TW202123479A - Glass frit and electrode paste composition for solar cell comprising the same - Google Patents

Abstract

The present invention relates to glass frit and a solar cell electrode paste composition comprising same, the glass frit, according to one embodiment of the present invention, being PbO-TeO2-Bi2O3-based, and further comprising Ag2O and a thallium compound.

Description

Glass frit and slurry composition for solar cell electrode including the same

The present invention relates to a glass frit and a slurry composition for solar cell electrodes including the glass frit.

In recent years, the depletion of existing natural resources such as oil and coal has been predicted, and the environmental problems of thermal power generation and the safety of nuclear power generation have been raised. As a result, people's interest in replacing them with renewable energy such as solar energy, solar energy and wind energy has increased. Among them, photovoltaic power generation can utilize infinite solar energy resources and is environmentally friendly. Therefore, a large amount of research and development on photovoltaic power generation have recently been carried out, and photovoltaic power generation has been installed and operated on many sites.

The photovoltaic power generation device for photovoltaic power generation includes a plurality of solar cell modules (panels), and the solar cell module is composed of a plurality of solar cells.

Solar cells are semiconductor devices that convert light energy from the sun into electrical energy, and are roughly classified into silicon solar cells and compound semiconductor solar cells according to raw materials, and silicon solar cells are widely used.

A silicon solar cell is constructed by forming a P-N junction on the silicon wafer, and forming a front electrode and a back electrode on the front and back of the silicon wafer, so that internal electrons can flow to the outside. When light is irradiated on the above-mentioned solar cell, due to the photoelectric effect, free electrons are generated in the silicon wafer, and the electrons move to the N-type semiconductor through the PN junction and flow to the external circuit through the electrodes formed on the surface of the silicon wafer to generate current . In addition, an anti-reflection film is formed on the surface of the silicon wafer to reduce the reflection loss of irradiated sunlight, thereby improving the efficiency of converting sunlight into electrical energy.

The electrode of the solar cell is formed by coating a conductive paste on one side of a silicon wafer. The conductive paste (hereinafter referred to as the solar cell electrode paste) composition includes conductive powder, glass frit and organic vehicle. During the sintering process after coating the solar cell electrode paste, the glass The material decomposes and removes the predetermined part of the anti-reflection film, and adheres to the silicon wafer, so that the electrode and the silicon wafer are electrically conductive.

As mentioned above, the method of combining silicon wafers and electrodes is called fire-through, and the conversion efficiency of solar cells may be affected by fire-through. For example, if burn-through is excessively performed, the electrodes may erode into the silicon wafer, causing battery degradation. If the burn-through is not sufficiently performed, the basic performance as a solar cell may decrease.

On the other hand, when the burn-through is performed at a high temperature, parts other than the electrode such as an anti-reflection film may be thermally damaged. Therefore, the slurry for solar cell electrodes preferably contains glass frit capable of low-temperature sintering.

It is well known that in order to lower the transition point of the glass frit to enable low-temperature sintering, the glass frit contains an alkaline oxide. However, since the alkaline oxide functions as a network modifier to cut off the network structure, there is a problem that the stability of the glass may be degraded.

[The problem to be solved by the invention]

The present invention was developed to solve the above-mentioned existing problems, and its purpose is to provide a glass frit that can be sintered at a low temperature and has a stable structure, and a slurry for solar cell electrodes including the glass frit.

In addition, an object of the present invention is to provide a glass frit capable of improving the contact characteristics of solar cell electrodes and improving conversion efficiency, and a paste for solar cell electrodes including the glass frit. [Technical means to solve the problem]

The glass frit of an embodiment of the present invention is a paste for solar cell electrodes. The glass frit is based on PbO-TeO ₂ -Bi ₂ O ₃ and further includes Ag ₂ O and thallium compounds.

According to an embodiment of the present invention, the thallium compound may be Tl ₂ O ₃ .

According to an embodiment of the present invention, the glass frit may include 15 mol% to 35 mol% PbO, 20 mol% to 40 mol% TeO ₂ and 1 mol% to 10 mol% Bi ₂ O _{3. Ag 2} O from 1 mol% to 10 mol% _{and Tl 2} O ₃ from 0.5 mol% to 20 mol%.

The glass frit of an embodiment of the present invention may also include SiO ₂ , ZnO, Li ₂ O, Na ₂ O, K ₂ O, MgO, CaO, SrO, BaO, V ₂ O ₅ , Al ₂ O ₃ , WO ₃ , At least one of Ga ₂ O ₃ , SnO ₂ , Sb ₂ O ₃ and Sb ₂ O _5.

The glass frit in another embodiment of the present invention is a paste for solar cell electrodes. The glass frit includes: a first glass frit based on PbO-TeO ₂ -Bi ₂ O ₃ and also includes Ag ₂ O; and a second glass frit based on PbO-TeO 2 -Bi 2 O 3; The glass frit, based on PbO-TeO ₂ -Bi ₂ O ₃ , also includes thallium compounds.

According to another embodiment of the present invention, the thallium compound may be Tl ₂ O ₃ .

Also, according to another embodiment of the present invention, the first glass frit may include 20 mol% to 35 mol% PbO, 25 mol% to 40 mol% TeO ₂ , and 1 mol% to 10 mol%. % Bi ₂ O ₃ and 1 mol% to 10 mol% Ag ₂ O, the second glass frit may include 15 mol% to 30 mol% PbO, 20 mol% to 35 mol% TeO ₂ , 3 to 10 mol% Bi ₂ O ₃ and 0.5 mol% to 20 mol% Tl ₂ O ₃ .

The slurry composition for solar cell electrodes according to an embodiment of the present invention includes conductive powder, glass frit, and organic carrier. Among them, the glass frit is based on PbO-TeO ₂ -Bi ₂ O ₃ and also includes Ag ₂ O and thallium compounds.

The slurry composition for solar cell electrodes according to an embodiment of the present invention includes conductive powder, glass frit, and organic carrier. Wherein, the glass frit includes a first glass frit and a second glass frit, the first glass frit is based on PbO-TeO ₂ -Bi ₂ O ₃ and also includes Ag ₂ O, and the second glass frit also includes a PbO-TeO ₂ -Bi _{2 based} O ₃ also includes thallium compounds. [Compared with the effect of previous technology]

According to an embodiment of the present invention, the PbO-TeO ₂ -Bi ₂ O ₃ based glass frit includes Ag ₂ O and thallium compound, so that it can be sintered at a low temperature and has a stable structure when forming a solar cell. Moreover, according to an embodiment of the present invention, the contact characteristics of the solar cell can be improved, and the conversion efficiency can be improved.

Hereinafter, with reference to the drawings, preferred embodiments of the present invention will be described in detail, so that the present invention can be easily implemented by those skilled in the art. For brevity of description, in the drawings, parts irrelevant to the description are omitted. [Structure of solar cell]

Fig. 1 is a cross-sectional view schematically showing the structure of a solar cell according to an embodiment of the present invention.

1, the solar cell 100 includes a silicon wafer 110 and a front electrode 130 and a back electrode 140 formed on the front and back of the silicon wafer 110, respectively. In addition, the solar cell 100 further includes an anti-reflection film 120 formed between the silicon wafer 110 and the front electrode 130.

The silicon wafer 110 includes a P-type semiconductor 111 and an N-type semiconductor 113. The P-type semiconductor 111 can be formed by doping silicon with group III elements such as B, Ga, and In as P-type impurities, and the N-type semiconductor 113 can be doped with silicon such as P, As, Sb and other group V elements as N-type impurities. to make. A P-N junction is formed between the P-type semiconductor 111 and the N-type semiconductor 113 so that when light is incident on the P-N junction, free electrons generated by the photoelectric effect move to the N-type semiconductor 113 to be able to generate photovoltaic power.

The anti-reflection film 120 is formed on the N-type semiconductor 113 of the silicon wafer 110 to reduce the reflectivity of the light incident on the front surface of the silicon wafer 110 and function as an insulating layer. Or the inactivation of internal defects. When the reflectance of incident light is reduced by the anti-reflection film 120, the amount of light reaching the P-N junction increases, and therefore the short-circuit current of the solar cell 100 increases, so that the conversion efficiency of the solar cell 100 can be improved. The anti-reflection film 120 may be formed of, for example, one of a silicon nitride film, a silicon oxide film, or a silicon oxynitride film, or may be formed of a multilayer film in which two or more films are stacked, in addition to It is formed of a film with a known composition.

The front electrode 130 of the solar cell 100 is used to collect electrons generated by the photoelectric effect and moved to the N-type semiconductor 113 and move the electrons to the outside to allow current to flow. The front electrode 130 is formed on the front surface of the silicon wafer 110 and, as shown in the figure, may be formed as an N-type semiconductor 113 that penetrates the anti-reflection film 120 and is connected to the silicon wafer 110. Specifically, the front electrode 130 may be formed as follows: after coating the electrode slurry on the anti-reflection film 120, the anti-reflection film 120 is etched by sintering, so that the slurry composition penetrates the anti-reflection film 120, so that the electrode The paste is connected to the N-type semiconductor 113 of the silicon wafer 110.

A back electrode 140 is formed on the back surface of the silicon wafer 110, that is, on the surface opposite to the surface on which the front electrode 130 is formed, and a back electric field layer 150 may be formed on the interface between the back electrode 140 and the silicon wafer 110. The back electrode 140 may be formed of a conductive paste composition containing aluminum, and in the process of forming the back electrode 140, aluminum is diffused through the back surface of the silicon wafer 110 to form the back back electric field layer 150. The back electric field layer 150 can prevent carriers from moving to the back of the silicon wafer 110 and recombining, thereby improving the conversion efficiency of the solar cell 100.

On the other hand, according to an embodiment of the present invention, the paste composition for solar cell electrodes can achieve the above-mentioned original effects of the present invention by using a glass frit of a specific composition. The glass frit used therefor will be described in detail. [Slurry composition for solar cell electrodes]

The paste for solar cell electrodes according to an embodiment of the present invention includes conductive powder, glass frit, and organic carrier.

The conductive powder of the slurry composition for solar cell electrodes is used to impart electrical characteristics to the slurry composition. According to this embodiment, Ag powder can be used as the conductive powder. Based on the total weight of the slurry composition, the content of Ag powder may be 80% to 90% by weight. The silver powder may have a particle size ranging from nanometers to micrometers, and it is also possible to mix and use Ag powders with two or more different sizes.

The glass frit of the paste composition for solar cell electrodes serves to etch the anti-reflection film 120 during the sintering process of the paste for solar cell electrodes to bring the paste into contact with the silicon wafer 110. According to this embodiment, the content of the glass frit may be 0.5% to 5% by weight based on the total weight of the slurry composition.

According to an embodiment of the present invention, the glass frit can be made based on PbO-TeO ₂ -Bi ₂ O ₃ .

PbO is used to increase the etching performance of the anti-reflection film through the slurry composition for solar cell electrodes, and its content may be 15 mol% to 35 mol% based on the glass frit. PbO makes the burn-through process of etching and penetrating the anti-reflective film smoothly proceed, and penetrates into the anti-reflective film to connect the electrode to the silicon wafer.

TeO _{2 is} used to prevent over-etching by adjusting the reactivity between the paste and the anti-reflection film during the sintering of the paste for the front electrode of the solar cell, and its content may be 20 mol% to 40 mol% based on the glass frit. As a result, excessive etching due to PbO can be prevented, so that deterioration of battery characteristics and occurrence of shunt can be prevented.

Bi ₂ O _{3 is} used to improve the conversion efficiency of solar cells, and its content can be 1 mol% to 10 mol% based on the glass frit.

In addition to PbO, TeO ₂ and Bi ₂ O ₃ , the glass frit according to this embodiment also includes Ag ₂ O and Tl ₂ O ₃ .

Ag ₂ O is a component for improving conductivity. According to this embodiment, its content may be 1 mol% to 10 mol% based on the glass powder.

Ag ₂ O not only improves the sinterability of the slurry composition and the conductive powder (Ag powder) during the sintering process, but also increases the solid solubility of Ag to obtain more Ag precipitates. As described above, Ag ₂ O can improve conductivity and fill factor (FF) by increasing the amount of Ag precipitation. In addition, Ag ₂ O is one of the stronger reticulation agents, so it can improve the low-temperature sintering characteristics by lowering the glass transition point.

However, Ag ₂ O lowers the glass transition point and increases spreadability, and thus can cause the phenomenon that the line width of the electrode increases after the paste is sintered. This may reduce the light-receiving area of the solar cell, resulting in a decrease in the open-circuit voltage Voc and short-circuit current Isc, resulting in a decrease in conversion efficiency.

In this embodiment, the glass frit further includes Tl ₂ O ₃ to solve possible problems caused by _{Ag 2 O.}

Like the alkali oxides mentioned above, Tl ₂ O ₃ functions as a network former that cuts off the network structure, but also functions as a network former that reconnects the cut network structure through the Tl element. . Therefore, Tl ₂ O _{3 is} also used to connect _{the network structure cut by Ag 2} O and alkaline oxide, so that a more stable glass structure can be formed. That is, by containing Tl ₂ O ₃ , the glass powder can greatly reduce the glass transition point while reducing alkali oxides, and can also stabilize the glass structure. Therefore, product reliability is improved by improving chemical resistance, which is a disadvantage of low-temperature sintered glass.

In addition, when the glass frit contains a small amount of Tl ₂ O ₃ , the glass transition point is lowered, and crystallization is easy to proceed. Therefore, when the glass frit contains Ag ₂ O, the problem of increased line width due to increased spreadability can be solved.

The content of Tl ₂ O ₃ may be 0.5 mol% to 20 mol% based on the glass frit. When _{the content of Tl 2} O ₃ is less than 0.5 mol%, the above effect cannot be fully achieved. When _{the content of Tl 2} O ₃ is greater than 20 mol%, not only does it become difficult to vitrify, but as the glass transition temperature decreases excessively, The spreading shape of the slurry may appear during firing. In addition, preferably, based on the glass powder, _{the content of Tl 2} O ₃ may be 1 mol% to 15 mol%, more preferably 1 mol% to 10 mol%.

In this embodiment, although the glass frit contains thallium oxide, the present invention is not limited to this, and other thallium compounds containing Tl elements, such as thallium nitride, thallium fluoride, and thallium carbide, can also be used.

In addition to the above components, the glass frit according to this embodiment may also include SiO ₂ , ZnO, Li ₂ O, Na ₂ O, K ₂ O, MgO, CaO, SrO, BaO, V ₂ O ₅ , Al ₂ O ₃ , At least one of _{WO 3} , Ga ₂ O ₃ , SnO ₂ , Sb ₂ O ₃ and Sb ₂ O _5.

On the other hand, although the glass frit based on PbO-TeO ₂ -Bi ₂ O ₃ and Ag ₂ O comprises Tl ₂ O ₃ in the above embodiment, but can be include Ag ₂ O and Tl ₂ O ₃ based on PbO -TeO ₂ -Bi ₂ O ₃ glass frit is mixed and used.

The glass frit of another embodiment of the present invention includes a first glass frit and a second glass frit, the first glass frit is based on PbO-TeO ₂ -Bi ₂ O ₃ and also includes Ag ₂ O, and the second glass frit is based on PbO-TeO _2- Bi ₂ O ₃ and also includes Tl ₂ O ₃ . Specifically, the first glass frit may include 20 mol% to 35 mol% PbO, 25 mol% to 40 mol% TeO ₂ , 1 mol% to 10 mol% Bi ₂ O ₃ and 1 mol% to 10 mol% Ag ₂ O, the second glass frit may include 15 mol% to 30 mol% PbO, 20 mol% to mol% TeO ₂ , 3 mol% to 10 mol% Mole% Bi ₂ O ₃ and 0.5 mol% to 20 mol% Tl ₂ O ₃ .

As described above, the glass frit includes _{two glass frits containing Ag 2} O and Tl ₂ O ₃ respectively, which can improve low-temperature sintering characteristics and maintain stability, increase electrical conductivity and fill factor, and suppress spreadability, so that excellent Conversion efficiency.

The organic vehicle of the paste composition for solar cell electrodes is used to impart a viscosity suitable for printing to the paste composition, and its content is the residual amount in the total paste excluding the amount of conductive powder and glass frit. Generally, the organic vehicle may include a binder resin and a solvent. For example, the binder resin may include acrylic or cellulose resins, ethyl cellulose, ethyl hydroxyethyl cellulose, nitrocellulose, a mixture of ethyl cellulose and phenolic resins, alkyd resins, phenolic resins , Acrylic resin, xylene resin, polybutene resin, polyester resin, urea resin, melamine resin, vinyl acetate resin, wood rosin (rosin) and polymethacrylate, solvent Examples may include at least one of hexane, toluene, ethyl cellosolve, cyclohexanone, butyl cellosolve, butyl carbitol (diethylene glycol monobutyl ether), dibutyl carbitol (diethylene two Alcohol Dibutyl Ether), Butyl Carbitol Acetate (Diethylene Glycol Monobutyl Ether Acetate), Propylene Glycol Monomethyl Ether, Hexylene Glycol, Terpineol (Terpineol), Methyl Ethyl Ketone , Benzyl alcohol, γ-butyrolactone or ethyl lactate, etc.

In addition, in order to improve flow characteristics and process characteristics, the slurry composition for solar cell electrodes of the present invention may also contain conventional additives. As additives, at least one of dispersants, plasticizers, viscosity stabilizers, antioxidants, etc. can be used. [Experimental example]

Hereinafter, the effect of the present invention will be specifically explained based on experimental results of measuring the glass transition point and conversion efficiency of the components of the glass frit used in the slurry composition for solar cell electrodes.

Table 1 shows the composition of the glass frit according to the paste composition of each Example and Comparative Example when forming solar cell electrodes. In this experimental example, the slurry composition contains 89% by weight of Ag powder as conductive powder, 3% by weight of glass frit, and residual organic vehicle. [Table 1] classification Composition ratio (mol%) PbO Bi ₂ O ₃ TeO ₂ SiO ₂ B ₂ O ₃ ZnO Al ₂ O ₃ CaO WO ₃ Li ₂ O Tl ₂ O ₃ Ag ₂ O Example 1 15.2 7.8 24.7 15.8 1.0 3.8 0.7 1.2 1.8 8.8 17.7 1.5 Example 2 19.3 6.9 27.2 14.7 1.0 3.5 0.7 1.1 1.7 7.6 14.3 2.0 Example 3 21.1 6.1 30.7 13.5 1.0 3.3 0.6 1.0 1.6 6.1 11.6 3.4 Example 4 22.2 5.3 33.3 12.4 0.9 3.0 0.6 1.0 1.5 5.6 8.3 5.9 Example 5 24.0 4.5 36.8 11.2 0.9 2.7 0.5 0.9 1.3 5.1 4.7 7.4 Example 6 19.4 6.0 26.5 14.0 0.9 3.5 0.6 1.0 1.6 8.1 16.6 1.8 Example 7 22.7 5.2 29.7 13.1 0.9 3.4 0.6 0.9 1.4 6.9 12.9 2.3 Example 8 25.7 4.3 32.4 12.3 0.9 3.2 0.5 0.8 1.2 5.6 9.4 3.7 Example 9 27.0 3.5 35.0 11.5 0.9 3.1 0.5 0.8 1.0 4.5 5.9 6.3 Example 10 28.3 2.8 38.9 10.7 0.8 2.8 0.4 0.7 0.8 3.4 2.3 8.1 Comparative example 1 24.8 7.2 36.1 15.9 1.2 3.9 0.7 1.2 1.9 7.2 - - Comparative example 2 23.9 6.9 34.7 15.3 1.1 3.7 0.7 1.1 1.8 6.9 - 3.8 Comparative example 3 21.8 6.3 31.8 14.0 1.0 3.4 0.6 1.0 1.7 6.3 12.0 - Comparative example 4 19.2 5.5 27.9 12.3 0.9 3.0 0.5 0.9 1.5 5.5 10.5 12.3 Comparative example 5 18.6 5.4 27.1 11.9 0.9 2.9 0.5 0.9 1.4 5.4 22.0 3.0

Table 2 shows the results of measuring the glass transition point of the glass frit of each of the Examples and Comparative Examples and the conversion efficiency of the solar cell formed from the paste composition for solar cell electrodes including the glass frit. [Table 2] classification Glass transition point (℃) Filling factor (%) Contact resistance (mΩ) Conversion efficiency (%) Adhesion (N) Example 1 248 79.90 0.057 21.05 2.0 Example 2 240 80.15 0.051 21.23 2.4 Example 3 226 80.28 0.053 21.43 2.6 Example 4 217 80.17 0.060 21.34 2.2 Example 5 203 79.93 0.063 21.17 1.8 Example 6 251 79.83 0.059 21.02 1.9 Example 7 244 80.11 0.052 21.17 2.2 Example 8 236 80.24 0.055 21.32 2.5 Example 9 227 80.14 0.063 21.21 2.0 Example 10 211 79.97 0.067 21.08 1.6 Comparative example 1 284 79.23 0.075 20.05 2.2 Comparative example 2 258 79.48 0.070 20.37 2.3 Comparative example 3 263 79.55 0.058 20.51 1.6 Comparative example 4 196 79.63 0.074 20.62 2.0 Comparative example 5 183 79.40 0.062 20.13 1.8

Referring to Table 1 and Table 2, first, it can be confirmed that in the case where the glass frit does not contain Ag ₂ O and Tl ₂ O ₃ (Comparative Example 1), the glass transition temperature is relatively lower than that of other examples according to the present invention. High and low conversion efficiency. In the case where the glass frit contains only Ag ₂ O (Comparative Example 2) _{, the glass transition point is lowered compared to the case where Ag 2} O is not contained, but there is a problem that the conversion efficiency is lower than that of the Examples. It is considered that this is due to the increase in line width and the decrease in light-receiving area due to excessive spreadability during sintering when _{only Ag 2 O is included.} In addition, when the glass frit contains only Tl ₂ O ₃ (Comparative Example 3), there is a problem that the conversion efficiency is relatively low. It is believed that this is because the _{glass transition temperature is excessively lowered due to Tl 2} O ₃ , which lowers the viscosity of the glass and increases fluidity, resulting in an increase in resistance due to the formation of a glass layer (insulating layer) between the silicon wafer and the electrode. , Making the fill factor relatively low, and as a result, the conversion efficiency is reduced.

In addition, it can be confirmed that even if the glass frit contains Ag ₂ O and Tl ₂ O ₃ , when the content is outside the above-mentioned range (Comparative Examples 4 and 5), the glass transition temperature is excessively reduced, and the conversion efficiency is reduced.

In contrast, in the case of a solar cell formed of a glass frit having the composition of an embodiment of the present invention and a paste for solar cell electrodes including the same, it can be confirmed that it has a lower glass transition temperature and excellent Fill factor and relatively low contact resistance, so excellent conversion efficiency.

As described above, the glass frit used in the solar cell electrode paste of one embodiment of the present invention can be made possible by _{further including Ag 2} O and Tl ₂ O _{3 in the PbO-TeO 2} -Bi ₂ O ₃ based glass frit. Improve low-temperature sintering characteristics and maintain stability, which is beneficial to low-temperature sintering, so it has the advantage of expanding the sintering range during the sintering process. In addition, according to an embodiment of the present invention, through _{the complementarity of Tl 2} O ₃ and Ag ₂ O, the conductivity and filling factor can be improved, and the spreadability can be suppressed, so as to obtain excellent efficiency characteristics.

Although the preferred embodiments of the present invention have been described above with reference to the drawings, those skilled in the art to which the present invention belongs can understand that they can be implemented without changing the technical ideas or essential features of the present invention. Other specific forms. Therefore, it should be understood that the above-mentioned embodiments are exemplary and non-limiting in all aspects.

100: solar cell 110: Silicon wafer 111: P-type semiconductor 113: N-type semiconductor 120: Anti-reflection film 130: front electrode 140: back electrode 150: back electric field layer

Fig. 1 is a cross-sectional view schematically showing the structure of a solar cell according to an embodiment of the present invention.

100: solar cell

110: Silicon wafer

111: P-type semiconductor

113: N-type semiconductor

120: Anti-reflection film

130: front electrode

140: back electrode

150: back electric field layer

Claims (9)

A glass frit, which is a slurry for solar cell electrodes, is characterized in that it is based on PbO-TeO ₂ -Bi ₂ O ₃ and further includes Ag ₂ O and thallium compounds. The glass frit according to claim 1, wherein the thallium compound is Tl ₂ O ₃ . The glass frit according to claim 2, wherein the glass frit comprises: 15 mol% to 35 mol% PbO; 20 mol% to 40 mol% TeO ₂ ; 1 mol% to 10 mol% % Bi ₂ O ₃ ; 1 mol% to 10 mol% Ag ₂ O; and 0.5 mol% to 20 mol% Tl ₂ O ₃ . The glass frit according to claim 1, wherein the glass frit further includes SiO ₂ , ZnO, Li ₂ O, Na ₂ O, K ₂ O, MgO, CaO, SrO, BaO, V ₂ O ₅ , Al ₂ At least one of O ₃ , WO ₃ , Ga ₂ O ₃ , SnO ₂ , Sb ₂ O ₃ and Sb ₂ O ₅ . A glass frit, which is a paste for solar cell electrodes, is characterized by comprising: a first glass frit based on PbO-TeO ₂ -Bi ₂ O ₃ and also comprising Ag ₂ O; and a second glass frit based on PbO-TeO 2 -Bi 2 O 3; The glass frit, based on PbO-TeO ₂ -Bi ₂ O ₃ , also includes thallium compounds. The glass frit according to claim 5, wherein the thallium compound is Tl ₂ O ₃ . The glass frit according to claim 5, wherein the first glass frit includes 20 mol% to 35 mol% PbO, 25 mol% to 40 mol% TeO ₂ , and 1 mol% to 10 mol%. Mole% Bi ₂ O ₃ and 1 mol% to 10 mol% Ag ₂ O, the second glass frit includes 15 mol% to 30 mol% PbO, 20 mol% to 35 mol% % TeO ₂ , 3 mol% to 10 mol% Bi ₂ O ₃ and 0.5 mol% to 20 mol% Tl ₂ O ₃ . A slurry composition for solar cell electrodes, characterized by comprising: conductive powder; glass frit; and an organic carrier, wherein the glass frit is based on PbO-TeO ₂ -Bi ₂ O ₃ and also includes Ag ₂ O and thallium Compound. A slurry composition for solar cell electrodes, characterized by comprising: conductive powder; glass frit; and an organic carrier, wherein the glass frit includes a first glass frit and a second glass frit, and the first glass frit is based on PbO-TeO ₂ -Bi ₂ O ₃ and also includes Ag ₂ O, and the second glass frit is based on PbO-TeO ₂ -Bi ₂ O ₃ and also includes a thallium compound.

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