H₂S Concentration Dependence of Properties of Cu₂ZnSnS₄ Thin Film Prepared under Nonvacuum Condition

Abstract

Cu 2 ZnSnS 4 (CZTS) thin films were prepared by a sol–gel sulfurization method. Sulfurization was carried out in H 2 S of various concentrations and the properties of the films were investigated. The CZTS thin films sulfurized at 500 °C for 1 h in 0.5 and 3% H 2 S atmospheres had large grains compared with the film sulfurized in 1% H 2 S atmosphere. From the X-ray diffraction analysis, the CZTS thin film sulfurized for 1 h in 0.5% H 2 S atmosphere included a small amount of Cu x S as a secondary phase. The films sulfurized for 1 h in 1 and 3% H 2 S atmospheres were composed of a CZTS phase without Cu x S. Owing to the long sulfurization process, the Cu x S phase was eliminated and the optical properties of the films were improved. The size of the grains sulfurized in 1% H 2 S increased with increasing sulfurization time from 2 to 3 h.