Sliver electrode slurry for back electric field of silicon solar cell and preparation method thereof

Abstract

The invention discloses sliver electrode slurry for a back electric field of a silicon solar cell and a preparation method thereof, and the silver electrode slurry for the back electric field of the silicon solar cell comprises the following components by weight percent: 60-70% of spherical silver powder, 0-5% of flaky silver powder, 2-6% of glass powder with a high-temperature softening point, 1-3% of glass powder with a low-temperature softening point and 20-30% of organic bonding agent. The particle size of the spherical silver powder is 0.5-2.5 mu m, and the tap density is above 4.5g/ml; the particle size of the flaky silver powder is below 5 mu m, and the tap density is above 4.0g/ml; and the glass powder with the high-temperature softening point is a PbO3-B2O3-SiO2-ZnO glass system, and the glass powder with the low-temperature softening point is a Bi2O3-B2O3-SiO2 glass system. The slurry is applied to a sliver electrode of the back electric field of the silicon solar cell; furthermore, after fast high-temperature sintering by a chained belt furnace, the adhesive capability is strong, the soldering resistance is good and the photoelectric conversion efficiency of a product is high.

Description

technical field [0001] The invention relates to a silver electrode paste for a back electric field of a silicon solar cell and a preparation method thereof, belonging to the technical field of electronic materials. Background technique [0002] With the rapid development of modern industry, on the one hand, the demand for energy is increased, causing an energy crisis; on the other hand, a large amount of carbon dioxide gas is released in the use of conventional energy, leading to a global "greenhouse effect". As the most ideal renewable energy, solar energy has the characteristics of "inexhaustible and inexhaustible", and the use of solar energy to generate electricity has the advantages of environmental protection, low cost, and high efficiency, and there is no need to consider its safety issues. In recent years, domestic silicon solar cells have developed rapidly, and the production capacity of my country alone in 2010 has exceeded 5GW. Therefore, the amount of solar paste...

AI Technical Summary

Problems solved by technology

[0003] At present, the glass binder used in the silver electrode or silver-aluminum electrode paste for back electric field produced by paste companies at home and abroad is basically a glass with a single low softening point. This glass has a low melting point and flows when sintered at high temperature. It has good wettability with the surface of the silicon wafer and has a lot of penetration into the interior of the silicon wafer. Although good adhesion can be obtained, it may cause the contact between the metal silver powder and the surface of the silicon wafer to change from surface contact to point contact, which seriously affects Photoelectric conversion efficiency

On the other hand, due to more glass phase penetration, the glass phase change on the surface of the silver electrode may be less, which makes the solder resistance of the silver electrode worse.

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