HIT solar cell recycling pretreatment method

Abstract

The invention discloses a HIT solar cell recycling pretreatment method. The method comprises the following steps that back aluminum, an aluminum silicon alloy and a silver electrode of an HIT solar cell are removed with a sodium hydroxide solution, a silicon nitride anti-reflection layer and the silver electrode are removed with hydrofluoric acid, silicic acid is dissolved with sodium hydroxide, air is introduced into the silicic acid to extract the silicic acid, and silica is generated after water loss; and the silver electrode is dissolved with the nitric acid, sodium chloride is added, AgCl+ precipitate is obtained, and silver is obtained after iron powder replacement. By the adoption of the method, the waste HIT solar cell and silver powder which are convenient for subsequent indium recovery are obtained and can be directly used as a raw material in the indium recovery process and a raw material for silver recycling.

Description

technical field [0001] The invention discloses a HIT solar cell recycling pretreatment method, which belongs to the technical field of photovoltaic material recycling. Background technique [0002] The HIT solar cell is based on N-type doped single crystal silicon as the substrate, with a thin layer of amorphous silicon layer on the upper and lower layers, and the top layer is P-type amorphous silicon that forms a PN junction with the N-type substrate for photoelectric conversion. ; There is a bottom-type amorphous silicon with a greater doping concentration than the N-type substrate, and the TCO conductive glass (idealized) that plays the dual role of light transmission and anti-reflection is the upper and lower sides, and is screen-printed on the outermost made of silver electrodes. For discarded HIT solar cells, there is still a lot of recycling value: the rare metal indium present in the TCO conductive glass, the silicon wafers, and the silver in the electrodes. At pre...

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Problems solved by technology

At present, the research on indium recovery at home and abroad is mainly based on the recovery of indium from indium-containing smelting waste residue, smoke dust, and indium-containing waste ITO targets, while the research on the recovery of metal indium from transparent conductive electrodes of crystalline silicon heterojunction solar cells is still limited. very rare

At the same time, directly dissolving and recycling HIT solar cells will lead to many impurities, which will affect the recovery of indium, silver and silicon wafers in HIT solar cells

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