Cu2ZnSnSe4 thin film solar cells based on a single-step co-evaporation process

Cu2ZnSnSe4 (CZTSe) thin films were deposited on Mo-coated soda–lime glass substrates by single-stage co-evaporation process and the effect of substrate temperature (Tsub) was investigated on the CZTSe thin film growth during the process. The film thickness decreased and the grain size increased with increasing Tsub. The optimum substrate temperature to obtain CZTSe films was found to be 593 K. The film grown at Tsub of 773 K seems to have the phase decomposition into CuxSe and ZnSe, probably because of Sn loss during the process. The best cell fabricated with a CZTSe absorber layer grown at Tsub of 593 K produced 2.88% of conversion efficiency.

► Cu2ZnSnSe4 thin films were grown via a single-step co-evaporation process. ► The effect of substrate temperature was investigated. ► The best solar cell efficiency was 2.88%.