Study of optical properties of amorphous se70-xte30inx chalcogenide thin films prepared by thermal evaporation technique

Thin films of amorphous Se_70-x Te₃₀In_x (x= 0, 2, 4 and 6) are deposited on glass substrate at room temperature by thermal evaporation technique. Transmittance measurements were used to calculate dissipation factor (tan δ) with the help of refractive index n and the extinction coefficient k using Swanepole's method. The optical band gap E_g is estimated using Tauc's relation and is found to increase with the increasing In content.