JP6896506B2 - Paste composition for solar cells - Google Patents

Description

The present invention relates to a paste composition for a solar cell, and particularly for a solar cell for the purpose of forming a ^{p +} layer with respect to a crystalline solar cell having a passivation film provided with an opening by using laser irradiation or the like. Regarding the paste composition.

In recent years, various researches and developments have been carried out for the purpose of improving the conversion efficiency (power generation efficiency), reliability, etc. of crystalline solar cells. As one of them, a PERC (Passivated emitter and rear cell) type high conversion efficiency cell having a passivation film made of silicon nitride, silicon oxide, aluminum oxide or the like on the back surface of the cell is attracting attention.

The PERC type high conversion efficiency cell has a structure including, for example, an electrode layer containing aluminum as a main component. This electrode layer (particularly the back electrode layer) is formed by applying, for example, a paste composition mainly composed of aluminum in a pattern shape so as to cover the opening of the passivation film, drying it if necessary, and then firing it. Will be done. For example, Patent Document 1 discloses a paste composition containing an aluminum powder, an aluminum-silicon alloy powder, a silicon powder, a glass powder, and an organic vehicle. It is known that the conversion efficiency of the PERC type high conversion efficiency cell can be increased by appropriately designing the structure of the electrode layer.

Japanese Unexamined Patent Publication No. 2013-143499

In the prior art such as Patent Document 1, silicon powder, aluminum-silicon alloy powder, etc. are added to the paste composition to increase the Si concentration, thereby suppressing the formation of cavities called voids at the interface of the electrode layer. .. When voids are generated at the interface of the electrode layer, the resistance may be increased and the long-term reliability of the crystalline solar cell may be deteriorated.

However, when the Si concentration is increased, the electrical resistance of the electrode layer increases and the conversion efficiency decreases. Further, it is said that a particulate matter having an aluminum or aluminum-silicon alloy composition and a diameter of about 20 to 200 μm (hereinafter, this particulate matter is also referred to as “Sandy”) is generated on the surface of the electrode layer after firing, resulting in poor appearance. There's a problem. When Sandy occurs, the cells may crack starting from Sandy when the crystalline solar cells are stacked and stored or modularized. Here, an example of Sandy is shown in FIGS. 3 and 4. FIG. 3 is an example in which a Sandy of 220 μm is recognized, and FIG. 4 is an example in which a Sandy of 30 μm is recognized. On the other hand, FIG. 5 shows an example in which Sandy is not observed (an example in which there is no appearance defect).

The present invention has been made in view of the above, and in a crystalline solar cell, the generation of voids at the electrode layer interface is suppressed, the conversion efficiency is good, and the generation of Sandy on the surface of the electrode layer is prevented. An object of the present invention is to provide a paste composition for a solar cell that can be suppressed.

As a result of intensive research to achieve the above object, the present inventor has found that a paste composition for a solar cell containing a specific silicon powder in addition to aluminum powder, an organic vehicle, and a glass frit can achieve the above object. The present invention has been completed.

That is, the present invention relates to the following paste composition for solar cells.
1. 1. A paste composition for solar cells containing aluminum powder, silicon powder, organic vehicle and glass frit.
The silicon powder has a minimum particle size (Dmin) of 5 μm or more and less than 10 μm as a volume reference measured by a laser diffraction / scattering method, and a maximum particle size (Dmax) of the particle size distribution of 10 μm or more and 50 μm or less. der is,
The particle size of the aluminum powder is such that the average particle size D50 at 50% accumulation calculated based on the volume average particle size distribution measured by a laser diffraction type particle size distribution meter is 5 μm or more and 20 μm or less .
A paste composition for a solar cell, characterized in that.
2. The glass frit is selected from the group consisting of lead (Pb), bismuth (Bi), vanadium (V), boron (B), silicon (Si), tin (Sn), phosphorus (P) and zinc (Zn). Item 2. The paste composition for a solar cell according to Item 1, which contains at least one of the above.
3. 3. Item 1 or 2 above, wherein the silicon powder contains 5 to 25 parts by mass, the organic vehicle contains 20 to 45 parts by mass, and the glass frit contains 1 to 8 parts by mass with respect to 100 parts by mass of the aluminum powder. The above-mentioned paste composition for solar cells.

According to the paste composition for a solar cell of the present invention, in a crystalline solar cell (particularly a PERC type high conversion efficiency cell), the generation of voids at the electrode layer interface is suppressed, the conversion efficiency is good, and the electrode The effect of suppressing the generation of Sandy on the surface of the layer can be obtained. That is, according to the paste composition for a solar cell of the present invention, it is possible to provide a crystalline solar cell with good conversion efficiency and high long-term reliability in which the occurrence of poor appearance is suppressed.

It is a schematic diagram which shows an example of the cross-sectional structure of a PERC type solar cell, (a) is an example of the embodiment, and (b) is another example of the embodiment. It is a schematic diagram of the cross section of the electrode structure produced in Example and Comparative Example. This is an example in which Sandy (220 μm) was observed on the surface of the electrode layer after firing. This is an example in which Sandy (30 μm) was observed on the surface of the electrode layer after firing. This is an example in which Sandy is not observed on the surface of the electrode layer after firing.

Hereinafter, the paste composition for a solar cell of the present invention will be described in detail. In this specification, the range indicated by "~" means "greater than or equal to or less than" unless otherwise specified.

The paste composition for a solar cell of the present invention can be used, for example, to form an electrode of a crystalline solar cell. The crystalline solar cell is not particularly limited, and examples thereof include a PERC (Passivated emitter and rear cell) type high conversion efficiency cell (hereinafter, referred to as “PERC type solar cell”). The paste composition for a solar cell of the present invention can be used, for example, to form a back electrode of a PERC type solar cell. Hereinafter, the paste composition of the present invention is also simply referred to as "paste composition".

First, an example of the structure of the PERC type solar cell will be described.

1. 1. PERC type solar cell FIGS. 1 (a) and 1 (b) are schematic views of a general cross-sectional structure of a PERC type solar cell. The PERC type solar cell comprises a silicon semiconductor substrate 1, an n-type impurity layer 2, an antireflection film (passivation film) 3, a grid electrode 4, an electrode layer (back electrode layer) 5, an alloy layer 6, and a p ⁺ layer 7. It can be provided as an element.

The silicon semiconductor substrate 1 is not particularly limited, and for example, a p-type silicon substrate having a thickness of 180 to 250 μm is used.

The n-type impurity layer 2 is provided on the light receiving surface side of the silicon semiconductor substrate 1. The thickness of the n-type impurity layer 2 is, for example, 0.3 to 0.6 μm.

The antireflection film 3 and the grid electrode 4 are provided on the surface of the n-type impurity layer 2. The antireflection film 3 is formed of, for example, a silicon nitride film and is also referred to as a passivation film. By acting as a so-called passivation film, the antireflection film 3 can suppress the recombination of electrons on the surface of the silicon semiconductor substrate 1, and as a result, it is possible to reduce the recombination rate of the generated carriers. As a result, the conversion efficiency of the PERC type solar cell is improved.

The antireflection film (passivation film) 3 is also provided on the back surface side of the silicon semiconductor substrate 1, that is, on the surface opposite to the light receiving surface. Further, a contact hole (opening) formed so as to penetrate the antireflection film (passivation film) 3 on the back surface side and scrape a part of the back surface of the silicon semiconductor substrate 1 is formed on the back surface of the silicon semiconductor substrate 1. It is formed on the side. The method of forming a contact hole is not limited, but a so-called LCO (Laser contact opening) method in which an opening is provided by using laser irradiation or the like is common.

The electrode layer 5 is formed so as to come into contact with the silicon semiconductor substrate 1 through the contact holes. The electrode layer 5 is a member formed by the paste composition of the present invention, and is formed in a predetermined pattern shape. The electrode layer 5 may be formed so as to cover the entire back surface of the PERC type solar cell as in the form of FIG. 1 (a), or the contact hole and the contact hole and the shape as in the form of FIG. 1 (b). It may be formed so as to cover the vicinity thereof. Since the main component of the electrode layer 5 is aluminum, the electrode layer 5 is an aluminum electrode layer.

The electrode layer 5 is formed, for example, by applying a paste composition to a predetermined pattern shape and firing the paste composition. The coating method is not particularly limited, and examples thereof include known methods such as screen printing. The electrode layer 5 is formed by applying the paste composition, drying it if necessary, and then firing it for a short time at a temperature exceeding the melting point (about 660 ° C.) of aluminum, for example.

In the present invention, the firing temperature may be a temperature exceeding the melting point of aluminum (about 660 ° C.), but is preferably about 750 to 950 ° C., more preferably about 780 to 900 ° C. The firing time can be appropriately set according to the firing temperature within the range in which the desired electrode layer 5 is formed.

When fired in this way, the aluminum contained in the paste composition diffuses inside the silicon semiconductor substrate 1. As a result, an aluminum-silicon (Al-Si) alloy layer (alloy layer 6) is formed between the electrode layer 5 and the silicon semiconductor substrate 1, and at the same time, p by diffusion of aluminum atoms causes p as an impurity layer. ⁺ Layer 7 is formed.

The p ⁺ layer 7 can bring about an effect of preventing electron recombination and improving the collection efficiency of generated carriers, that is, a so-called BSF (Back Surface Field) effect.

The electrode formed by the electrode layer 5 and the alloy layer 6 is the back electrode 8 shown in FIG. Therefore, the back surface electrode 8 is formed by using the paste composition, and is coated so as to cover the contact hole 9 (opening) provided in the antireflection film (passivation film) 3 on the back surface side, if necessary. The back electrode 8 can be formed by firing after drying accordingly. Here, by forming the back surface electrode 8 using the paste composition of the present invention, high conversion efficiency can be obtained in the solar cell, and the generation of Sandy on the surface of the electrode layer 5 after firing can be prevented or suppressed. At the same time, the generation of voids at the electrode layer interface can be suppressed. In particular, being able to prevent or suppress the occurrence of Sandy on the surface of the electrode layer 5 after sintering is useful in preventing poor appearance and cracking during modularization of the solar cell.

2. Paste Composition The paste composition of the present invention is a paste composition for a solar cell containing aluminum powder, silicon powder, an organic vehicle and a glass frit.
The silicon powder has a minimum particle size (Dmin) of 5 μm or more and less than 10 μm as a volume reference measured by a laser diffraction / scattering method, and a maximum particle size (Dmax) of the particle size distribution of 10 μm or more and 50 μm or less. Is,
It is characterized by that.

As described above, by using the paste composition, it is possible to form a back electrode of a solar cell such as a PERC type solar cell. That is, the paste composition of the present invention can be used to form a back electrode for a solar cell that makes electrical contact with a silicon substrate through an opening (contact hole) provided in a passivation film formed on the silicon substrate. it can. According to the paste composition of the present invention, in a crystalline solar cell (particularly a PERC type solar cell), the generation of voids at the electrode layer interface is suppressed, the conversion efficiency is good, and the surface of the electrode layer is good. It is possible to suppress the occurrence of Sandy in. That is, according to the paste composition for a solar cell of the present invention, it is possible to provide a crystalline solar cell with good conversion efficiency and high long-term reliability in which the occurrence of poor appearance is suppressed.

The paste composition contains aluminum powder, silicon powder, organic vehicle and glass frit as constituents. When the paste composition contains aluminum powder (conductive material), the sintered body formed by firing the coating film of the paste composition exhibits conductivity that electrically connects to the silicon substrate. ..

(Aluminum powder)
The aluminum powder contained in the paste composition exhibits conductivity in the aluminum electrode layer formed by firing the paste composition. Further, in the aluminum powder, the BSF effect can be obtained by forming the ^{aluminum-silicon alloy layer 6 and the p +} layer 7 between the aluminum powder and the silicon semiconductor substrate 1 when the paste composition is fired.

The shape of the aluminum powder is not particularly limited, and may be, for example, spherical, elliptical, indefinite, scaly, fibrous or the like. When the shape of the aluminum powder is spherical, the filling property of the aluminum powder is increased in the electrode layer 5 formed by the paste composition, and the electric resistance can be effectively reduced. Further, when the shape of the aluminum powder is spherical, the contact points between the silicon semiconductor substrate 1 and the aluminum powder increase in the electrode layer 5 formed by the paste composition, so that a good BSF layer can be easily formed.

As for the particle size of the aluminum powder, it is desirable that the average particle size D50 at the time of 50% accumulation calculated based on the volume average particle size distribution measured by the laser diffraction type particle size distribution meter is 5 μm or more and 20 μm or less. If the particle size distribution of the aluminum powder is less than 5 μm, the aluminum reacts excessively with the silicon semiconductor substrate 1 to easily generate Sandy, and if it exceeds 20 μm, the number of surfaces in contact with the silicon semiconductor substrate 1 decreases and the silicon semiconductor substrate 1 and the silicon semiconductor substrate 1 There is a risk that the reaction will be reduced and problems such as a decrease in conversion efficiency will occur.

The purity of the aluminum powder is not particularly limited, and known aluminum powder can be used, but a high-purity aluminum powder of 99.7% or more is particularly preferable. The presence of unavoidable impurities and trace amounts of additive elements derived from raw materials is not excluded from aluminum powder.

(Silicon powder)
The silicon powder contained in the paste composition controls an excessive reaction between aluminum in the paste composition and silicon in the silicon semiconductor substrate 1, and suppresses the formation of voids at the interface between the aluminum electrode layer 5 and the silicon semiconductor substrate 1. can do.

The shape of the silicon particles constituting the silicon powder is not particularly limited. The content ratio of the silicon powder contained in the paste composition is also not particularly limited, but is preferably 5 parts by weight or more and 25 parts by weight or less with respect to 100 parts by weight of the aluminum powder. If the content ratio of the silicon powder is less than 5 parts by weight with respect to 100 parts by weight of the aluminum powder, the suppression of void formation may be insufficient, and if it exceeds 25 parts by weight, the electric resistance of the aluminum electrode layer 5 increases and the conversion efficiency increases. May decrease.

In the silicon powder, the minimum particle size (Dmin) of the particle size distribution based on the volume measured by the laser diffraction scattering method is 5 μm or more and less than 10 μm, and the maximum particle size (Dmax) of the particle size distribution is 10 μm or more and 50 μm or less. Therefore, good conversion efficiency can be ensured while suppressing the formation of voids. Even within these ranges, Dmin is preferably 5 μm or more and 9 μm or less, and more preferably 5 μm or more and 8 μm or less. Dmax is preferably 11 μm or more and 30 μm or less, and more preferably 11 μm or more and 20 μm or less.

(Organic vehicle)
As the organic vehicle, a material in which various additives and resins are dissolved in a solvent can be used, if necessary. Alternatively, the resin itself may be used as an organic vehicle without containing a solvent.

Known types of solvents can be used, and specific examples thereof include diethylene glycol monobutyl ether, diethylene glycol monobutyl ether acetate, and dipropylene glycol monomethyl ether.

As various additives, for example, antioxidants, corrosion inhibitors, defoamers, thickeners, tack fires, coupling agents, antistatic agents, polymerization inhibitors, thixotropy agents, antisettling agents and the like are used. be able to. Specifically, for example, polyethylene glycol ester compound, polyethylene glycol ether compound, polyoxyethylene sorbitan ester compound, sorbitan alkyl ester compound, aliphatic polyvalent carboxylic acid compound, phosphoric acid ester compound, amidoamine salt of polyester acid, polyethylene oxide. System compounds, fatty acid amide wax and the like can be used.

Known types of resins can be used: ethyl cellulose, nitrocellulose, polyvinyl butyral, phenol resin, melanin resin, urea resin, xylene resin, alkyd resin, unsaturated polyester resin, acrylic resin, polyimide resin, furan resin, etc. Thermo-curable resins such as urethane resin, isocyanate compound, cyanate compound, polyethylene, polypropylene, polystyrene, ABS resin, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polyacetal, polycarbonate, polyethylene terephthalate, Two or more kinds of polybutylene terephthalate, polyphenylene oxide, polysulphon, polyimide, polyether sulfone, polyarylate, polyether ether ketone, polytetrafluoroethylene, silicon resin and the like can be used in combination.

The ratios of the resin, the solvent, and various additives contained in the organic vehicle can be arbitrarily adjusted, and for example, the component ratio can be the same as that of a known organic vehicle.

The content of the organic vehicle is not particularly limited, but for example, from the viewpoint of having good printability, it is preferably 10 to 500 parts by mass with respect to 100 parts by mass of the aluminum powder, and is 20 to 45 parts by mass. Is particularly preferable.

(Glass frit)
The glass powder is said to have an action of assisting the reaction between the aluminum powder and silicon and the sintering of the aluminum powder itself.

The glass powder is not particularly limited, and can be, for example, a known glass component contained in the paste composition used for forming the electrode layer of the solar cell. Specific examples of the glass powder include a group consisting of lead (Pb), bismuth (Bi), vanadium (V), boron (B), silicon (Si), tin (Sn), phosphorus (P) and zinc (Zn). At least one selected from. Further, lead-containing glass powder or lead-free glass powder such as bismuth-based, vanadium-based, tin-phosphorus-based, zinc borosilicate-based, and alkaline borosilicate-based can be used. In particular, considering the effect on the human body, it is desirable to use lead-free glass powder.

Specifically, the glass powder is B ₂ O ₃ , Bi ₂ O ₃ , ZnO, SiO ₂ , Al ₂ O ₃ , BaO, CaO, SrO, V ₂ O ₅ , Sb ₂ O ₃ , WO ₃ , P ₂ O ₅ And at least one component selected from the group consisting of _{TeO 2 can be included.} For example, in glass powder, a glass frit in which the molar ratio (B ₂ O ₃ / Bi ₂ O _{3 ) of the B 2} O ₃ component and the Bi ₂ O ₃ component is 0.8 or more and 4.0 or less, and V ₂ O. _A glass frit having a molar ratio (V ₂ O ₅ / BaO) of 5 components to the BaO component of 1.0 or more and 2.5 or less may be combined.

The softening point of the glass powder can be, for example, 750 ° C. or lower. The average particle size of the particles contained in the glass powder can be, for example, 1 to 3 μm.

The content of the glass powder contained in the paste composition is preferably 1 to 8 parts by mass with respect to 100 parts by mass of the aluminum powder, for example. With such a content, the adhesion between the silicon semiconductor substrate 1 and the antireflection film 3 (passivation film) is good, and the electrical resistance is unlikely to increase.

As described above, the paste composition of the present invention contains 5 to 25 parts by mass of silicon powder, 20 to 45 parts by mass of organic vehicle, and 1 to 8 parts by mass of glass frit with respect to 100 parts by mass of aluminum powder. The composition to be used is particularly preferable. By setting in such a range, in a crystalline solar cell (particularly a PERC type solar cell), the generation of voids at the electrode layer interface is suppressed, the conversion efficiency is good, and the sandy on the surface of the electrode layer is high. Occurrence can be suppressed.

The paste composition of the present invention is suitable for use, for example, for forming an electrode layer of a solar cell (particularly, a back electrode 8 of a PERC type solar cell as shown in FIG. 1). Therefore, the paste composition of the present invention can also be used as a solar cell back electrode forming agent.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.

Example 1
(Preparation of paste composition)
_{100 parts by mass of D 50} : 6 μm aluminum powder (Al purity 99.7%) produced by the gas atomization method, 20 parts by mass of silicon powder (Dmin: 5 μm, Dmax: 10 μm), and glass frit B ₂ O _3- Bi ₂ O _3- SrO-BaO-Sb ₂ O ₃ = 3 parts by mass of 40/40/10/5/5 (mol%) in order, and 35 parts by mass of a resin solution in which ethyl cellulose is dissolved in butyl diglycol. ) Was used to make a paste. This gave a paste composition.

(Manufacturing a fired substrate that is a solar cell)
A fired substrate, which is a solar cell for evaluation, was produced as follows.

First, as shown in FIG. 2A, a silicon semiconductor substrate 1 having a thickness of 180 μm (including a passivation film on the back surface side) was first prepared. Then, as shown in FIG. 2B, a YAG laser having a wavelength of 532 nm was used as a laser oscillator to form a contact hole 9 having a width D of 50 μm and a depth of 1 μm on the back surface of the silicon semiconductor substrate 1. The silicon semiconductor substrate 1 had a resistance value of 3 Ω · cm and was a backside passivation type single crystal.

In FIG. 2, the passivation film is not shown and is treated as being included in the silicon semiconductor substrate 1, and the passivation film is a laminate of a 30 nm aluminum oxide layer and a 100 nm silicon nitride layer on the back surface side of the silicon semiconductor substrate 1. Included as a body.

Next, as shown in FIG. 2C, the paste composition 10 obtained above is applied to the surface of the silicon semiconductor substrate 1 so as to cover the entire back surface (the surface on the side where the contact holes 9 are formed). On top of this, a screen printing machine was used to print at 1.0 to 1.1 g / pc. Next, although not shown, an Ag paste prepared by a known technique was printed on the light receiving surface.

Then, it was fired using an infrared belt furnace set at 800 ° C. By this firing, as shown in FIG. 2D, the electrode layer 5 is formed, and during this firing, aluminum diffuses inside the silicon semiconductor substrate 1, so that the electrode layer 5 and the silicon semiconductor substrate are formed. At the same time that the alloy layer 6 of Al—Si was formed between 1 and 1, a p ⁺ layer (BSF layer) 7 was formed as an impurity layer due to the diffusion of aluminum atoms. As a result, a fired substrate for evaluation was produced.

(Evaluation of solar cells)
In the evaluation of the obtained solar cell, the IV measurement was carried out using a solar simulator: WXS-156S-10 and an IV measuring device: IV15040-10 of Wacom Denso. It was evaluated that the Eff was 18.6% or more and the conversion characteristics were good.

(Confirmation of the presence or absence of voids and confirmation of electrical resistance)
Regarding the evaluation of voids, the cross section of each sample of the obtained fired substrate was observed with an optical microscope (200 times), and the presence or absence of voids at the interface between the substrate and the aluminum electrode layer was evaluated. Those with no cavities formed were marked with ◯, and those with 20% or more cavities were marked with x.

The evaluation of the electric resistance was measured by a four-terminal measuring method using a sheet resistance measuring instrument RT-70V manufactured by Napuson.

(Confirmation of the presence or absence of Sandy)
The presence or absence of Sandy was confirmed using an optical microscope (magnification 50 times).

Those in which Sandy was not confirmed were marked with ◯, and those in which Sandy was confirmed were marked with x. In addition, only ○ evaluation passed.

Example 2
A paste composition was prepared and evaluated in the same manner as in Example 1 except that silicon powder (Dmin: 5 μm, Dmax: 50 μm) was used.

Example 3
A paste composition was prepared and evaluated in the same manner as in Example 1 except that silicon powder (Dmin: 8 μm, Dmax: 50 μm) was used.

Comparative Example 1
A paste composition was prepared and evaluated in the same manner as in Example 1 except that silicon powder (Dmin: 0.1 μm, Dmax: 1 μm) was used.

Comparative Example 2
A paste composition was prepared and evaluated in the same manner as in Example 1 except that silicon powder (Dmin: 1 μm, Dmax: 10 μm) was used.

Comparative Example 3
A paste composition was prepared and evaluated in the same manner as in Example 1 except that silicon powder (Dmin: 3 μm, Dmax: 10 μm) was used.

Comparative Example 4
A paste composition was prepared and evaluated in the same manner as in Example 1 except that silicon powder (Dmin: 5 μm, Dmax: 60 μm) was used.

Comparative Example 5
A paste composition was prepared and evaluated in the same manner as in Example 1 except that silicon powder (Dmin: 10 μm, Dmax: 50 μm) was used.

The conditions of each example and comparative example and the evaluation results are shown in Table 1 below.

From the results in Table 1, by using the paste compositions of Examples 1 to 3 containing the silicon powder specified in the present invention, the generation of voids at the electrode layer interface in the crystalline solar cell was suppressed, and the conversion efficiency was increased. Is good, and the generation of Sandy on the surface of the electrode layer can be suppressed.

1: Silicon semiconductor substrate 2: n-type impurity layer 3: Antireflection film (passivation film)
4: Grid electrode 5: Electrode layer 6: Alloy layer 7: p + layer 8: Back surface electrode 9: Contact hole (opening)
10: Paste composition

Claims (3)

A paste composition for solar cells containing aluminum powder, silicon powder, organic vehicle and glass frit.
The silicon powder has a minimum particle size (Dmin) of 5 μm or more and less than 10 μm as a volume reference measured by a laser diffraction / scattering method, and a maximum particle size (Dmax) of the particle size distribution of 10 μm or more and 50 μm or less. der is,
The particle size of the aluminum powder is such that the average particle size D50 at 50% accumulation calculated based on the volume average particle size distribution measured by a laser diffraction type particle size distribution meter is 5 μm or more and 20 μm or less .
A paste composition for a solar cell, characterized in that. The glass frit is selected from the group consisting of lead (Pb), bismuth (Bi), vanadium (V), boron (B), silicon (Si), tin (Sn), phosphorus (P) and zinc (Zn). The paste composition for a solar cell according to claim 1, which contains at least one of these. According to claim 1 or 2, the silicon powder contains 5 to 25 parts by mass, the organic vehicle contains 20 to 45 parts by mass, and the glass frit contains 1 to 8 parts by mass with respect to 100 parts by mass of the aluminum powder. The above-mentioned paste composition for solar cells.

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