Light and Thermal Induced Modification of the Refractive Index in As45S15Se40 Glasses

Abstract

The experimental investigations of the influence of the light irradiation on the optical parameters of amorphous As45S15Se40 thin films prepared by „flash” thermal evaporation was investigated. From the experimental transmission spectra T=f() the value of the refractive index n, and optical band gap Eg was determined. It was established that the light exposure and the heat treatment modify the optical constants of the investigated amorphous films. From the Tauc plot (h)1/2 vs. (h) the optical band gap Eg for amorphous As45S15Se40 thin films is Eg=1.929 eV. For amorphous As45S15Se40 thin films the exposure time decrease the optical band gap Eg and the refractive index n, but the annealing temperature increase these values. The modifications of the optical constants under the light exposure and heat treatment allow using these materials as effective media for registration of the optical and holographic information.