p-Type CuSbS2 thin films by thermal diffusion of copper into Sb2S3

Abstract We report the preparation of copper antimony sulfide (CuSbS 2 ) thin films by heating Sb 2 S 3 /Cu multilayer in vacuum. Sb 2 S 3 thin film was prepared from a chemical bath containing SbCl 3 and Na 2 S 2 O 3 salts at room temperature (27 °C) on well cleaned glass substrates. A copper thin film was deposited on Sb 2 S 3 film by thermal evaporation and Sb 2 S 3 /Cu layers were subjected to annealing at different conditions. Structure, morphology, optical and electrical properties of the thin films formed by varying Cu layer thickness and heating conditions were analyzed using different characterization techniques. XRD analysis showed that the thin films formed at 300 and 380 °C consist of CuSbS 2 with chalcostibite structure. These thin films showed p-type conductivity and the conductivity value increased with increase in copper content. The optical band gap of CuSbS 2 was evaluated as nearly 1.5 eV.