WO2011045989A1 - Method for producing compound semiconductor thin film, solar cell, and device for producing compound semiconductor thin film - Google Patents

Method for producing compound semiconductor thin film, solar cell, and device for producing compound semiconductor thin film Download PDF

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WO2011045989A1
WO2011045989A1 PCT/JP2010/065159 JP2010065159W WO2011045989A1 WO 2011045989 A1 WO2011045989 A1 WO 2011045989A1 JP 2010065159 W JP2010065159 W JP 2010065159W WO 2011045989 A1 WO2011045989 A1 WO 2011045989A1
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thin film
group
compound semiconductor
semiconductor thin
producing
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PCT/JP2010/065159
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French (fr)
Japanese (ja)
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和田　隆博
山添　誠司
山田　明
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学校法人龍谷大学
国立大学法人東京工業大学
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Publication of WO2011045989A1 publication Critical patent/WO2011045989A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
    • H01L31/0256—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by the material
    • H01L31/0264—Inorganic materials
    • H01L31/032—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312
    • H01L31/0322—Inorganic materials including, apart from doping materials or other impurities, only compounds not provided for in groups H01L31/0272 - H01L31/0312 comprising only AIBIIICVI chalcopyrite compounds, e.g. Cu In Se2, Cu Ga Se2, Cu In Ga Se2
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00—Energy generation through renewable energy sources
    • Y02E10/50—Photovoltaic [PV] energy
    • Y02E10/541—CuInSe2 material PV cells
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to a method for manufacturing a compound semiconductor thin film, a solar cell, and a compound semiconductor thin film manufacturing apparatus.
  • Cu (In, Ga) Se 2 (hereinafter also referred to as CIGS) has an optimum band gap and high light absorption coefficient for the absorption of sunlight, and therefore is a promising semiconductor as a light absorption layer of a high-efficiency thin film solar cell. It is a thin film forming material.
  • CIGS thin films used for solar cells are manufactured in Japan, Europe and America using a selenization method or a vapor deposition method.
  • a metal precursor is formed by sputtering, and the metal precursor is selenized with H 2 Se gas.
  • the CIGS light absorption layer is physically vapor-deposited from each constituent element.
  • a CIGS thin film manufacturing process that does not use vacuum is desired and studied, unlike selenization and vapor deposition (see, for example, Patent Document 1).
  • a non-vacuum manufacturing process an ink containing oxide particles is printed on a substrate, and the obtained oxide film is reduced with hydrogen gas to be converted into a metal film, and then selenized with H 2 Se gas.
  • Non-patent document 1 There is also a method of preparing a CIGS thin film by preparing an ink using CIGS powder, applying the ink by a screen printing method, and then sintering the CIGS powder by heat treatment under normal pressure and in an inert atmosphere (for example, Non-patent document 1).
  • the CIGS thin film produced by this method has voids inside, and it is difficult to produce a dense thin film.
  • a screen mesh mark remains on the film coated with ink by the screen printing method, and it is difficult to obtain a film having a smooth surface.
  • Se is likely to evaporate from the thin film, and it has been difficult to sinter many CIGS thin films at once under uniform conditions.
  • an object of the present invention is to provide a compound semiconductor thin film such as a CIGS thin film which is dense and excellent in surface smoothness and can be suitably used for a solar cell with high productivity and low cost easily in a non-vacuum process.
  • a method for producing a compound semiconductor thin film of the present invention is a method for producing a compound semiconductor thin film containing a group B element, a group B element, and a group V element, and includes a group B element, a group B element, A step of preparing a coating agent containing a V ⁇ B group element, a step of coating the coating agent on a substrate to form a coating film, and heating and baking the coating film under a mechanically pressurized condition. And a pressure firing step for binding.
  • the solar cell of the present invention is a solar cell having a compound semiconductor thin film, wherein the compound semiconductor thin film is manufactured by the compound semiconductor thin film manufacturing method of the present invention.
  • the compound semiconductor thin film manufacturing apparatus of the present invention is an apparatus used in the compound semiconductor thin film manufacturing method of the present invention, and is characterized by comprising at least a pressing means and a heating means.
  • a compound semiconductor thin film such as a CIGS thin film which is dense and excellent in surface smoothness and can be suitably used for a solar cell, can be easily provided at low cost with high productivity in a non-vacuum process.
  • FIG. 1 is a schematic cross-sectional view showing a method for producing a compound semiconductor thin film of the present invention.
  • FIG. 2 is an X-ray diffraction pattern of the compound semiconductor thin film obtained in Example 1.
  • 3 is a scanning electron microscope (SEM) image of the surface and cross section of the compound semiconductor thin film obtained in Example 1.
  • FIG. 4 is a graph showing the light transmittance of the compound semiconductor thin film obtained in Example 1.
  • 5 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 2.
  • FIG. 6 is an SEM image of the surface of the compound semiconductor thin film obtained in Example 3.
  • FIG. 7 is a schematic cross-sectional view illustrating the method for manufacturing the compound semiconductor in Example 4.
  • FIG. 1 is a schematic cross-sectional view showing a method for producing a compound semiconductor thin film of the present invention.
  • FIG. 2 is an X-ray diffraction pattern of the compound semiconductor thin film obtained in Example 1.
  • 3 is a scanning electron microscope (SEM) image
  • FIG. 8 is an SEM image of the surface of the compound semiconductor thin film obtained in Example 4.
  • FIG. 9 is an SEM image of the surface of the compound semiconductor thin film obtained in Example 5.
  • FIG. 10 is an X-ray diffraction pattern of the compound semiconductor thin film obtained in Example 6.
  • FIG. 11 is an SEM image of the surface of the compound semiconductor thin film obtained in Example 6.
  • 12 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Comparative Example 1.
  • FIG. FIG. 13 is a schematic diagram showing an example of the configuration of the compound semiconductor thin film manufacturing apparatus of the present invention.
  • FIG. 14 is a schematic cross-sectional view of a device structure of a solar cell having a substrate type structure.
  • FIG. 15 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 7.
  • FIG. 16 is a graph showing the light transmittance of the compound semiconductor thin film obtained in Example 7.
  • FIG. 17 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 8.
  • FIG. 18A is a transmission electron microscope (TEM) image of a cross section of the compound semiconductor (CIGS) thin film obtained in Example 8.
  • FIG. 18B is a chart showing the intensity of characteristic X-rays obtained by analyzing the portion indicated by the arrow in FIG. 18A by energy dispersive X-ray spectroscopy (EDX).
  • FIG. 19A is a TEM image of the microstructure of the interface between the CIGS layer and the Mo layer in the cross section of the compound semiconductor (CIGS) thin film.
  • FIG. 19B is a chart showing the intensity of characteristic X-rays obtained by analyzing the portion indicated by the arrow in FIG. 19A by EDX.
  • FIG. 20A is a photograph of the CIGS solar cell prototyped in Example 8.
  • FIG. 20B is an SEM image of a cross section of the CIGS solar cell.
  • FIG. 21 is a graph of the characteristics of the CIGS solar cell prototyped in Example 8.
  • FIG. 22 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 9.
  • FIG. 23 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 10.
  • 24 is a SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 11.
  • 25A is a graph showing the light transmittance of the compound semiconductor thin film obtained in Example 12.
  • FIG. 25B, 25C and 25D are graphs for obtaining the forbidden band width of the compound semiconductor thin film obtained in Example 12.
  • FIG. 26 is an X-ray diffraction pattern of the compound semiconductor thin film obtained in Example 13.
  • 27 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 13.
  • FIG. 28A is a graph showing the light transmittance of the compound semiconductor thin film obtained in Example 13.
  • FIG. FIG. 28B is a graph for obtaining the forbidden band width of the compound semiconductor thin film obtained in Example 13.
  • the coating agent containing the ⁇ B group element, ⁇ B group element, and V ⁇ B group element is an element of at least two kinds selected from ⁇ B group element, ⁇ B group element, and V ⁇ B group element. It is preferable to use a coating agent containing compound particles containing.
  • a coating agent containing the ⁇ B group element, ⁇ ⁇ ⁇ B group element and V ⁇ B group element a coating agent containing ⁇ B group element and V ⁇ B group element, ⁇ B group element powder, and V ⁇ B group element powder is used. Is also preferable.
  • the coating agent containing the ⁇ B group element, ⁇ ⁇ ⁇ B group element and V ⁇ B group element it is also preferable to use a coating agent containing compound particles containing the ⁇ B group element, ⁇ B group element and V ⁇ B group element.
  • the group B element is preferably at least one element selected from Cu and Ag.
  • the group B element is preferably at least one element selected from In, Ga, and Al.
  • the V ⁇ B group element is preferably at least one element selected from S, Se, and Te.
  • the coating agent further contains Sb.
  • a drying step for drying the coating film is further performed before the pressure firing step.
  • the pressure applied mechanically in the pressure firing step is in a range of more than 0 Pa and 100 MPa or less.
  • the pressure firing step is performed at a temperature within a range of 300 ° C. to 650 ° C.
  • a heat treatment step of heating in an atmosphere having a pressure in the range of normal pressure to 1 MPa after the pressure firing step.
  • the heat treatment step is preferably performed at a temperature higher than the temperature in the pressure firing step.
  • the step of applying the coating agent to a substrate is preferably performed by screen printing.
  • pressure baking is performed in a state where a plurality of substrates on which the coating film is formed are stacked.
  • spacer selected from the group consisting of metal, glass and ceramics as the spacer.
  • a group B element and a group VB element can be used in combination in place of or in place of the group B element.
  • the present invention is characterized in that a compound semiconductor thin film such as CIGS containing a group B element, a group B element, and a group VB element, which has been conventionally performed in a vacuum process, is manufactured by a non-vacuum process.
  • a coating agent containing a group B element, a group B element, and a group V element is prepared, and this coating agent is applied to a substrate, heated, and sintered to form a group B element and group B.
  • a compound semiconductor thin film containing an element and a V ⁇ B group element is manufactured. And when heating and sintering, it is a great feature that pressure firing is performed in a state where mechanical pressure is applied.
  • the group B element is preferably at least one element selected from Cu and Ag.
  • the element can be appropriately selected according to the design value of the band gap required for the compound semiconductor thin film. For example, when Ag is used, the band gap can be widened.
  • the group B element is preferably at least one element selected from In, Ga, and Al.
  • the band gap can be widened.
  • the ideal element ratio of Cu / In in the thin film is 0.95 to 0.7.
  • the ratio of excess Cu may be used. The ratio may be about 0.95 to 0.4.
  • the V ⁇ ⁇ ⁇ B group element is preferably at least one element selected from S, Se, and Te.
  • Sulfur (S) is used in the production of a compound semiconductor thin film in a vacuum process, but since it has a high vapor pressure, it is preferably contained as a main component of the process for producing the thin film by conventional heating and sintering. There wasn't. However, in the production method of the present invention, since the heat sintering is performed under pressure, the high vapor pressure is not a big problem. Since the presence of sulfur can be expected to improve the characteristics of CIGS grain boundaries, it is also preferable to use it as a small amount of additive.
  • the compound particles containing at least two kinds of elements selected from the group B elements, group B elements, and group V elements include compound particles containing group B elements and group V elements, group B elements, and group elements V and B.
  • Compound particles can be used.
  • the coating agent used in the present invention may be a mixture of particles containing two types of elements and group element powders not included in the particles, or particles containing at least two types of elements. May be prepared so as to contain all of the group B element, the group B element, and the group V element.
  • the compound particles containing the group B element and the group V group B are preferably CuSe.
  • Cu (In 1-X Ga X ) 2 Se 3 When (In 1-X Ga X ) 2 Se 3 is used as the compound particle containing the ⁇ B group element and the V ⁇ B group element, Cu (In 1-X Ga X ) Se 2 can be easily obtained by reaction with CuSe. Can do. Conventionally, Cu 2 Se and Ag 2 Se that have been used hardly react with compound particles containing a group B element and a group V element in a short time even when heated. On the other hand, in the case of CuSe, it decomposes into liquid phase Se containing a high concentration of Cu and a small amount of Cu 2-Z Se (solid) at 523 ° C. or higher.
  • This Cu 2-Z Se exists in the form of a non-stoichiometric compound in which Z can take a value of about 0 to 0.2.
  • the generated Se in the liquid phase reacts actively with the compound particles containing the ⁇ B group element and the V ⁇ B group element.
  • the simultaneously produced Cu 2-Z Se inhibits the reaction, but by adding a slight excess of Se into the reaction system, Cu 2-Z Se can be dissolved in the Se melt, and homogeneous Cu -Se melt is obtained.
  • a homogeneous Cu—Se melt is preferable because the above reaction can proceed well.
  • the coating agent containing the group B element, group B element and group V element the coating agent containing compound particles containing group B element and group V element, group B element powder, and group group V powder.
  • the compound particle containing a ⁇ B group element and a V ⁇ B group element is a ⁇ B 2 V ⁇ B 3 group compound.
  • a CuInSe 2 thin film is produced by the vapor deposition method, first, an In 2 Se 3 thin film is produced, Cu and Se are diffused in the thin film, and the orientation of the In 2 Se 3 thin film is changed.
  • CuInSe 2 thin film is obtained.
  • a high-quality thin film is obtained by using a coating agent containing a compound particle containing a Group B element and a Group V element, a Group B element powder, and a Group V element powder. Can be obtained.
  • the compound particles containing the ⁇ B group element and the V ⁇ B group element are preferably at least one selected from (In 1-X Ga X ) 2 Se 3 and (In 1-X Ga X ) Se.
  • X in the chemical formula which is a Ga / (In + Ga) ratio in the compound semiconductor thin film, is preferably in the range of 0 to 0.6, and more preferably in the range of 0.2 to 0.4.
  • the band gap is most preferably about 1.4 eV. From the viewpoint of the band gap, it is preferable to contain about 0.6 of Ga in the above ratio, but from the viewpoint of the conversion efficiency, it is more preferably in the range of 0.2 to 0.4.
  • the particle diameter of the compound particles reacts with the compound particles to produce a target compound semiconductor, so that the smaller the particle diameter, the higher the reactivity and the more desirable.
  • the particle diameter is preferably 1 ⁇ m or less, and more preferably 0.1 ⁇ m or less.
  • the compound particles may be prepared as a compound particle containing a group B element and a group VB element, or a compound particle containing a group B element and a group VB element, but each elemental element is prepared in a desired ratio.
  • Each compound particle can also be obtained by a mechanochemical process using a mixture of the above. By using this method, it becomes easy to freely design the composition of the compound particles.
  • the process of synthesizing composite particles by utilizing the phenomenon that the particles having increased activity and reaction cause a chemical reaction with surrounding substances is called a mechanochemical process.
  • the mechanochemical process is characterized by high energy efficiency, high productivity and short cycle time.
  • a sufficient machine is sufficient for a mechanochemical reaction to obtain CuSe or (In, Ga) -Se compound from each of Cu, Se, In, and Ga.
  • the apparatus is not particularly limited as long as it is a device capable of applying a dynamic energy. Examples of the apparatus include a planetary ball mill, a ball mill, a jet mill, an attritor mill, a rod mill, a roll mill, and a crusher mill. Among these, a planetary ball mill capable of obtaining an impact several times the gravitational acceleration is preferable.
  • the ball mill is for pulverizing the material to be treated with a large number of spheres.
  • a rolling ball mill a planetary ball mill, a vibrating ball mill, and the like that pulverize a material to be treated by a sphere (ball) using mechanical energy such as rotational force, planetary motion, and vibration.
  • the material of the ball is not particularly limited, but zirconia, alumina, silicon nitride, tungsten carbide, agate and the like are preferable from the viewpoint of contamination with impurities.
  • the number of rotations of the ball mill, the size of the container, and the diameter and amount of the balls used when performing the mechanochemical process are not particularly limited as long as the reaction can be promoted.
  • the content ratio of the group B element, group B element, and group VB element in the coating agent is preferably added in such a ratio that the composition of the target compound semiconductor thin film is obtained.
  • an element such as Se that easily volatilizes from a compound is contained in the heating (baking) step after coating
  • the element alone is excessively mixed in advance in the coating agent.
  • the coating agent contains a solvent.
  • the solvent may be an aqueous solvent or a non-aqueous solvent such as an organic solvent.
  • Organic solvents include acrylates, alcohols (butyl, ethyl, isopropyl or methyl), aldehydes, benzene, dibromomethane, chloroform, dichloromethane, dichloroethane, trichloroethane, cyclo compounds (eg, cyclopentanone, cyclohexanone), esters (eg, butyl) Acetate, ethyl acetate), ether, glycol (ethylene glycol, propylene glycol, etc.), hexane, heptane, aliphatic hydrocarbon, aromatic hydrocarbon, ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone), natural oil, terpene, There are terpinol and toluene.
  • a solvent having a high boiling point and high viscosity such as terpineol or ethylene glycol monophenyl ether is preferable from the viewpoint of coating property and workability during coating.
  • the aqueous solvent has a small environmental load, it has a drawback that the surface tension is relatively larger than that of the organic solvent, and repelling is likely to occur when it is applied to a substrate.
  • the surface tension of the coating agent may be reduced by adding a surfactant. The amount of the solvent added may be adjusted so as to be in the optimum viscosity range according to the coating method of the coating agent.
  • pigments, fillers, dispersants, plasticizers, UV absorbers, surfactants, binders, emulsifiers, antifoaming agents, desiccants, and leveling may be used as long as they do not impair performance.
  • An agent, corrosion inhibitor, antioxidant, thixotropic agent, etc. may be added. These additives may be used alone or in combination of two or more.
  • substrate can be improved by adding NaF to the said coating agent, it is preferable.
  • the coating agent further contains Sb.
  • Sb is considered to act as a sintering aid, and it was found that the addition of the CIGS thin film promotes the sintering, and a denser thin film is obtained.
  • the amount of Sb added can be set within a range in which the performance of the obtained compound semiconductor can be maintained, but is preferably about 0.25 to 5 mol%. Within this range, a dense thin film can be obtained as the amount of Sb added increases.
  • the coating agent can be prepared by a means such as a ball mill similar to the means for performing a mechanochemical process.
  • the desired coating agent has a low viscosity, it can also be obtained by stirring without using a ball mill or the like.
  • the particle size of the particles in the coating agent can be reduced by increasing the pulverization time (stirring time).
  • the pulverization time is preferably in the range of 30 minutes to 24 hours, and can be appropriately set according to the desired properties of the coating agent.
  • Examples of methods for applying the coating agent to the substrate include screen printing methods, phantom coating methods, die coating methods, spin coating methods, spray coating methods, gravure coating methods, roll coating methods, and bar coating methods. Can be used.
  • soda lime glass is used as the substrate on which the coating agent is applied.
  • the soda lime glass contains Na, but the contained Na may diffuse into the compound semiconductor thin film layer formed on the substrate, so that the electrical properties of the compound semiconductor thin film may be positively affected.
  • the compound semiconductor thin film is used as a solar cell.
  • a thin film is formed on a substrate by a coating process, so that the selection range of the substrate can be widened as compared with vapor deposition.
  • a flexible substrate such as a metal foil or a plastic film can be used. When a flexible substrate is used, it can also be applied to a mass-productive process such as a roll-to-roll method.
  • the step of applying the coating agent to a substrate to form a coating film, and heating the coating film under pressure under mechanical pressure the compound semiconductor It is also preferable to include a coating agent drying step between the sintering step.
  • a coating agent drying step between the sintering step.
  • the step of drying the coating film may be, for example, natural drying, air drying by blowing air, heat drying or vacuum drying. Moreover, the method which combined these may be used.
  • the thickness of the coating film is preferably in the range of 10 to 0.1 ⁇ m, more preferably in the range of 3 to 0.3 ⁇ m.
  • the substrate on which the coating film is formed is sandwiched between press plates from above and below, pressed, and heated in that state (hot pressing), so that the group B element contained in the coating agent
  • the compound semiconductor thin film is manufactured by sintering the group B element and the group V group B element.
  • This step can be performed using an apparatus including a pressing unit and a heating unit described below.
  • FIG. 13 shows an example of the configuration of the compound semiconductor thin film manufacturing apparatus of the present invention.
  • the manufacturing apparatus 130 includes a chamber 131, a heating tank 132, a heater 133, and push rods 134 and 134 'as main components.
  • a heating tank 132 and a set of push rods 134, 134 ' are arranged in the chamber 131.
  • the set of push bars 134, 134' is a pressing means in the present invention, and the heating tank 132 has a vertical direction. It is pierced opposite.
  • a heater 133 is installed in the heating tank 132.
  • a vacuum pump or a gas supply means may be connected to the chamber 131. By reducing the pressure in the chamber 131 with a vacuum pump and supplying a gas such as nitrogen from the gas supply means into the chamber, the air in the chamber can be replaced.
  • the gas supply means is connected to a gas cylinder, whereby a gas having an appropriate pressure can be supplied into the chamber 131.
  • the heater 133 is a means for controlling the temperature in the heating tank 132.
  • the heater 133 is installed in the heating tank 132, but is not limited thereto.
  • the heater 133 is preferably a quartz tube heater in which the heater is enclosed in a quartz tube. This is because Se and the like may evaporate from the coating layer due to heating, and the inside of the heating tank may become a Se atmosphere, but when the heater is exposed, Se and the like react with each other.
  • the temperature control means is not limited to a heater, and may be a current heating or a discharge plasma sintering machine.
  • the interval between the pair of push rods 134 and 134' is reduced.
  • mechanical pressure is applied to the substrate.
  • a pressing plate having the same size as the substrate is prepared so that the entire substrate is pressurized, and the substrate is arranged so as to sandwich the substrate.
  • the material of the pressing plate silicon nitride ceramics, alumina, zirconia, or the like can be suitably used.
  • a second push plate that serves as a cushioning material may be further provided between the push plate and the substrate in order to prevent damage to the substrate.
  • a graphite sheet, a Teflon (registered trademark) sheet, or the like can be used as the second push plate.
  • a spacer is disposed on the surface of the substrate on which the coating film is formed.
  • the spacer is used to prevent the coating film from adhering to the pressing plate.
  • the spacer it is preferable to use a material that does not react with an element constituting the compound semiconductor contained in the coating film, hardly transfers the coating film from the substrate, and does not deform excessively by pressurization.
  • metal, glass, ceramics and the like are preferable, and aluminum foil, borosilicate glass and the like can be used. Further, a material that can serve as a spacer may be coated on the surface of the pressing plate.
  • the equilibrium reaction proceeds in the following direction due to the evaporation of Se.
  • 2CuInSe 2 ⁇ Cu 2 Se + In 2 Se + Se 2 In the manufacturing method of the present invention, Se is difficult to evaporate in order to press the coated surface, and therefore, the above formula proceeds in the opposite direction (2CuInSe 2 ⁇ Cu 2 Se + In 2 Se + Se 2 ), which is preferable.
  • press firing may be performed in a state where a plurality of substrates on which the coating film is formed are stacked.
  • the pressure firing process is often low in productivity because it becomes a batch process.
  • the production efficiency is greatly improved.
  • the spacer may be inserted between the substrates on which a plurality of the coating films are formed.
  • the pressurization is preferably in the range where the mechanically applied pressure exceeds 0 Pa and is 100 MPa or less.
  • the crystal grains of the compound semiconductor whose surroundings are in a liquid phase by heating are easily bonded to the adjacent crystal grains, so that the grain growth is promoted.
  • reaction sintering and grain growth can be performed in a state where the contact area between the crystal grains and the crystal grains is large, so that a dense thin film can be manufactured.
  • the sintering proceeds in a three-dimensional process, so shrinkage occurs in the vertical and horizontal directions from the state in which the coating film is formed, and dimensional accuracy is obtained.
  • the thin film had many vacancies and was difficult to be densified. Another problem is that the film is cracked by the contraction of the film in the horizontal direction.
  • the production method of the present invention improves these problems.
  • the heating temperature in the pressure firing step is preferably performed at a temperature in the range of 300 ° C. to 650 ° C., more preferably in the range of 350 ° C. to 550 ° C.
  • the atmosphere is preferably a pressure atmosphere in the range of normal pressure to 1 MPa.
  • the compound semiconductor thin film can be produced under a low temperature condition as compared with the case of sintering without applying pressure. According to the production method of the present invention, crystal grains grow even at a lower heating temperature than in the conventional method.
  • the heating temperature in the heat treatment step is effective when performed at a temperature higher than the temperature in the heat treatment step, preferably in the range of 400 ° C. to 650 ° C., more preferably in the range of 450 ° C. to 600 ° C. Is within.
  • the heat treatment step while depositing Se.
  • the CIGS thin film is prevented from being decomposed, and the characteristics of the solar cell are improved.
  • it is effective when performed at a temperature higher than the temperature at the heating temperature in the pressure firing step, preferably in the range of 400 ° C. to 650 ° C., more preferably in the range of 450 ° C. to 600 ° C. Is within.
  • the manufacturing method of the compound semiconductor thin film containing the ⁇ B group element, the ⁇ B group element and the V ⁇ B group element has been described in detail.
  • the ⁇ B group element and the ⁇ VB group in addition to or instead of the ⁇ B group element, the ⁇ B group element and the ⁇ VB group.
  • a compound semiconductor thin film can also be manufactured by using it in combination with an element.
  • a ⁇ B group element and a ⁇ VB group element are used in combination instead of the ⁇ B group element, a compound semiconductor thin film containing a ⁇ B group element, a ⁇ B group element, a ⁇ VB group element, and a V ⁇ B group element can be produced.
  • Rare metals such as In and Ga, which are group B elements, have resource limitations.
  • Zn which is a ⁇ B group element
  • Sn which is a ⁇ VB group element
  • Zn can be suitably used as the ⁇ B group element
  • Sn or Ge can be suitably used as the ⁇ VB group element.
  • the compound semiconductor thin film produced by the method for producing a compound semiconductor thin film of the present invention can be suitably used for solar cells.
  • An example of the structure of the solar cell is a substrate type structure.
  • An example of a schematic cross-sectional view of the device structure of a solar cell having a substrate type structure is shown in FIG.
  • a back electrode 142 is provided on a substrate 141, and a light absorption layer 143 made of a compound semiconductor thin film, a buffer layer 144, a transparent electrode 145, and an extraction electrode 146 are formed thereon.
  • soda lime glass is used as the substrate 141
  • Mo is used as the back electrode 142
  • ZnO / CdS is used as the buffer layer 144
  • ZnO: Al or ZnO: B is used as the transparent electrode 145
  • Al / Ni is used as the extraction electrode 146.
  • Sunlight enters from the transparent electrode 145 side.
  • An antireflection film 147 may be provided on the transparent electrode 145 as necessary.
  • the compound semiconductor thin film When the compound semiconductor thin film is used for a solar cell, a thickness of the thin film of 1 ⁇ m or more is sufficient to absorb sunlight. Furthermore, by reflecting light on the back surface, the optical path length in the light absorption layer can be increased, and even a thin film of 1 ⁇ m or less can sufficiently absorb sunlight. In consideration of use in low-cost solar cells, the thickness of the thin film is desirably 10 ⁇ m or less. Moreover, the crystal grain of the CIGS film produced by the vapor deposition method is large, and the grain size has grown to about the film thickness. However, high conversion efficiency may be obtained even if the crystal grain size is not so large. The important point is that the crystal grains are sufficiently sintered and dense.
  • the compound semiconductor thin film was analyzed using an X-ray diffractometer (manufactured by Rigaku Corporation, trade name “automatic X-ray diffractometer RINT2400”). Using a Cu target, X-rays were generated at a tube voltage of 40 kV and a tube current of 100 mA. The measurement was performed by the 2 ⁇ / ⁇ method.
  • the compound semiconductor thin film formed on the glass substrate is measured for absorption spectrum using a multi-channel spectrometer (trade name “Multi-channel spectrometer PMA-12” manufactured by Hamamatsu Photonics Co., Ltd.), and light transmittance is calculated. Went.
  • a multi-channel spectrometer trade name “Multi-channel spectrometer PMA-12” manufactured by Hamamatsu Photonics Co., Ltd.
  • the substrate on which the coating layer was formed was dried at 145 ° C. for 7 minutes in a nitrogen atmosphere.
  • the dried substrate was pressure fired as follows, and the coated film was sintered to produce a CIGS thin film.
  • the substrate 2 on which the CIGS coating film 1 was formed was placed on the pressing plate 5.
  • the spacer 3 was placed in direct contact with the CIGS coating film 1, and a push plate 5 'was placed thereon.
  • the two pressing plates 5 and 5 ′ were sintered while being mechanically pressed by a pair of pressing rods 4 and 4 ′.
  • the spacer 3 was an aluminum foil (thickness 7 ⁇ m), the push rods 4 and 4 ′ were cylindrical zirconia ceramics having a diameter of 40 mm, and the push plates 5 and 5 ′ were 60 mm square silicon nitride ceramic plates.
  • pressure firing was performed for 30 minutes to obtain a sintered CIGS thin film. Heating was started at normal pressure in a nitrogen atmosphere after the chamber was sealed, and when the temperature reached 200 ° C., mechanical pressure (press) was applied with a pressing plate. After heating to a predetermined 450 ° C. in a pressurized state and holding at 450 ° C. for 30 minutes, the pressure on the pressing plate was released and the pressure was returned to normal pressure. After cooling to room temperature, the chamber was opened and the sintered substrate with a thin film was taken out.
  • the CIGS thin film of the present example is a single phase that does not contain impurities, and as the X increases, the diffraction peak shifts to the high angle side, and the solid solution amount of Ga increases. I can confirm that.
  • the surface and cross-sectional microstructure of the obtained thin film were observed with a scanning electron microscope (SEM). Those photographs are shown in FIG. From these photographs, CIGS crystal grain growth and densification are recognized, and it can be confirmed that a dense CIGS thin film can be obtained by the method of this example. In particular, the surface of the thin film is very smooth.
  • the light absorption spectrum of the CIGS thin film produced in Example 1 was measured in the wavelength range of 900 nm to 1600 nm.
  • FIG. 4 the graph of the light transmittance of the produced CIGS thin film is shown. This figure shows that the shortest wavelength of the light which permeate
  • Example 2 (Preparation of raw material powder) The element powders Cu, In, Ga, and Se were weighed so as to have a ratio of Cu 1.02 (In 0.995 Ga 0.005 ) Se 2.1 , and then 0.5 mol% of NaF was added thereto.
  • 20 g of the weighed powder and 40 g of 3 mm diameter zirconia cobblestone were placed in a zirconia 45 cc container for a planetary ball mill, and stirred at 800 rpm for 20 minutes in a nitrogen atmosphere. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
  • Example 3 (Preparation of raw material powder and coating agent) In the same manner as in Example 2, a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained, and an ink as a coating agent was prepared.
  • a substrate was prepared by forming a Mo electrode on 5 cm square soda lime glass (thickness 2 mm). The obtained ink was applied to the substrate under the same conditions as in Example 1 to form a coating layer, and then the substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
  • the sintered CIGS thin films obtained by the pressure firing were each heat-treated at 550 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
  • a substrate was prepared by forming a Mo electrode on 5 cm square soda lime glass (thickness 2 mm). The obtained ink was applied to the substrate under the same conditions as in Example 1 and dried to form a coating layer, and then the substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
  • the three substrates coated with the three kinds of inks were simultaneously fired under pressure, and the coating layer was sintered to produce a CIGS thin film.
  • the substrate 12 on which the CIGS coating film 11 was formed was disposed on the pressing plate 5 via the second pressing plate 6.
  • the spacer 13 was placed in direct contact with the CIGS coating film 11.
  • the intermediate pressing plate 17 was placed on the spacer 13 and the substrate 22 on which the CIGS coating film 21 was formed was disposed. Further, the spacer 23 was placed in direct contact with the CIGS coating film 21.
  • An intermediate pressing plate 27 was placed on the spacer 23, and a substrate 32 on which a CIGS coating film 31 was formed was disposed.
  • the spacer 33 was placed in direct contact with the CIGS coating film 31, and the intermediate push plate 37, the second push plate 6 ′, and the push plate 5 ′ were placed in this order.
  • the two pressing plates 5 and 5 ′ were sintered while being mechanically pressed by a pair of pressing rods 4 and 4 ′.
  • Aluminum spacers (thickness 7 ⁇ m) were used as the spacers 13, 23 and 33, cylindrical zirconia ceramics having a diameter of 40 mm were used as the push rods 4 and 4 ′, and 50 mm square silicon nitride ceramic plates were used as the push plates 5 and 5 ′.
  • the second pressing plates 6 and 6 ′ provided on the pressing surface side of the pressing plates 5 and 5 ′ serve as a cushioning material between the pressing plate and the substrate.
  • graphite sheets A thickness of 0.4 mm
  • borosilicate glass plates (thickness 2 mm) were used.
  • the substrate was set as shown in FIG. 7, and the sintered CIGS thin film was obtained by pressurizing and firing for 30 minutes in a nitrogen atmosphere at 450 ° C. with a mechanical pressure of 2 MPa. Heating was started at normal pressure in a nitrogen atmosphere after the chamber was sealed, and when the temperature reached 200 ° C., mechanical pressure (press) was applied with a pressing plate. After heating to a predetermined 450 ° C. in a pressurized state and holding at 450 ° C. for 30 minutes, the pressure on the pressing plate was released and the pressure was returned to normal pressure. After cooling to room temperature, the chamber was opened and the sintered substrate with a thin film was taken out.
  • the sintered CIGS thin films obtained by the pressure firing were each heat-treated at 550 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
  • a CdS buffer layer 144a is formed on the CIGS thin film 143 by a solution growth (CBD) method using cadmium sulfate CdSO 4 .
  • CBD solution growth
  • the i-ZnO layer 144b and the ZnO: B (B-doped ZnO) window layer 145 are deposited by metal organic chemical vapor deposition (MOCVD).
  • Diethyl zinc (Zn (C 2 H 5 ) 2 ) is used as a raw material for Zn, and pure water (H 2 O) is used as an oxidizing agent. Further, diborane (B 2 H 6 ) diluted with 1% hydrogen was used as the n-type doping gas. (3) A comb-shaped Al electrode 146 was formed by a vacuum deposition method. The CIGS solar cells of this example, which were experimentally produced by this process, all showed solar cell characteristics, and it was confirmed that the present invention was effective for producing a thin film of a compound semiconductor for solar cells.
  • Example 5 (Preparation of raw material powder)
  • a substrate was prepared by forming a Mo electrode on 5 cm square soda lime glass (thickness 2 mm). The obtained ink was applied to the substrate under the same conditions as in Example 1 to form a coating layer, and then the substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
  • Example 4 Pressure firing In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to produce a CIGS thin film.
  • the conditions for pressure firing are the same as in Example 4.
  • the sintered CIGS thin films obtained by the pressure firing were each heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
  • Example 6 (Preparation of CuSe powder) Cu powder and Se powder were weighed at a molar ratio of 1: 1. 100 g of powder weighed in an 80 cc container made of zirconia for a planetary ball mill (trade name “Planet Ball Mill P-5 / 2” manufactured by Fritsch) and 200 g of zirconia cobblestone having a diameter of 3 mm were placed in a nitrogen atmosphere. And stirred at 370 rpm for 120 minutes. By stirring, a mechanochemical reaction occurred and CuSe powder was obtained. It was confirmed by powder X-ray diffraction that the obtained CuSe was a highly crystalline CuSe.
  • the substrate on which the coating layer was formed was dried at 145 ° C. for 5 minutes in a nitrogen atmosphere.
  • Example 4 Pressure firing In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to produce a CIGS thin film.
  • the conditions for pressure firing are the same as in Example 4.
  • the sintered CIGS thin films obtained by the pressure firing were each heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
  • the X-ray diffraction pattern coincides with the X-ray diffraction pattern obtained by simulation based on crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 70051), and it was found that a CIGS thin film having a chalcopyrite structure was synthesized. From this X-ray diffraction pattern, as in Example 1, the CIGS thin film of this example is a single phase containing no impurities, the diffraction peak shifts to the high angle side as X increases, It can be confirmed that the amount of solid solution increases. Moreover, the surface microstructure of the obtained thin film was observed with SEM. The result is shown in FIG. From these SEM photographs, it can be seen that crystal grain growth and densification are observed in any sample.
  • Example 7 (Preparation of raw material powder)
  • the element powders Cu, In, Ga, and Se were weighed so as to have a ratio of Cu 1.02 (In 0.995 Ga 0.005 ) Se 2.1 , and then 0.5 mol% of NaF was added thereto.
  • 20 g of the weighed powder and 40 g of 1 mm diameter zirconia cobblestone were placed in a zirconia 45 cc container for a planetary ball mill, and stirred at 800 rpm for 20 minutes in a nitrogen atmosphere. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
  • the near infrared light absorption spectrum of the CIGS thin film prepared in Example 7 was measured in the wavelength range of 900 nm to 1600 nm.
  • FIG. 16 the graph of the light transmittance of the produced CIGS thin film is shown. From this figure, it can be seen that the ink stirring time is increased, the CIGS film thickness is decreased, and the transmittance of light having a wavelength of 1200 nm or more is increased.
  • the CIGS film having the same thickness as the CIGS film manufactured by the vapor deposition method is devised by devising the ink adjustment process and the screen to be used. Can be produced.
  • Example 8 (Preparation of raw material powder) The element powders Cu, In, Ga, and Se were weighed so as to have a ratio of Cu 1.02 (In 0.995 Ga 0.005 ) Se 2.1 , and then 0.5 mol% of NaF was added thereto. In the same manner as in Example 1, 20 g of the weighed powder and 40 g of 1 mm diameter zirconia cobblestone were placed in a zirconia 45 cc container for a planetary ball mill, and stirred at 800 rpm for 20 minutes in a nitrogen atmosphere. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
  • a substrate was prepared by forming a Mo electrode on 5 cm square soda lime glass (thickness 2 mm). The obtained ink was applied by screen printing (500 mesh) to form an application layer.
  • the sintered CIGS thin film obtained by the pressure firing was heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
  • TEM transmission electron microscope
  • the apparatus used was a focused ion beam processing apparatus (manufactured by Hitachi, Ltd., “FB-2100”) and an ion milling apparatus (manufactured by GATAN, “PIPS Model-691” (with cold stage)).
  • FB-2100 focused ion beam processing apparatus
  • GATAN ion milling apparatus
  • FIG. 19A shows a microstructure in which the vicinity of the interface between the CIGS layer and the Mo layer of the CIGS film is further enlarged and observed by TEM.
  • an interface layer is formed between the CIGS layer and the Mo layer.
  • the chemical composition at the point P2 indicated by the arrow in FIG. 19A was analyzed by EDX in the same manner as the point P1.
  • the analysis result is shown in FIG. From the interface layer, it can be seen that only Mo and Se are detected while only noise levels of Cu and In are detected.
  • the MoSe 2 is generated in the vicinity of the interface between the CIGS layer and the Mo layer. It is presumed that MoSe 2 of the interface layer was generated by a reaction between CIGS and Mo during the sintering and heat treatment processes. In the deposition method, the interface between the CIGS layer and the Mo layer, MoSe 2 is produced, MoSe 2 of this interface is known to contribute to improvement in characteristics of the CIGS solar cells (e.g., Jpn. J. Appl.Phys., Vol.35 (1996) pp.L1253-L1256).
  • FIG. 20A shows a photograph of the CIGS solar cell of this example.
  • FIG. 20B shows the microstructure of the fracture surface of the CIGS solar cell of this example observed with a scanning electron microscope. It is observed that a ZnO layer is formed on the CIGS light absorption layer. Since the thickness of the CdS layer is 0.1 ⁇ m or less, it cannot be identified from this photograph.
  • Example 9 (Preparation of raw material powder) The ratio of elemental powder Cu, In, Ga, Se to Cu 1.00 (In 0.995 Ga 0.005 ) Se 2.1 and Cu 0.95 (In 0.995 Ga 0.005 ) Se 2.1 After weighing each so, 0.5 mol% of NaF and 2 mol% of Sb powder were added thereto. The Sb powder acts as a sintering aid and can control crystal growth.
  • 20 g of the weighed powder and 40 g of 1 mm diameter zirconia cobblestone were placed in a zirconia 45 cc container for a planetary ball mill, and stirred at 800 rpm for 20 minutes in a nitrogen atmosphere. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
  • the sintered CIGS thin film was obtained by simultaneous pressure firing under the same conditions as in Example 4 except that the number of substrates was two.
  • the sintered CIGS thin films obtained by the pressure firing were each heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
  • Example 10 (Preparation of (In 0.995 Ga 0.005 ) 2 Se 3 powder)
  • Ga powder and Se powder were weighed at a molar ratio of 1.99: 0.01: 3.
  • the powder weighed in a 45 cc container made of zirconia for a planetary ball mill and 40 g of 1 mm diameter zirconia cobblestone were placed.
  • the filling amount of the powder in the container was adjusted to 20 g by adding Cu powder and Se powder when preparing the coating agent. They were stirred at 800 rpm for 20 minutes under a nitrogen atmosphere to obtain a powder having a composition ratio of (In 0.995 Ga 0.005 ) 2 Se 3 .
  • a total of 4 pots having such a composition ratio of (In 0.995 Ga 0.005 ) 2 Se 3 were prepared.
  • the substrate on which the coating layer was formed was dried at 110 ° C. for 5 minutes in a nitrogen atmosphere.
  • Example 10 The four types of CIGS thin films obtained in Example 10 (addition amounts of Sb of 0.25 mol%, 1.0 mol%, 2.0 mol%, and Sb were not added) were subjected to XRD analysis.
  • the X-ray diffraction pattern coincides with the X-ray diffraction pattern obtained by simulation based on crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 70051), and it was found that a CIGS thin film having a chalcopyrite structure was synthesized. From this X-ray diffraction pattern, it was confirmed that the CIGS thin film of this example was a single phase containing no impurities, as in the case of Example 1.
  • Example 11 (Preparation of (In 0.995 Ga 0.005 ) 2 Se 3 and (In 0.9 Ga 0.1 ) 2 Se 3 powder)
  • Ga powder and Se powder were weighed in a molar ratio of 1.99: 0.01: 3 and 1.80: 0.20: 3.
  • the powder weighed in a 45 cc container made of zirconia for a planetary ball mill and 40 g of 1 mm diameter zirconia cobblestone were placed.
  • the filling amount of the powder in the container was adjusted to 20 g by adding Cu powder and Se powder during the preparation of the coating agent. They are stirred at 800 rpm for 20 minutes in a nitrogen atmosphere to obtain a powder having a composition ratio of (In 0.995 Ga 0.005 ) 2 Se 3 and (In 0.9 Ga 0.1 ) 2 Se 3. It was.
  • the substrate on which the coating layer was formed was dried at 110 ° C. for 5 minutes in a nitrogen atmosphere.
  • Example 4 Pressure firing In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to produce a CIGS thin film.
  • the conditions for pressure firing are the same as in Example 4.
  • the X-ray diffraction pattern basically matches the X-ray diffraction pattern obtained by simulation based on crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 70051), and a CIGS thin film having a chalcopyrite structure is synthesized. all right. From this X-ray diffraction pattern, it was confirmed that the CIGS thin film of this example was a single phase containing no impurities, as in the case of Example 1. Moreover, the surface microstructure of the obtained thin film was observed with SEM. The result is shown in FIG.
  • the solar cell characteristics were confirmed, and it was found that a dense CIGS thin film produced by the method of this example was useful as a light absorption layer of a solar cell.
  • the substrate on which the coating layer was formed was dried at 145 ° C. for 7 minutes in a nitrogen atmosphere.
  • Example 4 Pressure firing In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to prepare a CuIn (Se 1-X Te X ) 2 thin film.
  • the conditions for pressure firing are the same as in Example 4.
  • the sintered CuIn (Se 1-X Te X ) 2 thin films obtained by the pressure firing were each heat-treated at 550 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
  • FIG. 25A shows a graph of light transmittance of the prepared CuIn (Se 1-X Te X ) 2 thin film.
  • Example 13 (Preparation of raw material powder) Conducted after weighing element powders Cu, Zn, Sn, Se to a ratio of Cu 2.04 ZnSnSe 4.2 (equivalent to Cu 1.02 (Zn 0.5 Sn 0.5 ) Se 2.1 ) In the same manner as in Example 1, a powder containing Cu 2 ZnSnSe 4 as a main component was obtained.
  • the substrate on which the coating layer was formed was dried at 145 ° C. for 7 minutes in a nitrogen atmosphere.
  • Example 2 Pressure firing
  • the coating layer was sintered to prepare a Cu 2 ZnSnSe 4 thin film.
  • the conditions for pressure firing are the same as in Example 1.
  • the Cu 2 ZnSnSe 4 thin film obtained in Example 13 was analyzed by X-ray diffraction (XRD).
  • XRD X-ray diffraction
  • the obtained X-ray diffraction pattern is shown in FIG.
  • This X-ray diffraction pattern basically coincides with the X-ray diffraction pattern by simulation based on the crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 95007) of Cu 2 ZnSnSe 4 shown below, and the Cu 2 ZnSnSe 4 thin film was found to be synthesized. From this X-ray diffraction pattern, it can be confirmed that the Cu 2 ZnSnSe 4 thin film of this example is a single phase containing no impurities.
  • FIG. 28 (a) shows a graph of the light transmittance of the prepared Cu 2 ZnSnSe 4 thin film.
  • FIG. 28B shows a diagram in which ( ⁇ h ⁇ ) 2 is plotted against h ⁇ , assuming a direct transition semiconductor, in order to obtain the forbidden band width of the Cu 2 ZnSnSe 4 thin film from this transmission spectrum.
  • FIG. 28B shows that the forbidden band width of the Cu 2 ZnSnSe 4 thin film is 1.05 eV.
  • the substrate on which the coating layer was formed was dried at 145 ° C. for 7 minutes in a nitrogen atmosphere.
  • Example 4 (Pressurized firing) In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to produce a (Cu 1-X Ag X ) GaSe 2 thin film.
  • the conditions for pressure firing are the same as in Example 4.
  • the sintered (Cu 1-X Ag X ) GaSe 2 thin films obtained by the above-mentioned pressure firing were each heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
  • the compound semiconductor thin film can be easily provided at a low cost by a non-vacuum process.
  • This manufacturing method enables material application under normal pressure, reduces capital investment in the manufacturing equipment, and reduces the amount of material used. Manufacturing that can greatly reduce costs in the manufacturing process of solar cell modules It is applicable as a method.
  • the obtained compound semiconductor thin film can be applied to a wide range of uses such as solar cells.

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Abstract

Provided is a compound semiconductor thin film, such as a CIGS thin film, which is compact, has excellent surface smoothness, and is ideal for use in a solar cell, and which is produced readily at a low cost and with good productivity in a non-vacuum process. A method for producing a compound semiconductor thin film containing a group IB element, group IIIB element, and group VIB element comprises: a step for preparing an application agent containing a group IB element, group IIIB element, and group VIB element; a step for forming an application film by applying the application agent to a substrate; and a step for baking under pressure in which the application film is heated and sintered while pressure is mechanically applied.

Description

化合物半導体薄膜の製造方法、太陽電池および化合物半導体薄膜製造装置Compound semiconductor thin film manufacturing method, solar cell, and compound semiconductor thin film manufacturing apparatus
　本発明は、化合物半導体薄膜の製造方法、太陽電池および化合物半導体薄膜製造装置に関する。 The present invention relates to a method for manufacturing a compound semiconductor thin film, a solar cell, and a compound semiconductor thin film manufacturing apparatus.
　Ｃｕ（Ｉｎ，Ｇａ）Ｓｅ２（以下、ＣＩＧＳともいう）は、太陽光の吸収に対して最適なバンドギャップと高い光吸収係数を持つため、高効率薄膜太陽電池の光吸収層として有望な半導体薄膜形成材料である。現在、日本および欧米でセレン化法や蒸着法を用いて、太陽電池に用いるＣＩＧＳ薄膜の製造が行われている。セレン化法では、金属プレカーサをスパッタ法で形成し、その金属プレカーサをＨ２Ｓｅガスでセレン化する。蒸着法ではＣＩＧＳ光吸収層を各構成元素から物理蒸着する。しかし、ＣＩＧＳ太陽電池のさらなる低コスト化のために、セレン化法や蒸着法とは異なり、真空を用いないＣＩＧＳ薄膜の製造プロセスが望まれ、検討されている（例えば、特許文献１参照）。非真空での製造プロセスとしては、酸化物粒子を含んだインクを基板上に印刷し、得られた酸化物膜を水素ガスで還元して金属膜に転換した後、Ｈ２Ｓｅガスでセレン化してＣＩＧＳ薄膜を得る方法がある。また、ＣＩＧＳ粉末を用いてインクを調製し、スクリーン印刷法で前記インクを塗布した後、常圧下・不活性雰囲気での熱処理によりＣＩＧＳ粉末を焼結させてＣＩＧＳ薄膜を得る方法もある（例えば、非特許文献１参照）。しかし、この方法で作製したＣＩＧＳ薄膜は、内部に空孔が生じており、緻密な薄膜を作製することは困難であった。また、スクリーン印刷法でインクを塗布した膜には、スクリーンメッシュの跡が残り、表面の平滑な膜を得ることは困難であった。さらに、焼結工程において、薄膜からＳｅの蒸散が起こりやすく、多数のＣＩＧＳ薄膜を均一な条件で一度に焼結させることは困難であった。 Cu (In, Ga) Se 2 (hereinafter also referred to as CIGS) has an optimum band gap and high light absorption coefficient for the absorption of sunlight, and therefore is a promising semiconductor as a light absorption layer of a high-efficiency thin film solar cell. It is a thin film forming material. Currently, CIGS thin films used for solar cells are manufactured in Japan, Europe and America using a selenization method or a vapor deposition method. In the selenization method, a metal precursor is formed by sputtering, and the metal precursor is selenized with H 2 Se gas. In the vapor deposition method, the CIGS light absorption layer is physically vapor-deposited from each constituent element. However, in order to further reduce the cost of CIGS solar cells, a CIGS thin film manufacturing process that does not use vacuum is desired and studied, unlike selenization and vapor deposition (see, for example, Patent Document 1). As a non-vacuum manufacturing process, an ink containing oxide particles is printed on a substrate, and the obtained oxide film is reduced with hydrogen gas to be converted into a metal film, and then selenized with H 2 Se gas. There is a method of obtaining a CIGS thin film. There is also a method of preparing a CIGS thin film by preparing an ink using CIGS powder, applying the ink by a screen printing method, and then sintering the CIGS powder by heat treatment under normal pressure and in an inert atmosphere (for example, Non-patent document 1). However, the CIGS thin film produced by this method has voids inside, and it is difficult to produce a dense thin film. In addition, a screen mesh mark remains on the film coated with ink by the screen printing method, and it is difficult to obtain a film having a smooth surface. Furthermore, in the sintering process, Se is likely to evaporate from the thin film, and it has been difficult to sinter many CIGS thin films at once under uniform conditions.
特表２００８－５３７６４０号公報Special table 2008-537640
　そこで、本発明は、緻密で表面平滑性に優れた、太陽電池に好適に使用できるＣＩＧＳ薄膜等の化合物半導体薄膜を、非真空プロセスにおいて、生産性よく、容易に低コストで提供することを目的とする。 Accordingly, an object of the present invention is to provide a compound semiconductor thin film such as a CIGS thin film which is dense and excellent in surface smoothness and can be suitably used for a solar cell with high productivity and low cost easily in a non-vacuum process. And
　前記目的を達成するために、本発明の化合物半導体薄膜の製造方法は、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物半導体薄膜の製造方法であって、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含有する塗布剤を調製する工程と、前記塗布剤を基板に塗布して塗布膜を形成する工程と、前記塗布膜を、機械的に圧力を加えた条件下で加熱して焼結させる加圧焼成工程とを含むことを特徴とする。 In order to achieve the above object, a method for producing a compound semiconductor thin film of the present invention is a method for producing a compound semiconductor thin film containing a group B element, a group B element, and a group V element, and includes a group B element, a group B element, A step of preparing a coating agent containing a VΙB group element, a step of coating the coating agent on a substrate to form a coating film, and heating and baking the coating film under a mechanically pressurized condition. And a pressure firing step for binding.
　本発明の太陽電池は、化合物半導体薄膜を有する太陽電池であって、前記化合物半導体薄膜が、前記本発明の化合物半導体薄膜の製造方法によって製造されたことを特徴とする。 The solar cell of the present invention is a solar cell having a compound semiconductor thin film, wherein the compound semiconductor thin film is manufactured by the compound semiconductor thin film manufacturing method of the present invention.
　本発明の化合物半導体薄膜製造装置は、前記本発明の化合物半導体薄膜の製造方法において使用される装置であって、少なくとも押圧手段と加熱手段とを備えることを特徴とする。 The compound semiconductor thin film manufacturing apparatus of the present invention is an apparatus used in the compound semiconductor thin film manufacturing method of the present invention, and is characterized by comprising at least a pressing means and a heating means.
　本発明によると、緻密で表面平滑性に優れた、太陽電池に好適に使用できるＣＩＧＳ薄膜等の化合物半導体薄膜を、非真空プロセスにおいて、生産性よく、容易に低コストで提供することができる。 According to the present invention, a compound semiconductor thin film such as a CIGS thin film, which is dense and excellent in surface smoothness and can be suitably used for a solar cell, can be easily provided at low cost with high productivity in a non-vacuum process.
図１は、本発明の化合物半導体薄膜の製造方法を示す模式断面図である。FIG. 1 is a schematic cross-sectional view showing a method for producing a compound semiconductor thin film of the present invention. 図２は、実施例１で得られた化合物半導体薄膜のＸ線回折図形である。FIG. 2 is an X-ray diffraction pattern of the compound semiconductor thin film obtained in Example 1. 図３は、実施例１で得られた化合物半導体薄膜の表面および断面の走査電子顕微鏡（ＳＥＭ）像である。3 is a scanning electron microscope (SEM) image of the surface and cross section of the compound semiconductor thin film obtained in Example 1. FIG. 図４は、実施例１で得られた化合物半導体薄膜の光透過率を示すグラフである。FIG. 4 is a graph showing the light transmittance of the compound semiconductor thin film obtained in Example 1. 図５は、実施例２で得られた化合物半導体薄膜の表面および断面のＳＥＭ像である。5 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 2. FIG. 図６は、実施例３で得られた化合物半導体薄膜の表面のＳＥＭ像である。6 is an SEM image of the surface of the compound semiconductor thin film obtained in Example 3. FIG. 図７は、実施例４における化合物半導体の製造方法を示す模式断面図である。FIG. 7 is a schematic cross-sectional view illustrating the method for manufacturing the compound semiconductor in Example 4. 図８は、実施例４で得られた化合物半導体薄膜の表面のＳＥＭ像である。FIG. 8 is an SEM image of the surface of the compound semiconductor thin film obtained in Example 4. 図９は、実施例５で得られた化合物半導体薄膜の表面のＳＥＭ像である。FIG. 9 is an SEM image of the surface of the compound semiconductor thin film obtained in Example 5. 図１０は、実施例６で得られた化合物半導体薄膜のＸ線回折図形である。FIG. 10 is an X-ray diffraction pattern of the compound semiconductor thin film obtained in Example 6. 図１１は、実施例６で得られた化合物半導体薄膜の表面のＳＥＭ像である。FIG. 11 is an SEM image of the surface of the compound semiconductor thin film obtained in Example 6. 図１２は、比較例１で得られた化合物半導体薄膜の表面および断面のＳＥＭ像である。12 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Comparative Example 1. FIG. 図１３は、本発明の化合物半導体薄膜製造装置の構成の一例を示す模式図である。FIG. 13 is a schematic diagram showing an example of the configuration of the compound semiconductor thin film manufacturing apparatus of the present invention. 図１４は、サブストレイト型構造の太陽電池のデバイス構造の模式断面図である。FIG. 14 is a schematic cross-sectional view of a device structure of a solar cell having a substrate type structure. 図１５は、実施例７で得られた化合物半導体薄膜の表面および断面のＳＥＭ像である。FIG. 15 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 7. 図１６は、実施例７で得られた化合物半導体薄膜の光透過率を示すグラフである。FIG. 16 is a graph showing the light transmittance of the compound semiconductor thin film obtained in Example 7. 図１７は、実施例８で得られた化合物半導体薄膜の表面および断面のＳＥＭ像である。FIG. 17 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 8. 図１８（ａ）は、実施例８で得られた化合物半導体（ＣＩＧＳ）薄膜の断面の透過電子顕微鏡（ＴＥＭ）像である。図１８（ｂ）は、図１８（ａ）中に矢印で示した部分を、エネルギー分散Ｘ線分光法（ＥＤＸ）で分析した特性Ｘ線の強度を示すチャートである。FIG. 18A is a transmission electron microscope (TEM) image of a cross section of the compound semiconductor (CIGS) thin film obtained in Example 8. FIG. FIG. 18B is a chart showing the intensity of characteristic X-rays obtained by analyzing the portion indicated by the arrow in FIG. 18A by energy dispersive X-ray spectroscopy (EDX). 図１９（ａ）は、前記化合物半導体（ＣＩＧＳ）薄膜の断面におけるＣＩＧＳ層とＭｏ層との界面の微構造のＴＥＭ像である。図１９（ｂ）は、図１９（ａ）中に矢印で示した部分を、ＥＤＸで分析した特性Ｘ線の強度を示すチャートである。FIG. 19A is a TEM image of the microstructure of the interface between the CIGS layer and the Mo layer in the cross section of the compound semiconductor (CIGS) thin film. FIG. 19B is a chart showing the intensity of characteristic X-rays obtained by analyzing the portion indicated by the arrow in FIG. 19A by EDX. 図２０（ａ）は、実施例８で試作したＣＩＧＳ太陽電池の写真である。図２０（ｂ）は、前記ＣＩＧＳ太陽電池の断面のＳＥＭ像である。FIG. 20A is a photograph of the CIGS solar cell prototyped in Example 8. FIG. FIG. 20B is an SEM image of a cross section of the CIGS solar cell. 図２１は、実施例８で試作したＣＩＧＳ太陽電池の特性のグラフである。FIG. 21 is a graph of the characteristics of the CIGS solar cell prototyped in Example 8. 図２２は、実施例９で得られた化合物半導体薄膜の表面および断面のＳＥＭ像である。FIG. 22 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 9. 図２３は、実施例１０で得られた化合物半導体薄膜の表面および断面のＳＥＭ像である。FIG. 23 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 10. 図２４は、実施例１１で得られた化合物半導体薄膜の表面および断面のＳＥＭ像である。24 is a SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 11. FIG. 図２５（ａ）は、実施例１２で得られた化合物半導体薄膜の光透過率を示すグラフである。図２５（ｂ）、（ｃ）および（ｄ）は、実施例１２で得られた化合物半導体薄膜の禁制帯幅を求めるグラフである。FIG. 25A is a graph showing the light transmittance of the compound semiconductor thin film obtained in Example 12. FIG. 25B, 25C and 25D are graphs for obtaining the forbidden band width of the compound semiconductor thin film obtained in Example 12. FIG. 図２６は、実施例１３で得られた化合物半導体薄膜のＸ線回折図形である。FIG. 26 is an X-ray diffraction pattern of the compound semiconductor thin film obtained in Example 13. 図２７は、実施例１３で得られた化合物半導体薄膜の表面および断面のＳＥＭ像である。27 is an SEM image of the surface and cross section of the compound semiconductor thin film obtained in Example 13. FIG. 図２８（ａ）は、実施例１３で得られた化合物半導体薄膜の光透過率を示すグラフである。図２８（ｂ）は、実施例１３で得られた化合物半導体薄膜の禁制帯幅を求めるグラフである。FIG. 28A is a graph showing the light transmittance of the compound semiconductor thin film obtained in Example 13. FIG. FIG. 28B is a graph for obtaining the forbidden band width of the compound semiconductor thin film obtained in Example 13.
　本発明の化合物半導体薄膜の製造方法において、前記ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む塗布剤として、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素から選ばれる少なくとも２種類の族の元素を含む化合物粒子を含有する塗布剤を用いることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, the coating agent containing the ΙB group element, ΙΙΙB group element, and VΙB group element is an element of at least two kinds selected from ΙB group element, ΙΙΙB group element, and V 元素 B group element. It is preferable to use a coating agent containing compound particles containing.
　前記ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む塗布剤として、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子と、ΙＢ族元素粉末と、ＶΙＢ族元素粉末とを含有する塗布剤を用いることも好ましい。 As a coating agent containing the ΙB group element, お よ び B group element and VΙB group element, a coating agent containing ΙΙΙB group element and VΙB group element, ΙB group element powder, and VΙB group element powder is used. Is also preferable.
　前記ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む塗布剤として、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子を含有する塗布剤を用いることも好ましい。 As the coating agent containing the ΙB group element, お よ び B group element and VΙB group element, it is also preferable to use a coating agent containing compound particles containing the ΙB group element, ΙΙΙB group element and VΙB group element.
　前記化合物粒子として、メカノケミカルプロセスを行って得られた化合物粒子を用いることが好ましい。 It is preferable to use compound particles obtained by performing a mechanochemical process as the compound particles.
　本発明の化合物半導体薄膜の製造方法において、ΙＢ族元素が、ＣｕおよびＡｇから選ばれる少なくとも一つの元素であることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, the group B element is preferably at least one element selected from Cu and Ag.
　本発明の化合物半導体薄膜の製造方法において、ΙΙΙＢ族元素が、Ｉｎ、Ｇａ、およびＡｌから選ばれる少なくとも一つの元素であることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, the group B element is preferably at least one element selected from In, Ga, and Al.
　本発明の化合物半導体薄膜の製造方法において、ＶΙＢ族元素が、Ｓ、ＳｅおよびＴｅから選ばれる少なくとも一つの元素であることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, the VΙB group element is preferably at least one element selected from S, Se, and Te.
　本発明の化合物半導体薄膜の製造方法において、前記塗布剤が、さらにＳｂを含んでいることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, it is preferable that the coating agent further contains Sb.
　本発明の化合物半導体薄膜の製造方法において、さらに前記塗布膜を乾燥させる乾燥工程を、前記加圧焼成工程の前に行うことが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, it is preferable that a drying step for drying the coating film is further performed before the pressure firing step.
　本発明の化合物半導体薄膜の製造方法において、前記加圧焼成工程における機械的に加える圧力が、０Ｐａを超え１００ＭＰａ以下の範囲にあることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, it is preferable that the pressure applied mechanically in the pressure firing step is in a range of more than 0 Pa and 100 MPa or less.
　本発明の化合物半導体薄膜の製造方法において、前記加圧焼成工程が、３００℃～６５０℃の範囲内の温度で行われることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, it is preferable that the pressure firing step is performed at a temperature within a range of 300 ° C. to 650 ° C.
　本発明の化合物半導体薄膜の製造方法において、前記加圧焼成工程が、常圧から１ＭＰａの範囲の圧力の雰囲気下で行われることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, it is preferable that the pressure firing step is performed in an atmosphere having a pressure ranging from normal pressure to 1 MPa.
　本発明の化合物半導体薄膜の製造方法において、前記加圧焼成工程の後に、さらに常圧から１ＭＰａの範囲の圧力の雰囲気下で加熱する熱処理工程を行うことが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, it is preferable to perform a heat treatment step of heating in an atmosphere having a pressure in the range of normal pressure to 1 MPa after the pressure firing step.
　本発明の化合物半導体薄膜の製造方法において、前記熱処理工程が、前記加圧焼成工程における温度よりも高い温度で行われることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, the heat treatment step is preferably performed at a temperature higher than the temperature in the pressure firing step.
　本発明の化合物半導体薄膜の製造方法において、前記塗布剤を基板に塗布する工程が、スクリーン印刷によって行われることが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, the step of applying the coating agent to a substrate is preferably performed by screen printing.
　本発明の化合物半導体薄膜の製造方法において、前記加圧焼成工程において、前記塗布膜が形成された基板を複数枚重ねた状態で加圧焼成することが好ましい。 In the method for producing a compound semiconductor thin film of the present invention, it is preferable that in the pressure baking step, pressure baking is performed in a state where a plurality of substrates on which the coating film is formed are stacked.
　前記複数枚重ねた基板の間には、スペーサーを設けて加圧焼成することが好ましい。 It is preferable to provide a spacer between the plurality of stacked substrates and perform pressure firing.
　また、前記スペーサーとして、金属、ガラスおよびセラミックスからなる群から選ばれるスペーサーを用いることが好ましい。 Moreover, it is preferable to use a spacer selected from the group consisting of metal, glass and ceramics as the spacer.
　本発明の化合物半導体薄膜の製造方法において、前記ΙΙΙＢ族元素に加え、もしくは代えて、ΙΙＢ族元素とΙＶＢ族元素とを組み合わせて用いることもできる。 In the method for producing a compound semiconductor thin film of the present invention, a group B element and a group VB element can be used in combination in place of or in place of the group B element.
　つぎに、本発明について詳細に説明する。ただし、本発明は、以下の記載により制限されない。 Next, the present invention will be described in detail. However, the present invention is not limited by the following description.
　本発明は、従来は真空プロセスで行われていたΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む、ＣＩＧＳ等の化合物半導体薄膜の製造を、非真空プロセスにより行うことが特徴である。非真空プロセスにおいては、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含有する塗布剤を調製しておき、この塗布剤を基板に塗布し、加熱、焼結させることでΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物半導体薄膜を製造する。そして、加熱、焼結をさせる際に、機械的な圧力を加えた状態での加圧焼成をすることが大きな特徴である。 The present invention is characterized in that a compound semiconductor thin film such as CIGS containing a group B element, a group B element, and a group VB element, which has been conventionally performed in a vacuum process, is manufactured by a non-vacuum process. In the non-vacuum process, a coating agent containing a group B element, a group B element, and a group V element is prepared, and this coating agent is applied to a substrate, heated, and sintered to form a group B element and group B. A compound semiconductor thin film containing an element and a VΙB group element is manufactured. And when heating and sintering, it is a great feature that pressure firing is performed in a state where mechanical pressure is applied.
　ΙＢ族元素は、ＣｕおよびＡｇから選ばれる少なくとも一つの元素であることが好ましい。化合物半導体薄膜に要求されるバンドギャップの設計値に応じて、前記元素を適宜選択することができ、例えば、Ａｇを使用すると、バンドギャップを広げることができる。 The group B element is preferably at least one element selected from Cu and Ag. The element can be appropriately selected according to the design value of the band gap required for the compound semiconductor thin film. For example, when Ag is used, the band gap can be widened.
　ΙΙΙＢ族元素としては、Ｉｎ、Ｇａ、およびＡｌから選ばれる少なくとも一つの元素であることが好ましい。例えば、ＧａやＡｌを使用すると、バンドギャップを広げることができる。ΙＢ族元素としてＣｕを含み、ΙΙΙＢ族元素としてＩｎを含む化合物半導体薄膜の場合、前記薄膜中のＣｕ／Ｉｎの元素比率は、０．９５～０．７が理想値である。しかし、薄膜形成後にＫＣＮ水溶液によるエッチングで容易に過剰のＣｕを除去することができるので、Ｃｕ過剰の比率でもよい。前記比率は０．９５～０．４程度でもよい。 The group B element is preferably at least one element selected from In, Ga, and Al. For example, when Ga or Al is used, the band gap can be widened. In the case of a compound semiconductor thin film containing Cu as a group B element and In as a group B element, the ideal element ratio of Cu / In in the thin film is 0.95 to 0.7. However, since excessive Cu can be easily removed by etching with an aqueous KCN solution after forming a thin film, the ratio of excess Cu may be used. The ratio may be about 0.95 to 0.4.
　ＶΙＢ族元素は、Ｓ、ＳｅおよびＴｅから選ばれる少なくとも一つの元素であることが好ましい。硫黄（Ｓ）は、真空プロセスにおける化合物半導体薄膜の製造においては使用されるが、蒸気圧が高いため、従来の加熱、焼結により前記薄膜の製造を行うプロセスの主成分として含有することは好ましくなかった。しかし、本発明の製造方法においては、加圧下で加熱焼結させるので、蒸気圧の高さは大きな問題にはならない。硫黄の存在はＣＩＧＳの結晶粒界の特性改善が期待できるので、少量の添加物として用いることも好ましい。 The V こ と が B group element is preferably at least one element selected from S, Se, and Te. Sulfur (S) is used in the production of a compound semiconductor thin film in a vacuum process, but since it has a high vapor pressure, it is preferably contained as a main component of the process for producing the thin film by conventional heating and sintering. There wasn't. However, in the production method of the present invention, since the heat sintering is performed under pressure, the high vapor pressure is not a big problem. Since the presence of sulfur can be expected to improve the characteristics of CIGS grain boundaries, it is also preferable to use it as a small amount of additive.
　前記ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素から選ばれる少なくとも２種類の族の元素を含む化合物粒子としては、ΙＢ族元素およびＶΙＢ族元素を含む化合物粒子やΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子を用いることができる。本発明において用いる塗布剤は、２種類の族の元素を含む粒子と、前記粒子に含まれない族の元素粉末とを混合して用いてもよいし、少なくとも２種類の族の元素を含む粒子を複数種類用いて、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素のすべてを含むように調製してもよい。前記ΙＢ族元素およびＶΙＢ族元素を含む化合物粒子は、ＣｕＳｅであることが好ましい。前記ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子として（Ｉｎ１－ＸＧａＸ）２Ｓｅ３を用いる場合、ＣｕＳｅとの反応で、Ｃｕ（Ｉｎ１－ＸＧａＸ）Ｓｅ２を容易に得ることができる。従来、使用されているＣｕ２ＳｅやＡｇ２Ｓｅでは、加熱しても短時間でのΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子との反応が進行し難い。これに対して、ＣｕＳｅの場合には、５２３℃以上で、高濃度のＣｕを含んだ液相のＳｅと少量のＣｕ２－ＺＳｅ（固体）とに分解する。このＣｕ２－ＺＳｅは、Ｚが０～０．２程度の値を取り得る不定比化合物の形で存在する。生成した液相のＳｅはΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子と活発に反応する。同時に生成したＣｕ２－ＺＳｅは、反応を阻害するが、反応系内に微過剰のＳｅを添加することにより、Ｃｕ２－ＺＳｅをＳｅ融液中に溶解させることができ、均質なＣｕ－Ｓｅ融液が得られる。均質なＣｕ－Ｓｅ融液であれば、上記反応を良好に進めることができ、好ましい。 The compound particles containing at least two kinds of elements selected from the group B elements, group B elements, and group V elements include compound particles containing group B elements and group V elements, group B elements, and group elements V and B. Compound particles can be used. The coating agent used in the present invention may be a mixture of particles containing two types of elements and group element powders not included in the particles, or particles containing at least two types of elements. May be prepared so as to contain all of the group B element, the group B element, and the group V element. The compound particles containing the group B element and the group V group B are preferably CuSe. When (In 1-X Ga X ) 2 Se 3 is used as the compound particle containing the ΙΙΙB group element and the VΙB group element, Cu (In 1-X Ga X ) Se 2 can be easily obtained by reaction with CuSe. Can do. Conventionally, Cu 2 Se and Ag 2 Se that have been used hardly react with compound particles containing a group B element and a group V element in a short time even when heated. On the other hand, in the case of CuSe, it decomposes into liquid phase Se containing a high concentration of Cu and a small amount of Cu 2-Z Se (solid) at 523 ° C. or higher. This Cu 2-Z Se exists in the form of a non-stoichiometric compound in which Z can take a value of about 0 to 0.2. The generated Se in the liquid phase reacts actively with the compound particles containing the ΙΙΙB group element and the VΙB group element. The simultaneously produced Cu 2-Z Se inhibits the reaction, but by adding a slight excess of Se into the reaction system, Cu 2-Z Se can be dissolved in the Se melt, and homogeneous Cu -Se melt is obtained. A homogeneous Cu—Se melt is preferable because the above reaction can proceed well.
　上記において、前記ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む塗布剤として、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子と、ΙＢ族元素粉末と、ＶΙＢ族元素粉末とを含有する塗布剤を用いることが好ましい。さらに、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子が、ΙΙΙＢ２ＶΙＢ３族化合物であることがより好ましい。例えば、ＣｕＩｎＳｅ２の結晶構造において、最近の発明者らの理論計算によると、Ｃｕ－Ｓｅ間結合は、Ｉｎ－Ｓｅ間結合に比べて、非常に弱いことがわかった。それで、蒸着法においてＣｕＩｎＳｅ２薄膜を作製する場合、まず、Ｉｎ２Ｓｅ３薄膜を作製して、その薄膜にＣｕとＳｅを拡散させ、Ｉｎ２Ｓｅ３薄膜の配向性を変化させることで高品質のＣｕＩｎＳｅ２薄膜が得られる。本発明の化合物半導体薄膜の製造方法においても、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子と、ΙＢ族元素粉末と、ＶΙＢ族元素粉末とを含有する塗布剤を用いることで、高品質の薄膜を得ることができる。前記ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子は、（Ｉｎ１－ＸＧａＸ）２Ｓｅ３および（Ｉｎ１－ＸＧａＸ）Ｓｅから選ばれる少なくとも一種であることが好ましい。（Ｉｎ１－ＸＧａＸ）Ｓｅを用いる場合には、Ｓｅ量が（Ｉｎ１－ＸＧａＸ）２Ｓｅ３を用いる場合と比較して少なくなる。それで、（Ｉｎ１－ＸＧａＸ）２Ｓｅ３を用いる場合と同じ組成比にするためには、１ｍｏｌの（Ｉｎ１－ＸＧａＸ）Ｓｅに対し０．５ｍｏｌのＳｅを加えて調製する。また、化合物半導体薄膜中のＧａ／（Ｉｎ＋Ｇａ）比率である前記化学式中のＸは、０～０．６の範囲にあることが好ましく、０．２～０．４の範囲にあることがより好ましい。太陽電池として化合物半導体薄膜を用いる場合、バンドギャップは１．４ｅＶ程度あることが最も好ましい。バンドギャップの観点からは、Ｇａを前記比率で０．６程度含有させるとよいが、変換効率の観点からは０．２～０．４の範囲にあることがより好ましい。 In the above, as the coating agent containing the group B element, group B element and group V element, the coating agent containing compound particles containing group B element and group V element, group B element powder, and group group V powder. Is preferably used. Furthermore, it is more preferable that the compound particle containing a ΙΙΙB group element and a VΙB group element is a ΙΙΙB 2 VΙB 3 group compound. For example, in the crystal structure of CuInSe 2 , according to recent theoretical calculations by the inventors, it has been found that the Cu—Se bond is much weaker than the In—Se bond. Therefore, when a CuInSe 2 thin film is produced by the vapor deposition method, first, an In 2 Se 3 thin film is produced, Cu and Se are diffused in the thin film, and the orientation of the In 2 Se 3 thin film is changed. CuInSe 2 thin film is obtained. Also in the method for producing a compound semiconductor thin film of the present invention, a high-quality thin film is obtained by using a coating agent containing a compound particle containing a Group B element and a Group V element, a Group B element powder, and a Group V element powder. Can be obtained. The compound particles containing the ΙΙΙB group element and the VΙB group element are preferably at least one selected from (In 1-X Ga X ) 2 Se 3 and (In 1-X Ga X ) Se. When (In 1-X Ga X ) Se is used, the amount of Se is smaller than when (In 1-X Ga X ) 2 Se 3 is used. Therefore, in order to obtain the same composition ratio as when (In 1-X Ga X ) 2 Se 3 is used, 0.5 mol of Se is added to 1 mol of (In 1-X Ga X ) Se. Further, X in the chemical formula, which is a Ga / (In + Ga) ratio in the compound semiconductor thin film, is preferably in the range of 0 to 0.6, and more preferably in the range of 0.2 to 0.4. . When a compound semiconductor thin film is used as a solar cell, the band gap is most preferably about 1.4 eV. From the viewpoint of the band gap, it is preferable to contain about 0.6 of Ga in the above ratio, but from the viewpoint of the conversion efficiency, it is more preferably in the range of 0.2 to 0.4.
　前記化合物粒子の粒子径は、それら化合物粒子が反応して目的とする化合物半導体が生成するので、小さいほど反応性が高くなり望ましい。前記粒子径は、１μｍ以下にあることが好ましく、０．１μｍ以下にあることがより好ましい。 The particle diameter of the compound particles reacts with the compound particles to produce a target compound semiconductor, so that the smaller the particle diameter, the higher the reactivity and the more desirable. The particle diameter is preferably 1 μm or less, and more preferably 0.1 μm or less.
　前記化合物粒子は、ΙＢ族元素およびＶΙＢ族元素を含む化合物粒子、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子を各々準備してもよいが、それぞれの元素単体を準備し、所望の比率で単体を混合した混合物を用い、メカノケミカルプロセスによって各化合物粒子を得ることもできる。この方法を用いることにより、化合物粒子の組成を自在に設計することが容易となる。 The compound particles may be prepared as a compound particle containing a group B element and a group VB element, or a compound particle containing a group B element and a group VB element, but each elemental element is prepared in a desired ratio. Each compound particle can also be obtained by a mechanochemical process using a mixture of the above. By using this method, it becomes easy to freely design the composition of the compound particles.
　物質を粉砕する過程において、微粒子化した物質に衝撃、せん断、ずり応力、摩擦などの機械エネルギーを与えると、前記機械エネルギーの一部が微粒子内に蓄積され、物質粒子の活性や反応性が高まる。活性・反応が高まった前記粒子が、周囲の物質と化学反応を起こす現象を利用して、複合化粒子を合成するプロセスをメカノケミカルプロセスという。メカノケミカルプロセスは、高いエネルギー効率、高い生産性および短いサイクルタイムという特徴を有している。 When mechanical energy such as impact, shear, shear stress, and friction is applied to a finely divided material in the process of pulverizing the material, a part of the mechanical energy is accumulated in the fine particle, thereby increasing the activity and reactivity of the material particle. . The process of synthesizing composite particles by utilizing the phenomenon that the particles having increased activity and reaction cause a chemical reaction with surrounding substances is called a mechanochemical process. The mechanochemical process is characterized by high energy efficiency, high productivity and short cycle time.
　本発明において、メカノケミカルプロセスを行うための手段としては、Ｃｕ、Ｓｅ、Ｉｎ、Ｇａの各単体からＣｕＳｅや（Ｉｎ，Ｇａ）－Ｓｅ化合物を得るメカノケミカル反応が進行するのに、十分な機械的エネルギーを加えることができる装置であれば特に制限されるものではない。装置としては、例えば、遊星型ボールミル、ボールミル、ジェットミル、アトライターミル、ロッドミル、ロールミル、クラッシャーミル等が挙げられる。これらの中でも重力加速度の数倍の衝撃が得られる遊星型ボールミルが好ましい。 In the present invention, as a means for performing a mechanochemical process, a sufficient machine is sufficient for a mechanochemical reaction to obtain CuSe or (In, Ga) -Se compound from each of Cu, Se, In, and Ga. The apparatus is not particularly limited as long as it is a device capable of applying a dynamic energy. Examples of the apparatus include a planetary ball mill, a ball mill, a jet mill, an attritor mill, a rod mill, a roll mill, and a crusher mill. Among these, a planetary ball mill capable of obtaining an impact several times the gravitational acceleration is preferable.
　前記ボールミルとは、多数の球体により被処理物質を粉砕処理するものである。具体的には、回転力、遊星運動、振動等の機械的エネルギーを利用して球体（ボール）によって被処理物質を粉砕する転動ボールミル、遊星ボールミル、振動ボールミル等がある。なお、ボールの材質は、特に限定されるものではないが、不純物混入の観点から、ジルコニア、アルミナ、窒化珪素、タングステンカーバイド、メノウ等が好ましい。 The ball mill is for pulverizing the material to be treated with a large number of spheres. Specifically, there are a rolling ball mill, a planetary ball mill, a vibrating ball mill, and the like that pulverize a material to be treated by a sphere (ball) using mechanical energy such as rotational force, planetary motion, and vibration. The material of the ball is not particularly limited, but zirconia, alumina, silicon nitride, tungsten carbide, agate and the like are preferable from the viewpoint of contamination with impurities.
　本発明において、メカノケミカルプロセスを行う際のボールミルの回転数や容器の大きさ、用いるボールの径や量については、反応を促進することができれば特に制限されるものではない。 In the present invention, the number of rotations of the ball mill, the size of the container, and the diameter and amount of the balls used when performing the mechanochemical process are not particularly limited as long as the reaction can be promoted.
　塗布剤における、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素の含有割合は、目的とする化合物半導体薄膜の組成となるような比で加えるとよい。塗布後の加熱（焼成）工程で化合物から揮発しやすいＳｅのような元素が含まれている場合、その元素の単体をあらかじめ塗布剤中に過剰に混合しておくことも好ましい。あるいは、揮発しやすい前記元素の単体を、反応容器中に共存させておくと、焼成時に、薄膜からの前記元素の揮発を防ぐことができ、好ましい。 The content ratio of the group B element, group B element, and group VB element in the coating agent is preferably added in such a ratio that the composition of the target compound semiconductor thin film is obtained. When an element such as Se that easily volatilizes from a compound is contained in the heating (baking) step after coating, it is also preferable that the element alone is excessively mixed in advance in the coating agent. Alternatively, it is preferable that a single element of the element that is likely to volatilize coexist in the reaction vessel because the element can be prevented from volatilizing from the thin film during firing.
　塗布剤は、溶媒を含んでいることも好ましい。溶媒としては、水系溶媒であっても、有機溶媒等の非水系溶媒であってもよい。有機溶媒には、アクリラート、アルコール（ブチル、エチル、イソプロピルまたはメチル）、アルデヒド、ベンゼン、ジブロモメタン、クロロホルム、ジクロロメタン、ジクロロエタン、トリクロロエタン、シクロ化合物（例えば、シクロペンタノン、シクロヘキサノン）、エステル（例えば、ブチルアセテート、エチルアセテート）、エーテル、グリコール（エチレングリコール、プロピレングリコールなど）、ヘキサン、ヘプタン、脂肪族炭化水素、芳香族炭化水素、ケトン（例えば、アセトン、メチルエチルケトン、メチルイソブチルケトン）、天然油、テルペン、テルピノール、トルエンがある。塗布剤をスクリーン印刷等の方法で基板に塗布する場合には、溶媒はターピネオールやエチレングリコールモノフェニルエーテル等のような高沸点、高粘度のものが塗布性や塗布時の作業性の点から好ましい。水系溶媒は、環境負荷は少ないが、表面張力が有機溶媒より相対的に大きいという欠点があり、基板に塗布する場合には、はじきが生じやすい。基板への塗布性を改善するために、界面活性剤を添加することで塗布剤の表面張力を小さくしてもよい。溶媒の添加量は、塗布剤の塗布方法に応じて最適な粘度範囲となるように調整して加えるとよい。 It is also preferable that the coating agent contains a solvent. The solvent may be an aqueous solvent or a non-aqueous solvent such as an organic solvent. Organic solvents include acrylates, alcohols (butyl, ethyl, isopropyl or methyl), aldehydes, benzene, dibromomethane, chloroform, dichloromethane, dichloroethane, trichloroethane, cyclo compounds (eg, cyclopentanone, cyclohexanone), esters (eg, butyl) Acetate, ethyl acetate), ether, glycol (ethylene glycol, propylene glycol, etc.), hexane, heptane, aliphatic hydrocarbon, aromatic hydrocarbon, ketone (eg, acetone, methyl ethyl ketone, methyl isobutyl ketone), natural oil, terpene, There are terpinol and toluene. When the coating agent is applied to the substrate by a method such as screen printing, a solvent having a high boiling point and high viscosity such as terpineol or ethylene glycol monophenyl ether is preferable from the viewpoint of coating property and workability during coating. . Although the aqueous solvent has a small environmental load, it has a drawback that the surface tension is relatively larger than that of the organic solvent, and repelling is likely to occur when it is applied to a substrate. In order to improve the coating property to the substrate, the surface tension of the coating agent may be reduced by adding a surfactant. The amount of the solvent added may be adjusted so as to be in the optimum viscosity range according to the coating method of the coating agent.
　前記塗布剤には、必要に応じて、性能を損なわない範囲で、顔料、充填剤、分散剤、可塑剤、紫外線吸収剤、界面活性剤、結合剤、乳化剤、消泡剤、乾燥剤、レベリング剤、腐食防止剤、酸化防止剤、チクソトロピー化剤等を添加してもよい。これらの添加剤は一種類を単独で使用してもよく、また二種類以上併用してもよい。なお、前記塗布剤には、ＮａＦを添加することで、基板との密着性を向上させることができるので、好ましい。 For the coating agent, pigments, fillers, dispersants, plasticizers, UV absorbers, surfactants, binders, emulsifiers, antifoaming agents, desiccants, and leveling may be used as long as they do not impair performance. An agent, corrosion inhibitor, antioxidant, thixotropic agent, etc. may be added. These additives may be used alone or in combination of two or more. In addition, since the adhesiveness with a board | substrate can be improved by adding NaF to the said coating agent, it is preferable.
　前記塗布剤は、さらにＳｂを含んでいることが好ましい。Ｓｂは、焼結助剤として作用するものと考えられ、添加によってＣＩＧＳ薄膜の焼結が促進され、より緻密な薄膜が得られることがわかった。Ｓｂの添加量は、得られる化合物半導体の性能を保持できる範囲で設定することができるが、０．２５～５ｍｏｌ％程度であることが好ましい。この範囲において、Ｓｂの添加量が増えるほど、緻密な薄膜が得られる。 It is preferable that the coating agent further contains Sb. Sb is considered to act as a sintering aid, and it was found that the addition of the CIGS thin film promotes the sintering, and a denser thin film is obtained. The amount of Sb added can be set within a range in which the performance of the obtained compound semiconductor can be maintained, but is preferably about 0.25 to 5 mol%. Within this range, a dense thin film can be obtained as the amount of Sb added increases.
　前記塗布剤は、メカノケミカルプロセスを行うための手段と同様の、例えば、ボールミル等の手段で調製することができる。所望の塗布剤が低粘度である場合には、ボールミル等を使用せずに、攪拌することで得ることもできる。前記ボールミルのように被処理物質を粉砕処理する手段を用いる場合、一般には、粉砕処理時間（攪拌時間）を長くすることによって、塗布剤中の粒子の粒径を小さくすることができる。本発明における塗布剤調製工程においては、粉砕処理時間は３０分～２４時間時間の範囲が好ましく、所望の塗布剤物性に応じて、適宜設定することができる。 The coating agent can be prepared by a means such as a ball mill similar to the means for performing a mechanochemical process. When the desired coating agent has a low viscosity, it can also be obtained by stirring without using a ball mill or the like. When using a means for pulverizing the material to be treated such as the ball mill, generally, the particle size of the particles in the coating agent can be reduced by increasing the pulverization time (stirring time). In the coating agent preparation step in the present invention, the pulverization time is preferably in the range of 30 minutes to 24 hours, and can be appropriately set according to the desired properties of the coating agent.
　前記塗布剤を基板に塗布する方法としては、例えば、スクリーン印刷法、ファンテンコート法、ダイコート法、スピンコート法、スプレーコート法、グラビアコート法、ロールコート法、バーコート法等の塗布法を用いることができる。 Examples of methods for applying the coating agent to the substrate include screen printing methods, phantom coating methods, die coating methods, spin coating methods, spray coating methods, gravure coating methods, roll coating methods, and bar coating methods. Can be used.
　前記塗布剤を塗布する基板としては、ソーダライムガラスを用いることが好ましい。ソーダライムガラスにはＮａが含まれるが、含有されるＮａが基板上に形成された化合物半導体薄膜層に拡散することにより、化合物半導体薄膜の電気物性によい影響を与えることができる場合がある。特に、前記化合物半導体薄膜を太陽電池として使用する場合には好ましい。本発明の化合物半導体薄膜の製造方法は、塗布工程により基板上に薄膜を形成するので、蒸着法等に比べ、基板の選択の幅を広げることができる。前記ソーダライムガラスのような堅い基板以外にも、例えば、金属箔やプラスチックフィルムのようなフレキシブルな基板を使用することもできる。フレキシブルな基板を使用する場合には、ロール・ツー・ロール方式といった量産性の高いプロセスにも適用可能である。 It is preferable to use soda lime glass as the substrate on which the coating agent is applied. The soda lime glass contains Na, but the contained Na may diffuse into the compound semiconductor thin film layer formed on the substrate, so that the electrical properties of the compound semiconductor thin film may be positively affected. In particular, it is preferable when the compound semiconductor thin film is used as a solar cell. In the method for producing a compound semiconductor thin film of the present invention, a thin film is formed on a substrate by a coating process, so that the selection range of the substrate can be widened as compared with vapor deposition. In addition to the hard substrate such as soda lime glass, for example, a flexible substrate such as a metal foil or a plastic film can be used. When a flexible substrate is used, it can also be applied to a mass-productive process such as a roll-to-roll method.
　本発明の化合物半導体薄膜の製造方法において、前記塗布剤を基板に塗布して塗布膜を形成する工程と、前記塗布膜を機械的に圧力を加えた加圧条件下で加熱して化合物半導体を焼結させる加圧焼成工程との間に、塗布剤の乾燥工程を含むことも好ましい。塗布膜中に溶媒が多く含まれる状態で高温に加熱すると、溶媒が一気に蒸発すること等に起因して膜にボイドが発生するおそれがある。また、機械的に加圧した状態での加熱となるため、溶媒が蒸発しきらず、膜中に残留してしまうおそれもある。そのため、加圧焼成工程前に、ある程度の溶媒を除去して塗布膜を乾燥させる工程を設けることは好ましい。 In the method for producing a compound semiconductor thin film of the present invention, the step of applying the coating agent to a substrate to form a coating film, and heating the coating film under pressure under mechanical pressure, the compound semiconductor It is also preferable to include a coating agent drying step between the sintering step. When the coating film is heated to a high temperature in a state where a large amount of solvent is contained, voids may be generated in the film due to evaporation of the solvent all at once. In addition, since the heating is performed in a mechanically pressurized state, the solvent may not be evaporated and may remain in the film. Therefore, it is preferable to provide a step of removing a certain amount of solvent and drying the coating film before the pressure firing step.
　前記塗布膜を乾燥する工程は、例えば、自然乾燥でもよいし、風を吹きつけての風乾であってもよいし、加熱乾燥や減圧乾燥であってもよい。また、これらを組み合わせた方法であってもよい。前記塗布膜の厚みは、好ましくは、１０～０．１μｍの範囲であり、より好ましくは、３～０．３μｍの範囲である。 The step of drying the coating film may be, for example, natural drying, air drying by blowing air, heat drying or vacuum drying. Moreover, the method which combined these may be used. The thickness of the coating film is preferably in the range of 10 to 0.1 μm, more preferably in the range of 3 to 0.3 μm.
　本発明における加圧焼成工程は、前記塗布膜が形成された基板を、上下から押し板で挟み込んで加圧し、その状態で加熱することで（ホットプレス）、前記塗布剤に含まれるΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を焼結させて化合物半導体薄膜を製造する工程である。本工程は、以下に述べる押圧手段と加熱手段とを備える装置を使用して実施することができる。 In the press firing process in the present invention, the substrate on which the coating film is formed is sandwiched between press plates from above and below, pressed, and heated in that state (hot pressing), so that the group B element contained in the coating agent In this step, the compound semiconductor thin film is manufactured by sintering the group B element and the group V group B element. This step can be performed using an apparatus including a pressing unit and a heating unit described below.
　図１３に、本発明の化合物半導体薄膜製造装置の構成の一例を示す。図示のとおり、この製造装置１３０は、チャンバー１３１、加熱槽１３２、ヒーター１３３、押し棒１３４、１３４’を主要な構成部材として有する。 FIG. 13 shows an example of the configuration of the compound semiconductor thin film manufacturing apparatus of the present invention. As illustrated, the manufacturing apparatus 130 includes a chamber 131, a heating tank 132, a heater 133, and push rods 134 and 134 'as main components.
　チャンバー１３１内には、加熱槽１３２および一組の押し棒１３４、１３４’が配置されており、前記一組の押し棒１３４、１３４’は本発明における押圧手段であり、加熱槽１３２に上下方向に対向して洞貫されている。前記加熱槽１３２内には、ヒーター１３３が設置されている。前記チャンバー１３１には、真空ポンプやガス供給手段（図示せず）が接続されていてもよい。真空ポンプにより前記チャンバー１３１内を減圧し、ガス供給手段から例えば窒素等のガスをチャンバー内に供給することで、チャンバー内の空気を置換することができる。前記ガス供給手段は、ガスボンベに接続されており、これにより、適度な圧力のガスを、前記チャンバー１３１内に供給することが可能となっている。前記ヒーター１３３は、加熱槽１３２内の温度制御をする手段である。本例においては、ヒーター１３３は加熱槽１３２内に設置されているが、これに限定されない。前記ヒーター１３３が加熱槽１３２内にある態様では、前記ヒーター１３３は、ヒーターが石英管内に封入されている石英管ヒーターであることが好ましい。加熱により、塗布層からＳｅ等が蒸発し、加熱槽内がＳｅ雰囲気になることがあるが、ヒーターが剥き出しの場合、ヒーター自体とＳｅ等が反応してしまうからである。温度制御手段は、ヒーターに限定されず、通電加熱や放電プラズマ焼結機によるものであってもよい。 In the chamber 131, a heating tank 132 and a set of push rods 134, 134 'are arranged. The set of push bars 134, 134' is a pressing means in the present invention, and the heating tank 132 has a vertical direction. It is pierced opposite. A heater 133 is installed in the heating tank 132. A vacuum pump or a gas supply means (not shown) may be connected to the chamber 131. By reducing the pressure in the chamber 131 with a vacuum pump and supplying a gas such as nitrogen from the gas supply means into the chamber, the air in the chamber can be replaced. The gas supply means is connected to a gas cylinder, whereby a gas having an appropriate pressure can be supplied into the chamber 131. The heater 133 is a means for controlling the temperature in the heating tank 132. In this example, the heater 133 is installed in the heating tank 132, but is not limited thereto. In an embodiment in which the heater 133 is in the heating tank 132, the heater 133 is preferably a quartz tube heater in which the heater is enclosed in a quartz tube. This is because Se and the like may evaporate from the coating layer due to heating, and the inside of the heating tank may become a Se atmosphere, but when the heater is exposed, Se and the like react with each other. The temperature control means is not limited to a heater, and may be a current heating or a discharge plasma sintering machine.
　本発明の製造方法においては、前記一組の押し棒１３４、１３４’の間に前記塗布膜が形成された基板を設置した後に、前記一組の押し棒１３４、１３４’を、その間隔を狭める方向に動かすことにより、前記基板に機械的な圧力を加える。前記基板に圧力を加える際には、前記基板全体に均等に加圧がされるようにするため、前記基板と同程度の大きさの押し板を用意し、前記基板を挟み込むように配置することが好ましい。前記押し板の材料としては、窒化珪素製セラミックス、アルミナ、ジルコニア等を好適に用いることができる。また、前記押し板と前記基板との間には、基板の破損を防止するために緩衝材としての役割を果たす第二の押し板をさらに設置してもよい。前記第二の押し板としては、グラファイトシート、テフロン（登録商標）シート等を使用することができる。 In the manufacturing method of the present invention, after the substrate on which the coating film is formed is installed between the pair of push rods 134 and 134 ', the interval between the pair of push rods 134 and 134' is reduced. By moving in the direction, mechanical pressure is applied to the substrate. When applying pressure to the substrate, a pressing plate having the same size as the substrate is prepared so that the entire substrate is pressurized, and the substrate is arranged so as to sandwich the substrate. Is preferred. As the material of the pressing plate, silicon nitride ceramics, alumina, zirconia, or the like can be suitably used. In addition, a second push plate that serves as a cushioning material may be further provided between the push plate and the substrate in order to prevent damage to the substrate. As the second push plate, a graphite sheet, a Teflon (registered trademark) sheet, or the like can be used.
　前記基板の前記塗布膜が形成された面には、スペーサーが配置されることが好ましい。前記スペーサーは、前記塗布膜の押し板への付着を防止するために用いる。前記スペーサーとしては、塗布膜に含有される化合物半導体を構成する元素と反応せず、基板からの塗布膜の転写が起こりにくく、加圧によって過度に変形しない材料を用いるとよい。スペーサーとしては、金属、ガラス、セラミックス等が好ましく、アルミニウム箔、ホウ珪酸ガラス等を使用することができる。また、押し板表面にスペーサーとなり得る材料をコーティングしておいてもよい。 It is preferable that a spacer is disposed on the surface of the substrate on which the coating film is formed. The spacer is used to prevent the coating film from adhering to the pressing plate. As the spacer, it is preferable to use a material that does not react with an element constituting the compound semiconductor contained in the coating film, hardly transfers the coating film from the substrate, and does not deform excessively by pressurization. As the spacer, metal, glass, ceramics and the like are preferable, and aluminum foil, borosilicate glass and the like can be used. Further, a material that can serve as a spacer may be coated on the surface of the pressing plate.
　たとえば、化合物半導体薄膜として、ＣｕＩｎＳｅ２を製造する場合、Ｓｅの蒸発によって、平衡反応が次の方向に進んでしまう。
　　２ＣｕＩｎＳｅ２→Ｃｕ２Ｓｅ＋Ｉｎ２Ｓｅ＋Ｓｅ２
本発明の製造方法では、塗布面をプレスするためにＳｅが蒸発しにくく、そのため、上記式は反対方向（２ＣｕＩｎＳｅ２←Ｃｕ２Ｓｅ＋Ｉｎ２Ｓｅ＋Ｓｅ２）に進むので、好ましい。 For example, when producing CuInSe 2 as a compound semiconductor thin film, the equilibrium reaction proceeds in the following direction due to the evaporation of Se.
2CuInSe 2 → Cu 2 Se + In 2 Se + Se 2
In the manufacturing method of the present invention, Se is difficult to evaporate in order to press the coated surface, and therefore, the above formula proceeds in the opposite direction (2CuInSe 2 ← Cu 2 Se + In 2 Se + Se 2 ), which is preferable.
　本発明における加圧焼成工程では、前記塗布膜が形成された基板を複数枚重ねた状態で加圧焼成することもできる。一般に、加圧焼成のプロセスは、バッチプロセスになる点で生産性が低くなる場合が多いが、本発明においては、基板を複数枚重ねて同時に処理をすることができるので、生産効率を大幅に向上させることができる。この場合、複数の前記塗布膜が形成された基板間には、前記スペーサーを挿入しておくとよい。 In the press firing process in the present invention, press firing may be performed in a state where a plurality of substrates on which the coating film is formed are stacked. In general, the pressure firing process is often low in productivity because it becomes a batch process. However, in the present invention, since a plurality of substrates can be processed simultaneously, the production efficiency is greatly improved. Can be improved. In this case, the spacer may be inserted between the substrates on which a plurality of the coating films are formed.
　前記加圧は、機械的に加えた圧力が０Ｐａを超え１００ＭＰａ以下の範囲にあることが好ましい。この範囲の圧力を加えることにより、加熱により周囲が液相となった化合物半導体の結晶粒が、隣接する結晶粒と結合しやすくなることから、粒成長が促進される。また、圧力を加えた状態では、緻密な、結晶粒と結晶粒との接触面積が大きい状態で、反応焼結や粒成長をさせることができるため、緻密な薄膜を作製することができる。従来のプロセスで加圧せずに焼結させる場合、焼結は三次元のプロセスで進行するため、塗布膜が形成された状態から上下方向にも左右方向にも収縮が起こり、寸法精度が得られず、また、薄膜には空孔が多数存在し、緻密化が困難であった。また、水平方向の膜の収縮によって、膜にひび割れが生じることも問題であった。本発明の製造方法は、これらの問題点を改善したものである。 The pressurization is preferably in the range where the mechanically applied pressure exceeds 0 Pa and is 100 MPa or less. By applying a pressure within this range, the crystal grains of the compound semiconductor whose surroundings are in a liquid phase by heating are easily bonded to the adjacent crystal grains, so that the grain growth is promoted. In addition, in a state where pressure is applied, reaction sintering and grain growth can be performed in a state where the contact area between the crystal grains and the crystal grains is large, so that a dense thin film can be manufactured. When sintering without pressure in the conventional process, the sintering proceeds in a three-dimensional process, so shrinkage occurs in the vertical and horizontal directions from the state in which the coating film is formed, and dimensional accuracy is obtained. In addition, the thin film had many vacancies and was difficult to be densified. Another problem is that the film is cracked by the contraction of the film in the horizontal direction. The production method of the present invention improves these problems.
　前記加圧焼成工程での加熱温度は、３００℃～６５０℃の範囲内の温度で行われることが好ましく、より好ましくは３５０℃～５５０℃の範囲内である。また、雰囲気としては、常圧から１ＭＰａの範囲の圧力雰囲気下であることが好ましい。前記塗布膜が形成された基板を室温常圧中でチャンバー内にセットした後、ＣＩＧＳ膜からのＳｅの蒸発を最小限に抑えるために、密閉したチャンバー内で加圧焼成する場合には、温度上昇とともにチャンバー内部の雰囲気圧力が高くなる。しかし、１ＭＰａを超えると、装置の材質や構造に要求されるスペックが高度になり、汎用性や安全性の点からも実用性が低くなる。本発明の製造方法では、加圧せずに焼結をさせる場合に比べて、低温の条件下で化合物半導体薄膜を製造することができる。本発明の製造方法によると、従来に比べ、加熱温度が低温でも結晶粒が成長する。 The heating temperature in the pressure firing step is preferably performed at a temperature in the range of 300 ° C. to 650 ° C., more preferably in the range of 350 ° C. to 550 ° C. The atmosphere is preferably a pressure atmosphere in the range of normal pressure to 1 MPa. In order to minimize the evaporation of Se from the CIGS film after setting the substrate on which the coating film has been formed in the chamber at room temperature and normal pressure, when the pressure baking is performed in a sealed chamber, the temperature As the temperature rises, the atmospheric pressure inside the chamber increases. However, if it exceeds 1 MPa, the specifications required for the material and structure of the device become high, and the practicality is low from the viewpoint of versatility and safety. In the production method of the present invention, the compound semiconductor thin film can be produced under a low temperature condition as compared with the case of sintering without applying pressure. According to the production method of the present invention, crystal grains grow even at a lower heating temperature than in the conventional method.
　前記加圧焼成工程の後に、さらに常圧から１ＭＰａの範囲の圧力の雰囲気下で加熱する熱処理工程を行うことも好ましい。前記熱処理工程を行うことによって、結晶粒径には変化がなくとも、太陽電池としたときの特性が向上する。前記熱処理工程における加熱温度は、前記加熱処理工程における温度よりも高い温度で行われると効果的であり、好ましくは４００℃～６５０℃の範囲内であり、より好ましくは４５０℃～６００℃の範囲内である。 It is also preferable to perform a heat treatment step of heating in an atmosphere having a pressure ranging from normal pressure to 1 MPa after the pressure firing step. By performing the heat treatment step, the characteristics of a solar cell are improved even if the crystal grain size does not change. The heating temperature in the heat treatment step is effective when performed at a temperature higher than the temperature in the heat treatment step, preferably in the range of 400 ° C. to 650 ° C., more preferably in the range of 450 ° C. to 600 ° C. Is within.
　前記熱処理工程は、Ｓｅを蒸着しながら行うことも好ましい。Ｓｅを蒸着しながら熱処理を行うことにより、ＣＩＧＳ薄膜の分解を防ぎ、太陽電池としたときの特性が向上する。この場合も、加圧焼成工程での加熱温度における温度よりも高い温度で行われると効果的であり、好ましくは４００℃～６５０℃の範囲内であり、より好ましくは４５０℃～６００℃の範囲内である。 It is also preferable to perform the heat treatment step while depositing Se. By performing the heat treatment while depositing Se, the CIGS thin film is prevented from being decomposed, and the characteristics of the solar cell are improved. In this case as well, it is effective when performed at a temperature higher than the temperature at the heating temperature in the pressure firing step, preferably in the range of 400 ° C. to 650 ° C., more preferably in the range of 450 ° C. to 600 ° C. Is within.
　以上において、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物半導体薄膜の製造方法について詳述したが、本発明においては、前記ΙΙΙＢ族元素に加え、もしくは代えて、ΙΙＢ族元素とΙＶＢ族元素とを組み合わせて用いることで、化合物半導体薄膜を製造することもできる。前記ΙΙΙＢ族元素に代えて、ΙΙＢ族元素とΙＶＢ族元素とを組み合わせて用いると、ΙＢ族元素、ΙΙＢ族元素、ΙＶＢ族元素およびＶΙＢ族元素を含む化合物半導体薄膜を製造することができる。ΙΙΙＢ族元素であるＩｎやＧａ等の希少金属は、資源的な制約がある。そのため、Ｉｎを、ΙΙＢ族元素であるＺｎおよびΙＶＢ族元素であるＳｎに置き換えて用いることもできる。ΙΙＢ族元素としてはＺｎを、ΙＶＢ族元素としては、ＳｎやＧｅを好適に用いることができる。 In the above, the manufacturing method of the compound semiconductor thin film containing the ΙB group element, the ΙΙΙB group element and the VΙB group element has been described in detail. In the present invention, in addition to or instead of the ΙΙΙB group element, the ΙΙB group element and the ΙVB group. A compound semiconductor thin film can also be manufactured by using it in combination with an element. When a ΙΙB group element and a ΙVB group element are used in combination instead of the ΙΙΙB group element, a compound semiconductor thin film containing a ΙB group element, a ΙΙB group element, a ΙVB group element, and a VΙB group element can be produced. Rare metals such as In and Ga, which are group B elements, have resource limitations. Therefore, In can be used in place of Zn which is a ΙΙB group element and Sn which is a ΙVB group element. Zn can be suitably used as the ΙΙB group element, and Sn or Ge can be suitably used as the ΙVB group element.
　本発明の化合物半導体薄膜の製造方法によって製造された化合物半導体薄膜は、太陽電池に好適に使用することができる。前記太陽電池の構造の一例としては、サブストレイト型構造が挙げられる。サブストレイト型構造の太陽電池のデバイス構造の模式断面図の一例を、図１４に示す。基板１４１上に裏面電極１４２があり、その上に化合物半導体薄膜による光吸収層１４３、バッファー層１４４、透明電極１４５、取り出し電極１４６という構成である。例えば、基板１４１としてはソーダライムガラス、裏面電極１４２にはＭｏ、バッファー層１４４にはＺｎＯ／ＣｄＳ、透明電極１４５にはＺｎＯ：ＡｌやＺｎＯ：Ｂ、取り出し電極１４６としてＡｌ／Ｎｉが用いられる。太陽光は、透明電極１４５側から入射する。透明電極１４５上には、必要に応じて反射防止膜１４７を設けてもよい。 The compound semiconductor thin film produced by the method for producing a compound semiconductor thin film of the present invention can be suitably used for solar cells. An example of the structure of the solar cell is a substrate type structure. An example of a schematic cross-sectional view of the device structure of a solar cell having a substrate type structure is shown in FIG. A back electrode 142 is provided on a substrate 141, and a light absorption layer 143 made of a compound semiconductor thin film, a buffer layer 144, a transparent electrode 145, and an extraction electrode 146 are formed thereon. For example, soda lime glass is used as the substrate 141, Mo is used as the back electrode 142, ZnO / CdS is used as the buffer layer 144, ZnO: Al or ZnO: B is used as the transparent electrode 145, and Al / Ni is used as the extraction electrode 146. Sunlight enters from the transparent electrode 145 side. An antireflection film 147 may be provided on the transparent electrode 145 as necessary.
　前記化合物半導体薄膜を太陽電池に用いる場合、薄膜の厚みは１μｍ以上あれば、太陽光の吸収に十分である。さらに、裏面で光を反射させることで、光吸収層内での光路長を長くすることができ、１μｍ以下の薄膜でも太陽光を十分に吸収することができるようになる。また、低コスト太陽電池に用いることを考えると、薄膜の厚みは１０μｍ以下が望ましい。また、蒸着法で作製したＣＩＧＳ膜の結晶粒は大きく、粒径は膜厚程度まで成長している。しかし、結晶粒径がそれほど大きくなくても高い変換効率が得られる場合もある。重要な点は、結晶粒子が十分に焼結して緻密であることである。 When the compound semiconductor thin film is used for a solar cell, a thickness of the thin film of 1 μm or more is sufficient to absorb sunlight. Furthermore, by reflecting light on the back surface, the optical path length in the light absorption layer can be increased, and even a thin film of 1 μm or less can sufficiently absorb sunlight. In consideration of use in low-cost solar cells, the thickness of the thin film is desirably 10 μm or less. Moreover, the crystal grain of the CIGS film produced by the vapor deposition method is large, and the grain size has grown to about the film thickness. However, high conversion efficiency may be obtained even if the crystal grain size is not so large. The important point is that the crystal grains are sufficiently sintered and dense.
　つぎに、本発明の実施例について説明する。なお、本発明は、下記の実施例によってなんら限定ないし制限されない。また、各実施例および各比較例における各種特性および物性の測定および評価は、下記の方法により実施した。 Next, examples of the present invention will be described. The present invention is not limited or restricted by the following examples. In addition, various properties and physical properties in each example and each comparative example were measured and evaluated by the following methods.
（表面形状観察）
　化合物半導体薄膜は、走査型電子顕微鏡（（株）キーエンス製、商品名「リアルサーフェイス顕微鏡　ＶＥ－９８００ＳＰ２１９９」）を用いて表面形状の観察を行った。 (Surface shape observation)
The surface of the compound semiconductor thin film was observed using a scanning electron microscope (manufactured by Keyence Corporation, trade name “Real Surface Microscope VE-9800SP2199”).
（結晶構造解析）
　化合物半導体薄膜は、Ｘ線回折装置（（株）リガク製、商品名「自動Ｘ線回折装置　ＲＩＮＴ２４００」）を用いて分析を行った。Ｃｕターゲットを用い、管電圧は４０ｋＶ、管電流は１００ｍＡでＸ線を発生した。測定は２θ／θ法で行った。 (Crystal structure analysis)
The compound semiconductor thin film was analyzed using an X-ray diffractometer (manufactured by Rigaku Corporation, trade name “automatic X-ray diffractometer RINT2400”). Using a Cu target, X-rays were generated at a tube voltage of 40 kV and a tube current of 100 mA. The measurement was performed by the 2θ / θ method.
（光透過率）
　ガラス基板上に形成した化合物半導体薄膜は、マルチチャンネル分光器（浜松ホトニクス（株）製、商品名「マルチチャンネル分光器　ＰＭＡ－１２」）を用いて吸収スペクトルの測定を行い、光透過率の算出を行った。光検出素子は感度波長範囲が９００ｎｍ～１６５０ｎｍのＩｎＧａＡｓリニアイメージセンサ　Ｃ１００２８－０１を用いた。 (Light transmittance)
The compound semiconductor thin film formed on the glass substrate is measured for absorption spectrum using a multi-channel spectrometer (trade name “Multi-channel spectrometer PMA-12” manufactured by Hamamatsu Photonics Co., Ltd.), and light transmittance is calculated. Went. As the light detection element, an InGaAs linear image sensor C10028-01 having a sensitivity wavelength range of 900 nm to 1650 nm was used.
［実施例１］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｉｎ、Ｇａ、ＳｅをＣｕ１．０２（Ｉｎ１－ＸＧａＸ）Ｓｅ２．１の比（Ｘ＝０．００５、０．１、０．２）となるように秤量後、そこにＮａＦを０．５ｍｏｌ％（Ｃｕ１．０２（Ｉｎ１－ＸＧａＸ）Ｓｅ２．１が１ｍｏｌに対して０．００５ｍｏｌに相当）添加した。遊星ボールミル（フリッチュ社製、商品名「遊星型ボールミル　ｐｒｅｍｉｕｍ　ｌｉｎｅ　Ｐ－７」）用のジルコニア製４５ｃｃ容器に秤量した粉末２０ｇと、３ｍｍ径のジルコニア製玉石４０ｇとを入れ、窒素雰囲気下で、８００ｒｐｍ、２０分間攪拌した。攪拌により、メカノケミカル反応が起こり、Ｃｕ（Ｉｎ１－ＸＧａＸ）Ｓｅ２（ＣＩＧＳ）を主成分とする粉末が得られた。ここで、Ｘ＝０．００５、０．１、０．２の３水準である。得られた粉末の主成分がカルコパイライト型の結晶構造を有する結晶性の良いＣＩＧＳであることを粉末Ｘ線回折により確認した。 [Example 1]
(Preparation of raw material powder)
After weighing the element powders Cu, In, Ga, Se to a ratio of Cu 1.02 (In 1-X Ga X ) Se 2.1 (X = 0.005, 0.1, 0.2), Thereto was added 0.5 mol% of NaF (Cu 1.02 (In 1-X Ga X ) Se 2.1 corresponds to 0.005 mol with respect to 1 mol). 20 g of powder weighed in a 45 cc container made of zirconia for planetary ball mill (product name “Planet type ball mill premium line P-7” manufactured by Fritsch) and 40 g of 3 mm diameter zirconia cobblestone were placed at 800 rpm in a nitrogen atmosphere. For 20 minutes. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 1-X Ga X ) Se 2 (CIGS) as a main component was obtained. Here, there are three levels of X = 0.005, 0.1, and 0.2. It was confirmed by powder X-ray diffraction that the main component of the obtained powder was CIGS having a chalcopyrite type crystal structure and good crystallinity.
（塗布剤の調製）
　前記ＣＩＧＳを主成分とする粉末の入ったジルコニア製容器に、それぞれエチレングリコールモノフェニルエーテルを４ｍｌ加え、容器内を窒素雰囲気にして、７００ｒｐｍ、１２０分間攪拌し、塗布剤であるインクを３種類得た。 (Preparation of coating agent)
Add 4 ml of ethylene glycol monophenyl ether to each of the zirconia containers containing the above-mentioned CIGS as a main component, make the container a nitrogen atmosphere, and stir at 700 rpm for 120 minutes to obtain three types of inks as coating agents. It was.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、スクリーン印刷（４００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing (400 mesh) to form a coating layer.
（乾燥）
　前記塗布層を形成した基板を、窒素雰囲気下で、１４５℃、７分間乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried at 145 ° C. for 7 minutes in a nitrogen atmosphere.
（加圧焼成）
　図１に模式断面図を示したように、本発明の化合物半導体薄膜製造装置を用い、以下のとおり前記乾燥後の基板を加圧焼成し、塗布膜を焼結させてＣＩＧＳ薄膜を作製した。ＣＩＧＳ塗布膜１を形成した基板２を押し板５の上に配置した。そして、ＣＩＧＳ塗布膜１に直接接触させてスペーサー３を載せ、さらに押し板５’を載せた。この２枚の押し板５および５’を一対の押し棒４、４’で、機械的に加圧しながら焼結を行った。スペーサー３としてアルミニウム箔（厚み７μｍ）、押し棒４、４’としてφ４０ｍｍの円柱状ジルコニア製セラミックス、押し板５、５’として６０ｍｍ角の窒化珪素製セラミックス板を用いた。このような装置を用いて、窒素雰囲気下、４５０℃で、機械的な圧力を２ＭＰａ加えた状態で、３０分間、加圧焼成して、焼結ＣＩＧＳ薄膜を得た。加熱は、チャンバーを密閉した後、窒素雰囲気下、常圧で開始し、２００℃に達したところで、押し板で機械的な圧力（プレス）を加えた。加圧状態のまま所定の４５０℃まで加熱し、４５０℃で３０分間保持した後、押し板での加圧を解除して常圧に戻した。常温まで冷却した後、チャンバーを開放して焼結させた薄膜付きの基板を取り出した。 (Pressurized firing)
As shown in the schematic cross-sectional view of FIG. 1, using the compound semiconductor thin film manufacturing apparatus of the present invention, the dried substrate was pressure fired as follows, and the coated film was sintered to produce a CIGS thin film. The substrate 2 on which the CIGS coating film 1 was formed was placed on the pressing plate 5. Then, the spacer 3 was placed in direct contact with the CIGS coating film 1, and a push plate 5 'was placed thereon. The two pressing plates 5 and 5 ′ were sintered while being mechanically pressed by a pair of pressing rods 4 and 4 ′. The spacer 3 was an aluminum foil (thickness 7 μm), the push rods 4 and 4 ′ were cylindrical zirconia ceramics having a diameter of 40 mm, and the push plates 5 and 5 ′ were 60 mm square silicon nitride ceramic plates. Using such an apparatus, under a nitrogen atmosphere at 450 ° C. with a mechanical pressure of 2 MPa applied, pressure firing was performed for 30 minutes to obtain a sintered CIGS thin film. Heating was started at normal pressure in a nitrogen atmosphere after the chamber was sealed, and when the temperature reached 200 ° C., mechanical pressure (press) was applied with a pressing plate. After heating to a predetermined 450 ° C. in a pressurized state and holding at 450 ° C. for 30 minutes, the pressure on the pressing plate was released and the pressure was returned to normal pressure. After cooling to room temperature, the chamber was opened and the sintered substrate with a thin film was taken out.
（薄膜の特性）
　実施例１で得られた３種類のＣＩＧＳ薄膜（Ｘ＝０．００５、０．１、０．２）をＸ線回折（ＸＲＤ）で分析した。得られたＸ線回折図形を図２に示す。これらのＸ線回折図形は、基本的にＣｕＩｎＳｅ２の結晶構造解析データ（ＩＣＳＤ：Ｉｎｏｒｇａｎｉｃ　Ｃｒｙｓｔａｌ　Ｓｔｒｕｃｔｕｒｅ　Ｄａｔａｂａｓｅ　＃７００５１）に基づくシミュレーションによるＸ線回折図形と一致し、カルコパイライト型構造を持つＣＩＧＳ薄膜が合成されていることがわかった。このＸ線回折図形から、本実施例のＣＩＧＳ薄膜が不純物を含まない単一相であること、Ｘの増加とともに回折ピークが高角度側にシフトして、Ｇａの固溶量が増加していることが確認できる。 (Thin film characteristics)
Three types of CIGS thin films (X = 0.005, 0.1, 0.2) obtained in Example 1 were analyzed by X-ray diffraction (XRD). The obtained X-ray diffraction pattern is shown in FIG. These X-ray diffraction patterns basically correspond to the X-ray diffraction patterns obtained by simulation based on the crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 70051) of CuInSe 2 , and a CIGS thin film having a chalcopyrite structure is synthesized. I found out. From this X-ray diffraction pattern, the CIGS thin film of the present example is a single phase that does not contain impurities, and as the X increases, the diffraction peak shifts to the high angle side, and the solid solution amount of Ga increases. I can confirm that.
　過剰のＳｅは焼結過程で蒸散すると考えられる。従って、過剰に加えるＳｅ量を、条件によって適時調節する必要がある。一般に、焼成温度が高いとＳｅの蒸散が激しいので最適な過剰Ｓｅ量も多くなる。また、過剰に加えたＣｕはＳｅと反応してＣｕＳｅになり、それがＣＩＧＳの焼結助剤として働くと考えられる。ＣｕＳｅは焼成後にはＣｕ－Ｓｅ系不純物としてＣＩＧＳ薄膜中に残留する。このＣｕ－Ｓｅ不純物はＫＣＮ水溶液によるエッチングによって容易に除去することができる。 Excess Se is considered to evaporate during the sintering process. Therefore, it is necessary to adjust the amount of Se added excessively according to conditions. In general, when the firing temperature is high, Se transpiration is severe, and the optimum amount of excess Se also increases. Moreover, Cu added excessively reacts with Se to form CuSe, which is considered to work as a sintering aid for CIGS. CuSe remains in the CIGS thin film as Cu—Se impurities after firing. This Cu—Se impurity can be easily removed by etching with an aqueous KCN solution.
　得られた薄膜の表面および断面微構造を走査電子顕微鏡（ＳＥＭ）で観察した。それらの写真を図３に示す。これらの写真から、ＣＩＧＳの結晶粒成長と緻密化が認められ、本実施例の方法によって、緻密なＣＩＧＳ薄膜が得られることが確認できる。特に、薄膜の表面が非常に平滑なことが特徴である。 The surface and cross-sectional microstructure of the obtained thin film were observed with a scanning electron microscope (SEM). Those photographs are shown in FIG. From these photographs, CIGS crystal grain growth and densification are recognized, and it can be confirmed that a dense CIGS thin film can be obtained by the method of this example. In particular, the surface of the thin film is very smooth.
実施例１で作製したＣＩＧＳ薄膜の光吸収スペクトルを、波長が９００ｎｍ～１６００ｎｍの範囲で測定した。図４に、作製したＣＩＧＳ薄膜の光透過率のグラフを示す。この図からＸ（Ｇａの固溶量）の増加とともに、ＣＩＧＳ薄膜を透過する光の最短波長が短波長側にシフトすることがわかる。これは、Ｇａの固溶量の増加とともにＣＩＧＳ薄膜の禁制帯幅が広くなり、ＣＩＧＳ薄膜の吸収端が短波長側にシフトするためである。この光透過率をもとに求めたＣＩＧＳ薄膜の禁制帯幅は、Ｘ＝０．００５でＥｇ＝１．００ｅＶ、Ｘ＝０．１でＥｇ＝１．０６ｅＶ、Ｘ＝０．２でＥｇ＝１．１０ｅＶであった。これらの値は文献値と一致する。 The light absorption spectrum of the CIGS thin film produced in Example 1 was measured in the wavelength range of 900 nm to 1600 nm. In FIG. 4, the graph of the light transmittance of the produced CIGS thin film is shown. This figure shows that the shortest wavelength of the light which permeate | transmits a CIGS thin film shifts to the short wavelength side with increase of X (Ga solid solution amount). This is because the forbidden band width of the CIGS thin film becomes wider as the amount of Ga dissolved increases, and the absorption edge of the CIGS thin film shifts to the short wavelength side. The forbidden band width of the CIGS thin film obtained based on this light transmittance is as follows: X = 0.005, Eg = 1.00 eV, X = 0.1, Eg = 1.06 eV, X = 0.2, Eg = 1.10 eV. These values are consistent with literature values.
［実施例２］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｉｎ、Ｇａ、ＳｅをＣｕ１．０２（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１の比となるように秤量後、そこにＮａＦを０．５ｍｏｌ％添加した。実施例１と同様に遊星ボールミル用のジルコニア製４５ｃｃ容器に秤量した粉末２０ｇと、３ｍｍ径のジルコニア製玉石４０ｇとを入れ、窒素雰囲気下で、８００ｒｐｍ、２０分間攪拌した。攪拌により、メカノケミカル反応が起こり、Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする粉末が得られた。 [Example 2]
(Preparation of raw material powder)
The element powders Cu, In, Ga, and Se were weighed so as to have a ratio of Cu 1.02 (In 0.995 Ga 0.005 ) Se 2.1 , and then 0.5 mol% of NaF was added thereto. In the same manner as in Example 1, 20 g of the weighed powder and 40 g of 3 mm diameter zirconia cobblestone were placed in a zirconia 45 cc container for a planetary ball mill, and stirred at 800 rpm for 20 minutes in a nitrogen atmosphere. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
（塗布剤の調製）
　前記Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする原料粉末の入ったジルコニア製容器に、エチレングリコールモノフェニルエーテルを４ｍｌ加え、実施例１と同様の条件で攪拌し、塗布剤であるインクを得た。 (Preparation of coating agent)
4 ml of ethylene glycol monophenyl ether was added to a container made of zirconia containing the raw material powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component, and the mixture was stirred and applied under the same conditions as in Example 1. An ink as an agent was obtained.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、実施例１と同じ条件でスクリーン印刷により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing under the same conditions as in Example 1 to form a coating layer.
（乾燥）
　前記塗布層を形成した基板を、実施例１と同じ条件で乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
（加圧焼成）
　焼結条件を、４００℃×３０分、４５０℃×３０分、４５０℃×６０分、５００℃×１０分の４水準について行ったほかは、実施例１と同様に加圧焼成し、焼結ＣＩＧＳ薄膜を得た。 (Pressurized firing)
Sintering was performed in the same manner as in Example 1 except that the sintering conditions were four levels of 400 ° C. × 30 minutes, 450 ° C. × 30 minutes, 450 ° C. × 60 minutes, and 500 ° C. × 10 minutes. A CIGS thin film was obtained.
（薄膜の特性）
　上記で得られた４種類のＣＩＧＳ薄膜の、表面および断面微構造をＳＥＭで観察した。それらの写真を図５に示す。図５のように、本実施例のＣＩＧＳ薄膜は結晶粒成長と緻密化が認められ、本実施例の方法によって、緻密なＣＩＧＳ薄膜が得られることが確認できた。 (Thin film characteristics)
The surface and cross-sectional microstructures of the four types of CIGS thin films obtained above were observed with an SEM. These photographs are shown in FIG. As shown in FIG. 5, the CIGS thin film of this example showed crystal grain growth and densification, and it was confirmed that a dense CIGS thin film was obtained by the method of this example.
［実施例３］
（原料粉末および塗布剤の調製）
　実施例２と同様に、Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする粉末を得て、塗布剤であるインクを調製した。 [Example 3]
(Preparation of raw material powder and coating agent)
In the same manner as in Example 2, a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained, and an ink as a coating agent was prepared.
（塗布と乾燥）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）にＭｏ電極を形成したものを用意した。得られたインクを、実施例１と同じ条件で前記基板に塗布して、塗布層を形成し、その後、前記塗布層を形成した基板を実施例１と同じ条件で乾燥した。 (Coating and drying)
A substrate was prepared by forming a Mo electrode on 5 cm square soda lime glass (thickness 2 mm). The obtained ink was applied to the substrate under the same conditions as in Example 1 to form a coating layer, and then the substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
（加圧焼成）
　スペーサーとして、実施例１と同様のアルミニウム箔（厚み７μｍ）、ホウ珪酸ガラス板（厚み２ｍｍ）の２種類をそれぞれ用いて行ったほかは、実施例１と同様に加圧焼成し、２水準の焼結ＣＩＧＳ薄膜を得た。 (Pressurized firing)
As the spacer, two types of aluminum foil (thickness: 7 μm) and borosilicate glass plate (thickness: 2 mm) similar to those in Example 1 were used, respectively. A sintered CIGS thin film was obtained.
（熱処理）
　前記加圧焼成で得られた焼結ＣＩＧＳ薄膜をそれぞれ、窒素雰囲気下で、５５０℃、１０分間加熱処理した。このとき、基板は石英ガラス製のシャーレに入れ、シャーレ内にＳｅを入れた。 (Heat treatment)
The sintered CIGS thin films obtained by the pressure firing were each heat-treated at 550 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
（エッチング処理）
　前記熱処理したＣＩＧＳ薄膜をそれぞれ、１０ｗｔ％のＫＣＮ水溶液に室温で３分間浸漬し、Ｃｕ－Ｓｅ系不純物を溶解除去した。 (Etching process)
Each of the heat-treated CIGS thin films was immersed in a 10 wt% KCN aqueous solution at room temperature for 3 minutes to dissolve and remove Cu—Se based impurities.
（膜の特性）
　前記加圧焼成後、前記熱処理後、前記エッチング処理後のそれぞれの状態でのＣＩＧＳ薄膜の表面微構造を、ＳＥＭで観察した。それらの写真を図６に示した。これらの写真から、いずれの試料においても結晶粒成長と緻密化が認められた。加圧焼成で焼結させた後の熱処理は、過剰に存在しているＳｅを蒸散させるとともに、ＣＩＧＳ薄膜の結晶性の向上、結晶粒成長と緻密化のために有効な手段であった。また、エッチング処理によって、熱処理後のＣＩＧＳ薄膜表面に観察されたＣｕ－Ｓｅ系不純物（図６の写真中丸印で囲んだ部分）を除去できることがわかる。 (Membrane characteristics)
The surface microstructure of the CIGS thin film in each state after the pressure firing, after the heat treatment, and after the etching treatment was observed with an SEM. These photographs are shown in FIG. From these photographs, crystal grain growth and densification were observed in all samples. The heat treatment after sintering by pressure firing was an effective means for evaporating excess Se and improving crystallinity of the CIGS thin film, crystal grain growth and densification. It can also be seen that the etching treatment can remove Cu—Se-based impurities observed on the surface of the CIGS thin film after the heat treatment (portions surrounded by circles in the photograph of FIG. 6).
［実施例４］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｉｎ、Ｇａ、ＳｅをＣｕ１．０２（Ｉｎ１－ＸＧａＸ）Ｓｅ２．１の比（Ｘ＝０．０５、０．１、０．２）となるように秤量後、実施例１と同様にして、Ｃｕ（Ｉｎ１－ＸＧａＸ）Ｓｅ２を主成分とする粉末を得た。ここで、Ｘ＝０．００５、０．１、０．２の３水準である。 [Example 4]
(Preparation of raw material powder)
After weighing the element powders Cu, In, Ga, Se to a Cu 1.02 (In 1-X Ga X ) Se 2.1 ratio (X = 0.05, 0.1, 0.2), In the same manner as in Example 1, a powder containing Cu (In 1-X Ga X ) Se 2 as a main component was obtained. Here, there are three levels of X = 0.005, 0.1, and 0.2.
（塗布剤の調製）
　前記Ｃｕ（Ｉｎ１－ＸＧａＸ）Ｓｅ２を主成分とする原料粉末の入ったジルコニア製容器に、それぞれエチレングリコールモノフェニルエーテル４．５ｍｌ加えたほかは、実施例１と同様の条件で攪拌し、塗布剤であるインクを３種類得た。 (Preparation of coating agent)
Stirring was carried out under the same conditions as in Example 1, except that 4.5 ml of ethylene glycol monophenyl ether was added to each of the zirconia containers containing the raw material powder containing Cu (In 1-X Ga X ) Se 2 as a main component. As a result, three types of inks as coating agents were obtained.
（塗布と乾燥）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）にＭｏ電極を形成したものを用意した。得られたインクを、実施例１と同じ条件で前記基板に塗布、乾燥して、塗布層を形成し、その後、前記塗布層を形成した基板を実施例１と同じ条件で乾燥した。 (Coating and drying)
A substrate was prepared by forming a Mo electrode on 5 cm square soda lime glass (thickness 2 mm). The obtained ink was applied to the substrate under the same conditions as in Example 1 and dried to form a coating layer, and then the substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
（加圧焼成）
　図７に示すように、前記３種類のインクをそれぞれ塗布した３枚の基板を、同時に加圧焼成し、塗布層を焼結させてＣＩＧＳ薄膜を作製した。ＣＩＧＳ塗布膜１１を形成した基板１２を押し板５の上に第二の押し板６を介して配置した。そして、ＣＩＧＳ塗布膜１１に直接接触させてスペーサー１３を載せた。スペーサー１３の上に中押し板１７を載せ、ＣＩＧＳ塗布膜２１を形成した基板２２を配置した。さらに、ＣＩＧＳ塗布膜２１に直接接触させてスペーサー２３を載せた。スペーサー２３の上に中押し板２７を載せ、ＣＩＧＳ塗布膜３１を形成した基板３２を配置した。ＣＩＧＳ塗布膜３１に直接接触させてスペーサー３３を載せ、さらに中押し板３７、第二の押し板６’、押し板５’をこの順に載せた。この２枚の押し板５および５’を一対の押し棒４、４’で、機械的に加圧しながら焼結を行った。スペーサー１３、２３、３３としてアルミニウム箔（厚み７μｍ）、押し棒４、４’としてφ４０ｍｍの円柱状ジルコニア製セラミックス、押し板５、５’として５０ｍｍ角の窒化珪素製セラミックス板を用いた。押し板５、５’の押圧面側に設けた第二の押し板６、６’は、押し板と基板との間の緩衝材としての役割を果たすものであり、ここでは、それぞれグラファイトシート（厚み０．４ｍｍ）を用いた。中押し板１７、２７、３７としては、ホウ珪酸ガラス板（厚み２ｍｍ）を用いた。図７のように基板をセットして、窒素雰囲気下、４５０℃で、機械的な圧力を２ＭＰａ加えた状態で、３０分間、加圧焼成して、焼結ＣＩＧＳ薄膜を得た。加熱は、チャンバーを密閉した後、窒素雰囲気下、常圧で開始し、２００℃に達したところで、押し板で機械的な圧力（プレス）を加えた。加圧状態のまま所定の４５０℃まで加熱し、４５０℃で３０分間保持した後、押し板での加圧を解除して常圧に戻した。常温まで冷却した後、チャンバーを開放して焼結させた薄膜付きの基板を取り出した。 (Pressurized firing)
As shown in FIG. 7, the three substrates coated with the three kinds of inks were simultaneously fired under pressure, and the coating layer was sintered to produce a CIGS thin film. The substrate 12 on which the CIGS coating film 11 was formed was disposed on the pressing plate 5 via the second pressing plate 6. The spacer 13 was placed in direct contact with the CIGS coating film 11. The intermediate pressing plate 17 was placed on the spacer 13 and the substrate 22 on which the CIGS coating film 21 was formed was disposed. Further, the spacer 23 was placed in direct contact with the CIGS coating film 21. An intermediate pressing plate 27 was placed on the spacer 23, and a substrate 32 on which a CIGS coating film 31 was formed was disposed. The spacer 33 was placed in direct contact with the CIGS coating film 31, and the intermediate push plate 37, the second push plate 6 ′, and the push plate 5 ′ were placed in this order. The two pressing plates 5 and 5 ′ were sintered while being mechanically pressed by a pair of pressing rods 4 and 4 ′. Aluminum spacers (thickness 7 μm) were used as the spacers 13, 23 and 33, cylindrical zirconia ceramics having a diameter of 40 mm were used as the push rods 4 and 4 ′, and 50 mm square silicon nitride ceramic plates were used as the push plates 5 and 5 ′. The second pressing plates 6 and 6 ′ provided on the pressing surface side of the pressing plates 5 and 5 ′ serve as a cushioning material between the pressing plate and the substrate. Here, graphite sheets ( A thickness of 0.4 mm) was used. As the intermediate pressing plates 17, 27 and 37, borosilicate glass plates (thickness 2 mm) were used. The substrate was set as shown in FIG. 7, and the sintered CIGS thin film was obtained by pressurizing and firing for 30 minutes in a nitrogen atmosphere at 450 ° C. with a mechanical pressure of 2 MPa. Heating was started at normal pressure in a nitrogen atmosphere after the chamber was sealed, and when the temperature reached 200 ° C., mechanical pressure (press) was applied with a pressing plate. After heating to a predetermined 450 ° C. in a pressurized state and holding at 450 ° C. for 30 minutes, the pressure on the pressing plate was released and the pressure was returned to normal pressure. After cooling to room temperature, the chamber was opened and the sintered substrate with a thin film was taken out.
（熱処理）
　前記加圧焼成で得られた焼結ＣＩＧＳ薄膜を、それぞれ窒素雰囲気下で、５５０℃、１０分間加熱処理した。このとき、基板は石英ガラス製のシャーレに入れ、シャーレ内にＳｅを入れた。 (Heat treatment)
The sintered CIGS thin films obtained by the pressure firing were each heat-treated at 550 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
（エッチング処理）
　前記熱処理したＣＩＧＳ薄膜をそれぞれ、１０ｗｔ％のＫＣＮ水溶液に室温で３分間浸漬し、Ｃｕ－Ｓｅ系不純物を溶解除去した。 (Etching process)
Each of the heat-treated CIGS thin films was immersed in a 10 wt% KCN aqueous solution at room temperature for 3 minutes to dissolve and remove Cu—Se based impurities.
（膜の特性）
　得られた膜の表面微構造を、ＳＥＭで観察した。それらの写真を図８に示した。これらの写真から、ＣＩＧＳの結晶粒成長と緻密化が認められ、本実施例の方法によって、緻密なＣＩＧＳ薄膜が得られることが確認できた。特に、膜の表面が非常に平滑なことが特徴である。本実施例においては、一度に複数枚のＣＩＧＳ薄膜を加圧焼成しているが、実施例１から３において示したような１枚ずつ処理したときと同様に、表面が非常に平滑で緻密なＣＩＧＳ薄膜を作製することができた。 (Membrane characteristics)
The surface microstructure of the obtained film was observed by SEM. These photographs are shown in FIG. From these photographs, CIGS crystal grain growth and densification were observed, and it was confirmed that a dense CIGS thin film was obtained by the method of this example. In particular, the surface of the film is very smooth. In this example, a plurality of CIGS thin films are pressure-fired at a time, but the surface is very smooth and dense as in the case of processing one by one as shown in Examples 1 to 3. A CIGS thin film could be produced.
（太陽電池の試作）
　これらのＣＩＧＳ薄膜を用いて、図１４に示すような構造を有する、Ａｌ／ｎ－ＺｎＯ：Ｂ／ｉ－ＺｎＯ／ＣｄＳ／ＣＩＧＳ／Ｍｏ／ソーダライムガラス構造の太陽電池を試作した。太陽電池は以下のプロセスで作製した。
（１）　ＣＩＧＳ薄膜上１４３に、硫酸カドミウムＣｄＳＯ４を用いた溶液成長（ＣＢＤ）法によりＣｄＳバッファー層１４４ａを形成する。
（２）　有機金属気相成長（ＭＯＣＶＤ）法によりｉ‐ＺｎＯ層１４４ｂ及びＺｎＯ：Ｂ（Ｂ添加ＺｎＯ）窓層１４５を堆積する。Ｚｎの原料にはジエチルジンク（Ｚｎ（Ｃ２Ｈ５）２）を用い、酸化剤として純水（Ｈ２Ｏ）を用いる。また、ｎ型ドーピングガスとして１％水素希釈したジボラン（Ｂ２Ｈ６）を用いた。
（３）　櫛型Ａｌ電極１４６を真空蒸着法によって形成した。
このプロセスで試作した本実施例のＣＩＧＳ太陽電池は、いずれも太陽電池特性を示し、本発明が太陽電池用化合物半導体の薄膜作製に有効なことを確認できた。 (Prototype solar cell)
Using these CIGS thin films, solar cells having an Al / n-ZnO: B / i-ZnO / CdS / CIGS / Mo / soda lime glass structure having a structure as shown in FIG. 14 were fabricated. The solar cell was produced by the following process.
(1) A CdS buffer layer 144a is formed on the CIGS thin film 143 by a solution growth (CBD) method using cadmium sulfate CdSO 4 .
(2) The i-ZnO layer 144b and the ZnO: B (B-doped ZnO) window layer 145 are deposited by metal organic chemical vapor deposition (MOCVD). Diethyl zinc (Zn (C 2 H 5 ) 2 ) is used as a raw material for Zn, and pure water (H 2 O) is used as an oxidizing agent. Further, diborane (B 2 H 6 ) diluted with 1% hydrogen was used as the n-type doping gas.
(3) A comb-shaped Al electrode 146 was formed by a vacuum deposition method.
The CIGS solar cells of this example, which were experimentally produced by this process, all showed solar cell characteristics, and it was confirmed that the present invention was effective for producing a thin film of a compound semiconductor for solar cells.
［実施例５］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｉｎ、Ｇａ、ＳｅをＣｕ１＋Ｙ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１の化学量論比（Ｙ＝０．０１、０．００、－０．００５）となるように秤量後、実施例１と同様にして、Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする原料粉末を得た。 [Example 5]
(Preparation of raw material powder)
The element powders Cu, In, Ga, and Se have a stoichiometric ratio of Cu 1 + Y (In 0.995 Ga 0.005 ) Se 2.1 (Y = 0.01, 0.00, −0.005). Then, in the same manner as in Example 1, a raw material powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
（塗布剤の調製）
　前記Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする原料粉末の入ったジルコニア製容器に、エチレングリコールモノフェニルエーテル４．５ｍｌ加えたほかは、実施例１と同様の条件で攪拌し、塗布剤であるインクを３種類得た。 (Preparation of coating agent)
Under the same conditions as in Example 1, except that 4.5 ml of ethylene glycol monophenyl ether was added to a container made of zirconia containing the raw material powder mainly containing Cu (In 0.995 Ga 0.005 ) Se 2. The mixture was stirred to obtain three types of inks as coating agents.
（塗布と乾燥）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）にＭｏ電極を形成したものを用意した。得られたインクを、実施例１と同じ条件で前記基板に塗布して、塗布層を形成し、その後、前記塗布層を形成した基板を実施例１と同じ条件で乾燥した。 (Coating and drying)
A substrate was prepared by forming a Mo electrode on 5 cm square soda lime glass (thickness 2 mm). The obtained ink was applied to the substrate under the same conditions as in Example 1 to form a coating layer, and then the substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
（加圧焼成）
　実施例４と同様にして、これらの基板を同時に加圧焼成し、塗布層を焼結させてＣＩＧＳ薄膜を作製した。加圧焼成の条件は実施例４と同じである。 (Pressurized firing)
In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to produce a CIGS thin film. The conditions for pressure firing are the same as in Example 4.
（熱処理）
　前記加圧焼成で得られた焼結ＣＩＧＳ薄膜を、それぞれ窒素雰囲気下で、６００℃、１０分間加熱処理した。このとき、基板は石英ガラス製のシャーレに入れ、シャーレ内にＳｅを入れた。 (Heat treatment)
The sintered CIGS thin films obtained by the pressure firing were each heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
（エッチング処理）
　前記熱処理したＣＩＧＳ薄膜をそれぞれ、１０ｗｔ％のＫＣＮ水溶液に３分間浸漬し、Ｃｕ－Ｓｅ系不純物を溶解除去した。 (Etching process)
Each of the heat-treated CIGS thin films was immersed in a 10 wt% KCN aqueous solution for 3 minutes to dissolve and remove Cu—Se impurities.
（膜の特性）
　得られた膜の表面微構造を、ＳＥＭで観察した。それらの写真を図９に示した。比較例と比べて、いずれのＣＩＧＳ薄膜においても緻密化が認められた。特に、Ｙの値が大きい組成のＣＩＧＳ薄膜は緻密な微構造を有し、結晶粒も大きいことがわかる。 (Membrane characteristics)
The surface microstructure of the obtained film was observed by SEM. Those photographs are shown in FIG. Compared with the comparative example, densification was observed in any CIGS thin film. In particular, it can be seen that a CIGS thin film having a composition with a large Y value has a dense microstructure and large crystal grains.
［実施例６］
（ＣｕＳｅ粉末の調製）
　Ｃｕ粉末とＳｅ粉末を１：１のモル比で秤量した。遊星ボールミル（フリッチュ社製、商品名「遊星型ボールミル　Ｐ－５／２」）用のジルコニア製８０ｃｃ容器に秤量した粉末１００ｇと、３ｍｍ径のジルコニア製玉石２００ｇとを入れ、容器内を窒素雰囲気にして、３７０ｒｐｍ、１２０分間攪拌した。攪拌により、メカノケミカル反応が起こり、ＣｕＳｅ粉末が得られた。得られたＣｕＳｅは結晶性の良いＣｕＳｅであることを粉末Ｘ線回折により確認した。 [Example 6]
(Preparation of CuSe powder)
Cu powder and Se powder were weighed at a molar ratio of 1: 1. 100 g of powder weighed in an 80 cc container made of zirconia for a planetary ball mill (trade name “Planet Ball Mill P-5 / 2” manufactured by Fritsch) and 200 g of zirconia cobblestone having a diameter of 3 mm were placed in a nitrogen atmosphere. And stirred at 370 rpm for 120 minutes. By stirring, a mechanochemical reaction occurred and CuSe powder was obtained. It was confirmed by powder X-ray diffraction that the obtained CuSe was a highly crystalline CuSe.
（（Ｉｎ１－ＸＧａＸ）２Ｓｅ３粉末の調製）
　Ｉｎ粉末、Ｇａ粉末およびＳｅ粉末を（２－２Ｘ）：２Ｘ：３のモル比で秤量した。ここで、Ｘ＝０．００５、０．１、０．２の３種類である。遊星ボールミル（フリッチュ社製、商品名「遊星型ボールミル　ｐｒｅｍｉｕｍ　ｌｉｎｅ　Ｐ－７」）用のジルコニア製４５ｃｃ容器に秤量した粉末と、３ｍｍ径のジルコニア製玉石４０ｇとを入れた。容器への粉末の充填量は、塗布剤の調製の際にＣｕＳｅを加えて２０ｇになるように調整した。それらを、窒素雰囲気下で、８００ｒｐｍ、２０分間攪拌し、（Ｉｎ１－ＸＧａＸ）２Ｓｅ３の組成比を有する粉末を得た。 (Preparation of (In 1-X Ga X ) 2 Se 3 powder)
In powder, Ga powder and Se powder were weighed at a molar ratio of (2-2X): 2X: 3. Here, there are three types of X = 0.005, 0.1, and 0.2. A powder weighed in a 45 cc container made of zirconia for a planetary ball mill (trade name “Planet type ball mill premium line P-7” manufactured by Fritsch) and 40 g of 3 mm diameter zirconia cobblestone were placed. The filling amount of the powder in the container was adjusted to 20 g by adding CuSe during the preparation of the coating agent. They were stirred at 800 rpm for 20 minutes in a nitrogen atmosphere to obtain a powder having a composition ratio of (In 1-X Ga X ) 2 Se 3 .
（塗布剤の調製）
　前記（Ｉｎ１－ＸＧａＸ）２Ｓｅ３の組成比を有する粉末の調製に用いたジルコニア製容器に、Ｃｕ１．０２（Ｉｎ１－ＸＧａＸ）Ｓｅ２．５１の比になるようにＣｕＳｅ粉末を加えた。さらに、そこに０．５ｍｏｌ％のＮａＦ（Ｃｕ１．０２（Ｉｎ１－ＸＧａＸ）Ｓｅ２　１ｍｏｌに対して０．００５ｍｏｌに相当）を入れた。さらに溶媒としてターピネオールを７ｍｌ加え、容器内を窒素雰囲気にして、５００ｒｐｍ、１２０分間攪拌し、塗布剤であるインクを得た。 (Preparation of coating agent)
In a container made of zirconia used for preparation of the powder having the composition ratio of (In 1-X Ga X ) 2 Se 3 , the ratio of Cu 1.02 (In 1-X Ga X ) Se 2.51 is set. CuSe powder was added. Further, 0.5 mol% of NaF (corresponding to 0.005 mol with respect to 1 mol of Cu 1.02 (In 1-X Ga X ) Se 2 ) was added thereto. Further, 7 ml of terpineol was added as a solvent, the inside of the container was placed in a nitrogen atmosphere, and the mixture was stirred at 500 rpm for 120 minutes to obtain an ink as a coating agent.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、スクリーン印刷（４００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing (400 mesh) to form a coating layer.
（乾燥）
　前記塗布層を形成した基板を、窒素雰囲気下で、１４５℃、５分間乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried at 145 ° C. for 5 minutes in a nitrogen atmosphere.
（加圧焼成）
　実施例４と同様にして、これらの基板を同時に加圧焼成し、塗布層を焼結させてＣＩＧＳ薄膜を作製した。加圧焼成の条件は実施例４と同じである。 (Pressurized firing)
In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to produce a CIGS thin film. The conditions for pressure firing are the same as in Example 4.
（熱処理）
　前記加圧焼成で得られた焼結ＣＩＧＳ薄膜をそれぞれ、窒素雰囲気下で、６００℃、１０分間加熱処理した。このとき、基板は石英ガラス製のシャーレに入れ、シャーレ内にＳｅを入れた。 (Heat treatment)
The sintered CIGS thin films obtained by the pressure firing were each heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
（膜の特性）
　実施例６で得られた３種類のＣＩＧＳ薄膜（Ｘ＝０．００５、０．１、０．２）をＸＲＤ分析した。その結果を図１０に示した。Ｘ線回折図形は、結晶構造解析データ（ＩＣＳＤ：Ｉｎｏｒｇａｎｉｃ　Ｃｒｙｓｔａｌ　Ｓｔｒｕｃｔｕｒｅ　Ｄａｔａｂａｓｅ　＃７００５１）に基づくシミュレーションによるＸ線回折図形と一致し、カルコパイライト型構造を持つＣＩＧＳ薄膜が合成されていることがわかった。このＸ線回折図形から、実施例１の場合と同様に本実施例のＣＩＧＳ薄膜が不純物を含まない単一相であること、Ｘの増加とともに回折ピークが高角度側にシフトして、Ｇａの固溶量が増加していることが確認できる。また、得られた薄膜の表面微構造をＳＥＭで観察した。その結果を図１１に示す。これらのＳＥＭ写真から、いずれの試料においても結晶粒成長と緻密化が認められることがわかる。 (Membrane characteristics)
Three types of CIGS thin films (X = 0.005, 0.1, 0.2) obtained in Example 6 were subjected to XRD analysis. The results are shown in FIG. The X-ray diffraction pattern coincides with the X-ray diffraction pattern obtained by simulation based on crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 70051), and it was found that a CIGS thin film having a chalcopyrite structure was synthesized. From this X-ray diffraction pattern, as in Example 1, the CIGS thin film of this example is a single phase containing no impurities, the diffraction peak shifts to the high angle side as X increases, It can be confirmed that the amount of solid solution increases. Moreover, the surface microstructure of the obtained thin film was observed with SEM. The result is shown in FIG. From these SEM photographs, it can be seen that crystal grain growth and densification are observed in any sample.
［比較例］
　実施例１と同様に、Ｃｕ１．０２（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１組成の原料粉末の調製、塗布剤の調製、塗布、乾燥を行った。乾燥後の膜の表面および断面微構造のＳＥＭ像を図１２に示した。この図から、乾燥後の段階のＣＩＧＳ薄膜は、非常に微細な粒子の集合体であることがわかる。前記乾燥後の薄膜を、実施例１と同様の装置を用いて、機械的な加圧はせずに窒素雰囲気下、４５０℃で、３０分間熱処理を行った。熱処理後のＣＩＧＳ薄膜の表面および断面微構造のＳＥＭ像も、あわせて同図に示した。これらの図から、機械的な加圧を行わないで熱処理した場合では、ほとんど緻密化していないことがわかる。 [Comparative example]
In the same manner as in Example 1, preparation of a raw material powder having a composition of Cu 1.02 (In 0.995 Ga 0.005 ) Se 2.1 , preparation of a coating agent, coating, and drying were performed. The SEM image of the surface of the film after drying and the cross-sectional microstructure is shown in FIG. From this figure, it can be seen that the CIGS thin film at the stage after drying is an aggregate of very fine particles. The dried thin film was heat-treated at 450 ° C. for 30 minutes in a nitrogen atmosphere without mechanical pressurization using the same apparatus as in Example 1. The SEM image of the surface and cross-sectional microstructure of the CIGS thin film after heat treatment is also shown in FIG. From these figures, it can be seen that when heat treatment is performed without mechanical pressurization, the material is hardly densified.
［実施例７］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｉｎ、Ｇａ、ＳｅをＣｕ１．０２（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１の比となるように秤量後、そこにＮａＦを０．５ｍｏｌ％添加した。実施例１と同様に遊星ボールミル用のジルコニア製４５ｃｃ容器に秤量した粉末２０ｇと、１ｍｍ径のジルコニア製玉石４０ｇとを入れ、窒素雰囲気下で、８００ｒｐｍ、２０分間攪拌した。攪拌により、メカノケミカル反応が起こり、Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする粉末が得られた。 [Example 7]
(Preparation of raw material powder)
The element powders Cu, In, Ga, and Se were weighed so as to have a ratio of Cu 1.02 (In 0.995 Ga 0.005 ) Se 2.1 , and then 0.5 mol% of NaF was added thereto. In the same manner as in Example 1, 20 g of the weighed powder and 40 g of 1 mm diameter zirconia cobblestone were placed in a zirconia 45 cc container for a planetary ball mill, and stirred at 800 rpm for 20 minutes in a nitrogen atmosphere. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
（塗布剤の調製）
　前記Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする原料粉末の入ったジルコニア製容器に、エチレングリコールモノフェニルエーテルを８ｍｌ加え、容器内を窒素雰囲気にして、７００ｒｐｍで所定時間の攪拌を行った。前記攪拌時間は、２時間、５時間、１０時間の３水準行い、塗布剤であるインクを３種類得た。ここで、一般的に粉砕（攪拌）時間を増やすことによって粉末の粒径は小さくなり、表面積が大きくなるため、インクの粘性が高くなる。そのため、攪拌時間を１０時間としたインクは、スクリーン印刷に適切な粘度とするために、溶剤を０．５ｍｌ追加した。 (Preparation of coating agent)
8 ml of ethylene glycol monophenyl ether is added to a container made of zirconia containing the raw material powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component, and the inside of the container is placed in a nitrogen atmosphere, and at 700 rpm for a predetermined time. Was stirred. The stirring time was three levels of 2 hours, 5 hours, and 10 hours, and three types of inks as coating agents were obtained. Here, in general, increasing the pulverization (stirring) time decreases the particle size of the powder and increases the surface area, so that the viscosity of the ink increases. Therefore, 0.5 ml of the solvent was added to the ink whose stirring time was 10 hours in order to obtain a viscosity suitable for screen printing.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、スクリーン印刷（５００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing (500 mesh) to form an application layer.
（乾燥）
　前記塗布層を形成した基板を、実施例１と同じ条件で乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
（加圧焼成）
　実施例１と同じ条件で加圧焼成し、焼結ＣＩＧＳ薄膜を得た。 (Pressurized firing)
Under pressure and firing under the same conditions as in Example 1, a sintered CIGS thin film was obtained.
（薄膜の特性）
　上記で得られた３種類のＣＩＧＳ薄膜の、表面および断面微構造をＳＥＭで観察した。それらの写真を図１５に示す。図１５のように、本実施例のＣＩＧＳ薄膜は結晶粒成長と緻密化が認められ、本実施例の方法によって、緻密なＣＩＧＳ薄膜が得られることが確認できた。また、得られたＣＩＧＳ薄膜の膜厚は、攪拌時間が２時間のインクを使用したものは２．３μｍ、攪拌時間が５時間のインクを使用したものは１．３μｍ、攪拌時間が１０時間のインクを使用したものは０．８μｍであった。 (Thin film characteristics)
The surface and cross-sectional microstructures of the three types of CIGS thin films obtained above were observed with an SEM. Those photographs are shown in FIG. As shown in FIG. 15, in the CIGS thin film of this example, crystal grain growth and densification were observed, and it was confirmed that a dense CIGS thin film was obtained by the method of this example. The thickness of the CIGS thin film obtained was 2.3 μm for the ink using the stirring time of 2 hours, 1.3 μm for the ink using the stirring time of 5 hours, and the stirring time of 10 hours. The one using ink was 0.8 μm.
　実施例７で作製したＣＩＧＳ薄膜の近赤外光吸収スペクトルを、波長が９００ｎｍ～１６００ｎｍの範囲で測定した。図１６に、作製したＣＩＧＳ薄膜の光透過率のグラフを示す。この図からインクの攪拌時間が長くなり、ＣＩＧＳ膜の膜厚が薄くなるとともに波長が１２００ｎｍ以上の光の透過率が大きくなることがわかる。このように、スクリ－ン印刷を用いた本実施例の製造方法でも、インクの調整プロセスや用いるスクリ－ンを工夫することによって、蒸着法で作製したＣＩＧＳ膜と同程度の厚さのＣＩＧＳ膜を作製することが出来る。 The near infrared light absorption spectrum of the CIGS thin film prepared in Example 7 was measured in the wavelength range of 900 nm to 1600 nm. In FIG. 16, the graph of the light transmittance of the produced CIGS thin film is shown. From this figure, it can be seen that the ink stirring time is increased, the CIGS film thickness is decreased, and the transmittance of light having a wavelength of 1200 nm or more is increased. As described above, even in the manufacturing method of the present embodiment using the screen printing, the CIGS film having the same thickness as the CIGS film manufactured by the vapor deposition method is devised by devising the ink adjustment process and the screen to be used. Can be produced.
［実施例８］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｉｎ、Ｇａ、ＳｅをＣｕ１．０２（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１の比となるように秤量後、そこにＮａＦを０．５ｍｏｌ％添加した。実施例１と同様に遊星ボールミル用のジルコニア製４５ｃｃ容器に秤量した粉末２０ｇと、１ｍｍ径のジルコニア製玉石４０ｇとを入れ、窒素雰囲気下で、８００ｒｐｍ、２０分間攪拌した。攪拌により、メカノケミカル反応が起こり、Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする粉末が得られた。 [Example 8]
(Preparation of raw material powder)
The element powders Cu, In, Ga, and Se were weighed so as to have a ratio of Cu 1.02 (In 0.995 Ga 0.005 ) Se 2.1 , and then 0.5 mol% of NaF was added thereto. In the same manner as in Example 1, 20 g of the weighed powder and 40 g of 1 mm diameter zirconia cobblestone were placed in a zirconia 45 cc container for a planetary ball mill, and stirred at 800 rpm for 20 minutes in a nitrogen atmosphere. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
（塗布剤の調製）
　前記Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする原料粉末の入ったジルコニア製容器に、エチレングリコールモノフェニルエーテルを９ｍｌ加え、容器内を窒素雰囲気にして、７００ｒｐｍで１０時間攪拌して、塗布剤であるインクを得た。 (Preparation of coating agent)
9 ml of ethylene glycol monophenyl ether is added to a container made of zirconia containing the raw material powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component, and the inside of the container is put in a nitrogen atmosphere, at 700 rpm for 10 hours. By stirring, an ink as a coating agent was obtained.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）にＭｏ電極を形成したものを用意した。得られたインクを、スクリーン印刷（５００メッシュ）により塗布し、塗布層を形成した。 (Application)
A substrate was prepared by forming a Mo electrode on 5 cm square soda lime glass (thickness 2 mm). The obtained ink was applied by screen printing (500 mesh) to form an application layer.
（乾燥）
　前記塗布層を形成した基板を、実施例１と同じ条件で乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
（加圧焼成）
　実施例１と同じ条件で加圧焼成し、焼結ＣＩＧＳ薄膜を得た。 (Pressurized firing)
Under pressure and firing under the same conditions as in Example 1, a sintered CIGS thin film was obtained.
（熱処理）
　前記加圧焼成で得られた焼結ＣＩＧＳ薄膜を、窒素雰囲気下で、６００℃、１０分間加熱処理した。このとき、基板は石英ガラス製のシャーレに入れ、シャーレ内にＳｅを入れた。 (Heat treatment)
The sintered CIGS thin film obtained by the pressure firing was heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
（エッチング処理）
　前記熱処理したＣＩＧＳ薄膜を、１０ｗｔ％のＫＣＮ水溶液に室温で３分間浸漬し、Ｃｕ－Ｓｅ系不純物を溶解除去した。 (Etching process)
The heat-treated CIGS thin film was immersed in a 10 wt% KCN aqueous solution at room temperature for 3 minutes to dissolve and remove Cu—Se impurities.
（膜の特性）
　得られたＣＩＧＳ膜の表面および断面微構造をＳＥＭで観察した。それらの写真を図１７に示す。これらの写真から、ＣＩＧＳの結晶粒成長と緻密化が認められ、本実施例の方法によって、膜厚が約２μｍの緻密なＣＩＧＳ薄膜が得られることが確認できた。 (Membrane characteristics)
The surface and cross-sectional microstructure of the obtained CIGS film were observed with an SEM. Those photographs are shown in FIG. From these photographs, CIGS crystal grain growth and densification were observed, and it was confirmed that a dense CIGS thin film having a thickness of about 2 μm was obtained by the method of this example.
　前記得られたＣＩＧＳ膜の微構造を詳しく調べるために、断面微構造を透過電子顕微鏡（ＴＥＭ）で観察した。まず、断面微構造をＴＥＭで観察するために、薄片試料を作製した。まず、試料最表面を保護するために、高真空蒸着装置でカーボン膜を、ＦＩＢ加工装置内でタングステン膜をコーティングした後、指定箇所をマイクロサンプリング法で摘出し、ＦＩＢ（Ｆｏｃｕｓｅｄ　Ｉｏｎ　Ｂｅａｍ）加工により薄片化した。その後イオンミリングによりＦＩＢダメージ層を除去した。使用した装置は、集束イオンビーム加工装置（（株）日立製作所製、「ＦＢ－２１００」）とイオンミリング装置（ＧＡＴＡＮ社製、「ＰＩＰＳ　Ｍｏｄｅｌ－６９１」（コールドステージ付き））である。次に、得られた薄片試料を電界放射型透過電子顕微鏡（日本電子（株）製、「ＪＥＭ－２０１０Ｆ」）で、加速電圧２００ｋＶの条件で観察した。図１８（ａ）に透過電子顕微鏡で観察した本実施例のＣＩＧＳ膜の断面微構造を示す。 In order to examine in detail the microstructure of the CIGS film obtained, the cross-sectional microstructure was observed with a transmission electron microscope (TEM). First, in order to observe the cross-sectional microstructure with a TEM, a thin piece sample was prepared. First, in order to protect the outermost surface of the sample, a carbon film is coated with a high-vacuum deposition apparatus, and a tungsten film is coated with an FIB processing apparatus. Then, a designated portion is extracted by a microsampling method and is subjected to FIB (Focused Ion Beam) processing. Thinned. Thereafter, the FIB damage layer was removed by ion milling. The apparatus used was a focused ion beam processing apparatus (manufactured by Hitachi, Ltd., “FB-2100”) and an ion milling apparatus (manufactured by GATAN, “PIPS Model-691” (with cold stage)). Next, the obtained thin piece sample was observed with a field emission transmission electron microscope (“JEM-2010F” manufactured by JEOL Ltd.) under an acceleration voltage of 200 kV. FIG. 18A shows a cross-sectional microstructure of the CIGS film of this example, which was observed with a transmission electron microscope.
　さらに、図１８（ａ）中に矢印で示した、前記ＣＩＧＳ膜の中央付近の点Ｐ１の化学組成を、エネルギー分散Ｘ線分光法（ＥＤＸ）で分析した。用いた装置は、Ｎｏｒａｎ社製ＥＤＸ分析装置「Ｖａｎｔａｇｅ」である。分析結果を図１８（ｂ）に示す。特性Ｘ線の強度からＣｕ：Ｉｎ：Ｇａ：Ｓｅの原子比を求めたところ、２３．２：２５．６：０．１：５１．１になり、目的とするＣＩＧＳ膜の化学組成（Ｃｕ：（Ｉｎ＋Ｇａ）：Ｓｅ＝２５：２５：５０）に非常に近いことがわかった。 Furthermore, the chemical composition of the point P1 near the center of the CIGS film, indicated by an arrow in FIG. 18A, was analyzed by energy dispersive X-ray spectroscopy (EDX). The apparatus used is a Noran EDX analyzer “Vantage”. The analysis result is shown in FIG. When the atomic ratio of Cu: In: Ga: Se was determined from the intensity of the characteristic X-ray, it was 23.2: 25.6: 0.1: 51.1, and the chemical composition of the target CIGS film (Cu: It was found to be very close to (In + Ga): Se = 25: 25: 50).
　次に、図１９（ａ）に、前記ＣＩＧＳ膜のＣＩＧＳ層とＭｏ層との界面近傍を、さらに拡大してＴＥＭ観察した微構造を示す。図１９（ａ）から明らかなように、前記ＣＩＧＳ層と前記Ｍｏ層との間には、界面層が形成されている。図１９（ａ）中に矢印で示した点Ｐ２の化学組成を、前記点Ｐ１と同様に、ＥＤＸで分析した。分析結果を図１９（ｂ）に示す。界面層からは、ＣｕやＩｎがノイズレベルしか検出されずに、ＭｏとＳｅのみが検出されていることがわかる。特性Ｘ線の強度からＭｏ：Ｓｅの原子比を求めたところ、６４．９：３５．１になり、ＭｏＳｅ２の化学組成（Ｍｏ：Ｓｅ＝６６．７：３３．３）に非常に近いことがわかった。このことから、本実施例では、ＣＩＧＳ層とＭｏ層との界面付近にＭｏＳｅ２が生成していることが確認できた。この前記界面層のＭｏＳｅ２は、焼結および熱処理過程で、ＣＩＧＳとＭｏとの反応により生成したと推定される。なお、蒸着法においては、ＣＩＧＳ層とＭｏ層との界面に、ＭｏＳｅ２が生成し、この界面のＭｏＳｅ２は、ＣＩＧＳ太陽電池の特性向上に寄与することが知られている（例えば、Ｊｐｎ．Ｊ．Ａｐｐｌ．Ｐｈｙｓ．　Ｖｏｌ．３５（１９９６）ｐｐ．Ｌ１２５３－Ｌ１２５６）。 Next, FIG. 19A shows a microstructure in which the vicinity of the interface between the CIGS layer and the Mo layer of the CIGS film is further enlarged and observed by TEM. As is clear from FIG. 19A, an interface layer is formed between the CIGS layer and the Mo layer. The chemical composition at the point P2 indicated by the arrow in FIG. 19A was analyzed by EDX in the same manner as the point P1. The analysis result is shown in FIG. From the interface layer, it can be seen that only Mo and Se are detected while only noise levels of Cu and In are detected. When the atomic ratio of Mo: Se was calculated from the intensity of the characteristic X-ray, it was 64.9: 35.1 and was very close to the chemical composition of MoSe 2 (Mo: Se = 66.7: 33.3). I understood. Thus, in the present embodiment, it was confirmed that the MoSe 2 is generated in the vicinity of the interface between the CIGS layer and the Mo layer. It is presumed that MoSe 2 of the interface layer was generated by a reaction between CIGS and Mo during the sintering and heat treatment processes. In the deposition method, the interface between the CIGS layer and the Mo layer, MoSe 2 is produced, MoSe 2 of this interface is known to contribute to improvement in characteristics of the CIGS solar cells (e.g., Jpn. J. Appl.Phys., Vol.35 (1996) pp.L1253-L1256).
（太陽電池の試作）
　このＣＩＧＳ薄膜を用いて、実施例４と同様に、図１４に示すような構造を有する、Ａｌ／ｎ－ＺｎＯ：Ｂ／ｉ－ＺｎＯ／ＣｄＳ／ＣＩＧＳ／Ｍｏ／ソーダライムガラス構造の太陽電池を試作した。図２０（ａ）に本実施例のＣＩＧＳ太陽電池の写真を示す。また、図２０（ｂ）に走査電子顕微鏡で観察した本実施例のＣＩＧＳ太陽電池の破断面の微構造を示す。ＣＩＧＳ光吸収層の上にＺｎＯ層が形成されているのが観察される。ＣｄＳ層の厚さは０．１μｍ以下なのでこの写真からは識別できない。 (Prototype solar cell)
By using this CIGS thin film, a solar cell having an Al / n-ZnO: B / i-ZnO / CdS / CIGS / Mo / soda lime glass structure having a structure as shown in FIG. Prototype. FIG. 20A shows a photograph of the CIGS solar cell of this example. FIG. 20B shows the microstructure of the fracture surface of the CIGS solar cell of this example observed with a scanning electron microscope. It is observed that a ZnO layer is formed on the CIGS light absorption layer. Since the thickness of the CdS layer is 0.1 μm or less, it cannot be identified from this photograph.
（太陽電池の特性評価）
　前記で試作した太陽電池の特性を評価した。測定条件は標準的な測定条件（Ｓｔａｎｄａｒｄ　Ｔｅｓｔ　Ｃｏｎｄｉｔｉｏｎ：ＳＴＣ）であるスペクトル：ＡＭ１．５、入射光の照度：１００ｍＷ／ｃｍ２で、温度を約２５℃に保って測定した。太陽電池のＩ－Ｖ特性は四端子法によって行った。一つの太陽電池セルの面積は０．２ｃｍ２である。このセルの太陽電池特性を図２１に示す。図２０（ａ）中、丸で囲んだセルが、最も高い変換効率を示した。その特性は、変換効率（η）：３．２％、開放電圧（Ｖｏｃ）：２８４．２ｍＶ、短絡電流（Ｊｓｃ）：２６．２ｍＡ／ｃｍ２、フィルファクタ－（Ｆ．Ｆ．）：４２．９％であった。 (Characteristic evaluation of solar cells)
The characteristics of the solar cell prototyped above were evaluated. Measurement conditions were standard measurement conditions (Standard Test Condition: STC): spectrum: AM1.5, illuminance of incident light: 100 mW / cm 2 , and the temperature was kept at about 25 ° C. The IV characteristics of the solar cell were measured by the four probe method. The area of one solar battery cell is 0.2 cm 2 . The solar cell characteristics of this cell are shown in FIG. In FIG. 20A, the circled cell showed the highest conversion efficiency. Its characteristics are conversion efficiency (η): 3.2%, open circuit voltage (V oc ): 284.2 mV, short circuit current (J sc ): 26.2 mA / cm 2 , fill factor (FF): It was 42.9%.
［実施例９］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｉｎ、Ｇａ、ＳｅをＣｕ１．００（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１とＣｕ０．９５（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１の比となるようにそれぞれ秤量後、それらにＮａＦを０．５ｍｏｌ％とＳｂ粉末を２ｍｏｌ％添加した。Ｓｂ粉末は、焼結助剤として作用し、結晶成長を制御することができる。実施例１と同様に遊星ボールミル用のジルコニア製４５ｃｃ容器に秤量した粉末２０ｇと、１ｍｍ径のジルコニア製玉石４０ｇとを入れ、窒素雰囲気下で、８００ｒｐｍ、２０分間攪拌した。攪拌により、メカノケミカル反応が起こり、いずれもＣｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする粉末が得られた。 [Example 9]
(Preparation of raw material powder)
The ratio of elemental powder Cu, In, Ga, Se to Cu 1.00 (In 0.995 Ga 0.005 ) Se 2.1 and Cu 0.95 (In 0.995 Ga 0.005 ) Se 2.1 After weighing each so, 0.5 mol% of NaF and 2 mol% of Sb powder were added thereto. The Sb powder acts as a sintering aid and can control crystal growth. In the same manner as in Example 1, 20 g of the weighed powder and 40 g of 1 mm diameter zirconia cobblestone were placed in a zirconia 45 cc container for a planetary ball mill, and stirred at 800 rpm for 20 minutes in a nitrogen atmosphere. By stirring, a mechanochemical reaction occurred, and a powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component was obtained.
（塗布剤の調製）
　前記Ｃｕ（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２を主成分とする原料粉末の入った二つのジルコニア製容器に、それぞれエチレングリコールモノフェニルエーテルを８ｍｌ加え、容器内を窒素雰囲気にして、７００ｒｐｍで５時間攪拌して２種類のインクを得た。 (Preparation of coating agent)
8 ml of ethylene glycol monophenyl ether was added to each of the two zirconia containers containing the raw material powder containing Cu (In 0.995 Ga 0.005 ) Se 2 as a main component, and the inside of the container was made into a nitrogen atmosphere, and 700 rpm Were stirred for 5 hours to obtain two types of inks.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られた２種類のインクを、スクリーン印刷（５００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained two types of inks were applied by screen printing (500 mesh) to form an application layer.
（乾燥）
　前記塗布層を形成した基板を、実施例１と同じ条件で乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried under the same conditions as in Example 1.
（加圧焼成）
　基板が２枚である他は実施例４と同じ条件で同時加圧焼成し、焼結ＣＩＧＳ薄膜を得た。 (Pressurized firing)
The sintered CIGS thin film was obtained by simultaneous pressure firing under the same conditions as in Example 4 except that the number of substrates was two.
（熱処理）
　前記加圧焼成で得られた焼結ＣＩＧＳ薄膜をそれぞれ、窒素雰囲気下で、６００℃、１０分間加熱処理した。このとき、基板は石英ガラス製のシャーレに入れ、シャーレ内にＳｅを入れた。 (Heat treatment)
The sintered CIGS thin films obtained by the pressure firing were each heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
（薄膜の特性）
　上記で得られた２種類のＣＩＧＳ薄膜の、表面および断面微構造をＳＥＭで観察した。それらの写真を図２２に示す。図２２のように、本実施例のＣＩＧＳ薄膜は結晶粒成長と緻密化が認められ、本実施例の方法によって、緻密なＣＩＧＳ薄膜が得られることが確認できた。本実施例で作製したインクを実施例４と同様に、図１４に示すような構造を有する、Ａｌ／ｎ－ＺｎＯ：Ｂ／ｉ－ＺｎＯ／ＣｄＳ／ＣＩＧＳ／Ｍｏ／ソーダライムガラス構造の太陽電池を試作したところ太陽電池特性を確認し、本実施例の方法によって作製した緻密なＣＩＧＳ薄膜が太陽電池の光吸収層として有用なことを確認した。 (Thin film characteristics)
The surface and cross-sectional microstructures of the two types of CIGS thin films obtained above were observed with an SEM. Those photographs are shown in FIG. As shown in FIG. 22, crystal growth and densification were observed in the CIGS thin film of this example, and it was confirmed that a dense CIGS thin film was obtained by the method of this example. A solar cell having an Al / n-ZnO: B / i-ZnO / CdS / CIGS / Mo / soda lime glass structure having the structure shown in FIG. As a result, the solar cell characteristics were confirmed, and it was confirmed that the dense CIGS thin film produced by the method of this example was useful as a light absorption layer of the solar cell.
［実施例１０］
（（Ｉｎ０．９９５Ｇａ０．００５）２Ｓｅ３粉末の調製）
　実施例６と同様にＩｎ粉末、Ｇａ粉末およびＳｅ粉末を１．９９：０．０１：３のモル比で秤量した。それらを遊星ボールミル用のジルコニア製４５ｃｃ容器に秤量した粉末と、１ｍｍ径のジルコニア製玉石４０ｇとを入れた。容器への粉末の充填量は、塗布剤の調製の際にＣｕ粉末とＳｅ粉末とを加えて２０ｇになるように調整した。それらを、窒素雰囲気下で、８００ｒｐｍ、２０分間攪拌し、（Ｉｎ０．９９５Ｇａ０．００５）２Ｓｅ３の組成比を有する粉末を得た。同様にしてこのような（Ｉｎ０．９９５Ｇａ０．００５）２Ｓｅ３の組成比を有する粉末を全部で４ポット作製した。 [Example 10]
(Preparation of (In 0.995 Ga 0.005 ) 2 Se 3 powder)
In the same manner as in Example 6, In powder, Ga powder and Se powder were weighed at a molar ratio of 1.99: 0.01: 3. The powder weighed in a 45 cc container made of zirconia for a planetary ball mill and 40 g of 1 mm diameter zirconia cobblestone were placed. The filling amount of the powder in the container was adjusted to 20 g by adding Cu powder and Se powder when preparing the coating agent. They were stirred at 800 rpm for 20 minutes under a nitrogen atmosphere to obtain a powder having a composition ratio of (In 0.995 Ga 0.005 ) 2 Se 3 . Similarly, a total of 4 pots having such a composition ratio of (In 0.995 Ga 0.005 ) 2 Se 3 were prepared.
（塗布剤の調製）
　前記４個の（Ｉｎ０．９９５Ｇａ０．００５）２Ｓｅ３の組成比を有する粉末の入ったジルコニア製容器に、それぞれ全部にＣｕ０．９５（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１０の比になるようにＣｕ粉末とＳｅ粉末とを加えた。さらに、それらに０．５ｍｏｌ％のＮａＦ（Ｃｕ０．９５（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１０が１ｍｏｌに対して０．００５ｍｏｌに相当）を加えた。その４個のポットの内の３個に、それぞれ焼結助剤としてＳｂを０．２５ｍｏｌ％、１．０ｍｏｌ％、２．０ｍｏｌ％（Ｃｕ０．９５（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１０が１ｍｏｌに対して０．００２５、０．０１、０．０２に相当）を入れ、残りの１個にはＳｂを添加しなかった。さらに、それらの４種類のポットに溶媒としてターピネオールを９ｍｌ加え、容器内を窒素雰囲気にして、７００ｒｐｍ、５時間攪拌し、塗布剤であるインクを得た。 (Preparation of coating agent)
Cu 0.95 (In 0.995 Ga 0.005 ) Se 2 was added to each of the four zirconia containers containing powders having a composition ratio of (In 0.995 Ga 0.005 ) 2 Se 3. Cu powder and Se powder were added to a ratio of .10 . Furthermore, 0.5 mol% of NaF (Cu 0.95 (In 0.995 Ga 0.005 ) Se 2.10 corresponds to 0.005 mol with respect to 1 mol) was added thereto. In three of the four pots, 0.25 mol%, 1.0 mol%, and 2.0 mol% (Cu 0.95 (In 0.995 Ga 0.005 ) Se) were used as sintering aids, respectively. 2.10 corresponds to 0.0025, 0.01, and 0.02 per 1 mol), and Sb was not added to the remaining one. Furthermore, 9 ml of terpineol as a solvent was added to these four types of pots, and the inside of the container was placed in a nitrogen atmosphere and stirred at 700 rpm for 5 hours to obtain an ink as a coating agent.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、スクリーン印刷（５００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing (500 mesh) to form an application layer.
（乾燥）
　前記塗布層を形成した基板を、窒素雰囲気下で、１１０℃、５分間乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried at 110 ° C. for 5 minutes in a nitrogen atmosphere.
（加圧焼成）
　基板が４枚である他は実施例４と同様にして、これらの基板を同時に加圧焼成し、塗布層を焼結させてＣＩＧＳ薄膜を作製した。加圧焼成の条件は実施例４と同じである。 (Pressurized firing)
These substrates were simultaneously fired under pressure in the same manner as in Example 4 except that the number of substrates was four, and the coating layer was sintered to produce a CIGS thin film. The conditions for pressure firing are the same as in Example 4.
（膜の特性）
　実施例１０で得られた４種類のＣＩＧＳ薄膜（Ｓｂの添加量　０．２５　ｍｏｌ％、１．０　ｍｏｌ％、２．０ｍｏｌ％、およびＳｂを添加しなかったもの）をＸＲＤ分析した。Ｘ線回折図形は、結晶構造解析データ（ＩＣＳＤ：Ｉｎｏｒｇａｎｉｃ　Ｃｒｙｓｔａｌ　Ｓｔｒｕｃｔｕｒｅ　Ｄａｔａｂａｓｅ　＃７００５１）に基づくシミュレーションによるＸ線回折図形と一致し、カルコパイライト型構造を持つＣＩＧＳ薄膜が合成されていることがわかった。このＸ線回折図形から、実施例１の場合と同様に本実施例のＣＩＧＳ薄膜が不純物を含まない単一相であることを確認した。また、得られた薄膜の表面微構造をＳＥＭで観察した。その結果を図２３に示す。これらのＳＥＭ写真から、焼結助剤としてＳｂを添加しなくても十分な緻密化が認められるが、焼結助剤としてＳｂを添加することで、添加量が増えるにしたがって、より緻密化が促進されることがわかる。 (Membrane characteristics)
The four types of CIGS thin films obtained in Example 10 (addition amounts of Sb of 0.25 mol%, 1.0 mol%, 2.0 mol%, and Sb were not added) were subjected to XRD analysis. The X-ray diffraction pattern coincides with the X-ray diffraction pattern obtained by simulation based on crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 70051), and it was found that a CIGS thin film having a chalcopyrite structure was synthesized. From this X-ray diffraction pattern, it was confirmed that the CIGS thin film of this example was a single phase containing no impurities, as in the case of Example 1. Moreover, the surface microstructure of the obtained thin film was observed with SEM. The result is shown in FIG. From these SEM photographs, sufficient densification is observed without adding Sb as a sintering aid, but by adding Sb as a sintering aid, the densification becomes more dense as the amount added increases. It turns out that it is promoted.
［実施例１１］
（（Ｉｎ０．９９５Ｇａ０．００５）２Ｓｅ３と（Ｉｎ０．９Ｇａ０．１）２Ｓｅ３粉末の調製）
　Ｉｎ粉末、Ｇａ粉末およびＳｅ粉末を１．９９：０．０１：３と１．８０：０．２０：３のモル比で秤量した。それらを遊星ボールミル用のジルコニア製４５ｃｃ容器に秤量した粉末と、１ｍｍ径のジルコニア製玉石４０ｇとを入れた。容器へ粉末の充填量は、塗布剤の調製の際にＣｕ粉末とＳｅ粉末とを加えて２０ｇになるように調整した。それらを、窒素雰囲気下で、８００ｒｐｍ、２０分間攪拌し、（Ｉｎ０．９９５Ｇａ０．００５）２Ｓｅ３と（Ｉｎ０．９Ｇａ０．１）２Ｓｅ３の組成比を有する粉末を得た。 [Example 11]
(Preparation of (In 0.995 Ga 0.005 ) 2 Se 3 and (In 0.9 Ga 0.1 ) 2 Se 3 powder)
In powder, Ga powder and Se powder were weighed in a molar ratio of 1.99: 0.01: 3 and 1.80: 0.20: 3. The powder weighed in a 45 cc container made of zirconia for a planetary ball mill and 40 g of 1 mm diameter zirconia cobblestone were placed. The filling amount of the powder in the container was adjusted to 20 g by adding Cu powder and Se powder during the preparation of the coating agent. They are stirred at 800 rpm for 20 minutes in a nitrogen atmosphere to obtain a powder having a composition ratio of (In 0.995 Ga 0.005 ) 2 Se 3 and (In 0.9 Ga 0.1 ) 2 Se 3. It was.
（塗布剤の調製）
　前記（Ｉｎ０．９９５Ｇａ０．００５）２Ｓｅ３と（Ｉｎ０．９Ｇａ０．１）２Ｓｅ３の組成比を有する粉末の調製に用いたジルコニア製容器に、それぞれＣｕ０．９（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１０とＣｕ０．９（Ｉｎ０．９Ｇａ０．１）Ｓｅ２．１０の比になるようにＣｕ粉末とＳｅ粉末とを加えた。さらに、それらに０．５ｍｏｌ％のＮａＦを（Ｃｕ０．９（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１０とＣｕ０．９（Ｉｎ０．９Ｇａ０．１）Ｓｅ２．１０が１ｍｏｌに対して０．００５ｍｏｌに相当）を入れた。その２個のポットに焼結助剤としてＳｂを２ｍｏｌ％（Ｃｕ０．９（Ｉｎ０．９９５Ｇａ０．００５）Ｓｅ２．１０とＣｕ０．９（Ｉｎ０．９Ｇａ０．１）Ｓｅ２．１０が１ｍｏｌに対して０．０２ｍｏｌに相当）入れた。さらに、それらのポットに溶媒としてターピネオールを９ｍｌ加え、容器内を窒素雰囲気にして、７００ｒｐｍ、５時間攪拌し、塗布剤であるインクを得た。 (Preparation of coating agent)
In the zirconia container used for the preparation of the powder having the composition ratio of (In 0.995 Ga 0.005 ) 2 Se 3 and (In 0.9 Ga 0.1 ) 2 Se 3 , Cu 0.9 ( Cu powder and Se powder were added so as to have a ratio of In 0.995 Ga 0.005 ) Se 2.10 to Cu 0.9 (In 0.9 Ga 0.1 ) Se 2.10 . Furthermore, 0.5 mol% of NaF was added to them (Cu 0.9 (In 0.995 Ga 0.005 ) Se 2.10 and Cu 0.9 (In 0.9 Ga 0.1 ) Se 2.10 ). Equivalent to 0.005 mol per 1 mol). In the two pots, 2 mol% (Cu 0.9 (In 0.995 Ga 0.005 ) Se 2.10 and Cu 0.9 (In 0.9 Ga 0.1 ) Se were used as sintering aids. 2.10 corresponds to 0.02 mol per 1 mol). Furthermore, 9 ml of terpineol was added to these pots as a solvent, and the inside of the container was placed in a nitrogen atmosphere and stirred at 700 rpm for 5 hours to obtain ink as a coating agent.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、スクリーン印刷（５００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing (500 mesh) to form an application layer.
（乾燥）
　前記塗布層を形成した基板を、窒素雰囲気下で、１１０℃、５分間乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried at 110 ° C. for 5 minutes in a nitrogen atmosphere.
（加圧焼成）
　実施例４と同様にして、これらの基板を同時に加圧焼成し、塗布層を焼結させてＣＩＧＳ薄膜を作製した。加圧焼成の条件は実施例４と同じである。 (Pressurized firing)
In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to produce a CIGS thin film. The conditions for pressure firing are the same as in Example 4.
（膜の特性）
　実施例１１で得られた２種類のＣＩＧＳ薄膜をＸＲＤ分析した。Ｘ線回折図形は、基本的に結晶構造解析データ（ＩＣＳＤ：Ｉｎｏｒｇａｎｉｃ　Ｃｒｙｓｔａｌ　Ｓｔｒｕｃｔｕｒｅ　Ｄａｔａｂａｓｅ　＃７００５１）に基づくシミュレーションによるＸ線回折図形と一致し、カルコパイライト型構造を持つＣＩＧＳ薄膜が合成されていることがわかった。このＸ線回折図形から、実施例１の場合と同様に本実施例のＣＩＧＳ薄膜が不純物を含まない単一相であることを確認した。また、得られた薄膜の表面微構造をＳＥＭで観察した。その結果を図２４に示す。これらのＳＥＭ写真から、いずれの試料においても結晶粒成長と緻密化が認められることがわかる。実施例で作製したインクを実施例４と同様に、図１４に示すような構造を有する、Ａｌ／ｎ－ＺｎＯ：Ｂ／ｉ－ＺｎＯ／ＣｄＳ／ＣＩＧＳ／Ｍｏ／ソーダライムガラス構造の太陽電池を試作したところ太陽電池特性を確認し、本実施例の方法によって作製した緻密なＣＩＧＳ薄膜が太陽電池の光吸収層として有用なことがわかった。 (Membrane characteristics)
Two types of CIGS thin films obtained in Example 11 were subjected to XRD analysis. The X-ray diffraction pattern basically matches the X-ray diffraction pattern obtained by simulation based on crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 70051), and a CIGS thin film having a chalcopyrite structure is synthesized. all right. From this X-ray diffraction pattern, it was confirmed that the CIGS thin film of this example was a single phase containing no impurities, as in the case of Example 1. Moreover, the surface microstructure of the obtained thin film was observed with SEM. The result is shown in FIG. From these SEM photographs, it can be seen that crystal grain growth and densification are observed in any sample. A solar cell having an Al / n-ZnO: B / i-ZnO / CdS / CIGS / Mo / soda lime glass structure having the structure shown in FIG. As a prototype, the solar cell characteristics were confirmed, and it was found that a dense CIGS thin film produced by the method of this example was useful as a light absorption layer of a solar cell.
［実施例１２］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｉｎ、Ｓｅ、ＴｅをＣｕ１．０２Ｉｎ（Ｓｅ１－ＸＴｅＸ）２．１の比（Ｘ＝０．０、０．３、０．５）となるように秤量後、実施例１と同様にして、ＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２を主成分とする粉末を得た。ここで、Ｘ＝０．０、０．３、０．５の３水準である。 [Example 12]
(Preparation of raw material powder)
After weighing element powders Cu, In, Se, Te to a ratio of Cu 1.02 In (Se 1-X Te X ) 2.1 (X = 0.0, 0.3, 0.5), In the same manner as in Example 1, a powder containing CuIn (Se 1-X Te X ) 2 as a main component was obtained. Here, the three levels of X = 0.0, 0.3, and 0.5.
（塗布剤の調製）
　前記ＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２を主成分とする原料粉末の入ったジルコニア製容器に、それぞれエチレングリコールモノフェニルエーテル１３ｍｌ加えたほかは、実施例１と同様の条件で攪拌し、塗布剤であるインクを３種類得た。 (Preparation of coating agent)
The mixture was stirred and coated under the same conditions as in Example 1 except that 13 ml of ethylene glycol monophenyl ether was added to each of the zirconia containers containing the raw material powder containing CuIn (Se 1-X Te X ) 2 as a main component. Three types of inks were obtained.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、スクリーン印刷（５００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing (500 mesh) to form an application layer.
（乾燥）
　前記塗布層を形成した基板を、窒素雰囲気下で、１４５℃、７分間乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried at 145 ° C. for 7 minutes in a nitrogen atmosphere.
（加圧焼成）
　実施例４と同様にして、これらの基板を同時に加圧焼成し、塗布層を焼結させてＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２薄膜を作製した。加圧焼成の条件は実施例４と同じである。 (Pressurized firing)
In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to prepare a CuIn (Se 1-X Te X ) 2 thin film. The conditions for pressure firing are the same as in Example 4.
（熱処理）
　前記加圧焼成で得られた焼結ＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２薄膜をそれぞれ、窒素雰囲気下で、５５０℃、１０分間加熱処理した。このとき、基板は石英ガラス製のシャーレに入れ、シャーレ内にＳｅを入れた。 (Heat treatment)
The sintered CuIn (Se 1-X Te X ) 2 thin films obtained by the pressure firing were each heat-treated at 550 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
（膜の特性）
　作製したＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２薄膜の近赤外光吸収スペクトルを、波長が９００ｎｍ～１６００ｎｍの範囲で測定した。図２５（ａ）に、作製したＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２薄膜の光透過率のグラフを示す。このように、ＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２薄膜においても緻密な膜がえられ、Ｔｅの固溶量の増加とともに光の吸収端が長波長側にシフトしていることがわかる。この透過スペクトルからＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２薄膜の禁制帯幅を求めるために、直接遷移半導体を仮定してｈνに対し（αｈν）２プロットした図を図２５（ｂ）、（ｃ）および（ｄ）に示す。図２５（ｂ）からＣｕＩｎ（Ｓｅ１－ＸＴｅＸ）２薄膜の禁制帯幅はＸ＝０．０では０．９８ｅＶ、図２５（ｃ）からＸ＝０．３では０．９０ｅＶ、図２５（ｄ）からＸ＝０．５では０．８８ｅＶであることがわかる。 (Membrane characteristics)
The near-infrared light absorption spectrum of the prepared CuIn (Se 1-X Te X ) 2 thin film was measured in the wavelength range of 900 nm to 1600 nm. FIG. 25A shows a graph of light transmittance of the prepared CuIn (Se 1-X Te X ) 2 thin film. Thus, it can be seen that a dense film is obtained even in the CuIn (Se 1-X Te X ) 2 thin film, and the absorption edge of light shifts to the long wavelength side as the amount of Te solid solution increases. In order to obtain the forbidden band width of the CuIn (Se 1-X Te X ) 2 thin film from this transmission spectrum, (αhν) 2 plots with respect to hν assuming a direct transition semiconductor are shown in FIGS. ) And (d). From FIG. 25B, the forbidden band width of the CuIn (Se 1-X Te X ) 2 thin film is 0.98 eV when X = 0.0, and 0.90 eV when X = 0.3 from FIG. It can be seen from (d) that at X = 0.5, it is 0.88 eV.
［実施例１３］
（原料粉末の調製）
　元素粉末Ｃｕ、Ｚｎ、Ｓｎ、ＳｅをＣｕ２．０４ＺｎＳｎＳｅ４．２（Ｃｕ１．０２（Ｚｎ０．５Ｓｎ０．５）Ｓｅ２．１に相当）の比となるように秤量後、実施例１と同様にして、Ｃｕ２ＺｎＳｎＳｅ４を主成分とする粉末を得た。 [Example 13]
(Preparation of raw material powder)
Conducted after weighing element powders Cu, Zn, Sn, Se to a ratio of Cu 2.04 ZnSnSe 4.2 (equivalent to Cu 1.02 (Zn 0.5 Sn 0.5 ) Se 2.1 ) In the same manner as in Example 1, a powder containing Cu 2 ZnSnSe 4 as a main component was obtained.
（塗布剤の調製）
　前記Ｃｕ２ＺｎＳｎＳｅ４を主成分とする原料粉末の入ったジルコニア製容器に、エチレングリコールモノフェニルエーテル１３ｍｌ加えたほかは、実施例１と同様の条件で攪拌し、塗布剤であるインクを得た。 (Preparation of coating agent)
An ink as a coating agent was obtained by stirring under the same conditions as in Example 1 except that 13 ml of ethylene glycol monophenyl ether was added to a container made of zirconia containing the raw material powder containing Cu 2 ZnSnSe 4 as a main component. .
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、スクリーン印刷（５００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing (500 mesh) to form an application layer.
（乾燥）
　前記塗布層を形成した基板を、窒素雰囲気下で、１４５℃、７分間乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried at 145 ° C. for 7 minutes in a nitrogen atmosphere.
（加圧焼成）
　実施例１と同様にして、塗布層を焼結させてＣｕ２ＺｎＳｎＳｅ４薄膜を作製した。加圧焼成の条件は実施例１と同じである。 (Pressurized firing)
In the same manner as in Example 1, the coating layer was sintered to prepare a Cu 2 ZnSnSe 4 thin film. The conditions for pressure firing are the same as in Example 1.
（薄膜の特性）
　実施例１３で得られたＣｕ２ＺｎＳｎＳｅ４薄膜をＸ線回折（ＸＲＤ）で分析した。得られたＸ線回折図形を図２６に示す。このＸ線回折図形は、基本的に下に示したＣｕ２ＺｎＳｎＳｅ４の結晶構造解析データ（ＩＣＳＤ：Ｉｎｏｒｇａｎｉｃ　Ｃｒｙｓｔａｌ　Ｓｔｒｕｃｔｕｒｅ　Ｄａｔａｂａｓｅ　＃９５００７）に基づくシミュレーションによるＸ線回折図形と一致し、Ｃｕ２ＺｎＳｎＳｅ４薄膜が合成されていることがわかった。このＸ線回折図形から、本実施例のＣｕ２ＺｎＳｎＳｅ４薄膜が不純物を含まない単一相であることが確認できる。 (Thin film characteristics)
The Cu 2 ZnSnSe 4 thin film obtained in Example 13 was analyzed by X-ray diffraction (XRD). The obtained X-ray diffraction pattern is shown in FIG. This X-ray diffraction pattern basically coincides with the X-ray diffraction pattern by simulation based on the crystal structure analysis data (ICSD: Inorganic Crystal Structure Database # 95007) of Cu 2 ZnSnSe 4 shown below, and the Cu 2 ZnSnSe 4 thin film Was found to be synthesized. From this X-ray diffraction pattern, it can be confirmed that the Cu 2 ZnSnSe 4 thin film of this example is a single phase containing no impurities.
　得られた薄膜の表面および断面微構造を走査電子顕微鏡（ＳＥＭ）で観察した。それらの写真を図２７に示す。これらの写真から、Ｃｕ２ＺｎＳｎＳｅ４の結晶粒成長と緻密化が認められ、本実施例の方法によって、緻密なＣｕ２ＺｎＳｎＳｅ４薄膜が得られることが確認できる。 The surface and cross-sectional microstructure of the obtained thin film were observed with a scanning electron microscope (SEM). Those photographs are shown in FIG. From these photographs, growth of crystal grains and densification of Cu 2 ZnSnSe 4 are recognized, and it can be confirmed that a dense Cu 2 ZnSnSe 4 thin film can be obtained by the method of this example.
　作製したＣｕ２ＺｎＳｎＳｅ４薄膜の近赤外光吸収スペクトルを、波長が９００ｎｍ～１６００ｎｍの範囲で測定した。図２８（ａ）に、作製したＣｕ２ＺｎＳｎＳｅ４薄膜の光透過率のグラフを示す。この透過スペクトルからＣｕ２ＺｎＳｎＳｅ４薄膜の禁制帯幅を求めるために、直接遷移半導体を仮定してｈνに対し（αｈν）２プロットした図を図２８（ｂ）に示す。図２８（ｂ）からＣｕ２ＺｎＳｎＳｅ４薄膜の禁制帯幅は１．０５ｅＶであることがわかる。 The near infrared light absorption spectrum of the prepared Cu 2 ZnSnSe 4 thin film was measured in the wavelength range of 900 nm to 1600 nm. FIG. 28 (a) shows a graph of the light transmittance of the prepared Cu 2 ZnSnSe 4 thin film. FIG. 28B shows a diagram in which (αhν) 2 is plotted against hν, assuming a direct transition semiconductor, in order to obtain the forbidden band width of the Cu 2 ZnSnSe 4 thin film from this transmission spectrum. FIG. 28B shows that the forbidden band width of the Cu 2 ZnSnSe 4 thin film is 1.05 eV.
［実施例１４］
（原料粉末の調製）
　元素粉末Ｃｕ、Ａｇ、Ｇａ、Ｓｅを（Ｃｕ１－ＸＡｇＸ）ＧａＳｅ２．１の比（Ｘ＝０．２、０．８）となるように秤量後、実施例１と同様にして、（Ｃｕ１－ＸＡｇＸ）ＧａＳｅ２を主成分とする粉末を得た。ここで、Ｘ＝０．２、０．８の２水準である。 [Example 14]
(Preparation of raw material powder)
After weighing the element powders Cu, Ag, Ga, Se so as to have a ratio of (Cu 1-X Ag X ) GaSe 2.1 (X = 0.2, 0.8), the same as in Example 1, A powder containing (Cu 1-X Ag X ) GaSe 2 as a main component was obtained. Here, two levels of X = 0.2 and 0.8.
（塗布剤の調製）
　前記（Ｃｕ１－ＸＡｇＸ）ＧａＳｅ２を主成分とする原料粉末の入った窒化珪素製容器に、それぞれエチレングリコールモノフェニルエーテル８ｍｌ加え、直径３ｍｍの窒化珪素製の玉石を用いたほかは、実施例１と同様の条件で攪拌し、塗布剤であるインクを２種類得た。 (Preparation of coating agent)
8 ml of ethylene glycol monophenyl ether was added to each of the silicon nitride containers containing the raw material powder containing (Cu 1-X Ag X ) GaSe 2 as a main component, and crush stone made of silicon nitride having a diameter of 3 mm was used. The mixture was stirred under the same conditions as in Example 1 to obtain two types of inks as coating agents.
（塗布）
　基板として、５ｃｍ□のソーダライムガラス（厚み２ｍｍ）を用意した。得られたインクを、スクリーン印刷（５００メッシュ）により塗布し、塗布層を形成した。 (Application)
As a substrate, 5 cm □ soda lime glass (thickness 2 mm) was prepared. The obtained ink was applied by screen printing (500 mesh) to form an application layer.
（乾燥）
　前記塗布層を形成した基板を、窒素雰囲気下で、１４５℃、７分間乾燥した。 (Dry)
The substrate on which the coating layer was formed was dried at 145 ° C. for 7 minutes in a nitrogen atmosphere.
（加圧焼成）
　実施例４と同様にして、これらの基板を同時に加圧焼成し、塗布層を焼結させて（Ｃｕ１－ＸＡｇＸ）ＧａＳｅ２薄膜を作製した。加圧焼成の条件は実施例４と同じである。 (Pressurized firing)
In the same manner as in Example 4, these substrates were simultaneously fired under pressure, and the coating layer was sintered to produce a (Cu 1-X Ag X ) GaSe 2 thin film. The conditions for pressure firing are the same as in Example 4.
（熱処理）
　前記加圧焼成で得られた焼結（Ｃｕ１－ＸＡｇＸ）ＧａＳｅ２薄膜をそれぞれ、窒素雰囲気下で、６００℃、１０分間加熱処理した。このとき、基板は石英ガラス製のシャーレに入れ、シャーレ内にＳｅを入れた。 (Heat treatment)
The sintered (Cu 1-X Ag X ) GaSe 2 thin films obtained by the above-mentioned pressure firing were each heat-treated at 600 ° C. for 10 minutes in a nitrogen atmosphere. At this time, the substrate was put in a petri dish made of quartz glass, and Se was put in the petri dish.
（膜の特性）
　本実施例によって緻密な（Ｃｕ１－ＸＡｇＸ）ＧａＳｅ２薄膜が作製できたので、得られた膜の紫外－可視－赤外光吸収スペクトルを、波長が３５０ｎｍ～１６００ｎｍの範囲で測定した。ＣｕＧａＳｅ２の禁制帯幅が１．６８ｅＶでＡｇＧａＳｅ２の禁制帯幅が１．８０ｅＶであることから予想されるように、Ａｇの固溶量の多いＸ＝０．８の膜の方がＸ＝０．２の膜よりも吸収端が短波長になり、Ａｇの固溶によって禁制帯幅が少し大きくなることがわかった。 (Membrane characteristics)
Since a dense (Cu 1-X Ag X ) GaSe 2 thin film could be produced by this example, the ultraviolet-visible-infrared light absorption spectrum of the obtained film was measured in the wavelength range of 350 nm to 1600 nm. As bandgap of AgGaSe 2 bandgap at 1.68eV of CuGaSe 2 it is expected because it is 1.80 eV, towards the solute intensive X = 0.8 of the membrane of Ag is X = It has been found that the absorption edge has a shorter wavelength than the 0.2 film, and that the forbidden band width is slightly increased due to the solid solution of Ag.
　本発明の化合物半導体薄膜の製造方法によると、化合物半導体薄膜を、非真空プロセスにより、容易に低コストで提供することができる。本製造方法では、常圧下での材料塗布を可能とし、製造装置への設備投資削減、材料の使用量低減を図ることができるため、太陽電池モジュールの製造工程において、大幅なコスト削減可能な製造方法として適用可能である。得られた化合物半導体薄膜は、太陽電池等の幅広い用途に適用できる。 According to the method for producing a compound semiconductor thin film of the present invention, the compound semiconductor thin film can be easily provided at a low cost by a non-vacuum process. This manufacturing method enables material application under normal pressure, reduces capital investment in the manufacturing equipment, and reduces the amount of material used. Manufacturing that can greatly reduce costs in the manufacturing process of solar cell modules It is applicable as a method. The obtained compound semiconductor thin film can be applied to a wide range of uses such as solar cells.
　この出願は、２００９年１０月１２日に出願された日本出願特願２００９－２３５８２７および２０１０年２月１５日に出願された日本出願特願２０１０－０３０４８５を基礎とする優先権を主張し、その開示の全てをここに取り込む。 This application claims priority based on Japanese Patent Application No. 2009-235827 filed on Oct. 12, 2009 and Japanese Application No. 2010-030485 filed on Feb. 15, 2010. The entire disclosure is incorporated herein.

Claims (22)

  1. ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物半導体薄膜の製造方法であって、ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含有する塗布剤を調製する工程と、
    前記塗布剤を基板に塗布して塗布膜を形成する工程と、
    前記塗布膜を、機械的に圧力を加えた条件下で加熱して焼結させる加圧焼成工程とを含むことを特徴とする化合物半導体薄膜の製造方法。     A method for producing a compound semiconductor thin film containing a group B element, a group B element, and a group V element, and a step of preparing a coating agent containing the group B element, the group B element, and the group V element,
    Applying the coating agent to a substrate to form a coating film;
    A method for producing a compound semiconductor thin film, comprising: a pressure firing step in which the coating film is heated and sintered under a condition where mechanical pressure is applied.
  2. 前記ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む塗布剤として、
    ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素から選ばれる少なくとも２種類の族の元素を含む化合物粒子を含有する塗布剤を用いる、請求の範囲１記載の化合物半導体薄膜の製造方法。     As a coating agent containing the ΙB group element, ΙΙΙB group element and VΙB group element,
    The method for producing a compound semiconductor thin film according to claim 1, wherein a coating agent containing compound particles containing at least two kinds of elements selected from a group B element, a group B element, and a group V element is used.
  3. 前記ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む塗布剤として、
    ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子と、ΙＢ族元素粉末と、ＶΙＢ族元素粉末とを含有する塗布剤を用いる、請求の範囲１記載の化合物半導体薄膜の製造方法。     As a coating agent containing the ΙB group element, ΙΙΙB group element and VΙB group element,
    The manufacturing method of the compound semiconductor thin film of Claim 1 using the coating agent containing the compound particle | grain containing a ΙΙΙB group element and a VΙB group element, a ΙB group element powder, and a VΙB group element powder.
  4. 前記ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む塗布剤として、
    ΙＢ族元素、ΙΙΙＢ族元素およびＶΙＢ族元素を含む化合物粒子を含有する塗布剤を用いる、請求の範囲１記載の化合物半導体薄膜の製造方法。     As a coating agent containing the ΙB group element, ΙΙΙB group element and VΙB group element,
    The manufacturing method of the compound semiconductor thin film of Claim 1 using the coating agent containing the compound particle | grain containing a ΙB group element, a ΙΙΙB group element, and a VΙB group element.
  5. 前記化合物粒子として、メカノケミカルプロセスを行って得られた化合物粒子を用いる、請求の範囲２記載の化合物半導体薄膜の製造方法。 The manufacturing method of the compound semiconductor thin film of Claim 2 using the compound particle obtained by performing a mechanochemical process as said compound particle.
  6. ΙＢ族元素が、ＣｕおよびＡｇから選ばれる少なくとも一つの元素である、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein the group B element is at least one element selected from Cu and Ag.
  7. ΙΙΙＢ族元素が、Ｉｎ、Ｇａ、およびＡｌから選ばれる少なくとも一つの元素である、請求の範囲１記載の化合物半導体薄膜の製造方法。 2. The method for producing a compound semiconductor thin film according to claim 1, wherein the group B element is at least one element selected from In, Ga, and Al.
  8. ＶΙＢ族元素が、Ｓ、ＳｅおよびＴｅから選ばれる少なくとも一つの元素である、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein the V が B group element is at least one element selected from S, Se, and Te.
  9. 前記塗布剤が、さらにＳｂを含んでいる、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein the coating agent further contains Sb.
  10. さらに前記塗布膜を乾燥させる乾燥工程を、前記加圧焼成工程の前に行う、請求の範囲１記載の化合物半導体薄膜の製造方法。 Furthermore, the manufacturing method of the compound semiconductor thin film of Claim 1 which performs the drying process which dries the said coating film before the said pressurization baking process.
  11. 前記加圧焼成工程における機械的に加える圧力が、０Ｐａを超え１００ＭＰａ以下の範囲にある、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein the pressure applied mechanically in the pressure firing step is in the range of more than 0 Pa and not more than 100 MPa.
  12. 前記加圧焼成工程が、３００℃～６５０℃の範囲内の温度で行われる、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein the pressure firing step is performed at a temperature within a range of 300 ° C to 650 ° C.
  13. 前記加圧焼成工程が、常圧から１ＭＰａの範囲の圧力の雰囲気下で行われる、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein the pressure firing step is performed in an atmosphere having a pressure in a range of normal pressure to 1 MPa.
  14. 前記加圧焼成工程の後に、さらに常圧から１ＭＰａの範囲の圧力の雰囲気下で加熱する熱処理工程を行う、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein a heat treatment step is further performed after the pressure firing step, wherein the heat treatment step is performed in an atmosphere having a pressure in the range of normal pressure to 1 MPa.
  15. 前記熱処理工程が、前記加圧焼成工程における温度よりも高い温度で行われる、請求の範囲１４記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 14, wherein the heat treatment step is performed at a temperature higher than a temperature in the pressure firing step.
  16. 前記塗布剤を基板に塗布する工程が、スクリーン印刷によって行われる、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein the step of applying the coating agent to the substrate is performed by screen printing.
  17. 前記加圧焼成工程において、前記塗布膜が形成された基板を複数枚重ねた状態で加圧焼成する、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein, in the pressure firing step, pressure firing is performed in a state where a plurality of substrates on which the coating film is formed are stacked.
  18. 前記複数枚重ねた基板の間にスペーサーを設けて加圧焼成する、請求の範囲１７記載の化合物半導体薄膜の製造方法。 18. The method for producing a compound semiconductor thin film according to claim 17, wherein a spacer is provided between the plurality of stacked substrates and pressure firing is performed.
  19. 前記スペーサーとして、金属、ガラスおよびセラミックスからなる群から選ばれるスペーサーを用いる、請求の範囲１８記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 18, wherein a spacer selected from the group consisting of metal, glass and ceramics is used as the spacer.
  20. 前記ΙΙΙＢ族元素に加え、もしくは代えて、ΙΙＢ族元素とΙＶＢ族元素とを組み合わせて用いることを特徴とする、請求の範囲１記載の化合物半導体薄膜の製造方法。 The method for producing a compound semiconductor thin film according to claim 1, wherein a combination of a group B element and a group VB element is used in addition to or instead of the group B element.
  21. 化合物半導体薄膜を有する太陽電池であって、
    前記化合物半導体薄膜が、請求の範囲１記載の化合物半導体薄膜の製造方法によって製造されたことを特徴とする太陽電池。     A solar cell having a compound semiconductor thin film,
    A solar cell, wherein the compound semiconductor thin film is manufactured by the method for manufacturing a compound semiconductor thin film according to claim 1.
  22. 請求の範囲１記載の化合物半導体薄膜の製造方法に使用される装置であって、少なくとも押圧手段と加熱手段とを備えることを特徴とする化合物半導体薄膜製造装置。 An apparatus used in the method for producing a compound semiconductor thin film according to claim 1, comprising at least a pressing means and a heating means.
PCT/JP2010/065159 2009-10-12 2010-09-03 Method for producing compound semiconductor thin film, solar cell, and device for producing compound semiconductor thin film WO2011045989A1 (en)

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103367543A (en) * 2013-07-05 2013-10-23 北京四方继保自动化股份有限公司 Method for preparing CIGS (copper indium gallium selenide) film with non-vacuum method
JP2016044217A (en) * 2014-08-21 2016-04-04 東京応化工業株式会社 Application liquid, light-absorbing layer for solar cell and solar cell, and production method thereof
CN117430346A (en) * 2023-12-21 2024-01-23 浙江大华技术股份有限公司 Glass processing method, glass and image pickup device

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2858119A4 (en) 2012-05-30 2015-06-17 Toppan Printing Co Ltd Production method for compound semiconductor thin film, and solar cell provided with said compound semiconductor thin film
US9960314B2 (en) 2013-09-13 2018-05-01 Nanoco Technologies Ltd. Inorganic salt-nanoparticle ink for thin film photovoltaic devices and related methods
JP6411499B2 (en) * 2013-11-15 2018-10-24 ナノコ テクノロジーズ リミテッド Preparation of copper-rich copper indium (gallium) diselenide / disulfide

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63134566A (en) * 1986-11-25 1988-06-07 ティーディーケイ株式会社 Manufacture of al2o3-tic sintered body
JPH01152766A (en) * 1987-12-10 1989-06-15 Matsushita Electric Ind Co Ltd Manufacture of indium copper selenide
JPH07215704A (en) * 1994-02-02 1995-08-15 Yamaha Corp Production of ib-iiib-vib group compound thin film
JPH09139514A (en) * 1995-11-13 1997-05-27 Nec Kansai Ltd Solar cell and its manufacture
JPH10506989A (en) * 1994-09-29 1998-07-07 イースム リサーチ ディベロップメント カンパニー オブ ザ ヒーブル ユニバーシティ オブ エルサレム Radiation detection device and method for preparing the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63134566A (en) * 1986-11-25 1988-06-07 ティーディーケイ株式会社 Manufacture of al2o3-tic sintered body
JPH01152766A (en) * 1987-12-10 1989-06-15 Matsushita Electric Ind Co Ltd Manufacture of indium copper selenide
JPH07215704A (en) * 1994-02-02 1995-08-15 Yamaha Corp Production of ib-iiib-vib group compound thin film
JPH10506989A (en) * 1994-09-29 1998-07-07 イースム リサーチ ディベロップメント カンパニー オブ ザ ヒーブル ユニバーシティ オブ エルサレム Radiation detection device and method for preparing the same
JPH09139514A (en) * 1995-11-13 1997-05-27 Nec Kansai Ltd Solar cell and its manufacture

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
HIRONORI KOMAKI ET AL.: "V-group elements doped CuInS_2 Crystals Grown by Hot-Press Method", MEMOIRS OF THE FACULTY OF ENGINEERING, vol. 32, 2003, pages 141 - 145 *
TAKAHIRO WADA ET AL.: "Mechanochemical Process to Screen Insatsu/ Shoketsu-ho o Mochiita CIGS Hakumaku no Keisei to Taiyo Denchi eno Oyo", DAI 55 KAI EXTENDED ABSTRACTS, JAPAN SOCIETY OF APPLIED PHYSICS AND RELATED SOCIETIES, vol. 0, 2008, pages 39 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103367543A (en) * 2013-07-05 2013-10-23 北京四方继保自动化股份有限公司 Method for preparing CIGS (copper indium gallium selenide) film with non-vacuum method
CN103367543B (en) * 2013-07-05 2016-08-10 北京四方继保自动化股份有限公司 A kind of method that antivacuum method prepares CIGS thin film
JP2016044217A (en) * 2014-08-21 2016-04-04 東京応化工業株式会社 Application liquid, light-absorbing layer for solar cell and solar cell, and production method thereof
CN117430346A (en) * 2023-12-21 2024-01-23 浙江大华技术股份有限公司 Glass processing method, glass and image pickup device

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