Effect of selenium partial pressure on the performance of Cu2ZnSn(S, Se)4 solar cells

摘要： Sputtering followed by selenization is one of the most common methods for preparing CZTSSe thin films. However, the influence of selenium partial pressure on the crystallinity of the CZTSSe film has been rarely reported. In this study, CZTSSe thin films were prepared by selenization using quartz tubes of different lengths. The influence of Se saturated vapor pressure and temperature on the structure, composition, optical, and electrical properties of CZTSSe films and solar cells was analyzed and these results were used to optimize the performance of the CZTSSe film. It was found that the maximum partial pressure of selenium was 22,542 Pa when the selenization process was carried out in a quartz tube with a length of 30 cm, which largely improved the structural and electrical properties of CZTSSe. However, quartz tube with an over-short length would bring strong partial pressure during selenization, which resulted in a generation of secondary phases. Finally, CZTSSe thin-film solar cell with a maximum efficiency of 3.27% was obtained at an optimal selenium partial pressure of 22542 Pa.