Optical properties and Raman studies of amorphous se-bi thin films

Abstract

Flash evaporated amorphous Se Bi (x = 0, 1, 2, 3, and 4 at. %) thin films of 350 ± 10 thickness have been investigated in the wavelength range of 200nm − 3000nm. It is found that the effect of increasing bismuth content on the as deposited films led to increased absorption coefficient, reflectance, refractive index and extinction coefficient while transmittance and optical band gap energy decreased. The Raman spectra showed peaks at 238.8¬ ,248.3¬ , 249.5¬ , 250.7¬ , 251.9¬ , 488.1 , and 489.3¬ due to selenium rings and chains at various bismuth concentrations.