Glass powder for solar back-silver electrode and preparation method of glass powder

Abstract

The invention relates to glass powder for a solar back-silver electrode in the field of solar cells. The glass powder comprises the following components in parts by mass: 58 parts of Bi2O3, 10-30 parts of B2O3, 5-15 parts of SiO2, 3-10 parts of ZnO, 5-10 parts of BaO2, 0.5-5 parts of BeO, 0.5-5 parts of MgO and 0.5-2 parts of MoO2, wherein a colored glaze powder binding phase has the softening point of 550-630 DEG C, the density of 2-3g/cm<3>, and the expansion coefficient of (38-50)*10<-7>/DEG C. The expansion coefficient, softening point and density of the glass powder are matched with those of a cell silicon wafer and an aluminum-back surface field, so that the adhesion of the glass powder to the silicon wafer and the aluminum-back surface field after sintering can be obviously improved, the welding property of silver paste and the matching property with aluminum paste can be improved, and the printing quantity can be reduced. The glass powder disclosed by the invention is moderate in expansion coefficient and softening point; in the sintering process of configured silver paste, with the increase of the temperature, the glass powder begins to be softened and melt, and silver powder begins to be melt; in the cooling process, the glass powder is shrunk to ensure that a back-surface silver electrode is densified, the excellent anti-aging property of the silver electrode is ensured, and the reliability of components is improved.

Description

technical field [0001] The invention relates to an electronic paste for a crystalline silicon solar cell, in particular to a glass powder for a back silver electrode of a solar cell, and also relates to a preparation method of the glass powder for a back silver electrode of a solar cell. Background technique [0002] my country's photovoltaic power generation industry started in the 1970s and has developed rapidly in recent years. In 2010, my country's solar cell output reached 8GW, accounting for 50% of the world's total solar cell output, and China is the world's largest producer of solar cells. However, the key equipment, raw materials and components of my country's solar cell production line basically rely on imports. Crystalline silicon solar cells occupy a dominant position in the field of solar cells due to their high photoelectric conversion efficiency, the material itself has no impact on the environment, the materials are easy to industrialize and the material per...

AI Technical Summary

Problems solved by technology

In the sintering process of the back silver electrode, the glass density is not suitable, which will cause the glass to float up, which will deteriorate the solderability of the battery and affect the performance of the battery sheet

If the softening point of the glass is too low, the glass will soften prematurely and react with the silicon cells during the sintering process. to make Excessive recombination centers will lead to a decrease in electrical performance, and may also cause "inset" at the contact point between the back silver electrode line and the aluminum paste, and poor solderability at the place where the "inset" is formed

If the softening point is too high, the slurry is not fully "cooked", and the electrical properties and adhesion will be affected