Crystallization mechanism and defect passivation of Cu2ZnSn(S,Se)4 thin film solar cells via in situ potassium doping

Alkali metal doping has achieved prominent results in Cu 2 ZnSn(S,Se) 4 (CZTSSe) thin film solar cells. In this paper, in situ K-doped CZTSSe thin film solar cells were prepared by magnetron sputtering with a K-containing CZTS target.