KR102507404B1 - a crystallized powder for an electrode of a solar cell, a paste mixture and a solar cell thereof - Google Patents

Abstract

In an embodiment of the present invention, 5 to 35 (wt%) of bismuth oxide (Bi ₂ O ₃ ) and 30 to 85 (wt%) of tellurium oxide (TeO ₂ ) are included, and the bismuth oxide and the oxidized Discloses a crystalline powder for solar cell electrodes in which tellurium is crystalline.

Description

Crystallized powder for an electrode of a solar cell, a paste composition thereof and a solar cell {a crystallized powder for an electrode of a solar cell, a paste mixture and a solar cell thereof}

The present invention relates to a crystalline powder for a crystalline solar cell electrode, a paste composition including the crystalline powder, and a solar cell manufactured therefrom.

A solar cell generates electrical energy by using the photoelectric effect of a pn junction that converts photons of sunlight into electricity. A solar cell has a front electrode and a rear electrode formed on the upper and lower surfaces of a semiconductor wafer or substrate where a pn junction is formed, respectively.

In such a solar cell, a photoelectric effect of a pn junction is induced by sunlight incident on a semiconductor wafer, and electrons generated therefrom provide current flowing to the outside through an electrode.

An electrode of such a solar cell can be made by applying a paste composition for an electrode to a substrate, patterning the paste composition, and firing the same.

The present invention was invented in such a technical background, and is to provide a crystalline powder for a solar cell electrode that can easily manufacture an electrode, a paste composition thereof, and a solar cell manufactured therefrom.

In order to achieve the above object, in an embodiment of the present invention, 5 to 35 (wt%) of bismuth oxide (Bi ₂ O ₃ ) and 30 to 85 (wt%) of tellurium oxide (TeO ₂ ) are included. , wherein the bismuth oxide and the tellurium oxide are crystalline. Disclosed is a crystalline powder for a solar cell electrode.

It is preferable that the bismuth oxide and the tellurium oxide form a chemical bond.

The crystalline powder is at least one of 1 to 25 (wt%) of lead oxide (PbO), 1 to 15 (wt%) of tungsten oxide (W ₃ O), and 1 to 15 (wt%) of zinc oxide (ZnO). may further include.

The crystalline powder may include at least one or more of lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), and potassium oxide (K ₂ O), the total of which may have a weight ratio of 1 to 15 (wt%) there is.

The chemically bonded crystalline powder containing the bismuth oxide and tellurium oxide is preferably melted at 500 to 900°C.

In another embodiment of the present invention, 65 to 93 (wt%) of the conductive metal powder, 0.5 to 5 (wt%) of the crystalline powder according to any one of claims 1 to 5, and 5 to 5 A paste composition for a solar cell electrode containing 30 (wt%) of an organic vehicle is disclosed.

The conductive metal powder includes silver (Ag), gold (Au), copper (Cu), palladium (Pd), platinum (Pt), chromium (Cr), cobalt (Co), tin (Sn), lead (Pb), Zinc (Zn), Iron (Fe), Iridium (Ir), Osmium (Os), Rhodium (Rh), Tungsten (W), Molybdenum (Mo), Nickel (Ni), Indium Tin Oxide (ITO) includes at least one of

The average particle diameter (D50) of the crystalline powder is preferably 0.1 to 5 (μm).

Another embodiment of the present invention discloses a solar cell manufactured using a paste comprising the above-described crystalline powder.

The present invention provides the following effects by using crystalline powder instead of glass frit used in conventional paste compositions for solar cell electrodes.

Since the crystalline powder exhibits a stable state at room temperature, unlike a supercooled liquid state such as glass, it is possible to design without being restricted by the glass forming region in terms of composition. In addition, since thermal characteristics such as transition point (Tg), softening point (Ts), and crystallization temperature (Tc) of the conventional glass frit act as important factors in the firing process of solar cell electrodes, the complexity of the design to control the thermal characteristics is reduced. However, since the thermal properties of the crystalline powder are controlled only by a simple melting point (Tm), it is possible to design a composition more easily. In addition, since the viscosity of the liquid phase formed from a temperature higher than the melting point (Tm) is lower than the viscosity near the transition point (Tg) and softening point (Ts) where the glass frit has viscosity, it can have greater fluidity and consequently the contact with the substrate. A uniform reaction can be expected. It is also possible to secure high stability for the temperature conditions of the solar cell firing process by controlling the reaction with the substrate using simple melting point (Tm) control of crystalline powder rather than the complex thermal characteristics of glass frit.

1 is a diagram explaining the configuration of a solar cell.

Hereinafter, preferred embodiments of the present invention will be described.

Electrode pastes developed so far contain glass frit and metal powder.

Such a conventional electrode paste contains glass frit, and when the electrode is fired, the reaction mainly proceeds at a temperature higher than the transition point (Tg) or softening point (Ts) of the glass frit, and the electrode is formed while reaching the crystallization temperature (Tc) of the glass. reaction is reduced.

However, since thermal characteristics such as the transition point (Tg), softening point (Ts), and crystallization temperature (Tc) of the conventional glass frit act as important factors in the firing process of making solar cell electrodes, in order to control the thermal characteristics, design The complexity of the image is required.

Meanwhile, in order to achieve uniform contact between the electrode and the substrate, the viscosity of the glass frit during firing is important. In firing, if the viscosity of the glass frit is high, the fluidity of the glass frit is low, resulting in poor contact.

And, in order to solve this problem, the prior art uses a large amount of metal oxides such as lead oxide (PbO) or bismuth oxide (Bi ₂ O ₃ ) for the purpose of lowering the transition point (Tg) or softening point (Ts) of the glass frit. However, when excessive amounts of lead oxide (PbO) and bismuth oxide (Bi ₂ O ₃ ) are added, an abnormal reaction occurs between the electrode formation and the semiconductor substrate, so it is not easy to obtain good contact between the electrode and the substrate.

crystalline powder

In this embodiment, the crystalline powder includes bismuth oxide (Bi ₂ O ₃ ) in a weight ratio of 5 to 35 (wt%) and tellurium oxide (TeO ₂ ) in a weight ratio of 30 to 85 (wt%), and bismuth oxide and the above All tellurium oxides exist in crystalline form.

As such, in the present invention, since crystalline powder is used instead of glass frit, the electrode formation reaction occurs at the melting point. However, as is well known, since the state change occurs rapidly at the melting point, the viscosity of the crystalline powder at the melting point is very low compared to that of the glass frit. Thus, uniform contact between the electrode and the substrate can be obtained.

In addition, in the present invention, since crystalline powder is used instead of glass frit, only the melting point needs to be controlled in terms of thermal characteristics, so design complexity is not required as in the past.

On the other hand, the bismuth oxide has a weight ratio of 5 to 35 (wt%) relative to the total, and the tellurium oxide has a weight ratio of 30 to 85 (wt%) relative to the total.

If the ratio of bismuth oxide and tellurium oxide exceeds this weight ratio, the reaction occurs too violently, causing damage to other layers constituting the solar cell, such as an antireflection film or an emitter, which are not desired. Conversely, if the weight ratio is lower than the above-mentioned weight ratio, the reaction is weak and it is difficult to form an electrode.

In the crystalline powder state corresponding to the content range of the present invention, the bismuth oxide and the tellurium oxide exist in a chemical bond state such as Chemical Formulas 1 and 2 exemplified below, and depending on the content range, some single material of tellurium oxide It also exists in mixed form.

[Formula 1]

Bi ₂ TeO ₅ (Smirnite)

[Formula 2]

Bi ₂ Te ₂ O ₇

As such, since the crystalline powder includes a state in which the bismuth oxide and the tellurium oxide are chemically bonded, when each exists alone, the melting point is about 817° C. in the case of bismuth oxide and about 732° C. in the case of tellurium oxide What was ℃, can be lowered to less than 600 through the eutectic point, or raised to about 900 ℃ through the harmonic phase conversion point (homogeneous melting point, congruent melting point). That is, it is possible to control the melting point in the range of about 575 to 906 ° C through the state in which bismuth oxide and tellurium oxide are chemically bonded, and it is also possible to control the melting point in a wider range through the addition of other components.

Such crystalline powder contains lead oxide (PbO) in a weight ratio of 1 to 25 (wt%), tungsten oxide (WO ₃ ) in a weight ratio of 1 to 15 (wt%), and zinc oxide (ZnO) in a weight ratio of 1 to 15 (wt%). At least one of them may be further included.

If the crystalline powder further includes such a metal oxide, it is effective in controlling the melting point or forming a better contact. If it is included in a weight ratio less than the above, the effect is not effective, or if it is included in an excess weight ratio, the contact becomes poor. It is desirable to have a composition ratio.

The lead oxide (PbO) has a weight ratio of 1 to 25 (wt%). If it is lower than 1 (wt%), it is difficult to expect an additive effect, and if it is higher than 25 (wt%), the reactivity between the electrode and the substrate becomes excessive, so contact it goes bad

The tungsten oxide has a weight ratio of 1 to 15 (wt%). If it is lower than 1 (wt%), it is difficult to expect an additive effect, and if it is higher than 25 (wt%), it greatly affects the melting point or changes the existing crystal phase. Contact goes bad.

The zinc oxide has a weight ratio of 1 to 15 (wt%). If it is lower than 1 (wt%), it is difficult to expect an additive effect, and if it is higher than 15 (wt%), it greatly affects the melting point or changes the existing crystal phase. Contact goes bad.

In addition, the crystalline powder may further include at least one of lithium oxide (Li ₂ O), sodium oxide (Na ₂ O), and potassium oxide (K ₂ O), and the total weight ratio thereof is 1 to 15.

Alkali oxide is a very effective material in controlling the melting point of the chemical bond composed of the bismuth oxide and tellurium oxide and the reactivity between the electrode and the substrate. If it is less than 1%, the effect is small, and if it is included in excess of 15%, it causes a large change in melting point and reactivity, resulting in poor contact.

Such crystalline powders can be prepared from the metal oxides described above using conventional methods. For example, one method of preparing the crystalline powder may be made through the steps of mixing, melting, slow cooling, coarse pulverization, and fine pulverization.

The mixing step is a process of mixing lumped bismuth oxide and tellurium oxide in a weight ratio of 5 to 35 and 30 to 85, respectively.

And, the melting step is a step of melting the mixture prepared in the mixing step, putting the mixed material in a platinum crucible or an alumina crucible or a water-cooled tank and completely melting it in a high-temperature electric furnace at a temperature of about 900 to 1300 ° C for 10 to 60 minutes. It is a process of

In addition, the slow cooling step heat-treats the mixture melted through the melting step at a temperature 200 ° C lower than the crystal formation temperature of the mixed composition to the crystal formation temperature for 20 minutes to 1 hour, and then slowly cools at 1 to 10 ° C per minute to completely crystallize It is a process.

Next, the coarse grinding step is a process of crushing the crystal mass obtained through the above slow cooling step using a ball mill to have an average particle diameter of several to several tens of microns. If the crystal lump is coarsely pulverized in this way, the efficiency of pulverization in the future can be increased, and the reproducibility of the particle size can be improved.

Lastly, in the pulverization step, the coarsely pulverized cullet has an average particle diameter (D50) of 0.1 to 10 (um), more preferably 0.1 to 5 (um) in an airjet mill or a fine mill. It is a step of grinding to complete crystalline particles. Contact characteristics are best formed within this range, and when the particle diameter is larger than this range, printability becomes poor during screen printing.

for solar cell electrode paste

The electrode paste of this embodiment includes the above-described crystalline powder, conductive metal powder, and organic vehicle.

In this embodiment, 65 to 93 (wt%) of the metal powder, 0.5 to 5 (wt%) of the crystalline powder, and 5 to 30 (wt%) of the organic vehicle are included, respectively.

When the metal powder is less than 65wt%, the content of inorganic solids is low, and when produced as a paste, the viscosity is formed too low, and as a result, it is difficult to obtain the desired printability of the paste. In addition, as the content of inorganic solids is low, the content of organic components increases, which becomes a factor that inhibits the sinterability of the metal powder during firing of the solar cell electrode. When the content of the metal powder exceeds 93wt%, the content of the inorganic solid content is high, and when made into a paste, the viscosity is formed too high, thereby impairing the printing performance.

In the case of crystalline powder, when the content is less than 0.5wt%, it is difficult to obtain good contact characteristics between the substrate and the electrode due to the low content of crystalline powder compared to the content of metal powder during firing of the solar cell electrode. In contrast, the high content of crystalline powder impairs the conductivity of the solar cell electrode or causes an abnormal reaction between the substrate and the electrode.

When the content of the organic vehicle is less than 5 wt%, the viscosity of the paste is high, which causes poor printability, and when the content exceeds 30 wt%, the viscosity of the paste is too low, making it difficult to realize desired printing performance. Similar to the case where the metal powder content mentioned above is less than 65 wt%, when the organic vehicle content exceeds 30 wt%, the content of organic components such as a binder increases, which causes the sintering of the metal powder to be hindered during the sintering of the solar cell electrode.

A) Conductive metal powder

Conductive metal powders include silver (Ag), gold (Au), copper (Cu), palladium (Pd), platinum (Pt), chromium (Cr), cobalt (Co), tin (Sn), lead (Pb), zinc Among (Zn), Iron (Fe), Iridium (Ir), Osmium (Os), Rhodium (Rh), Tungsten (W), Molybdenum (Mo), Nickel (Ni), Indium Tin Oxide (ITO) contains at least one

There is no particular limitation on the particle size or particle shape of the conductive metal powder, and metal powders having different particle shapes may be mixed or different types of metal powders may be mixed.

b) Organic vehicle

The organic vehicle may include an organic binder that imparts liquid phase properties to the paste. As the organic binder, a cellulose-based polymer such as ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose or hydroxyethyl hydroxypropyl cellulose, or a hydrophilic acrylic monomer such as a carboxyl group is copolymerized.

Keen acrylic copolymers, polyvinyl resins, etc. may be used alone or in combination of two or more of these, but are not limited thereto.

This organic vehicle may further contain a solvent. In this case, the organic vehicle may be a solution in which an organic binder is dissolved in a solvent. The organic vehicle may include 5 to 40 (wt%) of an organic binder and 60 to 95 (wt%) of a solvent. As the solvent, an organic solvent having a boiling point of 120° C. or higher may be used. Specifically, carbitol solvents, aliphatic alcohols, ester-based solvents, cellosolve solvents, hydrocarbon solvents, etc. commonly used in electrode production can be used. For example, the solvent is butyl carbitol, butyl carbitol acetate, methyl cellosolve, ethyl cellosolve, butyl cellosolve, aliphatic alcohol, terpineol, ethylene glycol, ethylene glycol mono butyl ether, butyl cellosolve acetate, texanol, or mixtures thereof.

In this embodiment, the electrode paste may further include conventional additives as needed to improve flow characteristics, process characteristics, and stability. The additives may include a dispersing agent, a thixotropic agent, a plasticizer, a viscosity stabilizer, an antifoaming agent, a pigment, a UV stabilizer, an antioxidant, a coupling agent, and the like, alone or in combination of two or more.

solar cell

In this embodiment, the solar cell has at least one of a front electrode and a rear electrode formed by using the electrode paste described above. Since various types of solar cells have already been developed and are being sold in the market, their detailed configuration is omitted here.

1 is a diagram showing a simple configuration of a solar cell.

Referring to FIG. 1 , a solar cell includes an emitter 102 forming a pn junction with a semiconductor substrate 101, a front electrode 230 and a rear electrode 210 respectively connected to the emitter and the substrate.

The semiconductor substrate 101 is a semiconductor containing impurities, and includes impurities to have a polarity opposite to that of the emitter 102 .

The emitter 102 is formed by implanting impurities into the surface of the semiconductor substrate 110, and includes impurities of a different polarity from the semiconductor substrate to form a pn junction between the two.

Here, the electrodes are referred to as the front electrode 230 and the rear electrode 210 according to their positions, but more precisely, they refer to the n-electrode and the p-electrode for collecting holes and holes, respectively. In addition, the n-electrode and the p-electrode may be both disposed on the rear surface or separately disposed on the front and rear surfaces, as illustrated in FIG. 1 .

Here, after forming the emitter 120 on the semiconductor substrate 110 so that the front electrode 230 and the rear electrode 210 form a pn junction, the above-described paste is printed on the top and bottom of the semiconductor substrate 110, respectively. year was formed.

After printing the paste, an electrode may be formed by pre-baking at a low temperature, approximately 200° C. to 400° C., patterning it, and then heating and firing at a temperature of 400° C. to 950° C.

Hereinafter, the above-described embodiments of the present invention will be described in more detail through experimental examples, but these experimental examples are only for the purpose of explanation and should not be construed as limiting the present invention.

experiments

Experimental example One

20wt% lead oxide (PbO) powder, 25wt% bismuth oxide (Bi2O3), 5wt% zinc oxide (ZnO) and 50wt% tellurium oxide (TeO2) powder were dry-dried for 5 hours using an alumina ball mill. After grinding and mixing, it was placed in a 500cc platinum crucible and melted at a temperature of about 1050 for 30 minutes in an elevator type electric furnace (Elevator Type Furnace). The formed melt was maintained at 600 ° C for 10 minutes and then slowly cooled at a rate of 3 ° C per minute to prepare a crystalline mass, which was first pulverized using an alumina ball mill, and then second pulverized and classified using an air jet mill Thus, a crystalline powder having a central particle diameter of 1 μm was prepared.

An organic vehicle was prepared by dissolving 0.5 parts by weight of Dow's trade name EC300 (binder) in 6.5 parts by weight of butyl carbitol (solvent) with respect to 100 parts by weight of the total. After adding 90 parts by weight of Ag powder (conductive powder) and 3 parts by weight of the above-described crystalline powder to the organic vehicle, the mixture was sufficiently stirred for 5 hours using a planetary mixer. After aging for 12 hours, it was mixed and dispersed 4 times using a 3 roll-milling machine. In addition, a paste composition was prepared by filtering and degassing twice using a SUS mesh having a wire diameter of 30 μm and 250 mesh.

Experimental example 2

Crystalline powder was prepared in the same manner as in Example 1 using 15wt% PbO, 15wt% Bi2O3, 5wt% ZnO, 2wt% Li2O, 3wt% Na2O and 60wt% TeO2 powder. A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

Experimental example 3

Crystalline powder was prepared in the same manner as in Example 1 using 10wt% PbO, 15wt% Bi2O3, 5wt% ZnO, 5wt% WO3, 2.5wt% Li2O, 2.5wt% Na2O and 60wt% TeO2 powder. was manufactured. A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

Experimental example 4

A crystalline powder was prepared in the same manner as in Example 1 using 25wt% Bi2O3, 7wt% ZnO, 10wt% WO3, 2wt% Li2O, 2wt% K2O, and 53wt% TeO2 powder. A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

Experimental example 5

Crystalline powder was prepared in the same manner as in Example 1 using 25wt% Bi2O3, 6wt% ZnO, 4wt% WO3, 2.5wt% Na2O, 2.5wt% K2O, and 60wt% TeO2 powder. A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

Experimental example 6

Crystalline powder was prepared in the same manner as in Example 1 using 25wt% of Bi2O3, 5wt% of ZnO, 5wt% of WO3 and 65wt% of TeO2 powder. A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

Experimental example 7

A crystalline powder was prepared in the same manner as in Example 1 using 15wt% of Bi2O3, 5wt% of ZnO, 10wt% of WO3 and 70wt% of TeO2 powder. A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

Experimental example 8

Crystalline powder was prepared in the same manner as in Example 1 using 15wt% of Bi2O3, 10wt% of WO3, 2.5wt% of Li2O, 2.5wt% of K2O, and 70wt% of TeO2 powder. A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

Experimental example 9

Crystalline powder was prepared in the same manner as in Example 1 using 20wt% PbO, 20wt% Bi2O3, 5wt% ZnO, 5wt% Li2O, 3wt% Na2O, 2wt% K2O and 45wt% TeO2 powder. did A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

Experimental example 10

A crystalline powder was prepared in the same manner as in Example 1 using 30wt% Bi2O3, 10wt% ZnO, 15wt% WO3, 5wt% Li2O, 5wt% Na2O, and 35wt% TeO2 powder. A paste composition was prepared in the same manner as in Example 1 using the crystalline powder thus prepared.

And, in order to compare the above experimental examples of the present invention, Comparative Examples 1 to 4 were prepared as follows.

comparative example One

82wt% of PbO, 7wt% of SiO ₂ and 11wt% of B ₂ O ₃ powder were pulverized and mixed in a dry way for 5 hours using an alumina ball mill, and then placed in a 500cc platinum crucible and placed in an elevator type electric furnace (Elevator Type Furnace). ) at a temperature of about 1050 for 30 minutes. The formed melt was quenched and passed through a water-cooled cooling roll made of SUS to make a plate-shaped glass cullet, and then pulverized in the same manner as in Example 1 to prepare a glass frit. A paste composition was prepared in the same manner as in Example 1 using the thus prepared glass frit.

comparative example 2

A glass frit was prepared in the same manner as in Comparative Example 1 using 74wt% of PbO, 9wt% of SiO ₂ , 6wt% of B ₂ O ₃ and 8wt% of ZnO powder. A paste composition was prepared in the same manner as in Example 1 using the thus-prepared grain glass frit.

comparative example 3

A glass frit was prepared in the same manner as in Comparative Example 1 using 70 wt% PbO, 7 wt% Bi ₂ O ₃ , 9 wt% SiO ₂ , 13 wt% ZnO, and 2 wt% Li ₂ O powder. A paste composition was prepared in the same manner as in Example 1 using the thus prepared glass frit.

comparative example 4

A glass frit was prepared in the same manner as in Comparative Example 1 using 62wt% of PbO, 11wt% of Bi ₂ O ₃ , 10wt% of SiO ₂ , 12wt% of ZnO, and 5wt% of WO ₃ powder. A paste composition was prepared in the same manner as in Example 1 using the thus prepared glass frit.

After manufacturing a solar cell under the same conditions in both Experimental Example and Comparative Example using the paste composition prepared as described above, its efficiency and series resistance (Rs) were measured. In manufacturing the solar cell, the paste composition prepared according to the above experimental examples or comparative examples was used for the front electrode, and CPR-707 manufactured by LG was used for the paste composition for the rear electrode.

In addition, the sheet resistance of the semiconductor substrate was 85 ohm (Ω), and Denken's product name DKSCT-100-180 was used as an efficiency measurement equipment. The measurement results are shown in Table 1 below.

efficiency(%) Series Resistance (Rs) Experimental Example 1 17.48 2.99 Experimental Example 2 17.68 2.70 Experimental Example 3 17.71 2.58 Experimental Example 4 17.61 2.72 Experimental Example 5 17.73 2.58 Experimental Example 6 17.15 3.29 Experimental Example 7 17.32 3.14 Experimental Example 8 17.85 2.43 Experimental Example 9 17.57 2.81 Experimental Example 10 17.50 2.83 Comparative Example 1 15.14 5.77 Comparative Example 2 15.21 5.75 Comparative Example 3 15.67 5.08 Comparative Example 4 15.55 5.23

As a result of the experiment, it can be seen that the crystalline powders of the experimental examples according to the present invention have higher efficiency due to lower series resistance than the comparative examples because the fluidity is improved by the thermal characteristics (melting point) of the TeO ₂ chemical bond crystalline. .

In addition, the melting point of the crystalline powders according to Experimental Examples 2 to 5 and 8 to 10 was further reduced and reactivity increased by alkali metals (Li ₂ O, Na ₂ O, K ₂ O). This resulted in lower series resistance and higher efficiency.

Experimental Examples 1 to 10 have excellent results compared to Comparative Examples 1 to 4 even though they are the result of crystallized powders containing no other materials than PbO, Bi ₂ O ₃ , ZnO, WO ₃ , TeO ₂ and alkali metals. Therefore, if a transition metal oxide or the like is further included, an even better effect is expected.

Claims (9)

65 to 93 (wt%) conductive metal powder;
0.5 to 5 (wt%) crystalline powder for solar cell electrodes;
5 to 30 (wt%) of an organic vehicle;
The crystalline powder for the solar cell electrode includes 5 to 35 (wt%) of bismuth oxide (Bi ₂ O ₃ ); 70 to 85 (wt%) of tellurium oxide (TeO ₂ ); 1 to 15 (wt%) of tungsten oxide (WO ₃ ); and 1 to 15 (wt%) of potassium oxide (K ₂ O) and no PbO;
The paste composition for a solar cell electrode, characterized in that the bismuth oxide and the tellurium oxide are crystalline. According to claim 1,
A paste composition for a solar cell electrode wherein the bismuth oxide and the tellurium oxide form a chemical bond. delete delete According to claim 2,
A paste composition for a solar cell electrode in which the chemically bonded crystalline powder containing the bismuth oxide and tellurium oxide is melted at 500 to 900 ° C. delete According to claim 1,
The conductive metal powder includes silver (Ag), gold (Au), copper (Cu), palladium (Pd), platinum (Pt), chromium (Cr), cobalt (Co), tin (Sn), lead (Pb), Zinc (Zn), Iron (Fe), Iridium (Ir), Osmium (Os), Rhodium (Rh), Tungsten (W), Molybdenum (Mo), Nickel (Ni), Indium Tin Oxide (ITO) A paste composition for a solar cell electrode comprising at least one of According to claim 1,
The average particle diameter (D50) of the crystalline powder is 0.1 to 5 (㎛) paste composition for a solar cell electrode. A semiconductor substrate forming a pn junction;
An electrode connected to the semiconductor substrate and made of the paste composition according to any one of claims 1, 2, 5, and 7 to 8,
A solar cell comprising a.

Images