Environment protection type silicon solar cell back electric field aluminum pulp and producing method thereof

Abstract

The invention relates to a manufacturing method of environment-friendly aluminum paste for a silicon solar battery back electric field. The aluminum paste comprises the following components and contents (weight percentage): 50 to 80 percent of aluminum conducting powder, 1 to 10 percent of crown glass binding agent, 0.05 to 5 percent of trivalent metal organic compound, 2 to 15 percent of organic resin, 10 to 25 percent of solvent and 2 to 10 percent of additive. The manufacturing method of the environment-friendly aluminum paste comprises the preparation of a glass binding agent, the preparation of an organic carrier, the formulation of aluminum paste stock and the processing technique of paste stock. The paste stock researched by the invention can not increase or generate substances which are harmful to human bodies and pollute the environment during the production and processing; the lead content of the paste stock is less than 100 ppm; and the contents of other hazardous substances such as Hg, Cd and the like can satisfy the environmental protection requirements. The aluminum past is applied to electrodes in the silicon solar battery back electric field; and the aluminum past has strong adhesion, good ohmic contact, and high conversion efficiency of a battery through the quick heat treatment in a continuous tunnel furnace.

Description

technical field [0001] The invention relates to an aluminum electrode paste used in the back electric field of a silicon solar cell. After the slurry passes through the production process, a p+ diffusion layer (aluminum back field) will be formed on the back of the silicon wafer to replace the expensive deposition process. Through screen printing, the slurry is evenly attached to the surface of the silicon wafer, and through drying, rapid heat treatment in a tunnel furnace, etc., a uniform aluminum-silicon alloy and an excellent aluminum conductive layer are formed on the backside of the silicon wafer, reducing the size of the semiconductor material. The Schottky barrier between the metal and aluminum forms a good ohmic contact, thereby obtaining a higher photoelectric conversion efficiency. Background technique [0002] In silicon solar cell technology, electrode fabrication is a very important link. Considering the semiconducting silicon material used in solar cells, its...

AI Technical Summary

Problems solved by technology

However, the lead content in the slurry is very high, and its use has caused very large pollution to the environment

However, lead-free glass is generally inferior to lead glass in terms of high-temperature fluidity and wettability between glass and substrate. Therefore, it is a difficult problem to find a lead-free glass frit suitable for silicon solar cells.