Wet etching method in silicon solar cell production

Abstract

The invention discloses a wet etching method in silicon solar cell production. The method comprises specific steps as follows. (1) A water film protective step. Deionized water is sprayed through a water spray system on a diffusion surface of a silicon wafer so as to form a water film protective layer, and the water film protective layer exists continuously until the silicon wafer completes an etching step. (2) A phosphorus silicon glass removing step. The silicon wafer after the water film protective step enters a hydrofluoric acid groove, the hydrofluoric acid groove is internally provided with hydrofluoric acid solution, the hydrofluoric acid solution is conveyed by a liquid rolling wheel to the back of the silicon wafer, and the phosphorus silicon glass at an edge and surface of the silicon wafer is removed, but the water film protective layer and a right side of the phosphorus silicon glass layer are not affected. (3) The etching step. The silicon wafer after the phosphorus silicon glass removing step enters an etching groove to etch a back and an edge of a PN junction; and the silicon wafer in the etching groove floats on etching solution for etching. According to the invention, the square resistance rise after the etching can be stably controlled, the effective area of the PN junction is increased, and the conversion efficiency of the battery plate improve.

Description

technical field [0001] The invention relates to a method for producing a silicon solar cell, in particular to a wet etching method in the production of a silicon solar cell. Background technique [0002] At present, in the production of silicon solar cells, there are mainly three wet etching methods used: the first method is to increase the surface tension of the solution by adding concentrated sulfuric acid to the etching tank to prevent the liquid from spreading to the upper surface and causing damage. In over-etching, the silicon wafer is etched in a floating manner in the etching tank. However, this method has high requirements on the precision of the equipment and the stability of the ventilation, and the silicon wafer etched by this method has etching lines, which will reduce the effective light-receiving area of ​​the cell, resulting in a decrease in the efficiency of the cell. The second method is to remove the phosphosilicate glass on both sides of the silicon wafe...

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Problems solved by technology

This method is easy to cause the edge of the silicon wafer to be unable to absorb the liquid due to the way of carrying the liquid with the liquid roller

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