Effect of Tin Composition on Cu<sub>2</sub>ZnSnS<sub>4</sub> Photovoltaic Absorbers

Abstract

Cu2ZnSnS4 (CZTS) thin films are prepared by sulfurizing the precursors deposited by vacuum evaporation methods. The samples sulfurized at 500°C for 3h shows the strong (112) diffraction peak at 28.45˚, suggesting the successful synthesis of CZTS thin films. The X-ray diffraction shows that CZTS thin film prepared in Sn-poor condition have the best crystallinity. The Sn-dependent crystallite size was calculated to be 19.53-21.03 nm. In addition, we found that the optical band gap with various Sn contents can be modulated at 1.48-1.85 eV