KR102152840B1 - Electrode Paste For Solar Cell's Electrode And Solar Cell using the same - Google Patents

Abstract

The present invention provides a conductive paste for solar cell electrodes, comprising a metal powder, a glass frit, and an organic vehicle, wherein the surface of the glass frit is coated with a fatty amine and a fatty acid. Thus, by improving the dispersibility, it is possible to improve the electric characteristics of the solar cell electrode formed using the same, thereby improving the power generation efficiency of the solar cell.

Description

Conductive paste for solar cell electrode and solar cell manufactured using it {Electrode Paste For Solar Cell's Electrode And Solar Cell using the same}

The present invention relates to a conductive paste used for forming an electrode of a solar cell and a solar cell manufactured using the same.

A solar cell is a semiconductor device that converts solar energy into electrical energy, and generally has a p-n junction type, and its basic structure is the same as a diode. Solar cell devices are generally constructed using a p-type silicon semiconductor substrate having a thickness of 180 to 250 μm. On the light-receiving surface side of the silicon semiconductor substrate, an n-type impurity layer having a thickness of 0.3 to 0.6 µm, and an antireflection film and a front electrode are formed thereon. Further, a rear electrode is formed on the rear side of the p-type silicon semiconductor substrate.

The front electrode is formed by applying a conductive paste mixed with silver-based conductive particles, glass frit, organic vehicle, and additives on the antireflection film and firing it. The rear electrode is formed by applying an aluminum paste composition composed of aluminum powder, glass frit, organic vehicle, and additives by screen printing or the like, drying, and firing at a temperature of 660°C (melting point of aluminum) or higher. During this firing, aluminum diffuses into the interior of the p-type silicon semiconductor substrate, thereby forming an Al-Si alloy layer between the rear electrode and the p-type silicon semiconductor substrate, and at the same time forming a p+ layer as an impurity layer by diffusion of aluminum atoms. do. By the presence of such a p+ layer, a BSF (Back Surface Field) effect of preventing recombination of electrons and improving collection efficiency of generated carriers is obtained. A rear silver electrode may be further positioned under the rear aluminum electrode.

On the other hand, the glass frit forms an ohmic contact between the n layer of the wafer and the Ag of the front electrode by etching the antireflection layer (SiNx) coated on the surface of the silicon wafer (Si-wafer). It is essential for Ag/Si contact of a silicon solar cell because it plays a role of securing reliability by forming a circuit, increasing efficiency, and increasing adhesion.

Because of the high-efficiency characteristics of solar cells, it is inevitable to use a glass frit having excellent contact resistance (Rc). In the conventional case, the etching of the anti-reflective layer was controlled by controlling the component system, particle size, or content of the glass frit, but many problems were caused in the dispersion of the glass frit. In addition, when observing the image after sintering, the thickness of the glass layer is not uniform, causing damage to the n-layer in a thick region, and less penetration of silver powder in a thin region, resulting in a problem that the current decreases or the resistance increases.

US Patent 8,748,327 B1 (2014.06.10.) WO Publication Patent 2013/105812 A1 (2013.07.18.) US Patent Publication 2011-0094578 A1 (2011.04.28.)

An object of the present invention is to improve dispersibility by coating the surface of a glass frit among the composition of a conductive paste for a solar cell electrode, thereby improving the electrical characteristics of a solar cell electrode formed using the same, thereby improving the power generation efficiency of a solar cell. .

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention provides a conductive paste for a solar cell electrode comprising a metal powder, a glass frit, and an organic vehicle, wherein the surface of the glass frit is coated with a fatty amine and a fatty acid.

In addition, the glass frit is characterized in that it is first coated with the fatty amine or fatty acid, and the second coated with the fatty amine or fatty acid.

In addition, the glass frit is characterized by using a glass frit that is first coated with a fatty amine and a second coated with a fatty amine or fatty acid.

In addition, the glass frit is characterized by using a glass frit that is first coated with a fatty amine and a second coated with a fatty acid.

In addition, the fatty amine is characterized in that it contains an alkylamine-based material having 6 to 24 carbon atoms.

In addition, the alkylamine-based material is triethylamine, heptylamine, octadecylamine, hexadecylamine, decylamine, octylamine, didecylamine ( Didecylamine) and trioctylamine (Trioctylamine) characterized by containing at least one selected from.

In addition, the fatty acid is characterized in that it contains at least one selected from lauric acid, oleic acid, stearic acid, palmitic acid, and acetic acid. .

In addition, the glass frit is characterized in that it is coated with an organic solvent or aqueous solution in which a fatty amine or fatty acid having a concentration of 0.1 to 0.3% is dissolved.

In addition, in the present invention, in a solar cell having a front electrode on an upper portion of the substrate and a rear electrode on the lower portion of the substrate, the front electrode is manufactured by drying and firing after applying the conductive paste for the solar cell electrode. It provides solar cells made of.

The conductive paste according to the present invention may include a glass frit coated with a fatty amine and a fatty acid to improve dispersibility, and uniformly apply the glass frit during electrode formation. Accordingly, the reactivity is excellent during firing, and particularly, damage to the n-layer at high temperature can be minimized, adhesion is improved, and open circuit voltage can be excellent. In addition, it is possible to reduce the contact resistance between the electrode and the n-layer by making it easy and uniform to penetrate the metal powder (eg, silver powder) during firing. As a result, the electrical properties of the solar cell electrode are improved, and the power generation efficiency of the solar cell may be improved.

1 to 3 are images photographing the state immediately after putting the coated glass frit and the uncoated glass frit in water and stirring and leaving it for 60 minutes and 24 hours according to the preparation example.
4 shows the results of thermogravimetric analysis on the surface-coated glass frit and the non-coated glass frit prepared according to Preparation Example.
5 shows a glass frit image taken after the thermogravimetric analysis.
6 shows the results of measuring adhesion between a solar cell electrode and a ribbon manufactured using a conductive paste manufactured according to Examples and Comparative Examples.
7 are surface images of electrodes taken after detachment of a conductor ribbon manufactured according to Examples and Comparative Examples.

Before describing the present invention in detail below, it is understood that the terms used in the present specification are for describing specific embodiments and are not intended to limit the scope of the present invention, which is limited only by the scope of the appended claims. shall. All technical and scientific terms used in the present specification have the same meaning as commonly understood by those of ordinary skill in the art unless otherwise stated.

Throughout this specification and claims, unless otherwise stated, the term "comprise, comprises, comprising" means to include the recited object, step or group of objects, and steps, and any other object It is not used in the sense of excluding a step, a group of objects, or a group of steps.

Meanwhile, various embodiments of the present invention may be combined with any other embodiments unless there is a clear opposite point. Any feature indicated to be particularly preferred or advantageous may be combined with any other feature and features indicated to be preferred or advantageous. Hereinafter, embodiments of the present invention and effects thereof will be described with reference to the accompanying drawings.

The paste according to an embodiment of the present invention is a paste suitable for use in forming a solar cell electrode, and provides a conductive paste including a glass frit coated with a fatty amine and a fatty acid. More specifically, the conductive paste according to the present invention includes metal powder, glass frit, organic vehicle, and other additives.

As the metal powder, silver powder, copper powder, nickel powder, aluminum powder, etc. may be used. Silver powder is mainly used for the front electrode, and aluminum powder is mainly used for the rear electrode. As the metal powder, one of the above-described powders may be used alone, an alloy of the above-described metal may be used, or a mixed powder in which at least two of the above-described powders are mixed.

The content of the metal powder is preferably 40 to 95% by weight based on the total weight of the conductive paste composition in consideration of the thickness of the electrode formed during printing and the line resistance of the electrode. If it is less than 40% by weight, the resistivity of the formed electrode may be high, and if it is more than 95% by weight, there is a problem in that the metal powder is not uniformly dispersed because the content of other components is insufficient. More preferably, it is good to contain 70 to 90% by weight.

When the conductive paste contains silver powder for the formation of the front electrode of a solar cell, the silver powder is preferably a pure silver powder. In addition, a silver-coated composite powder having at least a silver layer or an alloy containing silver as a main component (alloy) etc. can be used. In addition, other metal powders may be mixed and used. For example, aluminum, gold, palladium, copper, nickel, etc. are mentioned.

The average particle diameter (D50) of the metal powder may be 0.1 to 10 μm, and 0.5 to 5 μm is preferable in consideration of the ease of pasting and the density during firing, and the shape is at least one of spherical, needle, plate, and amorphous. It can be more than a species. The metal powder may be used by mixing two or more types of powders having different average particle diameter, particle size distribution, and shape.

The glass frit may be coated with fatty amines and fatty acids to improve dispersibility. More specifically, the glass frit may be first coated with the fatty amine or fatty acid, and the second coated with the fatty amine or fatty acid may be used.

The fatty amine includes an alkylamine-based material having 6 to 24 carbon atoms. More preferably, the surface of the glass frit may be coated with an alkylamine-based material having 10 to 20 carbon atoms. For example, the alkylamine-based material is triethylamine, heptylamine, octadecylamine, hexadecylamine, decylamine, octylamine, dide It may contain at least one selected from didecylamine and trioctylamine.

The fatty acid may include at least one selected from lauric acid, oleic acid, stearic acid, palmitic acid, and acetic acid.

When coating with the fatty amine, it is preferable to coat the surface of the glass frit with a thickness of 0.5 nm to 50 nm. The coating of the fatty amine may be performed by putting a glass frit in an organic solvent or aqueous solution (coating agent) in which the fatty amine is dissolved, stirring for a certain period of time, and filtering. When the thickness of the coating layer formed by the coating treatment of the fatty amine is less than 0.5 nm, the effect of improving the dispersibility of the glass frit is reduced, and when the thickness of the coating layer is larger than 50 nm, the electrode of the solar cell formed of a conductive paste containing the same is reduced. Characteristics may be deteriorated. The thickness of the coating layer may be adjusted through the content of the fatty amine used in the coating treatment. For example, it is possible to adjust the thickness of the coating layer by preparing the concentration of the coating agent in the range of 0.1 to 0.3%.

When coating with the fatty acid, it is preferable to coat the surface of the glass frit with a thickness of 0.5 nm to 50 nm. The fatty acid coating may be performed by placing a glass frit in an organic solvent or aqueous solution (coating agent) in which the fatty acid is dissolved, stirring for a certain period of time, and filtering. When the thickness of the coating layer formed by the fatty acid coating treatment is smaller than 0.5 nm, the effect of improving the dispersibility of the glass frit is reduced, and when the thickness of the coating layer is larger than 50 nm, the electrical properties of the electrode of a solar cell formed of a conductive paste containing the same This can be degraded. The thickness of the coating layer may be adjusted through the content of fatty acids used during coating treatment. For example, it is possible to adjust the thickness of the coating layer by preparing the concentration of the coating agent in the range of 0.1 to 0.3%.

Preferably, the glass frit is first coated with a fatty amine, and a glass frit is secondarily coated with a fatty amine or fatty acid. When first coating with fatty amine, dispersibility is improved, reducing reaching phenomenon, and increasing solar cell power generation efficiency by increasing short-circuit current and open-circuit voltage.

More preferably, it is preferable to use a glass frit that is first coated with a fatty amine and secondly coated with a fatty acid. When fatty acids are secondarily coated and coated on the outermost side, the coated content increases, and during coating, it has hydrophilicity and maintains dispersibility. When double-coated with fatty amines and fatty acids, the best adhesion can be provided.

The composition, particle diameter, and shape of the glass frit are not particularly limited. Lead-free glass frit as well as leaded glass frit can be used. Preferably, as a component and content of the glass frit, PbO is 5 to 29 mol%, TeO ₂ is 20 to 34 mol%, Bi ₂ O ₃ is 3 to 20 mol%, SiO ₂ 20 mol% or less, B ₂ O ₃ 10 mol% or less, alkali metals (Li, Na, K, etc.) and alkaline earth metals (Ca, Mg, etc.) preferably contain 10 to 20 mol%. By combining the organic content of each component, an increase in electrode line width can be prevented, contact resistance in high sheet resistance can be improved, and short-circuit current characteristics can be excellent.

The average particle diameter of the glass frit is not limited, but may have a particle diameter in the range of 0.5 to 10 μm, and multi-species particles having different average particle diameters may be mixed and used. Preferably, at least one glass frit has an average particle diameter (D50) of 2 μm or more and 10 μm or less.

The content of the glass frit is preferably 1 to 10% by weight based on the total weight of the conductive paste composition.If it is less than 1% by weight, there is a concern that the electrical resistivity may increase due to incomplete firing, and if it exceeds 10% by weight, glass in the fired body of metal powder There is a fear that the electrical resistivity will also increase due to too many components.

As described above, as the surface of the glass frit is coated with a fatty amine and a fatty acid, dispersibility is improved, and a uniform coating of the glass frit may be possible during electrode formation. As a result, the reactivity is excellent during firing, and in particular, damage to the n-layer at high temperature can be minimized, adhesion is improved, and open circuit voltage (Voc) can be excellent. In addition, it is possible to reduce the contact resistance between the electrode and the n-layer by making the penetration of metal powder (eg, silver powder) uniform during firing. Providing such an effect may provide an additional effect of making it easier to control the composition, particle size or shape of the glass frit.

The organic vehicle is not limited, but an organic binder and a solvent may be included. Sometimes solvents can be omitted. The organic vehicle is not limited, but is preferably 1 to 30% by weight based on the total weight of the conductive paste composition.

The organic vehicle is required to maintain a uniform mixture of metal powder and glass frit. For example, when the conductive paste is applied to the substrate by screen printing, the conductive paste is made homogeneous and the print pattern is blurred. And characteristics of suppressing flow and improving the ejection property and plate separation property of the conductive paste from the screen plate are required.

The organic binder included in the organic vehicle is not limited, but examples of the cellulose ester compound include cellulose acetate, cellulose acetate butyrate, and the like, and the cellulose ether compound includes ethyl cellulose, methyl cellulose, hydroxyflofil cellulose, and hydroxyethyl. Cellulose, hydroxypropyl methyl cellulose, hydroxyethyl methyl cellulose, and the like may be exemplified. Examples of acrylic compounds include polyacrylamide, poly methacrylate, polymethyl methacrylate, and polyethyl methacrylate. , Examples of the vinyl-based include polyvinyl butyral, polyvinyl acetate, and polyvinyl alcohol. At least one or more of the organic binders may be selected and used.

As a solvent used for dilution of the composition, alpha-terpineol, taxanol, dioctyl phthalate, dibutyl phthalate, cyclohexane, hexane, toluene, benzyl alcohol, dioxane, diethylene glycol, ethylene glycol monobutyl ether, ethylene It is preferable to use at least one selected from compounds consisting of glycol mono butyl ether acetate, diethylene glycol mono butyl ether, diethylene glycol mono butyl ether acetate, and the like.

The conductive paste composition according to the present invention may further contain commonly known additives, for example, a dispersant, a plasticizer, a viscosity modifier, a surfactant, an oxidizing agent, a metal oxide, a metal organic compound, and the like, if necessary.

The above-described conductive paste composition for a solar cell electrode may be prepared by mixing and dispersing a metal powder, a coated glass frit, an organic vehicle and an additive, and then filtering and defoaming.

The present invention also provides a method of forming an electrode for a solar cell, comprising applying the conductive paste on a substrate, drying, and firing, and a solar cell electrode manufactured by the method. Except for the use of a conductive paste containing a glass frit coated as described above in the solar cell electrode formation method of the present invention, the substrate, printing, drying, and firing may be performed by methods commonly used in the manufacture of solar cells. Yes, of course. For example, the substrate may be a silicon wafer.

On the other hand, since the unit solar cell including the solar cell electrode formed as described above has a small electromotive force, a photovoltaic module having an appropriate electromotive force is constructed and used by connecting a plurality of unit solar cell cells. Each unit solar cell is connected by lead-coated conductor ribbons of a certain length.

In addition, the conductive paste according to the present invention includes structures such as crystalline solar cells (P-type, N-type), Passivated Emitter Solar Cell (PESC), Passivated Emitter and Rear Cell (PERC), Passivated Emitter Real Locally Diffused (PERL), and the like. It can be applied to all changed printing processes such as double printing and dual printing.

Manufacturing example

(1) Preparation Example 1

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.1% concentration prepared by dissolving octadecylamine (ODA) in ethanol, it was carried out for 24 hours at room temperature with a ball-mill 80 rpm. Then, a drying operation was performed for 1 hour in an oven at 50° C. to obtain a glass frit coated with octadecylamine.

(2) Preparation Example 2

In Preparation Example 1, a glass frit coated with stearic acid was obtained in the same manner as in Preparation Example 1, except that an organic solution having a concentration of 0.3% was prepared by dissolving stearic acid in ethanol.

(3) Preparation Example 3

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.1% concentration prepared by dissolving octadecylamine (ODA) in ethanol, it was carried out for 24 hours at room temperature with a ball-mill 80 rpm. After that, a drying operation was performed for 1 hour in an oven at 50° C. to obtain a glass frit subjected to a primary coating treatment with octadecylamine.

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.1% concentration prepared by dissolving octadecylamine (ODA) in ethanol, it was carried out for 24 hours at room temperature with a ball-mill 80 rpm. After that, a drying operation was performed in an oven at 50° C. for 1 hour to obtain a glass frit subjected to secondary coating treatment with octadecylamine.

(4) Preparation Example 4

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.1% concentration prepared by dissolving octadecylamine (ODA) in ethanol, it was carried out for 24 hours at room temperature with a ball-mill 80 rpm. After that, a drying operation was performed for 1 hour in an oven at 50° C. to obtain a glass frit subjected to a primary coating treatment with octadecylamine.

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.3% concentration prepared by dissolving stearic acid in ethanol, it was carried out at room temperature at 80 rpm for 24 hours. Then, a drying operation was performed in an oven at 50° C. for 1 hour to obtain a glass frit subjected to secondary coating treatment with stearic acid.

(5) Production Example 5

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.3% concentration prepared by dissolving stearic acid in ethanol, it was carried out at room temperature at 80 rpm for 24 hours. After that, a drying operation was performed in an oven at 50° C. for 1 hour to obtain a glass frit first coated with stearic acid.

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.1% concentration prepared by dissolving octadecylamine (ODA) in ethanol, it was carried out for 24 hours at room temperature with a ball-mill 80 rpm. After that, a drying operation was performed in an oven at 50° C. for 1 hour to obtain a glass frit subjected to secondary coating treatment with octadecylamine.

(6) Production Example 6

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.3% concentration prepared by dissolving stearic acid in ethanol, it was carried out at room temperature at 80 rpm for 24 hours. After that, a drying operation was performed in an oven at 50° C. for 1 hour to obtain a glass frit first coated with stearic acid.

After adding a Pb-Te-Bi type glass frit to an organic solution of 0.3% concentration prepared by dissolving stearic acid in ethanol, it was carried out at room temperature at 80 rpm for 24 hours. Then, a drying operation was performed in an oven at 50° C. for 1 hour to obtain a glass frit subjected to secondary coating treatment with stearic acid.

Examples and Comparative Examples

In a composition as shown in Table 1 (eg, weight %), a coated glass frit, an organic binder, a solvent, and a dispersant were added and dispersed using a mixing mixer, and then silver powder (spherical, average particle diameter of 1 μm) was added. It was mixed and also dispersed using a sambon mill. Then, degassing was performed under reduced pressure to prepare a conductive paste. Examples 1 to 6 used the glass frit obtained according to Preparation Examples 1 to 6, respectively, and Comparative Example 1 used a Pb-Te-Bi type glass frit that was not coated.

division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Silver powder 88 88 88 88 88 88 88 bookbinder 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Solvent (texanol) 6 6 6 6 6 6 6 Dispersant 3.6 3.6 3.6 3.6 3.6 3.6 3.6 Glass frit Manufacturing Example 1 2 Manufacturing Example 2 2 Manufacturing Example 3 2 Manufacturing Example 4 2 Manufacturing Example 5 2 Manufacturing Example 6 2 No coating 2

Experimental example

(1) Evaluation of coating properties of glass frit

The surface-coated glass frit and the non-coated glass frit prepared according to Preparation Examples 1 to 6 were added to water, stirred and left to stand to evaluate the coating properties. The comparative evaluation of the coating properties was carried out by visually observing the coating properties by allowing the solution to which the glass frit was added to stand for 60 minutes and 24 hours after stirring. 1 to 3 are for evaluating the coating properties of the glass frit, taking pictures of the state immediately after the glass frit was put in water and stirred (FIG. 1), 60 minutes (FIG. 2), and left for 24 hours (FIG. 3). It is an image. Referring to Figures 1 to 3, it can be seen that the glass frit coated with a fatty amine alone (Preparation Example 1) has the fastest precipitation and is well coated to maintain hydrophobicity. It can be seen that it has hydrophilicity when coated with fatty acids and maintains dispersibility compared to uncoated glass frit.

(2) Thermogravimetric analysis (TGA)

Thermogravimetric analysis was performed on the surface-coated glass frit and the uncoated glass frit prepared according to Preparation Examples 1 to 6. Figure 4 shows the results of the thermogravimetric analysis of the surface-coated glass frit and the non-coated glass frit prepared according to Preparation Examples 1 to 6, Figure 5 shows the photographed image after the thermogravimetric analysis. Referring to FIG. 4, it is confirmed that the weight reduction width increases according to the coating agent content (concentration), and through this, it can be seen that the coating is uniformly coated. In particular, it can be seen that the coated content is increased when secondary coating is performed with fatty acids (Preparation Examples 4 and 6). Referring to FIG. 5, it can be seen that black xanthan is generated on the glass surface as the content of the coating agent increases, which means that the coating is well performed.

(3) Evaluation of adhesion 1

After manufacturing solar cells in the same manner as described above by using the conductive pastes prepared according to the Examples and Comparative Examples, a conductor ribbon was attached to the electrodes of each cell through a tabbing process. The ribbon used was a product of 60Sn40Pb (kosbon company), and adhesion was progressed at 350°C using an iron machine. After that, the adhesive force between the solar cell electrode and the ribbon was measured. The adhesion measurement equipment was manufactured by LS1 (Lloyd), and adhesion was measured at a speed of 250mm/min in the 180 degree direction. 6 shows measurement results of adhesion between a solar cell electrode and a ribbon manufactured using a conductive paste manufactured according to Examples and Comparative Examples. 6, it can be seen that Preparation Examples 1, 3, and 4 coated with fatty amines have improved dispersibility and uniform adhesion, and Preparation Examples 2, 5, and 6 coated with fatty acids first were It can be seen that the acidity is lowered and the adhesion is uneven. In conclusion, it can be seen that the adhesion is determined according to the type of the first coating, and it can be seen that the adhesion is the most excellent when the first coating with fatty amine and then the second coating with fatty acid (Preparation Example 4).

(4) Adhesion evaluation 2

After manufacturing solar cells in the same manner as described above using the conductive paste prepared in Examples 1, 4, 6 and Comparative Example 1, the electrodes of each cell were then subjected to the above-described tabbing process. Ribbon was attached. After that, the conductor ribbon was detached and the interface images were measured. 7 is an image of the surface of the electrode taken after the conductor ribbon is detached. Referring to FIG. 7, when the first coating with fatty amine (Examples 1 and 4) improved dispersibility, the reaching phenomenon was less, and when additionally coated with fatty acid (Example 4), the Ag electrode was broken. , It can be seen that the adhesion between Glass and Si wafer is excellent. When coating only with fatty acids (Example 6), it can be seen that reaching occurs throughout the Ag electrode.

(5) Conversion efficiency and resistance measurement

The conductive pastes prepared according to Examples 1 to 6 and Comparative Example 1 were pattern printed on the entire surface of the wafer by a screen printing technique of 40 μm mesh, and a belt-type drying furnace was used at 200 to 350° C. for 20 to 30 seconds. Dried. Thereafter, Al paste was printed on the back side of the wafer and dried in the same manner. The cell formed by the above process was fired at 500 to 900° C. for 20 to 30 seconds using a belt-type kiln to produce a solar cell.

The manufactured cell uses a solar cell efficiency measuring device (Halm, cetisPV-Celltest 3), and short-circuit current (Isc), open-circuit voltage (Voc), conversion efficiency (Eff), curve factor (FF), series resistance ( Rs) and line resistance (Rline) were measured and shown in Table 2 below.

division Isc
(A) Voc
(V) Eff
(%) FF
(%) Rser
(Ω) Rsht
(Ω) Grid resistance
(1-2) Grid resistance
(2-3) Comparative Example 1 10.0872 0.6631 22.238 80.516 0.00073 832 26.8 27.0 Example 1 10.1058 0.6641 22.311 80.551 0.00078 389 27.2 27.8 Example 2 10.0839 0.6629 22.230 80.546 0.00075 393 26.7 28.5 Example 3 10.1077 0.6639 22.297 80.583 0.00076 555 27.4 28.4 Example 4 10.1097 0.6647 22.323 80.582 0.00077 606 27.8 28.1 Example 5 10.0859 0.6631 22.250 80.576 0.00080 592 26.8 28.7 Example 6 10.0939 0.6629 22.229 80.458 0.00079 775 27.3 27.8

As shown in Table 2 above, in the case of a solar cell including an electrode made of a conductive paste (eg, Examples 1, 3, and 4) containing a glass frit treated with a primary coating with a fatty amine, a short circuit current and It can be seen that the efficiency has increased due to the increase in the open-circuit voltage. Most excellently, it can be seen that the power generation efficiency of the solar cell is most improved when a glass frit coated with a fatty amine is first coated and then a fatty acid coated second is used (Example 4).

Features, structures, effects, and the like illustrated in each of the above-described embodiments can be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Accordingly, contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

Claims (9)

Including metal powder, glass frit, and an organic vehicle,
A conductive paste for solar cell electrodes, characterized in that the surface of the glass frit is first coated with fatty amine and secondary coated with fatty acid.
delete delete delete The method of claim 1,
The fatty amine is a conductive paste for a solar cell electrode comprising an alkylamine-based material having 6 to 24 carbon atoms.
The method of claim 1,
The fatty amines are triethylamine, heptylamine, octadecylamine, hexadecylamine, decylamine, octylamine, didecylamine, and Conductive paste for a solar cell electrode, comprising at least one selected from trioctylamine.
The method of claim 1,
The fatty acid comprises at least one selected from lauric acid, oleic acid, stearic acid, palmitic acid, and acetic acid. Conductive paste for battery electrodes. The method of claim 1,
The glass frit is a conductive paste for a solar cell electrode, characterized in that coated with an organic solvent or aqueous solution in which a fatty amine or fatty acid having a concentration of 0.1 to 0.3% is dissolved.
In a solar cell having a front electrode on an upper portion of the substrate and a rear electrode on the lower portion of the substrate,
The front electrode is manufactured by applying the conductive paste for a solar cell electrode according to any one of claims 1 and 5 to 8, followed by drying and firing.

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