Deposition and characterization of Cu2ZnTiS4 thin films bysputtering

Cu2ZnSnS4 (CZTS), whose elements are abundant in nature, is a new type of absorber for thin film solar cells. CZTS is a semiconductor with direct band gap 1.5 eV band gap and p-type electrical conductivity. As an alternative to CZTS thin films in this work, Cu2ZnTiS4 thin films were deposited on glass by reactive sputtering technique. High purity ZnS and Cu and Ti metals were used as targets and H2S was used as reactive gas. Cu2ZnTiS4 thin films were deposited at different temperatures and in different H2S gas flows and then annealed in H2S environment. Morphological, structural and optical properties of Cu2ZnTiS4 thin films were investigated with the help of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and UV-vis data. the agglomeration on the surface increased with increasing substrate temperature. XRD peaks of Cu2ZnTiS4 thin films were found to be compatible with Cu2ZnSnS4 structure. It was also found that the optical bandwidth of Cu2ZnTiS4 films was lower than that of conventional Cu2ZnSnS4 thin films.