H₂S Concentration Dependence of Properties of Cu₂ZnSnS₄Thin Film Prepared under Nonvacuum Condition

Abstract

Cu2ZnSnS4 (CZTS) thin films were prepared by a sol–gel sulfurization method. Sulfurization was carried out in H2S 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% H2S atmospheres had large grains compared with the film sulfurized in 1% H2S atmosphere. From the X-ray diffraction analysis, the CZTS thin film sulfurized for 1 h in 0.5% H2S atmosphere included a small amount of CuxS as a secondary phase. The films sulfurized for 1 h in 1 and 3% H2S atmospheres were composed of a CZTS phase without CuxS. Owing to the long sulfurization process, the CuxS phase was eliminated and the optical properties of the films were improved. The size of the grains sulfurized in 1% H2S increased with increasing sulfurization time from 2 to 3 h.