A glass powder for a topcon cell leco front silver paste and a preparation method thereof

Abstract

This invention discloses a glass powder for the LECO front-side silver paste of TOPCON batteries and its preparation method, belonging to the field of solar cell material technology. The glass powder, by molar parts, comprises: PbO 52.00–56.00, B₂O₃ 26.00–30.00, ZnO 10.00–14.00, Ag₂O 1.00–1.80, NdF₃ 1.20–2.00, and Eu₂O₃ 2.00–4.00. This glass powder can achieve good bonding with silver particles and silicon wafers in the LECO front-side silver paste of TOPCON batteries, effectively improving the photoelectric performance and long-term stability of the battery. Combined with specific specifications of silver powder and organic carrier formulations, the overall performance of the front-side silver paste can be further optimized, showing promising application prospects.

Description

Technical Field

[0001] This invention belongs to the field of solar cell material technology, specifically relating to a glass powder for LECO front-side silver paste in TOPCON cells and its preparation method. Background Technology

[0002] TOPCON cells, as a new generation of high-efficiency solar cell technology, have significant advantages in improving photoelectric conversion efficiency. In the manufacturing process of TOPCON cells, the front-side silver paste is one of the key materials, its performance directly affecting the cell's conductivity, photoelectric conversion efficiency, and long-term stability. Glass powder, as an important component of the front-side silver paste, plays a crucial role in the sintering process, such as lowering the sintering temperature of the silver paste and promoting good ohmic contact between the silver particles and the silicon wafer surface.

[0003] LECO process is an advanced high-temperature rapid sintering technology that requires glass powders to possess specific properties, such as a suitable melting temperature window, good wettability, and chemical stability. Traditional glass powders present several problems in LECO process applications. For example, they cannot form a stable and low-resistance contact interface with the silicon wafer surface under the high-temperature and rapid conditions of LECO, leading to increased contact resistance and reduced photoelectric conversion efficiency. Therefore, there is a need for a glass powder suitable for the front-side silver paste in the LECO process of TOPCON cells.

[0004] Patent CN 116986822 A discloses an inorganic glass powder composition, inorganic glass powder, conductive paste, and solar cells and modules, wherein the elemental composition of the inorganic glass powder composition includes Si. a -Bi b -Zn c -W d -M e M is another element, and the composition contains oxides of the aforementioned elements and / or compounds capable of forming oxides of the aforementioned elements.

[0005] Patent CN 109074895 A discloses a front metallization paste for solar cell electrodes, which is prepared from a glass melt containing rare earth metals such as lanthanum and yttrium.

[0006] The aforementioned prior art discloses an inorganic glass powder and a front-side paste. However, on the one hand, the technical effects of the aforementioned patents are not outstanding, especially the photoelectric conversion efficiency is still relatively low. On the other hand, although the aforementioned patents mention the use of rare earth elements, the specific rare earth elements used are different from those used in this invention, and they do not mention that europium and neodymium elements can be preferred to be used in this invention. Summary of the Invention

[0007] Technical issues

[0008] Traditional glass powders used in the LECO process result in increased contact resistance and reduced photoelectric conversion efficiency in the cells. Therefore, there is a need for a glass powder suitable for the front-side silver paste in the TOPCON cell LECO process.

[0009] Technical solution

[0010] To address the aforementioned technical problems, this invention aims to provide a glass powder suitable for the LECO front-side silver paste of TOPCON batteries and its preparation method. By rationally controlling the composition and preparation process of the glass powder, the invention fully leverages the promoting effect of Eu2O3 on the LECO process and the improving effect of NdF3 on battery contact performance, thereby enhancing the photoelectric conversion efficiency and stability of TOPCON batteries. Simultaneously, the invention provides a front-side silver paste formulation and performance testing method based on this glass powder, comprehensively verifying the technical effects of this invention.

[0011] This invention provides a glass powder for the front silver paste of TOPCON batteries (LECO type). The glass powder, in molar parts, comprises: PbO 52.00~56.00, B2O3 26.00~30.00, ZnO 10.00~14.00, Ag2O 1.00~1.80, NdF 3 1.20~2.00, and Eu2O3 2.00~4.00.

[0012] Preferably, the glass powder, in molar parts, has the following composition: PbO 53.50~54.50, B2O3 27.00~28.50, ZnO 11.00~13.00, Ag2O 1.20~1.60, NdF 3 1.40~1.80, and Eu2O 3 3.00~3.50.

[0013] Most preferably, the glass powder has the following composition in molar parts: PbO 53.50, B2O3 27.00, ZnO 13.00, Ag2O 1.20, NdF 3 1.80 and Eu2O 3 3.50.

[0014] This invention also provides a method for preparing the glass powder for the LECO front-side silver paste of the above-mentioned TOPCON battery, comprising the following steps:

[0015] (1) Mixing and grinding: Grind the raw materials for 10-15 minutes to make the raw materials initially mixed evenly; then, use a ball mill to add an appropriate amount of anhydrous ethanol as the grinding medium and put in agate balls. Set the ball mill speed to 300-400 rpm and the ball milling time to 3-5 hours.

[0016] (2) High-temperature melting: The ball-milled raw material is placed in a heating environment and heated to 1000-1200℃ at a heating rate of 5-10℃ / min, and kept at that temperature for 1-2 hours to completely melt the raw material and form a glass melt;

[0017] (3) Water quenching: The glass melt is poured into water for water quenching and cooling to form glass fragments;

[0018] (4) Crushing and sieving: The glass fragments are ball-milled, anhydrous ethanol is added and the ball milling is carried out for 2-3 hours. The glass fragments are crushed until the particle size is uniform, and then sieved to obtain the glass powder for the front silver paste of TOPCON battery LECO.

[0019] Furthermore, the mass ratio of the raw material to ethanol is 1:0.5 - 1:1.

[0020] Furthermore, the mass ratio of the agate ball to the raw material is 3:1 to 5:1.

[0021] Furthermore, the glass powder used in the TOPCON battery LECO front silver paste has a particle size of 1-5μm.

[0022] The application of the glass powder for the front silver paste of TOPCON battery LECO provided by this invention in the field of solar cell material technology.

[0023] The present invention also provides a TOPCON battery LECO front silver paste prepared based on the above-mentioned glass powder, wherein the front silver paste comprises, by mass fraction, 85-90% silver powder, 3-8% glass powder and 7-12% organic carrier.

[0024] Furthermore, the silver powder is spherical, with an average particle size of 0.5-1.5μm, a tap density of ≥5.5g / cm³, and a purity of ≥99.99%.

[0025] Furthermore, the organic carrier consists of 10-15 wt% resin, 80-85% solvent and 2-5% additives.

[0026] Furthermore, ethyl cellulose is selected as the resin.

[0027] Furthermore, terpineol is selected as the solvent.

[0028] Furthermore, the additives include a dispersant and a leveling agent, with a mass ratio of 1-3:1-2; the dispersant is a polyacrylate and the leveling agent is an organosilicon.

[0029] This invention also provides a method for preparing TOPCON battery LECO front-side silver paste based on the above-mentioned glass powder, the preparation method comprising the following steps:

[0030] Weigh out 85-90% silver powder, 3-8% glass powder, and 7-12% organic carrier by mass fraction. Then, pour the glass powder into the organic carrier at a stirring speed of 200-300 rpm and stir for 1-2 hours to ensure full dispersion. Then add the silver powder, increase the stirring speed to 400-500 rpm, and stir for 3-4 hours to obtain the front silver paste.

[0031] The application of the TOPCON battery LECO front-side silver paste provided by this invention in the field of solar cell material technology.

[0032] Beneficial effects

[0033] Overall performance improvement: This invention, through optimized design of component ratios and precise control of the manufacturing process, achieves excellent bonding between glass powder and silver particles and silicon wafers in the TOPCON battery's LECO front-side silver paste, effectively improving the battery's photoelectric performance and long-term stability. Combined with a specific silver powder and organic carrier formulation, the overall performance of the front-side silver paste is further optimized, reducing the resistivity to 1.5 mΩ. With a diameter of less than cm², the fill factor and photoelectric conversion efficiency are increased to over 82% and 24.5% respectively, showing promising application prospects and providing strong technical support for the efficient production of TOPCON batteries. Detailed Implementation

[0034] Example 1

[0035] Glass powder preparation:

[0036] Weigh out 54.00 mol PbO, 28.00 mol B₂O₃, 12.00 mol ZnO, 1.40 mol Ag₂O, 1.60 mol NdF, and 3.00 mol Eu₂O₃. Place these raw materials in an agate mortar and grind manually for 12 minutes. Then transfer to a planetary ball mill, add 0.8 times the mass of the raw materials in anhydrous ethanol and agate balls at a mass ratio of 4:1, and ball mill at 350 rpm for 4 hours. Next, pour the mixture into a platinum crucible and place it in a high-temperature resistance furnace, heating to 1100℃ at a rate of 8℃ / min and holding for 1.5 hours. Afterward, remove the platinum crucible and quench the glass melt in deionized water. Finally, place the cooled glass fragments into a planetary high-energy ball mill, add anhydrous ethanol, and ball mill for 2.5 hours. Use a vibrating sieve to select glass powder with a particle size of 1-5 μm.

[0037] Preparation of front-side silver paste:

[0038] Weigh out 88% silver powder, 5% of the glass powder prepared above, and 7% organic carrier by mass ratio. First, pour the organic carrier into a container, and slowly add the glass powder while stirring at 250 rpm for 1.5 hours; then add the silver powder, increase the stirring speed to 450 rpm, and stir for 3.5 hours to obtain the front silver paste.

[0039] Performance testing:

[0040] The silver paste was screen-printed onto the front of the TOPCON solar cell, and then sintered using the LECO process before performance testing. The test results showed a series resistance of 1.2 mΩ. The fill factor is 83.5% and the photoelectric conversion efficiency is 24.8%.

[0041] Example 2

[0042] Glass powder preparation:

[0043] Weigh out 52.00 mol PbO, 30.00 mol B₂O₃, 10.00 mol ZnO, 1.80 mol Ag₂O, 1.20 mol NdF, and 4.00 mol Eu₂O₃. Place these raw materials in an agate mortar and grind manually for 15 minutes. Then transfer to a planetary ball mill, add 0.6 times the mass of the raw materials in anhydrous ethanol and agate balls at a mass ratio of 3:1, and ball mill at 320 rpm for 5 hours. Next, pour the mixture into a platinum crucible and place it in a high-temperature resistance furnace, heating to 1050℃ at a rate of 6℃ / min and holding for 2 hours. Afterward, remove the platinum crucible and quench the glass melt in deionized water. Finally, place the cooled glass fragments into a planetary high-energy ball mill, add anhydrous ethanol, and ball mill for 3 hours. Use a vibrating sieve to select glass powder with a particle size of 1-5 μm.

[0044] Preparation of front-side silver paste:

[0045] The same method for preparing the front silver paste as in Example 1 was used to prepare the front silver paste.

[0046] Performance testing:

[0047] The performance testing method is the same as in Example 1. After sintering using the LECO process, the series resistance was 1.5 mΩ. cm², fill factor of 82.8%, photoelectric conversion efficiency of 24.5%.

[0048] Example 3

[0049] Glass powder preparation:

[0050] Weigh out 56.00 mol PbO, 26.00 mol B₂O₃, 14.00 mol ZnO, 1.00 mol Ag₂O, 32.00 mol NdF, and 2.00 mol Eu₂O₃. Place these raw materials in an agate mortar and grind manually for 10 minutes. Then transfer to a planetary ball mill, add anhydrous ethanol (1 times the mass of the raw materials) and agate balls at a mass ratio of 5:1, and ball mill at 400 rpm for 3 hours. Next, pour the mixture into a platinum crucible and place it in a high-temperature resistance furnace. Heat to 1200℃ at a rate of 10℃ / min and hold for 1 hour. Afterward, remove the platinum crucible and quench the glass melt in deionized water. Finally, place the cooled glass fragments into a planetary high-energy ball mill, add anhydrous ethanol, and ball mill for 2 hours. Use a vibrating sieve to select glass powder with a particle size of 1-5 μm.

[0051] Preparation of front-side silver paste:

[0052] The same method for preparing the front silver paste as in Example 1 was used to prepare the front silver paste.

[0053] Performance testing:

[0054] Using the same performance testing method as in Example 1, the series resistance was 1.3 mΩ after sintering using the LECO process. cm², fill factor of 83.0%, and photoelectric conversion efficiency of 24.6%.

[0055] Example 4

[0056] Glass powder preparation:

[0057] Weigh out 53.50 mol PbO, 27.00 mol B₂O₃, 13.00 mol ZnO, 1.20 mol Ag₂O, 1.80 mol NdF₃, and 3.50 mol Eu₂O₃. Place the raw materials in an agate mortar and grind manually for 13 minutes. Then transfer to a planetary ball mill, add 0.7 times the mass of the raw materials in anhydrous ethanol and agate balls at a mass ratio of 4:1, and ball mill at 360 rpm for 4 hours. Next, pour the mixture into a platinum crucible and place it in a high-temperature resistance furnace, heating to 1120℃ at a rate of 7℃ / min and holding for 1.5 hours. Afterward, remove the platinum crucible and quench the glass melt in deionized water. Finally, place the cooled glass fragments into a planetary high-energy ball mill, add anhydrous ethanol, and ball mill for 2.5 hours. Use a vibrating sieve to select glass powder with a particle size of 1-5 μm.

[0058] Preparation of front-side silver paste:

[0059] The same method for preparing the front silver paste as in Example 1 was used to prepare the front silver paste.

[0060] Performance testing:

[0061] The performance testing method is the same as in Example 1. After sintering using the LECO process, the series resistance was 1.0 mΩ. The fill factor is 84.2% and the photoelectric conversion efficiency is 25.3%.

[0062] Example 5

[0063] Glass powder preparation:

[0064] Weigh out 54.50 mol PbO, 28.50 mol B₂O₃, 11.00 mol ZnO, 1.60 mol Ag₂O, 1.40 mol NdF, and 3.00 mol Eu₂O₃. Place the raw materials in an agate mortar and grind manually for 14 minutes. Then transfer to a planetary ball mill, add 0.9 times the mass of the raw materials in anhydrous ethanol and agate balls at a mass ratio of 4:1, and ball mill at 340 rpm for 4.5 hours. Next, pour the mixture into a platinum crucible and place it in a high-temperature resistance furnace, heating to 1100℃ at a rate of 8℃ / min and holding for 1.7 hours. Afterward, remove the platinum crucible and quench the glass melt in deionized water. Finally, place the cooled glass fragments into a planetary high-energy ball mill, add anhydrous ethanol, and ball mill for 2.7 hours. Use a vibrating sieve to select glass powder with a particle size of 1-5 μm.

[0065] Preparation of front-side silver paste:

[0066] The same method for preparing the front silver paste as in Example 1 was used to prepare the front silver paste.

[0067] Performance testing:

[0068] The performance testing method is the same as in Example 1. After sintering using the LECO process, the series resistance was 1.1 mΩ. The fill factor is 83.9% and the photoelectric conversion efficiency is 25.1%.

[0069] Example 6

[0070] Glass powder preparation:

[0071] Weigh out 55.00 mol PbO, 27.50 mol B₂O₃, 12.00 mol ZnO, 1.50 mol Ag₂O, 1.50 mol NdF₃, and 2.50 mol Eu₂O₃. Place the raw materials in an agate mortar and grind manually for 12 minutes. Then transfer to a planetary ball mill, add 0.8 times the mass of the raw materials in anhydrous ethanol and agate balls at a mass ratio of 4:1, and ball mill at 350 rpm for 4 hours. Next, pour the mixture into a platinum crucible and place it in a high-temperature resistance furnace, heating to 1150℃ at a rate of 9℃ / min and holding for 1.3 hours. Afterward, remove the platinum crucible and quench the glass melt in deionized water. Finally, place the cooled glass fragments into a planetary high-energy ball mill, add anhydrous ethanol, and ball mill for 2.5 hours. Use a vibrating sieve to select glass powder with a particle size of 1-5 μm.

[0072] Preparation of front-side silver paste:

[0073] The same method for preparing the front silver paste as in Example 1 was used to prepare the front silver paste.

[0074] Performance testing:

[0075] The performance testing method is the same as in Example 1. After sintering using the LECO process, the series resistance was 1.2 mΩ. The fill factor is 83.6% and the photoelectric conversion efficiency is 24.9%.

[0076] Comparative Example 1

[0077] Silver paste was prepared using conventional glass powder (molar ratio of PbO - 60.00, B2O3 - 30.00, ZnO - 10.00, excluding NdF3 and Eu2O3) according to the same method as in Example 1. After sintering using the LECO process, the series resistance was measured to be 1.8 mΩ. The fill factor is 82.0% and the photoelectric conversion efficiency is 24.1%.

[0078] Comparative Example 2

[0079] Using the glass powder formulation of Example 2, Sm2O3 was used to replace Eu2O3 in the same proportion (molar ratio of PbO -52.00, B2O3 -30.00, ZnO -10.00, Ag2O -1.80, NdF3 -1.20, Sm2O3 -4.00). Silver paste was prepared according to the same method as in Example 2, and after sintering using the LECO process, the series resistance was tested to be 1.9 mΩ. The fill factor is 81.89%, and the photoelectric conversion efficiency is 23.8%.

[0080] Comparative Example 3

[0081] Using the glass powder formulation of Example 2, NdF3 was replaced with LaF3 in the same proportion (molar ratio of PbO - 52.00, B2O3 - 30.00, ZnO - 10.00, Ag2O - 1.80, LaF3 - 1.20, Eu2O3 - 4.00). Silver paste was prepared according to the same method as in Example 2, and after sintering using the LECO process, the series resistance was tested to be 1.7 mΩ. The photoelectric conversion efficiency is 24%, with a fill factor of 81.95% and a photoelectric conversion efficiency of 24%.

[0082] Comparative Example 4

[0083] Using the glass powder formulation of Example 2, Nd2O3 was used to replace NdF3 in the same proportion (molar ratio of PbO - 52.00, B2O3 - 30.00, ZnO - 10.00, Ag2O - 1.80, Nd2O3 - 1.20, Eu2O3 - 4.00). Silver paste was prepared according to the same method as in Example 2, and after sintering using the LECO process, the series resistance was tested to be 2.2 mΩ. cm², fill factor of 81.5%, photoelectric conversion efficiency of 23.5%.

[0084] Table 1. Molar ratio of glass powder in the examples and comparative examples

[0085]

[0086] Table 2 Performance test data from the examples and comparative examples

[0087]

[0088] Comparative analysis of the performance test results of the above 6 examples and 4 comparative examples shows that: glass powder formulations without Eu2O3 / NdF3, or those using other rare earth oxides such as Sm2O3 to replace Eu2O3, or those using other fluorides such as LaF3 to replace NdF3, or those using oxide forms of Nd2O3 to replace NdF3, all failed to achieve the same effect as the Eu2O3 / NdF3 combination. This is because Eu2O3 and NdF3 play a crucial role in the LECO process and offer several significant advantages.

[0089] From a thermodynamic perspective, Eu2O3 can lower the crystallization temperature of glass powder and broaden the amorphous stability region of glass. During the high-temperature rapid sintering process of the LECO process, traditional glass powder is prone to structural inhomogeneity due to crystallization, affecting the bonding between silver paste and silicon wafers and battery performance. Eu2O3, by altering the glass network structure, inhibits crystal growth, allowing the glass powder to remain amorphous over a wider temperature range. This ensures uniform melting and spreading during sintering, forming a good interface, reducing contact resistance, and improving carrier transport efficiency.

[0090] From an optical perspective, Eu₂O₃'s unique 4f electronic structure endows it with strong absorption and conversion capabilities for laser light. During the localized laser heating process in the LECO process, Eu₂O₃ can efficiently absorb laser energy and convert it into heat, enabling rapid melting and precise localized sintering of the glass powder. This improves sintering efficiency and precision, reduces laser energy loss, and lowers production costs. Simultaneously, Eu₂O₃ optimizes the optical properties of the glass powder, reduces visible light absorption, increases cell transmittance, and thus enhances photoelectric conversion efficiency.

[0091] In terms of chemical stability, Eu2O3 enhances the chemical inertness of glass powder, inhibiting excessive reaction with silicon wafers at high temperatures. Eu2O3 forms stable chemical bonds in the glass powder, reducing erosion of the silicon wafer surface and protecting the silicon wafer structure. Furthermore, Eu2O3 can form a dense oxide protective film on the silver paste surface, blocking the intrusion of oxygen and impurities, improving the oxidation resistance and corrosion resistance of the silver paste, and extending battery life.

[0092] Furthermore, NdF3 can significantly reduce the surface tension of glass powder, improving its wettability on silicon wafer surfaces. The low surface tension allows the molten glass to spread more easily during sintering, filling the microscopic irregularities and pores on the silicon wafer surface to form a continuous, uniform contact interface. This enhances the adhesion between the silver paste and the silicon wafer, reduces interface voids and defects, lowers contact resistance, and improves the battery's conductivity.

[0093] On the other hand, the fluorides generated during the high-temperature sintering process of NdF3 can effectively etch the oxide layer on the silicon wafer surface. The oxide layer on the silicon wafer surface is one of the main factors hindering good contact between the silver paste and the silicon wafer. The volatile fluorides generated by NdF3 can remove the oxide layer, exposing a fresh silicon surface and creating conditions for direct contact between the silver paste and the silicon wafer. Simultaneously, NdF3 can adjust the viscosity characteristics of the glass powder, allowing it to exhibit suitable flowability at different stages of sintering. In the early stages of sintering, lower viscosity helps the glass powder quickly fill the gaps between the silver powder; in the later stages of sintering, higher viscosity ensures the stability of the electrode structure, thereby optimizing battery contact performance and improving the overall performance and reliability of the battery.

[0094] Therefore, Examples 1-6 all achieved higher photoelectric conversion efficiency and lower series resistance than Comparative Examples 1-4. Among Examples 1-6, the formulation of Example 4 (PbO - 53.50, B2O3 - 27.00, ZnO - 13.00, Ag2O - 1.20, NdF3 - 1.80, Eu2O3 - 3.50) performed best, with the lowest series resistance (1.0 mΩ). The formula has the highest fill factor (84.2%) and a photoelectric conversion efficiency of 25.3%. This is because the formula maintains a moderate PbO content while appropriately increasing the proportion of Eu2O3 to 3.50 mol, which enhances the promoting effect on the LECO process; and increases the proportion of NdF3 to 1.80 mol, which further optimizes the melting characteristics and contact performance of the glass powder.

[0095] In summary, the formulation in Example 4, through the synergistic effect of its components, most effectively reduced the series resistance of the battery, improved the fill factor and photoelectric conversion efficiency, and can be determined as the optimal formulation.

[0096] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A glass powder for the front silver paste of TOPCON batteries (LECO type), characterized in that, The glass powder, in molar parts, comprises: PbO 52.00~56.00, B2O3 26.00~30.00, ZnO 10.00~14.00, Ag2O 1.00~1.80, NdF3 1.20~2.00, and Eu2O3 2.00~4.

00.

2. The glass powder for the TOPCON battery LECO front-side silver paste as described in claim 1, characterized in that, The glass powder, in molar parts, has the following composition: PbO 53.50~54.50, B2O3 27.00~28.50, ZnO 11.00~13.00, Ag2O 1.20~1.60, NdF3 1.40~1.80, and Eu2O3 3.00~3.

50.

3. The glass powder for the TOPCON battery LECO front-side silver paste as described in claim 1, characterized in that, The glass powder, in molar parts, has the following composition: PbO 53.50, B2O3 27.00, ZnO 13.00, Ag2O 1.20, NdF3 1.80 and Eu2O3 3.

50.

4. The method for preparing the glass powder for the TOPCON battery LECO front-side silver paste according to any one of claims 1 to 3, characterized in that, Includes the following steps: (1) Mixing and grinding: Grind the raw materials for 10-15 minutes to make the raw materials initially mixed evenly; then, transfer the raw materials to a ball mill, add anhydrous ethanol as the grinding medium, and put in agate balls. Set the ball mill speed to 300-400 rpm and the ball milling time to 3-5 hours. (2) High-temperature melting: The ball-milled raw material is placed in a heating environment and heated to 1000-1200℃ at a heating rate of 5-10℃ / min, and kept at that temperature for 1-2 hours to completely melt the raw material and form a glass melt; (3) Water quenching: The glass melt is poured into water for water quenching and cooling to form glass fragments; (4) Crushing and sieving: The glass fragments are ball-milled, anhydrous ethanol is added and the ball milling is carried out for 2-3 hours. The glass fragments are crushed until the particle size is uniform, and then sieved to obtain the glass powder for the front silver paste of TOPCON battery LECO.

5. The preparation method according to claim 4, characterized in that, The mass ratio of raw materials to ethanol is 1:0.5 - 1:1; the mass ratio of agate balls to raw materials is 3:1 - 5:

1.

6. The application of the glass powder for the TOPCON battery LECO front-side silver paste as described in any one of claims 1 to 3 in the field of solar cell materials technology.

7. A TOPCON battery LECO front-side silver paste, characterized in that, The front silver paste, by mass fraction, comprises 85-90% silver powder, 3-8% glass powder for the TOPCON battery LECO front silver paste as described in any one of claims 1 to 3, and 7-12% organic carrier; the organic carrier consists of 10-15 wt% resin, 80-85% solvent, and 2-5% additives.

8. The TOPCON battery LECO front-side silver paste according to claim 7, characterized in that, The silver powder is spherical with an average particle size of 0.5-1.5 μm; the resin is ethyl cellulose; the solvent is terpineol; the additives are dispersant and leveling agent, with a mass ratio of 1-3:1-2; the dispersant is a polyacrylate and the leveling agent is an organosilicon.

9. The method for preparing the TOPCON battery LECO front-side silver paste according to claim 7 or 8, characterized in that, The preparation method includes the following steps: Take silver powder, glass powder and organic carrier. Then, at a stirring speed of 200-300 rpm, pour the glass powder into the organic carrier and stir for 1-2 hours to fully disperse it. Then add the silver powder, increase the stirring speed to 400-500 rpm and stir for 3-4 hours to obtain the front silver paste.

10. The application of the TOPCON battery LECO front-side silver paste as described in claim 7 or 8 in the field of solar cell material technology.

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