Method for preparing black silicon material

Abstract

The invention belongs to the field of black silicon material preparation, and particularly relates to a method for preparing a selenium-silicon composite film in a thermal evaporation and magnetron sputtering mode and preparing black silicon in a femtosecond laser etching mode. According to the method, as a silicon film formed on a selenium film in the existing technology in a sputtering mode serves as a protection layer, volatilization of chalcogens in the femtosecond laser etching process is reduced, the doping content is increased, impurities Se introduced by laser pulse irradiation can be prevented from dispersing to the grain boundary, and thus the doping concentration of impurities Se on the surface is guaranteed to improve the absorptivity of black silicon. The absorptivity of black silicon prepared through the method is higher than 95% at the 400-1100 nm band, and the absorptivity of black silicon is higher than 90% at the 1100-2200 nm band. Compared with a black silicon material prepared through a method that only a selenium film is formed in a thermal evaporation mode, but no silicon protection layer is formed for covering, the absorptivity of black silicon prepared through the method is obviously increased at the near-infrared band.

Description

technical field [0001] The invention belongs to the field of black silicon material preparation, and in particular relates to a method for preparing a selenium-silicon composite film by means of thermal evaporation and magnetron sputtering, and using femtosecond laser etching to prepare black silicon. Background technique [0002] Crystalline silicon is rich in resources and has the advantages of easy acquisition, easy purification, high temperature resistance, and easy doping. It plays an important role in the semiconductor industry and has a wide range of applications in the fields of detectors, sensors, and solar cell preparation. However, the inherent defects of crystalline silicon limit its application in optoelectronic devices. Crystalline silicon is an indirect bandgap material with a forbidden band width of 1.124eV at room temperature and a cut-off wavelength of crystalline silicon absorption of 1100nm. When the incident light wavelength is greater than 1100nm, the ...

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Problems solved by technology

However, in the process of femtosecond laser etching, a large number of impurities absorb pulse energy and volatilize, which affects the doping content of black silicon.

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