In2S3 buffer layer prepared by chemical bath deposition

Binary In₂S₃ thin films were prepared by chemical bath deposition (CBD) using an aqueous solution containing low concentration of InCl₃ (0.01 M), thioacetamide (TA) and citric acid as complexing agent. The effect of annealing under sulphur atmosphere on the structural, morphological and optical properties of these films was investigated. X-ray diffraction characterizations reveal that the as-deposited films are amorphous and the formation of β-In₂S₃ phase after annealing under sulphur pressure at temperature 693 K. The EDS analyzes reveal that the films composition dependent on TA concentration in the solution, the nearly stoichiometric compound was obtained with concentrations: 0.01 M InCl₃, 0.2 M TA and 0.1 M citric acid. Optical transmissions show high transmission rate for 0.2 M TA and decrease by increasing TA in solution. The optical band gap values of these films varied between 2.8 and 2.9 eV as function of TA concentration and refraction index is in order of 2.64.