Structural and Optical Studies of In2S3 Thin Films Prepared by Sulferization of Indium Thin Films

The In2S3 thin film is prepared using sulfurate method under a vacuum in a sealed tube of amorphous indium thin film. The later film is pre-deposited on glass with thermal evaporation. We have studied the effect of the temperature and the annealing time on the structural and morphological properties In2S3 thin films. The X-ray diffraction (XRD) shows a good crystallinity found until the annealing temperature reach 280°C for an annealing duration of 30 mn. The scanning electron microscopy (SEM) for the thin films of In2S3 layer, synthesized at different temperature for the annealing time at 15mn, revealed more homogenous layer until 320°C. Optical analyses by absorption spectroscopy show that the energy band gap is a function of the annealing condition. This band gap decreases from 3 eV to 2.6 eV when the annealing temperature is varied from 200°C to 400°C. The obtained In2S3 thin films have a transmittance higher than 65%.