A kind of solar cell silicon chip etching water film solution and application thereof

Abstract

The present invention belongs to the field of solar cell technology, and particularly relates to a water film solution for etching a silicon wafer of a solar cell and the use thereof. Provided is a water film solution for etching a silicon wafer of a solar cell. The water film solution is formed by dispersing glucose and a bis(fluorosulfonyl)imide salt into water; and by using the above-mentioned water film solution, a protective layer is formed on the diffusing surface (front side) of the silicon wafer, and the water film solution then enters an etching groove to etch the PN junctions at the back side and edges, such that the acid volatilized from the etching liquid is inhibited from re-dissolving in the water film, thereby reducing the damage caused to PSG on the diffusing surface (front surface) and the PN junctions.

Description

technical field [0001] The invention belongs to the technical field of solar cells, and in particular relates to a water film solution for etching silicon wafers of solar cells and an application thereof. Background technique [0002] The general method of manufacturing silicon solar cells is as follows: first, the P-type or N-type silicon wafer with a clean surface undergoes a texturing process to form a textured structure; secondly, it is diffused on the surface of the silicon wafer to form an N+ or P+ emitter. Etch to remove the diffusion layer on the side and back of the silicon wafer; then form a layer of SiN film with anti-reflection function on the front surface; finally make metal electrodes on the front and back of the silicon wafer, and form a crystalline silicon solar cell through the sintering process. [0003] Among them, before wet etching, it is generally necessary to use a water film protection method. Before the silicon wafer enters the etching tank, a layer...

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Problems solved by technology

But the problem is: when etching or polishing with mixed acid, the high-concentration acid (such as HF, nitric acid, etc.) in the etching tank is easy to volatilize, and the volatilized acid will re-dissolve in the water film as the volatilization increases. Cause gas phase corrosion on the surface of the battery, destroying the PN junction on the surface; secondly, in order to remove the suede on the back of the silicon wafer to form a back polishing structure, a large amount of etching is required (generally refers to when the etching amount on the back of the silicon wafer is greater than or equal to 6 microns ), which further aggravates the corrosion damage to the PN junction, and the pure water film can no longer protect the front PN junction very well.

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