Production process of silicon wafter for solar cell with waste IC chips

Abstract

The production process of silicon chip for solar cell with waste integrated circuit chips includes the following steps: treating waste integrated circuit chips with HCl and H2SO4 to eliminate Mg, Al, Mn, Zn, Cr, Fe, Ni, Sn, Pb and other metals with activity higher than hydrogen; treating with HNO3 to eliminate Cu, Hg, Ag and other transition metals; treating with mixed acid of HF and HNO3 to eliminate metal silicide, silicon oxide and silicon nitride; single-side thinning and double-side thinning to eliminate active area and silicon chip with original resistivity; cleaning, classifying, detecting and grading to obtain silicon chip for solar cell. The process can obtain silicon chip with less impurity and intact crystal structure for producing solar device with high photoelectronic conversion efficiency.

Description

Technical field

[0001] The invention relates to a manufacturing method for producing silicon wafers for solar cells by using waste silicon wafers of integrated circuits. Background technique

[0002] There are generally two manufacturing methods for silicon wafers used in solar cells. One is the method of casting polycrystalline silicon. This method is simple in process and low in production cost. It can be directly cut into square ingots, which can be easily cut into solar cells. Square silicon wafers, but the silicon wafers produced by this method have polycrystalline structure, many defects, high impurity content, and low photoelectric conversion efficiency of the produced solar cells. Another method is the Czochralski method to produce silicon single crystals. The crystal structure of silicon wafers produced by this method is more complete than that of cast polycrystalline silicon wafers, and the impurity content is lower than that of cast polycrystalline silicon wafers. Sola...