JP2010129648A - Method of manufacturing thin-film solar cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a thin-film solar cell for accelerating growth of particles for composing a light absorption layer. <P>SOLUTION: The method of manufacturing thin-film solar cells includes: a process for forming a light absorption coating film by coating a first electrode layer 2 with a light absorption layer solution containing at least one of Cu, In, and Ga; a process for forming a light absorption layer 3 containing at least one of Cu, In and Ga by heat-treating the light absorption coating film in a reducing atmosphere; a process for forming an Se-containing film containing Se on the light absorption layer 3; a process for heat-treating the Se-containing film in a reducing atmosphere for diffusing Se to the light absorption layer 3; and a process for forming a second electrode layer 5 on the light absorption layer 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a thin film solar cell having a light absorption layer between a pair of electrode layers.

  FIG. 1 shows a basic structure of a general thin film solar cell. As shown in FIG. 1, the thin-film solar cell has a first electrode layer 2 made of, for example, Mo formed on a substrate 1 made of soda lime glass, for example, and is formed on the first electrode layer 2. A light absorption layer 3 made of a compound semiconductor thin film is formed, and a transparent second electrode layer 5 made of ZnO or the like is formed on the light absorption layer 3 through a buffer layer 4 made of ZnS, CdS, or the like. .

As the light absorption layer 3 made of a compound semiconductor, a compound semiconductor thin film made of Cu (In, Ga) Se ₂ is used as one capable of obtaining high energy conversion efficiency.

  Conventionally, the first electrode layer 2, the light absorption layer 3, the buffer layer 4, and the second electrode layer 5 are usually formed by a vapor deposition method or a sputtering method called a dry method.

In such a thin-film solar cell, alkali metal from the substrate 1 made of soda lime glass diffuses into the light absorption layer 3 to grow Cu (In, Ga) Se ₂ particles, thereby improving energy conversion efficiency. Can be improved.

Conventionally, a manufacturing method is known in which sodium selenide is deposited on the first electrode layer 2 by vapor deposition, and the light absorption layer 3 is formed thereon by sputtering (see Patent Document 1). In such a method for manufacturing a thin-film solar cell, sodium in the sodium selenide layer diffuses into the light absorption layer 3, and particles in the light absorption layer 3 can be grown.
JP-A-8-222750

  However, when an alkali metal layer is formed on the first electrode layer 2 by vapor deposition or sputtering as in the manufacturing method of Patent Document 1, the alkali metal layer such as Na has hygroscopicity. After the formation of the layer, there is a problem that the alkali metal layer is exposed to the atmosphere and changed in quality between the first electrode layer 2 and the formation of the laminated precursor.

  Therefore, in recent years, a method for growing particles in the light absorption layer 3 by a method other than using an alkali metal has been required.

  An object of this invention is to provide the manufacturing method of the thin film solar cell which can accelerate | stimulate the grain growth of the particle | grains which comprise a light absorption layer.

  The manufacturing method of the thin film solar cell of this invention is a manufacturing method of the thin film solar cell which has a light absorption layer between the 1st electrode layer and the 2nd electrode layer, Comprising: At least 1 sort (s) among Cu, In, and Ga is contained. Applying a light absorbing layer solution to the first electrode layer to form a light absorbing coating film; and heat-treating the light absorbing coating film in a reducing atmosphere to at least one of Cu, In, and Ga. Forming a light-absorbing layer containing seeds, forming a Se-containing film containing Se on the light-absorbing layer, and heat-treating the Se-containing film in a reducing atmosphere to form Se into the light-absorbing layer And a step of forming the second electrode layer on the light absorption layer.

In such a method for manufacturing a thin-film solar cell, an Se-containing film containing Se is formed on the light absorption layer, and the Se-containing film is heat-treated in a reducing atmosphere to diffuse Se in the Se-containing film to the light absorption layer. Therefore, particles containing at least one of Cu, In and Ga constituting the light absorption layer and Se are generated, and Se is excessively present, so that the liquid phase is formed at the heat treatment temperature in the light absorption coating film. Thus, a large amount of Se ₂ Cu compound Cu ₂ Se is generated, and the grain growth of the particles can be promoted.

  The manufacturing method of the thin film solar cell of this invention is a manufacturing method of the thin film solar cell which has a light absorption layer between the 1st electrode layer and the 2nd electrode layer, Comprising: At least 1 sort (s) among Cu, In, and Ga is contained. Forming a light-absorbing coating film by applying the light-absorbing layer solution on the first electrode layer, and forming Se by applying a Se-containing solution containing Se on the light-absorbing coating film. A step of forming a containing film, and heat treatment in a reducing atmosphere to diffuse Se in the light-absorbing coating film, and to absorb light containing at least one of Cu, In, and Ga and Se A step of forming a layer, and a step of forming the second electrode layer on the light absorption layer.

In such a method for manufacturing a thin-film solar cell, an Se-containing film is formed on a light-absorbing coating film and heat-treated in a reducing atmosphere to diffuse Se in the light-absorbing coating film. A light-absorbing layer containing at least one of In and Ga and Se can be produced, and since Se is excessive, a compound Cu of Se and Cu that becomes a liquid phase at the heat treatment temperature in the light-absorbing coating film ₂ Se is generated in a large amount, and the grain growth of the particles constituting the light absorption layer can be promoted.

  The method for producing a thin film solar cell of the present invention is a method for producing a thin film solar cell having a light absorption layer between a first electrode layer and a second electrode layer, and contains Se containing Se on the first electrode layer. Forming a film; heat treating the Se-containing film in a reducing atmosphere to diffuse Se in the Se-containing film into the first electrode layer; and Cu, In and On on the first electrode layer A step of forming a light-absorbing coating film by applying a light-absorbing layer solution containing at least one of Ga, and a heat treatment in a reducing atmosphere, whereby the Se of the first electrode layer is formed on the light-absorbing coating film. And forming a light absorption layer containing at least one of Cu, In and Ga and Se on the first electrode layer, and forming the second electrode layer on the light absorption layer And a process.

In such a method for manufacturing a thin-film solar cell, an Se-containing film is formed on the first electrode layer, the Se-containing film is heat-treated in a reducing atmosphere, and Se in the Se-containing film is diffused in the first electrode layer. A light absorbing coating film is formed on the first electrode layer and heat-treated in a reducing atmosphere to diffuse Se of the first electrode layer into the light absorbing coating film, and at least one of Cu, In, and Ga and Se. In addition, since Se is present in excess, a large amount of Cu ₂ Se that becomes a liquid phase at the heat treatment temperature is generated in the light absorption coating film, and the particles constituting the light absorption layer Grain growth can be promoted.

  The method for producing a thin film solar cell of the present invention is a method for producing a thin film solar cell having a light absorption layer between a first electrode layer and a second electrode layer, and contains Se containing Se on the first electrode layer. A step of forming a film, a step of forming a light absorption coating film by applying a light absorption layer solution containing at least one of Cu, In and Ga on the Se-containing film, and a reducing atmosphere. By heat-treating, Se of the Se-containing film is diffused into the light-absorbing coating film, and a light-absorbing layer containing at least one of Cu, In, and Ga and Se is formed on the first electrode layer. And a step of forming the second electrode layer on the light absorption layer.

In such a method for manufacturing a thin-film solar cell, a light-absorbing coating film is formed on a Se-containing film by applying a light-absorbing layer solution, and heat treatment is performed in a reducing atmosphere, whereby the Se-containing film is formed in the light-absorbing coating film. Se can be diffused to form a light absorption layer containing at least one of Cu, In and Ga and Se, and since Se is excessive, it becomes a liquid phase at the heat treatment temperature in the light absorption coating film. A large amount of Cu ₂ Se is generated, and the grain growth of the particles constituting the light absorption layer can be promoted.

  Moreover, in the manufacturing method of the thin film solar cell of this invention, in the manufacturing method which forms a Se containing film | membrane on a 1st electrode layer, it is desirable for a 1st electrode layer to contain Mo. In such a method for manufacturing a thin-film solar cell, since a large amount of Se is present on the surface of the first electrode layer, the bonding strength between the first electrode layer and the light absorption layer can be improved.

  Furthermore, in the manufacturing method of the thin film solar cell of this invention, it is desirable that the light absorption layer solution contains Se. In such a method for manufacturing a thin-film solar cell, Se is not only supplied from the Se-containing film to the light absorption layer, but also Se is contained in the light absorption layer solution, so that Se is sufficiently contained in the light absorption layer. And can exist uniformly.

According to the method for manufacturing a thin film solar cell of the present invention, a light absorption layer containing at least one of Cu, In, and Ga and Se can be formed, and since Se is excessively present, the liquid phase is formed at the heat treatment temperature. Thus, a large amount of Cu ₂ Se is generated, and the grain growth of the particles constituting the light absorption layer can be promoted. Thereby, energy conversion efficiency can be improved.

  The thin film solar cell produced by the manufacturing method of the present invention is a thin film solar cell having a light absorption layer between a pair of electrode layers. For example, as shown in FIG. A layer 2 is formed, a light absorption layer 3 made of a compound semiconductor thin film is formed on the first electrode layer 2, and a transparent second electrode layer 5 is formed on the light absorption layer 3 via a buffer layer 4. ing.

  As the substrate 1, for example, a soda lime glass substrate, a metal substrate such as Mo or SUS, a resin substrate such as polyimide, or the like can be used. A first electrode layer 2 is formed on the substrate 1, and a light absorption layer 3 is formed on the first electrode layer 2. A second electrode layer 5 is formed on the light absorption layer 3 via the buffer layer 4, and the light absorption layer 3 is sandwiched between the first electrode layer 2 and the second electrode layer 5. 1, a thin film solar cell having a light absorption layer 3 between the second electrode layers 2 and 5 is configured.

  In addition, although the example which laminated | stacked the board | substrate 1, the 1st electrode layer 2, the light absorption layer 3, the buffer layer 4, and the 2nd electrode layer 5 was demonstrated sequentially, in this invention, a pair of 1st, 2nd electrode layer 2, As long as the light absorption layer 3 is provided between the layers 5, various intermediate layers may be formed between the layers. Further, the present invention may be of a type that does not have the substrate 1, in other words, a type in which the first electrode layer 2 functions as a substrate.

As the light absorption layer 3 made of a compound semiconductor, CuInSe ₂ , CuGaSe ₂ , and Cu (In, Ga) Se ₂ , which are compound semiconductors made of a chalcopyrite structure, are used to obtain high energy conversion efficiency. .

The manufacturing method of the thin film solar cell of this invention is demonstrated. First, for example, a substrate 1 made of soda lime glass is prepared. A first electrode layer 2 is formed on the substrate 1. The first electrode layer 2 is made of any electrode material selected from molybdenum (Mo), tungsten (W), chromium (Cr), polysilicon (SiO ₂ ), metal silicide, aluminum (Al), and the like. desirable. The first electrode layer 2 can be formed by a vapor deposition method, a sputtering method, a coating method, or the like.

  Next, the light absorption layer 3 is formed on the first electrode layer 2. First, a light absorption layer solution for forming the light absorption layer 3 is prepared. This light absorption layer solution is a solution in which Cu and In are dissolved, and includes Cu and In and a nitrogen-containing solvent. The light absorbing layer solution is preferably a solution in which Cu, In and Ga are dissolved. Furthermore, a solution in which Cu, In, Ga, and Se are dissolved is desirable. Hereinafter, the case where the light absorption layer solution contains Cu, In, and Ga will be described.

  As the nitrogen-containing solvent, for example, at least one of ammonia, hydrazine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, ethanolamine, allylamine, ethanolamine, diethanolamine, triethanolamine, and aniline should be used. Can do.

  The light absorption layer solution is constituted by dissolving a copper compound, an indium compound, and a gallium compound in the nitrogen-containing solvent described above. Examples of the copper compound include copper, copper selenide, and copper sulfide. Examples of the indium compound include indium, indium selenide, and indium sulfide. Examples of the gallium compound include gallium, gallium selenide, and sulfide. Gallium is used. In addition, although copper is not a copper compound, in this specification, copper was described as a copper compound for convenience. The same applies to indium in an indium compound and gallium in a gallium compound.

  The light absorption layer solution is prepared by, for example, mixing three types of solutions: a solution in which a copper compound is dissolved in a nitrogen-containing solvent, a solution in which an indium compound is dissolved in a nitrogen-containing solvent, and a solution in which a gallium compound is dissolved in a nitrogen-containing solvent. Can be made. Thereby, the light absorption layer solution which Cu, In, and Ga melt | dissolved in the organic solvent in the predetermined ratio can be prepared.

  And this light absorption layer solution is apply | coated on the above-mentioned 1st electrode layer 2 of the board | substrate 1, a light absorption coating film is produced, this light absorption coating film is heat-processed in reducing atmosphere, and 1st electrode layer On 2, a light absorption layer containing Cu and at least one of In and Ga as elements can be produced. The thickness of the light absorption layer 3 is, for example, 1.0 to 2.5 μm.

  The application of the light absorption layer solution onto the first electrode layer 2 is desirably performed using a spin coater, screen printing, dipping, spraying, a die coater, or the like. Drying is performed after application of the light absorbing solution. Drying is desirably performed in a reducing atmosphere. The temperature at the time of drying is 50-300 degreeC, for example.

  The light absorption layer solution includes organic solvents or ligands such as C, H, and N that are bonded to Cu, In, and Ga, and C, H, and N that are not bonded to Cu, In, and Ga. However, the coating film (also referred to as a precursor) obtained by drying is composed of a combination of C, H, N, etc., and Cu, In, and Ga.

  The heat treatment is desirably performed in a reducing atmosphere. In particular, any one of a nitrogen atmosphere, a forming gas atmosphere, and a hydrogen atmosphere is desirable. The heat treatment temperature is set to 400 ° C. to 600 ° C., for example.

  The drying and heat treatment of the light absorption coating film can be performed by cooling after drying and then heating again, but the light absorption coating film can be continuously dried and heat treatment. It can be simplified.

  Thereafter, a Se-containing film containing Se is formed on the light absorption layer 3, and the Se-containing film is heat-treated in a reducing atmosphere to diffuse Se in the Se-containing film into the light absorption layer 3.

  The Se-containing film containing Se is configured, for example, by applying and drying a Se-containing solution in which a selenium compound is dissolved in the nitrogen-containing solvent described above. Examples of the selenium compound include selenium and selenium sulfide. Such a Se-containing solution is preferably applied by using a spin coater, screen printing, dipping, spraying, a die coater, or the like. The thickness of the Se-containing film is 0.5 to 2.0 μm, and Se is diffused into the light absorption layer 3 by a heat treatment in a subsequent reducing atmosphere, so that the film does not exist as a film. It is desirable that

  The reducing atmosphere in which the Se-containing film is heat-treated can be an atmosphere for producing the light absorption layer 3 and is the same as the atmosphere for producing the light absorption layer 3 for the purpose of further promoting grain growth. Is desirable. Moreover, the heat processing temperature in that case shall be 400 to 600 degreeC.

Thereafter, the high resistance layer made of Cu ₂ Se or the like on the surface is preferably removed by etching with an aqueous KCN solution.

In such a method for manufacturing a thin-film solar cell, a Se-containing film containing Se is formed on the light absorption layer 3, and the Se-containing film is heat-treated in a reducing atmosphere to convert Se in the Se-containing film into the light absorption layer 3. Because of the diffusion, particles containing Cu, In, Ga and Se constituting the light absorption layer 3 are generated, and since Se is excessively present, a compound Cu ₂ Se of Se and Cu that becomes a liquid phase by heat treatment Can be produced in a large amount, and the grain growth of the particles can be promoted. The Cu ₂ Se that has become a liquid phase generates particles made of Cu (In, Ga) Se ₂ when almost solidified.

  In addition, since a light absorption layer solution containing Cu, In and Ga is prepared, applied and heat-treated to form the light absorption layer 3, and a Se-containing film can also be applied and formed in the same manner as in the prior art. In addition, since a vapor deposition method or a sputtering method is not used, a manufacturing process can be simplified, and an expensive gas or apparatus is not used, so that a manufacturing cost can be reduced.

Thereafter, an n-type buffer layer 4 for heterojunction is formed on the light absorption layer 3. CdS, ZnS, ZnSe, ZnMgO, ZnS / ZnMgO, ZnO, InS, InSe, In (OH) ₃ , ZnInSe, ZnInS, ZnSSe, CuI, Mg Materials such as OH) ₂ are used. These can be produced by immersing the substrate 1 formed up to the light absorption layer 3 by an dip coating method, CBD method (solution growth method) or the like in an aqueous solution to deposit fine particles, followed by heat treatment.

  Next, a transparent second electrode layer 5 made of ITO or ZnO is formed on the buffer layer 4. The second electrode layer 5 can be formed by sputtering, spraying or coating. The thickness of the buffer layer 4 is, for example, 10 to 200 nm, and the thickness of the second electrode layer 5 is, for example, 0.5 to 3.0 μm.

In the above embodiment, a Se-containing film containing Se is formed on the light absorption layer 3 formed by heat treatment, and the Se-containing film is heat-treated in a reducing atmosphere to convert Se in the Se-containing film into the light absorption layer. Although the example diffused to 3 was described, a light absorbing coating film was prepared by applying a light absorbing layer solution onto the first electrode layer 2, and a Se containing solution was applied onto the light absorbing coating film to contain Se. A film is formed, and the light-absorbing coating film and the Se-containing film are heat-treated in a reducing atmosphere to diffuse Se in the light-absorbing coating film and to absorb light containing Cu, In, Ga and Se as elements. Layer 3 can also be made. Also in this case, since Se is excessively present in the light absorption coating film, a large amount of Se and Cu compound Cu ₂ Se that becomes a liquid phase by heat treatment is generated in the light absorption coating film, and the light absorption layer 3 is formed. Grain growth of the constituent particles can be promoted, and the heat treatment in the reducing atmosphere between the light absorption coating film and the Se-containing film can be completed by one time, and the process can be simplified.
(Other forms)
In the above embodiment, the example in which the Se-containing film is formed on the light absorption layer 3 has been described. However, the Se-containing film may be formed on the first electrode layer 2.

That is, a Se-containing film is formed on the first electrode layer 2, and the Se-containing film is heat-treated in a reducing atmosphere to diffuse Se of the Se-containing film into the first electrode layer 2. A light absorbing coating film is formed on the substrate, and heat treatment is performed in a reducing atmosphere to diffuse Se in the first electrode layer 2 into the light absorbing coating film, and Cu, In, Ga, and Se constituting the light absorbing layer 3 are diffused. The light-absorbing layer 3 containing Cu, In, Ga, and Se as elements can be produced. Also in this case, since Se is excessively present in the light absorption coating film, a large amount of Cu ₂ Se, which is a compound of Se and Cu, which becomes a liquid phase by heat treatment, is generated, and the particles constituting the light absorption layer 3 are formed. It can promote growth. In this case, the bonding strength between the first electrode layer 2 and the light absorption layer 3 can be improved by forming a light absorption coating film on the first electrode layer 2 containing Mo.

Also, by forming a Se-containing film containing Se on the first electrode layer 2, forming a light-absorbing coating film by applying a light-absorbing layer solution on the Se-containing film, and performing a heat treatment in a reducing atmosphere. Then, Se of the Se-containing film is diffused into the light-absorbing coating film, and particles containing Cu, In, Ga and Se constituting the light-absorbing layer 3 are generated, and Cu, In, Ga and Se are contained as elements. The light absorption layer 3 can also be produced. Also in this case, since Se is excessively present in the light absorption coating film, a large amount of Cu ₂ Se that is a compound of Se and Cu, which becomes a liquid phase by heat treatment, is generated in the light absorption coating film, and the light absorption layer 3 is formed. The grain growth of the constituent particles can be promoted. Furthermore, by forming the light absorption coating film on the first electrode layer 2 containing Mo, the bonding strength between the first electrode layer 2 and the light absorption layer 3 can be improved, and the light absorption coating film and the Se-containing film can be improved. Heat treatment in a reducing atmosphere can be completed once, and the process can be simplified.

  In addition, although the case where the light absorption layer solution which consists of Cu, In, and Ga was demonstrated with the said form, in this invention, not only Cu, In, Ga but Se is contained in a light absorption layer solution. It is also possible. In this case, Se is not only supplied from the Se-containing film to the light absorption layer 3, but also contains Se in the light absorption layer solution, so that Se is sufficiently and uniformly contained in the light absorption layer 3. Can exist. Se is composed of a selenium compound dissolved in the above-mentioned nitrogen-containing solvent. Examples of the selenium compound include selenium and selenium sulfide, which are mixed with a solution of Cu, In, and Ga. A light absorbing coating film can be formed using the solution. Moreover, Se is contained in the light absorption layer 3 by using copper selenide as the copper compound, indium selenide as the indium compound, gallium selenide as the gallium compound, or alkali metal selenide as the alkali metal compound. You can also.

  In the above example, the metal chalcogenide such as copper selenide was dissolved in a nitrogen-containing solvent, and this light absorbing solution was applied and baked. However, copper, indium, gallium, and selenium were further contained in one molecule. Single precursors such as ammonia, hydrazine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, ethanolamine, allylamine, ethanolamine, diethanolamine, triethanolamine, aniline, pyridine, and more Light absorption solution dissolved in alcohols such as methanol, ethanol, propanol, butanol, terpineol, propylene glycol, acetone, acetonitrile, toluene, xylene, etc. is applied and baked. It can also be applied in that way.

  Hereinafter, although the example and the comparative example are given and the manufacturing method of the thin film solar cell of this invention is demonstrated in detail, this invention is not limited only to a following example.

0.206 g (1 mmol) of copper selenide (Cu ₂ Se) as the copper compound, 0.467 g (1 mmol) of indium selenide (In ₂ Se ₃ ) as the indium compound, and gallium selenide (Ga ₂ Se ₃ as the gallium compound) ) Was dissolved in 30 ml of pyridine to prepare three types of solutions in which Cu ₂ Se, In ₂ Se ₃ and Ga ₂ Se ₃ were dissolved. In the three types of solutions, Cu, In, or Ga was dissolved in pyridine.

  Thereafter, three kinds of solutions in which Cu, In and Ga were dissolved in pyridine were mixed to prepare a light absorption layer solution in which Cu, In and Ga were dissolved in an organic solvent.

  This light absorption layer solution was formed into a thin film on the first electrode layer made of Mo of the soda lime glass substrate by spray pyrolysis. The thin film was applied to the first electrode layer by spraying the light absorption layer solution using nitrogen gas as a carrier gas in the glove box. At the time of coating, the soda lime glass substrate was heated to 110 ° C. with a hot plate, and the light absorbing layer solution was sprayed for 10 minutes to form a light absorbing coating film and dried.

  After forming the light absorbing coating film, heat treatment was performed in an atmosphere of hydrogen gas. The heat treatment was performed by raising the temperature to 525 ° C. over 5 minutes and holding at 525 ° C. for 1 hour, followed by natural cooling to form a light absorption layer composed of a compound semiconductor thin film having a thickness of 2 μm.

  Thereafter, a Se-containing solution in which a selenium compound composed of selenium metal was dissolved in 30 ml of pyridine was prepared, and this Se-containing solution was applied to the upper surface of the light absorption layer by a spray pyrolysis method to form a Se-containing film. The thin film is made of nitrogen gas as a carrier gas in a glove box, while a soda lime glass substrate is heated to 110 ° C. on a hot plate, sprayed with a Se-containing solution for 10 minutes, formed into a thin film, dried, and contains Se A membrane was prepared.

  This was heat-treated in an atmosphere of hydrogen gas. The heat treatment was performed by raising the temperature to 525 ° C. over 5 minutes and holding at 525 ° C. for 1 hour. After the heat treatment, no Se-containing film was present on the light absorption layer, and the light absorption layer was exposed.

  Thereafter, cadmium acetate and thiourea were dissolved in ammonia, and the substrate was immersed therein to form a buffer layer made of CdS having a thickness of 50 nm on the compound semiconductor thin film. Furthermore, a transparent second electrode layer made of an Al-doped zinc oxide film was formed on the buffer layer by sputtering. Finally, an aluminum electrode (extraction electrode) was formed by vapor deposition to produce a thin film solar cell.

  When the cross section of the thin film solar cell was observed with a scanning electron microscope (SEM), the particles constituting the light absorption layer were composed of Cu, In, Ga and Se, and the average particle size of the particles was 1. It was 5 μm. The average particle size was determined by measuring the length of the light absorption layer in the thickness direction of the crystal particles appearing in the SEM photograph of 30,000 times, and obtaining the average value thereof.

  As a comparative example, after forming the light-absorbing coating film, heat treatment is performed in an atmosphere of hydrogen gas, and the second electrode layer is formed as it is without forming the Se-containing film in the light-absorbing layer. When the thin-film solar battery was manufactured, the average particle diameter of the light absorption layer was 0.2 μm.

Therefore, according to the manufacturing method of the present invention, a Se-containing film containing Se is formed on the light absorption layer, and the Se-containing film is heat-treated in a reducing atmosphere to diffuse Se in the Se-containing film into the light absorption layer. As a result, Se can be excessively present in the light absorption layer, and a large amount of liquid-phase Cu ₂ Se, which is a compound of Se and Cu, can be produced and particles can be grown. It can be seen that can be improved.

  In the same manner as in Example 1, a light absorbing coating film is formed by coating the light absorbing layer solution on the first electrode layer, and a Se-containing film is formed on the light absorbing coating film in the same manner as described above. Then, a light absorption layer was formed on the first electrode layer by heat treatment in a reducing atmosphere. Thereafter, in the same manner as in Example 1, a buffer layer and a second electrode layer were formed on the light absorption layer to produce a thin film solar cell.

  And it was 1.6 micrometers when the average particle diameter of the particle | grains which comprise a light absorption layer was measured like the said Example 1. FIG.

  A Se-containing film containing Se was formed on the first electrode layer in the same manner as in Example 1 described above, and the Se-containing film was heat-treated to diffuse Se in the first electrode layer. Thereafter, a light absorption layer solution was applied on the first electrode layer in the same manner as in Example 1 to form a light absorption coating film, and heat treatment was performed to form a light absorption layer on the first electrode layer. Thereafter, in the same manner as in Example 1, a buffer layer and a second electrode layer were formed on the light absorption layer to produce a thin film solar cell.

  And when it carried out similarly to the said Example 1 and measured the average particle diameter of the particle | grains which comprise a light absorption layer, it was 1.5 micrometers.

  A Se-containing film containing Se is formed on the first electrode layer in the same manner as in the first embodiment, and then a light-absorbing layer is formed on the Se-containing film containing Se in the same manner as in the first embodiment. The solution was applied to form a light absorption coating film, and heat treatment was performed to form a light absorption layer on the first electrode layer. Thereafter, in the same manner as in Example 1, a buffer layer and a second electrode layer were formed on the light absorption layer to produce a thin film solar cell.

  And it was 1.6 micrometers when the average particle diameter of the particle | grains which comprise a light absorption layer was measured like the said Example 1. FIG.

It is sectional drawing which shows an example of a thin film solar cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... 1st electrode layer 3 ... Light absorption layer 4 ... Buffer layer 5 ... 2nd electrode layer

Claims (6)

  A method of manufacturing a thin film solar cell having a light absorption layer between a first electrode layer and a second electrode layer, wherein a light absorption layer solution containing at least one of Cu, In, and Ga is used as the first A step of forming a light absorption coating film by coating on the electrode layer, and a light absorption layer containing at least one of Cu, In, and Ga by heat-treating the light absorption coating film in a reducing atmosphere A step of forming a Se-containing film containing Se on the light absorption layer, a step of heat-treating the Se-containing film in a reducing atmosphere to diffuse Se into the light absorption layer, and the light absorption layer Forming the second electrode layer thereon. A method for producing a thin-film solar cell.   A method of manufacturing a thin film solar cell having a light absorption layer between a first electrode layer and a second electrode layer, wherein a light absorption layer solution containing at least one of Cu, In, and Ga is used as the first Forming a light-absorbing coating film by coating on the electrode layer; forming a Se-containing film formed by applying a Se-containing solution containing Se on the light-absorbing coating film; and reducing atmosphere A step of diffusing Se in the Se-containing film into the light-absorbing coating film by heat treatment to form a light-absorbing layer containing at least one of Cu, In, and Ga and Se, and the light absorption Forming the second electrode layer on the layer, and a method for producing a thin-film solar cell.   A method for manufacturing a thin-film solar cell having a light absorption layer between a first electrode layer and a second electrode layer, wherein a Se-containing film containing Se is formed on the first electrode layer; A step of diffusing Se in the Se-containing film in the first electrode layer by heat-treating the film in a reducing atmosphere; and containing at least one of Cu, In and Ga on the first electrode layer A step of forming a light-absorbing coating film by applying a light-absorbing layer solution and a heat treatment in a reducing atmosphere diffuse Se in the first electrode layer in the light-absorbing coating film. A step of forming a light absorption layer containing at least one of Cu, In and Ga and Se, and a step of forming the second electrode layer on the light absorption layer. Thin film solar cell manufacturing method.   A method for manufacturing a thin-film solar cell having a light absorption layer between a first electrode layer and a second electrode layer, wherein a Se-containing film containing Se is formed on the first electrode layer; A step of forming a light absorption coating film by applying a light absorption layer solution containing Cu, at least one of In and Ga on the film, and a heat treatment in a reducing atmosphere, whereby the light absorption coating film Diffusing Se in the Se-containing film to form a light absorption layer containing at least one of Cu, In, and Ga and Se on the first electrode layer; and And a step of forming a second electrode layer.   The method of manufacturing a thin-film solar cell according to claim 3 or 4, wherein the first electrode layer contains Mo.   The method for manufacturing a thin-film solar cell according to claim 1, wherein the light absorption layer solution contains Se.

Images