Optical characterisation of amorphous Se–Te–Sn thin films

Optical characterization of Sn doped Se–Te thin films has been carried out. The characterization has been carried out using transmission spectra in range 500–2500 nm. Bulk samples were prepared using melt quenching technique and thin films were deposited using thermal evaporation. XRD analysis was used to confirm the amorphous nature of prepared samples. Optical constants such as refractive index and extinction coefficient have been determined using Swanepoel’s method. Variation of refractive index with wavelength has been analysed using single effective oscillator model. Optical band gap of the deposited films was calculated using Tauc plots. The observed properties have been explained using the chemical bond approach.