A cleaning method of solar polycrystalline black silicon wafer

Abstract

The invention relates to the field of solar polycrystalline black silicon wafers, and discloses a cleaning method of a solar polycrystalline black silicon wafer. The cleaning method comprises primarywater washing, alkali washing, primary rinsing, mixed acid washing and secondary rinsing, and is suitable for cleaning black silicon wafers whose surfaces are oxidized or contaminated by a wet methodafter being stored or transported for a long time. This cleaning method can ensure that the reflectance of black silicon wafer changes less than 2% before and after cleaning, and can obtain higher short-circuit current. Cleaned silicon wafer surface cleanliness is improved, which is conducive to the subsequent diffusion, coating and other processes. At the same time, the alkaline washing step of the cleaning method can modify the surface of black silicon wafer, thereby obtaining higher open circuit voltage and filling factor, and obtaining a battery piece with higher conversion efficiency.

Description

technical field [0001] The invention relates to the field of solar polycrystalline black silicon wafers, in particular to a cleaning method for solar polycrystalline black silicon wafers. Background technique [0002] Polycrystalline black silicon wafers have relatively low reflectivity and will be the mainstream of polycrystalline solar cells in the future. However, expensive dry process equipment and wet processes with environmental protection pressure make some enterprises have to hold back from the preparation technology of black silicon. Because the efficiency of traditional additive diamond wire is low, replacing the original silicon wafer with textured black silicon wafer is an effective way to improve the conversion efficiency of polycrystalline cells. [0003] At present, the preparation methods of black silicon mainly include reactive ion etching method and metal-assisted chemical solution etching method. No matter which kind of black silicon wafers are purchased b...

AI Technical Summary

Problems solved by technology

Although this cleaning method can remove the metal impurities on the surface of the black silicon wafer, it cannot remove the damage to the suede surface of the black silicon wafer after being placed or transported, and the conversion efficiency of the cleaned black silicon wafer is not significantly improved.