Investigations of RF magnetron sputtered CZTS absorber layer thin films prepared using sulfur induced binary targets without sulfurization

Abstract

Thin films of copper zinc tin sulfide (CZTS), a quaternary semiconductor, was deposited onto well-cleaned soda lime glass substrates using binary sulfur based sputtering targets - copper sulfide (CuS), zinc sulfide (ZnS), and tin sulfide (SnS) by RF Magnetron Sputtering at 300 °C. The stacking order of ZnS/CuS/SnS was used to deposit CZTS thin films. The composition of CZTS thin films were confirmed using X- Ray photoelectron spectroscopy (XPS) and the atomic ratio of the individual elements were quantitatively estimated. X-ray diffraction (XRD) studies were used to understand the CZTS phase formation and the presence of CZTS kesterite phase along <112> direction was detected with the secondary phase of SnS and ZnS. XRD results were validated with Raman results were the presence of CZTS and SnS was corroborated. The optical properties of CZTS thin films were studied using UV–Vis–NIR spectrophotometer where the optical band gap was 1.46 eV and as well as other optical parameters such as interference and optical band gap were ascertained and the results are discussed.