JP5545277B2 - Solar cell and manufacturing method thereof - Google Patents

Description

  The present invention relates to a method for manufacturing a solar cell that directly converts light energy into electric energy, and a solar cell obtained by the method.

A solar cell is a semiconductor element that converts light energy into electric power, and includes a pn junction type, a pin type, a Schottky type, and the like, and in particular, a pn junction type is widely used. Further, when solar cells are classified based on their substrate materials, they are broadly classified into three types: silicon crystal solar cells, amorphous (amorphous) silicon solar cells, and compound semiconductor solar cells. Silicon crystal solar cells are further classified into single crystal solar cells and polycrystalline solar cells. Since a silicon crystal substrate for a solar cell can be manufactured relatively easily, its production scale is currently the largest and is expected to become more widespread in the future (for example, Patent Document 1: JP-A-8-073297). Publication).
The output characteristics of a solar cell are generally evaluated by measuring an output current voltage curve using a solar simulator. The product of the output current I _max and the output voltage V _max on this curve, the point at which I _max × V _max is maximum is called the maximum output P _max , and this P _max is the total light energy (S × (I: S is the element area, I is the intensity of the irradiated light))
η = {P _max / (S × I)} × 100 (%)
Is defined as the conversion efficiency η of the solar cell.

In order to increase the conversion efficiency η, the short-circuit current Isc (output current value when V = 0 in the current-voltage curve) or Voc (output voltage value when I = 0 in the current-voltage curve) is increased. It is important to make the output current voltage curve as close to a square as possible. The squareness of the output current voltage curve is generally
FF = P _max / (Isc × Voc)
It can be evaluated by the fill factor (curve factor) defined by the equation (1). The closer the FF value is to 1, the closer the output current-voltage curve becomes to an ideal square, and the higher the conversion efficiency η.
In order to improve the conversion efficiency η, it is important to reduce the surface recombination of carriers. In a silicon crystal solar cell, minority carriers generated by incident light of sunlight reach the pn junction surface mainly by diffusion, and then are transferred to the outside as majority carriers from the electrodes attached to the light receiving surface and the back surface. It is taken out and becomes electric energy.
At that time, carriers that could be extracted as current through the interface states existing on the substrate surface other than the electrode surface may be recombined and lost, leading to a decrease in conversion efficiency η.

Therefore, in a high-efficiency solar cell, a passivation film made of SiO ₂ is formed on the surface of the silicon substrate except for the contact portion with the electrode, thereby suppressing carrier recombination at the interface between the silicon substrate and the passivation film. The conversion efficiency η is improved.
As a method for forming a passivation film, a thermal oxidation method is mainly used. A silicon substrate is heated to 900 ° C. or higher in a thermal oxidation furnace in an oxygen atmosphere or an air atmosphere to form an oxide film on the surface of the silicon substrate. To do. However, when the passivation film is formed by a thermal oxidation method, it is necessary to process the silicon substrate at a high temperature of 900 ° C. or higher, and the lifetime of the silicon substrate is reduced due to re-diffusion of impurities by such high temperature processing. A problem occurs.

  Further, in Patent Document 2 (Japanese Patent Laid-Open No. 58-23486), a passivation film is formed by applying a tantalum oxide film and a niobium oxide film to a substrate surface by spin coating, spraying, or dipping as a passivation film, followed by baking. A method for forming the above has been reported. According to this method, it is possible to form a passivation film without reducing the lifetime of the silicon substrate because high temperature processing is not required, but tantalum oxide and niobium oxide films themselves have low passivation ability. There is a problem that a sufficient passivation effect cannot be obtained, carrier recombination on the surface of the silicon substrate increases, and conversion efficiency of the solar cell decreases.

  Patent Document 3 (Japanese Patent Laid-Open No. 58-220477) reports that a passivation effect can be obtained by forming a silicon nitride film on the surface of a silicon substrate by a plasma CVD method. Since the silicon nitride film has a function as an antireflection film for a crystalline silicon solar cell and also has an excellent passivation effect on the surface and inside of the silicon substrate, the silicon nitride film is used as a useful film as a passivation film. However, since the plasma CVD method has a high film formation rate even at a relatively low process temperature of about 400 ° C., it is frequently used in the dielectric film formation process of solar cells, but is generated in plasma. Since high energy charged particles are likely to damage the deposited film and the surface of the silicon substrate, the resulting silicon nitride film has a high interface state density, and a sufficient passivation effect cannot be obtained with the silicon nitride film alone. was there.

  In recent years, research that focuses on the relationship between the fixed charge of the diffusion layer and the dielectric film has been actively conducted. In general, a silicon nitride film having a positive fixed charge has an effective passivation performance as a passivation film in an n-type region, but is considered inappropriate as a passivation film for a p-type region. There is a problem that a sufficient passivation effect cannot be obtained in the p-type region.

JP-A-8-073297 JP 58-23486 A JP 58-220477 A

  The present invention has been made in view of the above circumstances, and by forming an optimum passivation film on the diffusion layer on the light-receiving surface side of the silicon substrate, particularly on the p-type diffusion layer, the solar cell having excellent surface passivation is provided. It is an object of the present invention to provide a manufacturing method and a high conversion efficiency solar cell manufactured by the method.

As a result of intensive studies to achieve the above object, after forming a diffusion layer having a conductivity type different from the conductivity type of the silicon substrate on the light receiving surface side of the silicon substrate in the step of forming the solar cell, the following general formula (1) By applying a composition containing the compound shown and then subjecting it to a condensation reaction by heat treatment to form a cured film on the diffusion layer, the formed cured film has a negative fixed charge. As a result, it was found that the passivation effect in the diffusion layer, particularly in the p-type region, was improved, and the present invention was achieved.
R ¹ ₂ -Al-O-Si-R ² ₃ (1)
(In the formula, R ¹ represents an organic group having 1 to 4 carbon atoms, R ² represents a hydrolyzable group or a hydroxyl group. Each R ¹ and R ² may be the same or different.)

Accordingly, the present invention provides a solar cell and a manufacturing how below.
[1] A p-type diffusion layer having a conductivity type different from that of the silicon substrate formed on the light-receiving surface side of the silicon substrate, a dielectric film formed on the p-type diffusion layer, and the p-type diffusion layer A solar cell having a light receiving surface electrode electrically connected to the p-type diffusion layer and the dielectric film, the following general formula (1):
R ¹ ₂ -Al-O-Si-R ² ₃ (1)
(In the formula, R ¹ represents an organic group having 1 to 4 carbon atoms, R ² represents a hydrolyzable group or a hydroxyl group. Each R ¹ and R ² may be the same or different.)
The compound of formula (1) is hydrolyzed by applying a composition comprising an acid catalyst having a compounding amount of 10 to 1000 ppm to the compound and a solvent on the p-type diffusion layer and then heat-treating the composition. - solar cell characterized by having a condensed cured film as a passivation film.
[ 2 ] A p-type diffusion layer having a conductivity type different from the conductivity type of the silicon substrate is formed on the light-receiving surface side of the silicon substrate, and then a dielectric film is formed, and then light reception electrically connected to the p-type diffusion layer. A method for producing a solar cell including a step of forming a surface electrode, wherein the compound represented by the following general formula (1) is added to the p-type diffusion layer on the p-type diffusion layer before the formation of the dielectric film, and the compounding amount for the compound The process comprising applying a composition comprising 10 to 1000 ppm of an acid catalyst and a solvent, followed by heat treatment to form a cured film obtained by hydrolysis and condensation of the compound of the general formula (1). Battery manufacturing method.
R ¹ ₂ -Al-O-Si-R ² ₃ (1)
(In the formula, R ¹ represents an organic group having 1 to 4 carbon atoms, R ² represents a hydrolyzable group or a hydroxyl group. Each R ¹ and R ² may be the same or different.)
[ 3 ] Further, an n-type diffusion layer having the same conductivity type as that of the silicon substrate is formed on at least a part of the back side of the silicon substrate, and then a dielectric film is formed. look including the step of forming a back surface electrode connected to, before forming the dielectric film of the light-receiving surface side, on the light-receiving surface side p-type diffusion layer, and wherein a step of forming the cured film The method for producing a solar cell according to [2] .
[ 4 ] The method for producing a solar cell according to [ 2 ] or [ 3 ], wherein the heat treatment temperature is 80 to 200 ° C.
[ 5 ] The method for manufacturing a solar cell according to any one of [ 2 ] to [ 4 ], wherein the cured film has a thickness of 10 to 100 nm.
[6] The dielectric film is a silicon nitride film, a titanium dioxide film, a zinc oxide film, a tin film oxide, tantalum oxide film, a niobium oxide film, characterized in that it is a magnesium film or aluminum oxide film fluoride [2 ] The manufacturing method of the solar cell in any one of [ 5 ].
[ 7 ] The method for manufacturing a solar cell according to any one of [ 2 ] to [ 6 ], wherein the dielectric film is formed by a plasma CVD method.

According to the present invention, R ¹ ₂ -Al-O-Si-R ² ₃ (wherein R ¹ represents an organic group having 1 to 4 carbon atoms, R ² represents a hydrolyzable group or a hydroxyl group. ¹ and R ² may be the same or different.) And a composition comprising an acid catalyst and a solvent in an amount of 10 to 1000 ppm based on the compound, a light-receiving surface side diffusion layer of a silicon substrate, particularly p-type By applying / heat-treating on the region and forming a cured film, it becomes possible to form a light-receiving surface side diffusion layer, particularly a passivation film having an excellent passivation effect in the p-type region, and as a result, a solar cell with high conversion efficiency. Can be provided.

It is a schematic sectional drawing which shows an example of the manufacturing process of the solar cell of this invention, (A) is a board | substrate, (B) is the state which formed the n-type diffused layer in the board | substrate back surface, (C) is p-type diffusion on the substrate surface. (D) is a state in which a cured film is formed on the substrate surface, (E) is a state in which an antireflection film (silicon nitride film) is formed on the front and back surfaces of the substrate, and (F) is a light receiving surface and a non-light receiving surface. The state in which the surface electrodes are formed is shown respectively.

In the manufacturing method of the present invention, a diffusion layer having a conductivity type different from the conductivity type of the silicon substrate is formed on the light-receiving surface side of the silicon substrate, and then a dielectric film is formed on the diffusion layer. Forming a light receiving surface electrode to be electrically connected, forming a diffusion layer of the same conductivity type as the conductivity type of the silicon substrate on at least a part of the back surface side of the silicon substrate, and then forming a dielectric film and then the diffusion A method for producing a solar cell comprising a step of forming a back electrode electrically connected to a layer, comprising a compound represented by the following general formula (1) on the light-receiving surface side diffusion layer: And a step of forming a cured film on the light-receiving surface side diffusion layer by subjecting it to a hydrolysis / condensation reaction by heat treatment after application of the composition.
R ¹ ₂ -Al-O-Si-R ² ₃ (1)
(In the formula, R ¹ represents an organic group having 1 to 4 carbon atoms, R ² represents a hydrolyzable group or a hydroxyl group. Each R ¹ and R ² may be the same or different.)

Hereinafter, although the manufacturing method of the solar cell of this invention is demonstrated using drawing, this invention is not limited by this description.
1 (A) to 1 (F) are schematic cross-sectional views showing a manufacturing process of one embodiment in the method for manufacturing a solar cell of the present invention. Hereinafter, each step will be described in detail.

(1) Substrate The silicon substrate 1 used in the present invention may be n-type or p-type, but FIG. 1A shows an n-type substrate. This silicon single crystal substrate may be produced by any of the Czochralski (CZ) method and the float zone (FZ) method. The specific resistance of the silicon substrate 1 is preferably 0.3 to 3.0 Ω · cm, and more preferably 0.5 to 2.0 Ω · cm, from the viewpoint of producing a high-performance solar cell. As the silicon substrate, a phosphorus-doped n-type single crystal silicon substrate is preferable because a relatively high lifetime can be obtained. The phosphorus-doped dopant concentration is preferably 1 × 10 ¹⁵ cm ^{−3 to} 5 × 10 ¹⁶ cm ⁻³ [FIG. 1 (A)].

(2) Damage etching / texture formation For example, the silicon substrate 1 is immersed in a sodium hydroxide aqueous solution, and a damaged layer caused by slicing is removed by etching. For removing damage from the substrate, a strong alkaline aqueous solution such as potassium hydroxide may be used, and a similar purpose can be achieved with an acid aqueous solution such as hydrofluoric acid.
A random texture is formed on the substrate 1 subjected to damage etching. In general, a solar cell preferably has an uneven shape on the surface (light receiving surface). The reason is that in order to reduce the reflectance of incident light on the light receiving surface, it is necessary to cause the light receiving surface to perform reflection at least twice as much as possible. The size of each of these peaks is preferably about 1 to 20 μm. Typical surface uneven structures include V-grooves and U-grooves. These can be formed using a grinding machine. In order to create a random uneven structure, wet etching by immersion in an aqueous solution of sodium hydroxide and isopropyl alcohol, or acid etching, reactive ion etching, or the like can be used. In the drawing, the texture structure formed on both sides is fine and therefore omitted.

(3) Formation of n-type diffusion layer When the silicon substrate 1 is n-type, the n-type diffusion layer 3 is applied to at least a part of the back surface by applying a heat treatment after applying a coating agent containing a dopant to the back surface, particularly the entire back surface. [FIG. 1B]. When the silicon substrate is p-type, an n-type diffusion layer is formed on the light receiving surface by applying a coating agent containing a dopant to the light receiving surface and then performing heat treatment. After the heat treatment, the glass component attached to the silicon substrate 1 is washed by glass etching or the like. The dopant is preferably phosphorus. The surface dopant concentration of the n-type diffusion layer 3 is preferably 1 × 10 ^{18 to} 5 × 10 ²⁰ cm ^{−3 and} more preferably 5 × 10 ¹⁸ to 1 × 10 ²⁰ cm ⁻³ .

(4) Formation of p-type diffusion layer A similar process is performed on the light-receiving surface to form the p-type diffusion layer 2 over the entire light-receiving surface [FIG. 1 (C)]. A p-type diffusion layer 2 is formed by applying a coating agent containing a dopant to the light receiving surface and performing a heat treatment. The dopant is preferably boron, and the surface dopant concentration of the p-type diffusion layer 2 is preferably 1 × 10 ^{18 to} 5 × 10 ²⁰ cm ^−3, more preferably 5 × 10 ¹⁸ to 1 × 10 ²⁰ cm ^−3. preferable.

(5) Pn junction isolation Pn junction isolation is performed using a plasma etcher. In this process, the sample is stacked so that plasma and radicals do not enter the light-receiving surface and the back surface, and the end face is cut by several microns in this state. After bonding and separation, glass components, silicon powder, and the like attached to the substrate are washed by glass etching or the like.

(6) Formation of Cured Film Subsequently, as shown in FIG. 1D, the cured film 4 is formed on the p-type diffusion layer 2. The cured film is a film obtained by subjecting a composition containing a compound represented by the following general formula (1) to a hydrolysis / condensation reaction.
R ¹ ₂ -Al-O-Si-R ² ₃ (1)
(In the formula, R ¹ represents an organic group having 1 to 4 carbon atoms, particularly an alkoxy group, R ² represents a hydrolyzable group or a hydroxyl group. Each R ¹ and R ² may be the same or different.)

Here, examples of the hydrolyzable group R ² include an alkoxy group, an acetoxy group, a hydroxyl group, and a halogen group. Among these hydrolyzable groups, an alkoxy group is preferable from the viewpoint of the stability of the composition and the handleability.

Examples of the composition of the general formula (1) in which the hydrolyzable group R ² is an alkoxy group include dibutoxyaluminoxytrimethoxysilane, dibutoxyaluminoxytriethoxysilane, dibutoxyaluminoxytripropoxysilane, and the like. As the composition of the general formula hydrolysable group R ² is an acetoxy group (1), the alkoxy group include those substituted with an acetoxy group. Further, regarding the hydroxyl group and the halogen group, those in which an alkoxy group is substituted with a hydroxyl group and a halogen group, respectively, can be mentioned.

  Also, for the purpose of promoting hydrolysis / condensation reaction, organic acids such as formic acid, acetic acid, oxalic acid, carboxylic acid, benzoic acid and alkyl acid, inorganic acids such as hydrochloric acid, phosphoric acid, sulfuric acid, nitric acid, boric acid and hydrofluoric acid An acid can be used as a catalyst and can be blended in the composition.

  As the usage-amount of the said catalyst, the range of 10-1,000 ppm is preferable with respect to the compound represented by General formula (1). When the amount used exceeds 1,000 ppm, the progress of gelation by the condensation reaction is accelerated, and the applicability to the surface of the silicon substrate tends to deteriorate. When the amount used is less than 10 ppm, the condensation reaction may not proceed.

  Moreover, you may use a solvent in order to adjust the film thickness of a cured film. Examples of the solvent used include alcohols such as methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol and glycerol, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate and butyl acetate, tetrahydrofuran and dioxane Ethers such as benzene, toluene, etc., aliphatic or alicyclic hydrocarbons such as n-heptane, n-hexane, cyclohexane, water, dimethyl sulfoxide, N, N-dimethylformamide, N, N Examples include polar solvents such as dimethylacetamide, formamide, N-methylformamide, N-methylpyrrolidone, ethylene carbonate, and propylene carbonate. These can be used alone or in admixture of two or more. Among these, polar solvents are more preferable.

  Next, the composition is applied to the silicon substrate surface to form a cured film. The method for coating the silicon substrate surface is not particularly limited, such as spin coating, spray coating, dip coating, and roll coating, but spin coating is simple and suitable. The heating temperature for forming the cured film is preferably 80 to 200 ° C., particularly 90 to 150 ° C., for 1 to 100 minutes, particularly 1 to 10 minutes. If the heating temperature is too low, the hydrolysis / condensation reaction is slowed down, and there is a disadvantage that it takes time to form a cured film. If the heating temperature is too high, there is a possibility that the performance of the silicon substrate is deteriorated. In addition, if the heating time is too short, the hydrolysis / condensation reaction may be insufficient, and if it is too long, there is no problem in forming a cured film, but the useless heating time may deteriorate productivity. is there.

The heating method is not particularly limited, and examples thereof include a method of heating with a hot plate and a method of using an electric furnace, and the method of using a hot plate is preferable from the viewpoint of cost and convenience of work. The film thickness of the cured film is determined in consideration of the film thickness of the dielectric film, but is preferably 10 to 100 nm, more preferably 30 to 70 nm. If the film thickness is too thin or too thick, the passivation effect may not be obtained.
The cured film obtained here is a hydrolysis condensate of the compound of the above formula (1), and contains Al, Si, and O.

(7) Dielectric Film Formation Subsequently, as shown in FIG. 1D, a silicon nitride film as the dielectric film 5 is deposited on the n-type diffusion layer 3 and / or the p-type diffusion layer 2 by plasma CVD. To do. This film thickness is preferably 70 to 100 nm. Other antireflection films include a titanium dioxide film, a zinc oxide film, a tin oxide film, a tantalum oxide film, a niobium oxide film, a magnesium fluoride film, and an aluminum oxide film, which can be substituted. In addition to the above, the forming method includes a coating method, a vacuum deposition method, and the like. From the economical viewpoint, it is preferable to form the silicon nitride film by the plasma CVD method.

(8) Electrode formation Using a screen printing device or the like, a paste made of, for example, silver is printed on the p-type diffusion layer and the n-type diffusion layer using the screen printing device on the light-receiving surface side and the back surface side, and the comb electrode pattern Apply to shape and dry. When p-type silicon is used for the silicon substrate, a paste obtained by mixing aluminum powder with an organic binder on the back side is screen-printed and dried. Finally, firing is performed at 500 to 900 ° C. for 1 to 30 minutes in a firing furnace to form the finger electrode 6, the back electrode 7, and the bus bar electrode 8 that are electrically connected to the p-type diffusion layer and the n-type diffusion layer. [FIG. 1 (F)].

  In FIG. 1 (F), the finger electrode 6 and the back electrode 7 are shown as not being connected to the diffusion layers 2 and 3, but are fired through by firing and are actually connected to the diffusion layer.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example. In addition, in the following example, a part shows a mass part.

[Example 1]
As shown in FIG. 1, a crystal plane orientation (100), 15.65 cm square, 200 μm thickness, as-slice specific resistance 2 Ω · cm (dopant concentration 7.2 × 10 ¹⁵ cm ⁻³ ) phosphorus-doped n-type single crystal silicon substrate Then, it was immersed in an aqueous solution of sodium hydroxide to remove the damaged layer by etching, and texture formation was performed by immersion in an aqueous solution of potassium hydroxide solution added with isopropyl alcohol and alkaline etching. After applying the coating agent containing a phosphorus dopant to the back surface of the obtained silicon substrate 1, heat treatment was performed at 900 ° C. for 1 hour to form the n-type diffusion layer 3 on the back surface. After the heat treatment, the glass component attached to the substrate was removed by high concentration hydrofluoric acid solution and then washed.
Subsequently, a coating agent containing boron dopant was applied to the light receiving surface, followed by heat treatment at 1,000 ° C. for 1 hour to form the p-type diffusion layer 2 over the entire light receiving surface.

Next, pn junction isolation was performed using a plasma etcher. In order to prevent plasma and radicals from entering the light-receiving surface and back surface, the end face was cut several microns with the target stacked. The glass component attached to the substrate was removed with a high-concentration hydrofluoric acid solution and then washed.
Subsequently, a composition obtained by mixing 5 parts of dibutoxyaluminoxytriethoxysilane, 10 parts of N, N-dimethylacetamide, and 0.02 part of 0.01 mol / l hydrochloric acid aqueous solution was applied by a spin coating method, and then at 200 ° C. for 5 minutes. The cured film 4 was formed by heating and condensing reaction with a hot plate. The film thickness was 30 nm.

Next, using a parallel plate type CVD apparatus and using a mixed gas of monosilane, ammonia and hydrogen as a film forming gas, the dielectric film 5 is formed on the light receiving surface side p-type diffusion layer and the back surface n-type diffusion layer. A silicon nitride film was laminated. This film thickness was 60 nm.
Subsequently, a silver paste was electrode-printed on each of the light-receiving surface side and the back surface side, dried, and then baked at 800 ° C. for 20 minutes to form the finger electrode 6, the back electrode 7 and the bus bar electrode 8.

[Comparative Example 1]
It was produced by the same method as in Example 1 except that the step of forming a cured film was omitted after pn junction separation.
That is, it was produced without forming the cured film 4 on the p-type diffusion layer 2.
The current-voltage characteristics of the solar cells obtained in Examples and Comparative Examples were measured in a 25 ° C. atmosphere under a solar simulator (light intensity: 1 kW / m ² , spectrum: AM1.5 global). The results are shown in Table 1. The numbers in the table are average values of 10 cells prepared in Example 1 and Comparative Example 1.

  As described above, the solar cell produced by the production method of the present invention can produce a solar cell having an excellent passivation effect in the p-type region, and a high conversion efficiency solar cell can be obtained.

1 silicon substrate 2 p-type diffusion layer 3 n-type diffusion layer 4 cured film 5 dielectric film (antireflection film)
6 Light-receiving surface electrode (finger electrode)
7 Back electrode 8 Bus bar electrode

Claims (7)

A p-type diffusion layer having a conductivity type different from that of the silicon substrate formed on the light-receiving surface side of the silicon substrate, a dielectric film formed on the p-type diffusion layer, and the p-type diffusion layer electrically A solar cell having a light-receiving surface electrode connected to, and between the p-type diffusion layer and the dielectric film, the following general formula (1):
R ¹ ₂ -Al-O-Si-R ² ₃ (1)
(In the formula, R ¹ represents an organic group having 1 to 4 carbon atoms, R ² represents a hydrolyzable group or a hydroxyl group. Each R ¹ and R ² may be the same or different.)
The compound of formula (1) is hydrolyzed by applying a composition comprising an acid catalyst having a compounding amount of 10 to 1000 ppm to the compound and a solvent on the p-type diffusion layer and then heat-treating the composition. - solar cell characterized by having a condensed cured film as a passivation film. A p-type diffusion layer having a conductivity type different from the conductivity type of the silicon substrate is formed on the light-receiving surface side of the silicon substrate, a dielectric film is formed, and a light-receiving surface electrode electrically connected to the p-type diffusion layer is then formed. A method for manufacturing a solar cell including a step of forming a compound represented by the following general formula (1) on the p-type diffusion layer and a blending amount of 10 to 1000 ppm with respect to the compound before forming the dielectric film: A process for producing a solar cell comprising a step of forming a cured film obtained by applying a composition comprising an acid catalyst and a solvent, followed by heat treatment to hydrolyze and condense the compound of general formula (1) Method.
R ¹ ₂ -Al-O-Si-R ² ₃ (1)
(In the formula, R ¹ represents an organic group having 1 to 4 carbon atoms, R ² represents a hydrolyzable group or a hydroxyl group. Each R ¹ and R ² may be the same or different.) Further, an n-type diffusion layer having the same conductivity type as that of the silicon substrate is formed on at least a part of the back side of the silicon substrate, and then a dielectric film is formed, and then electrically connected to the n-type diffusion layer. look including the step of forming a back electrode, the claims before the formation of the dielectric film of the light-receiving surface side, on the light-receiving surface side p-type diffusion layer, and having a step of forming the cured film 2. The method for producing a solar cell according to 2 . The method for manufacturing a solar cell according to claim 2 or 3 , wherein the heat treatment temperature is 80 to 200 ° C. Thickness of the cured film, method of manufacturing a solar cell of any one of claims 2 to 4 is 10 to 100 nm. The dielectric film is a silicon nitride film, a titanium dioxide film, a zinc oxide film, a tin film oxide, tantalum oxide film, a niobium oxide film, according to claim 2 to 5, characterized in that a magnesium film or aluminum oxide film fluoride The manufacturing method of the solar cell of any one of these. The dielectric film photovoltaic cell manufacturing method according to any one of claims 2 to 6, characterized in that formed by a plasma CVD method.

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