Electroconductive paste for silicon solar cell electrode and preparation method thereof

Abstract

The invention discloses electroconduction slurry for silicon solar cell electrodes and a preparation method thereof. Copper-based metal powder replaces the traditional silver powder as an electric conductor for the electroconduction slurry, so that the preparation cost is reduced greatly; moreover, the problems of oxidation and diffusion of copper in the sintering process are overcome, and the electroconduction slurry can be completely compatible with the existing solar cell technology; the cost of the solar cell for preparing the positive surface electrode by utilizing the electroconduction slurry is reduced greatly, and the electroconduction slurry is more suitable for the need of photovoltaic large-scale application.

Description

technical field [0001] The invention relates to a conductive paste for silicon solar cell electrodes and a preparation method thereof, belonging to the technical field of solar cells. Background technique [0002] At present, screen printing technology is widely used in the field of commercial solar cells, especially the metallization process of silicon solar cells. The process of preparing the front electrode of solar cells by screen printing technology is simple and suitable for large-scale production. At present, silver paste is commonly used in the front screen printing technology of silicon solar cells. Silver paste has excellent performance in electrical properties, solderability, and mechanical adhesion. However, due to the limited reserves of silver on the earth and the huge consumption , causing the price of silver to rise year by year. In current silicon solar cells, the cost of silver paste accounts for a large part of the total cost of the cell. However, the co...

AI Technical Summary

Problems solved by technology

[0003] The resistivity of copper is almost the same as that of silver, but the price is only one percent of silver. It is an excellent electrode material. Due to the high-temperature sintering step in the solar cell process, when copper is directly used as the electrode material of the solar cell, Copper will be oxidized during the sintering process, resulting in an increase in electrode resistivity. In addition, copper is a fast-diffusing atom in silicon. During high-temperature sintering, copper will diffuse into the silicon wafer, resulting in breakdown of the solar cell due to the diffusion junction. and fail

The above two points limit the application of copper materials in conductive paste

[0004] In the prior art, there is a method of coating silver on the outside of copper powder to make a conductive paste for the positive electrode of solar cells. However, due to the agglomeration of silver during high-temperature sintering, part of the copper component is exposed to the outside, resulting in the sintering of this part of copper. Oxidation during the process and diffusion into the silicon wafer at the same time, so this technology has obvious defects