Optical Parameters of Varies Thickness of Bismuth (Iii) Iodide Thin Films for Photovoltaic and Nonlinear Applications

We report in varies thickness of BiI3 thin films by thermal evaporation techniques onto glass substrate. The films were strongly oriented along the (113) plane. The structural parameters of these films (crystallite size and lattice strain) were determined using (XRD) pattern. The thicknesses and refractive indices of the films were considered using Swanepoels method. The band gap was determined in terms of T and R spectrum in the UV-region of the absorption. The possible optical transitions of all films are found to be allowed direct transition with energy gap fluctuate bout 1.96 ± 2% eV. Dielectric constant, volume-energy-loss function (VELF) and surface-energy-loss function (SELF) for as deposited films were discussed in terms of film thickness rising. The change in optical parameters have been interpreted in terms of the change in microstructure parameters. BiI3 is recommended for photovoltaics and nonlinear optics because of its higher absorption coefficient, dielectric constant, and fair band gap