ABSTRACT
Amorphous samples of Se80-xTe20Bix (x=0, 3, 9) glasses have been prepared using the melt quenching technique and thin film of the samples have been prepared using vacuum evaporation method. The thin film samples were characterized using XRD. The absorption and transmission spectra have been recorded on UV-Vis spectrophotometer in wavelength range 400-2500 nm and the data is analyzed to obtain refractive index, extinction coefficient, energy band gap etc. It was observed that refractive index increases while band gap decreases on increase of Bi content in Se-Te matrix. The narrowing of band gap may be due to large number of localized states introduced near the band edges due to structural defects
