorphous titanium oxide and crystalline titanium oxide is utilized without being particularly controlled.
  • the crystalline titanium oxide layer 4b has a thickness in the range of 20 to 200 nm as an underlayer for providing an effect of promoting crystal growth of the crystalline zinc oxide 5 laminated on the film. For example, it is set to 100 nm.
  • the crystalline zinc oxide layer 5 has a characteristic necessary as a substrate for a thin film solar cell, that is, a film having an uneven structure, a high conductivity and a high light transmittance.
  • the thickness is set in the range of 200 to 2000 nm, for example, 800 nm. If the thickness is less than about 200 nm, the size of the crystal grains to be formed is not sufficient, and as a result, the surface roughness, which is one measure of the concavo-convex structure, does not fall within the arithmetic average roughness of 15 to 150 nm. is there. On the other hand, when the film thickness exceeds about 2000 nm, the film forming time becomes longer and the cost is increased, and there is a problem that the light transmittance is lowered.
  • the amorphous titanium oxide layer 4a having a thickness of 40 nm is formed using a high frequency plasma CVD apparatus for manufacturing a titanium oxide (TiO2) film shown in FIG. Regarding the film forming conditions, the results of the preliminary film forming shown in FIGS. 4 and 5 are referred to.
  • a substrate 108 glass having a size of 1.5 mx 0.25 mx 4 mm in thickness is placed on the second electrode 103 using a substrate lifter 112 and a substrate carry-in / out gate 118 (not shown). In this case, the interval between the pair of electrodes 101 and 103 is set to 25 mm.
  • the substrate heater 102 sets the temperature of the substrate 108 in a range of 50 to 450 ° C., for example, 200 ° C.
  • the vacuum pump which is not illustrated is operated and the impurity gas etc. in the vacuum vessel 1 are removed.
  • the pressure in the vacuum vessel 100 is set to a range of 0.01 Torr to 1 Torr (1.33 Pa to 133 Pa), for example, 0.05 Torr (6.65 Pa) by the pressure adjusting device.
  • the amorphous titanium oxide layer 4a is formed in the same manner as in the case of forming the amorphous titanium oxide layer in the preliminary film forming test (preliminary film forming step).
  • the flow rate of the mixed gas of the carrier gas and the TTIP raw material is set to 800 sccm
  • the flow rate of the oxygen gas is set to 400 sccm
  • the high-frequency power is 1.5 kW.
  • the film formation time is 4 minutes.
  • the amorphous titanium oxide layer to be formed generally follows the characteristics shown in FIG.
  • the film forming speed in the preliminary film forming test is 10 nm / min
  • an amorphous titanium oxide layer 4 a having a film thickness of 40 nm is formed on the glass substrate 108.
  • the crystalline titanium oxide layer 4a is formed in the same manner as in the case of forming the crystalline titanium oxide layer in the preliminary film forming test (preliminary film forming step).
  • the substrate temperature is set to 350 ° C.
  • the flow rate of the mixed gas of the carrier gas and the TTIP raw material is set to 800 sccm
  • the flow rate of the oxygen gas is set to 400 sccm
  • the high frequency power is 1.5 kW.
  • the film formation time is 10 minutes.
  • the amorphous titanium oxide 4a and crystalline titanium oxide mixed phase titanium oxide 4c to be formed and the crystalline titanium oxide layer 4b generally follow the characteristics shown in FIG.
  • the film-forming speed of the crystalline titanium oxide layer 4b in the preliminary film-forming test is 10 nm / min, so that the amorphous titanium oxide layer 4a formed on the glass substrate 108 is formed.
  • a crystalline titanium oxide layer 3a having a thickness of 100 nm is formed thereon.
  • the crystalline zinc oxide layer 5 is formed in the same manner as in the case of forming the crystalline zinc oxide layer in the preliminary film forming test (preliminary film forming step).
  • the substrate temperature is set to 350 ° C.
  • the flow rate of the mixed gas of the carrier gas and the raw material is set to 800 sccm
  • the flow rate of the oxygen gas is set to 400 sccm
  • the flow rate of the mixed gas of the carrier gas and the doping material gas is set to 70 sccm. .5KW.
  • the film formation time is 16 minutes.
  • the amorphous titanium oxide layer to be formed generally follows the characteristics shown in FIG.
  • the film-forming speed of the crystalline zinc oxide layer in the preliminary film-forming test is 50 nm / min.
  • the amorphous titanium oxide layer 4a laminated on the glass substrate 108 and A 800 nm-thick Ga-doped crystalline zinc oxide layer 5 is formed on the crystalline titanium oxide and the mixed phase titanium oxide 4c of crystalline titanium oxide and the crystalline titanium oxide layer 4b.
  • the pressure in the vacuum vessel 100 is returned to atmospheric pressure, and an amorphous titanium oxide layer 4a and a mixed phase titanium oxide of amorphous titanium oxide and crystalline titanium oxide are used by using a substrate carry-in / out gate 118 (not shown).
  • the glass substrate 108 on which 4c, the crystalline titanium oxide layer 4b and the Ga-doped crystalline zinc oxide layer 5 are laminated is taken out. As a result, the required thin film solar cell substrate 1b is obtained.
  • the substrate temperature is set to 350 ° C.
  • the flow rate of the mixed gas of the carrier gas and the TTIP raw material is set to 800 sccm
  • the flow rate of the oxygen gas is set to 400 sccm
  • the high frequency power is 1.5 kW.
  • the film formation time is 10 minutes.
  • the mixed phase titanium oxide 4c of amorphous titanium oxide and crystalline titanium oxide to be formed and the crystalline titanium oxide layer 4b generally follow the characteristics shown in FIG.
  • an amorphous titanium oxide layer, a mixed phase of amorphous titanium oxide and crystalline titanium oxide, and crystalline titanium oxide are laminated in order from the glass substrate side.
  • the amorphous titanium oxide layer and two layers of a mixed phase of amorphous titanium oxide and crystalline titanium oxide are formed with a thickness of about 10 to 40 nm as a base on the glass substrate side. That is, when the film forming time is relatively long, most of the upper layer is a crystalline titanium oxide film.
  • the deposition rate of the crystalline titanium oxide film based on the mixed phase titanium oxide 4c of amorphous titanium oxide and crystalline titanium oxide formed on the amorphous titanium oxide layer is 10 nm / min. Therefore, if the film forming time is 10 minutes, the film thickness is 100 nm.
  • a thin film solar cell substrate according to the second embodiment of the present invention is obtained by forming a zinc oxide film on the crystalline titanium oxide film having a thickness of 100 nm.
  • the substrate size of the first electrode 101 is 1.5 mx width 0.3 mx 20 mm in thickness
  • the substrate size is limited to the glass substrate of 1.5 mx 0.25 mx 4 mm in thickness.
  • the width of the substrate size can be increased by increasing the number of the pair of electrodes including the first and second electrodes 101 and 103.
  • FIG. 2 a thin film solar cell substrate and a method for manufacturing the same according to a third embodiment of the present invention will be described with reference to FIG. Reference is also made to FIG. 2, FIG. 3 and FIG.
  • FIG. 12 is a structural view schematically showing a cross section of a thin film solar cell substrate according to the third embodiment of the present invention.
  • reference numeral 2 denotes a translucent insulating substrate, for example, a glass substrate having a thickness of 4 to 5 mm.
  • Reference numeral 3c denotes a titanium oxide layer, which is a titanium oxide film in which amorphous titanium oxide and crystalline titanium oxide are mixed (referred to herein as a mixed phase titanium oxide film of amorphous titanium oxide and crystalline titanium oxide). 4c and a crystalline titanium oxide layer 4b.
  • the mixed phase titanium oxide 4c and the crystalline titanium oxide layer 4b of amorphous titanium oxide and crystalline titanium oxide are both formed by the above-described high-frequency plasma CVD apparatus shown in FIG.
  • Reference numeral 5 denotes a crystalline zinc oxide (ZnO) film layer.
  • This crystalline zinc oxide (ZnO) film layer is formed by the above-described high-frequency plasma CVD apparatus shown in FIG.
  • the crystalline zinc oxide (ZnO) film layer 5 may be formed by using a sputtering apparatus.
  • the substrate temperature is set to 390 ° C.
  • the flow rate of the mixed gas of the carrier gas and the TTIP raw material is set to 800 sccm
  • the flow rate of the oxygen gas is set to 400 sccm
  • the high frequency power is 1.5 kW.
  • the film forming time is 5 minutes.
  • the mixed phase titanium oxide layer of amorphous titanium oxide and crystalline titanium oxide and the crystalline titanium oxide layer to be formed generally follow the characteristics shown in FIG. In the structure of the titanium oxide film shown in FIG.
  • a mixed phase titanium oxide layer 4c of amorphous titanium oxide and crystalline titanium oxide and a crystalline titanium oxide 4b are laminated in order from the glass substrate side.
  • the mixed phase titanium oxide layer 4c of amorphous titanium oxide and crystalline titanium oxide is formed with a thickness of about 20 to 40 nm as a base on the glass substrate side. That is, when the film formation time is relatively long, most of the upper layer is the crystalline titanium oxide film 4b. Since the deposition rate of the crystalline titanium oxide film having the mixed phase titanium oxide layer 4c of the amorphous titanium oxide and the crystalline titanium oxide as a base is 20 nm / min, if the deposition time is 5 minutes, The film thickness is 100 nm.
  • a thin film solar cell substrate according to the third embodiment of the present invention is obtained by forming a zinc oxide film 5 on the crystalline titanium oxide film 4b having a thickness of 100 nm.
  • a separate SiO 2 film having a thickness of about 20 to 100 nm is formed between the glass 2 and the mixed phase titanium oxide layer 4c of amorphous titanium oxide and crystalline titanium oxide. It is also possible to form a barrier layer of alkali components and moisture by forming a film.
  • the amorphous titanium oxide and the crystalline titanium oxide are formed on the light transmissive insulating substrate.
  • a substrate for a thin film solar cell in which crystalline zinc oxide having a large crystal grain size doped with Ga or Al is laminated.

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Abstract

L'invenion permet d'obteinr un substrat pour cellule solaire à couche mince économique et dont les performances électriques et optiques sont excellentes comparées à celles d’un substrat pour cellule solaire à couche mince conventionnel (électrode transparente). ’invention concerne un substrat pour cellule solaire à couche mince à structure innovante et un  dispositif et un procédé employés pour sa fabrication.  Un dispositif de CVD à plasma haute fréquence constitué d'un matériau métallique et organique stratifie une pellicule d’électrode transparente constituée d’une structure à trois couches d’une pellicule d’oxyde de titane amorphe, d’une pellicule d’oxyde de titane cristallin, et d’une pellicule d’oxyde de zinc cristallin sur un substrat d’isolation transparent.  Cela permet de fabriquer un substrat pour cellule solaire à couche mince qui est économique, présente un effet de confinement optique (la structure en relief d’une pellicule) et est hautement conducteur et hautement transmetteur de lumière.
PCT/JP2009/055623 2008-04-02 2009-03-23 Substrat pour cellule solaire à couche mince, son procédé de fabrication, et cellule solaire à couche mince l’utilisant WO2009122938A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2008095764A JP2008153714A (ja) 2008-04-02 2008-04-02 薄膜太陽電池用基板及びその製造方法、並びにそれを用いた薄膜太陽電池
JP2008-095764 2008-04-02

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Publication Number Publication Date
WO2009122938A1 true WO2009122938A1 (fr) 2009-10-08

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GB201314699D0 (en) * 2013-08-16 2013-10-02 Pilkington Group Ltd Heat treatable coated glass pane
EP3853908A1 (fr) * 2018-09-24 2021-07-28 First Solar, Inc. Dispositifs photovoltaïques à couches de tco texturées, et procédés de fabrication de piles tco

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