A method for preparing a sulfur-selenium antimony thin film based on liquid-gas cooperative post-processing and application thereof in solar cells

Abstract

This invention belongs to the field of solar cell technology and relates to a method for preparing antimony sulfide selenide thin films based on liquid-gas synergistic post-treatment and its application in solar cells. The method utilizes gaseous substances generated by the melting and in-situ pyrolysis of a modifier to act on the antimony sulfide selenide thin film. Specifically, it includes the following steps: spin-coating a modifier post-treatment liquid onto the surface of the antimony sulfide selenide thin film, followed by heat treatment. During heating, as the temperature rises, the components of the treatment liquid first melt into a liquid state, promoting atomic mass transfer within the film and inducing grain growth; as the temperature further increases, the treatment liquid undergoes pyrolysis, generating gaseous substances until complete evaporation. These gaseous decomposition products can regulate the local vapor pressure of selenium and sulfur, inhibiting the escape of selenium and sulfur elements, exerting post-sulfidation and post-selenization effects, thereby optimizing the crystallization kinetics of the thin film. This method can reform grain growth, make the surface smoother and flatter, regulate the thin film composition to approach stoichiometry, passivate deep defects, improve the back interface quality of the device, alleviate the gradient distribution of the valence band position in the thin film, optimize band matching, and enhance carrier transport dynamics. This liquid-gas synergistic effect significantly improves the overall quality of the film, ultimately enhancing its photoelectric properties. This invention is the first to employ a liquid-gas synergistic approach to treat the surface of antimony sulfoselenide films, providing a new avenue for subsequent optimization of these films.

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