Effect of deposition time on structural and physical properties of Cu_2CdSnS_4 thin films prepared by spray pyrolysis technique: experimental and ab initio study

摘要

Cu_2CdSnS_4 (CCdTS) thin films were synthesized using chemical spray pyrolysis deposition technique. The effect of various deposition times (20, 40, 60 min) on growth of these films was investigated. The as-synthesized Cu_2CdSnS_4 thin films were characterized by X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy, Raman spec-troscopy and Hall Effect measurements. The XRD pattern of Cu_2CdSnS_4 structured in stannite phase with preferential orientations along (112) planes. Raman spectrum revealed very strong peak at about 333 cm~(-1). The films have the direct optical band gaps of 1.39-1.5 eV. The optimum hole mobility was found to be 3.212 × 10~1 cm~2 v~(-1) s~(-1) for the film deposited on 60 min. The electronic structure and optical properties of the stannite structure Cu_2CdSnS_4 were obtained by ab initio calculations using the Korringa-Kohn-Rostoker method combined with the Coherent Potential Approximation (CPA), as well as CPA confirms our results.