Tailoring of optical properties of Se80Te20-xInx films by annealing process.

Bulk chalcogenide glass materials of Se80Te20-xInx (x = 0, 3, 6, 9 and 11) were prepared via the melting-quenching technique. Se80Te20-xInx thin films were evaporated thermally on glass substrates. The results of this study revealed that In doping and annealing time resulted in significant tailoring of some physical properties of Se80Te20-xInx thin films. The annealing process changes the amorphous nature of Se80Te20-xInx thin films to a crystal one. As both In content and annealing time increase, crystallite size decreases and internal lattice strain increases for all samples except those with x = 11. Refractive indices for Se80Te20-xInx thin films were fitted according to the main parameters of the single-oscillator model. It was also discovered that Se80Te20-xInx thin films have a high absorption of high-energy photons. The increasing annealing time improves the refractive index. The bandgap got smaller when the annealing time was increased. [ABSTRACT FROM AUTHOR]