Effect of annealing time on the optical properties of AZTSe thin films

Ag2ZnSnSe4 (AZTSe) thin films have prepared by thermal evaporation method and annealed at 300 °C for different annealing times (2 h, 4 h and 6 h) in air atmosphere. The annealed films show tetragonal AZTSe structure and the crystallite size decreases with increase in annealing temperature. Atomic force microscope (AFM) images shows voids for 6 h annealed films and particle size increases with annealing time. Diffuse reflection spectroscopy (DRS) spectrum shows good optical absorption in the entire visible range for all the films and the band gap is found in the range of 1.37-1.71 eV.