Cleaning process after acid texturing of polycrystalline silicon solar cells

Abstract

The invention discloses a cleaning technology after polycrystalline silicon solar cell silicon wafer acid texturing. A polycrystalline silicon wafer is cleaned through an acid solution containing an oxidizing agent or a base solution containing the oxidizing agent after acid texturing. According to the cleaning technology, the surface structure of the silicon wafer is optimized, residual composition on the surface of the silicon wafer is removed, texturing liquid remaining on the surface of the silicon wafer after the silicon wafer is textured can be cleaned, porous silicon can be removed as well, so that the recombination centers on the surface of the silicon wafer are greatly reduced, the short-circuit current and start voltage are improved, and the effect that the photoelectric conversion efficiency of a solar cell is improved is achieved. After the cleaning technology after polycrystalline silicon solar cell silicon wafer acid texturing is adopted, the porous silicon generated after acid texturing can be removed, pointed structures on the textured face are reduced, the color and the luster of the appearance of the silicon wafer are even, the difference between different crystalline grains is small, and the polycrystallization degree is not enhanced. In addition, the cleaning technology after polycrystalline silicon solar cell silicon wafer acid texturing is simple, easy to operate, compatible with an existing technology and good in repeatability.

Description

technical field [0001] The invention relates to a cleaning process for solar cell silicon wafers, in particular to a cleaning process for polycrystalline silicon solar cell silicon wafers after acid texturing. Background technique [0002] In the manufacturing process of polycrystalline silicon solar cells, the surface texturing of silicon wafers is a key link. The effect of texturing directly affects the conversion efficiency of the final cell. Using the isotropic etching of polysilicon in hydrofluoric acid and nitric acid to texture the surface of the silicon wafer is a very important way to improve the efficiency. However, after the silicon wafer is texturized, a lot of texturing liquid will remain on the surface, and it must be cleaned with alkali to neutralize the acid remaining on the surface after texturing. In addition, after the polycrystalline silicon wafer is textured with an acidic texturing solution, a layer of porous silicon will be formed on the surface of t...

AI Technical Summary

Problems solved by technology

Due to the limitation of equipment in the current industrial production, the traditional alkaline cleaning process is not strong enough, and the surface porous silicon has not been completely removed.

Moreover, the process is particularly difficult to control. If the silicon wafer stays in the alkali bath for a little longer, the surface of the silicon wafer will be polished, and all the processed cells will be degraded.