Jing Mi

Enhanced compactness and element distribution uniformity of Cu2ZnSnS4 thin film by increasing precursor S content

Cu2ZnSnS4 thin films were prepared by co-sputtering with Cu (or Cu2S), ZnS and SnS2 targets in this study. S amount in the precursor of Cu2ZnSnS4 thin film was verified by using Cu or Cu2S target. The effect of S amount in the precursor on the microstructure and element distribution of Cu2ZnSnS4 thin film was discussed. It was found that S content is sufficient in the precursor thin film using Cu2S instead of Cu target. The microstructure, composition homogeneity, and secondary phase formation of the Cu2ZnSnS4 thin film are seriously affected by S amount in the precursor thin film. Namely, sufficient S can improve the crystallization and orientation of the precursor thin film and enhance the compactness as well as composition homogeneity of the Cu2ZnSnS4 thin film after sulfurization. Moreover, the secondary phase formation in Cu2ZnSnS4 thin film can be greatly inhibited by increasing S content in the precursor thin film.