Cleaning treatment method for n-type crystalline silicon substrate of solar cell

Abstract

The invention discloses a cleaning treatment method of an N-type crystalline silicon substrate of a solar cell. The method comprises the following steps of washing a textured N-type crystalline silicon substrate with deionized water, then impregnating the N-type crystalline silicon substrate in a mixed solution of concentrated sulfuric acid and hydrogen peroxide, and then washing the substrate with deionized water after completion; then soaking the substrate in a mixed solution containing 2% of hydrogen chloride and 3% of hydrofluoric acid for 2-3 minutes, and then washing the substrate with deionized water until the substrate is clean; then impregnating the substrate in a mixed solution of hydrogen chloride, hydrogen peroxide and water in a ratio of 1:1:6 to be washed for 10-15 minutes, then washing the substrate with deionized water, and then drying the substrate surface for later use; then etching the dried substrate, and then washing the substrate with deionized water, wherein the temperature of the mixed solution of hydrogen chloride, hydrogen peroxide and water is 60-80 DEG C. By adopting the method, the cleanliness of the substrate surface can be improved and the substrate surface is flat and smooth, thus improving the open-circuit voltage, short-circuit current and filling factors of the prepared solar cell and improving the photoelectric conversion property of the cell.

Description

technical field [0001] The invention relates to a cleaning treatment method for an N-type crystalline silicon substrate of a solar cell, and is particularly suitable for the manufacture of devices such as thin-film silicon / crystalline silicon heterojunction solar cells and full-back electrode solar cells. Background technique [0002] At present, the preparation of a typical crystalline silicon solar cell often includes many steps. Generally speaking, high-quality texture preparation and post-cleaning treatment of crystalline silicon substrates are the key first steps for the entire device to achieve high efficiency. Contains pollutants to implement perfect treatment. [0003] For traditional general high-temperature diffusion junction solar cells, the surface cleaning work after texturing only includes two steps of reaction neutralization and surface oxide film removal, specifically using diluted hydrochloric acid (HCL) solution to neutralize and remove texturing. The res...

AI Technical Summary

Problems solved by technology

In short, if the amorphous silicon film is grown directly on the surface of the textured surface that has only been cleaned by RCA, the surface passivation will deteriorate sharply due to the uneven thickness and penetration of the film at different pyramid structures, which will lead to the loss of charge carriers. The surface recombination rate is very high, which makes the open circuit voltage and short circuit current of the device significantly lower

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