Optical effects induced by gamma and UV irradiation in chalcogenic glass

The influence of γγ and UV irradiation on the optical properties of thin film chalcogenide glasses Ge15Se82.5Ag2.5Ge15Se82.5Ag2.5 has been studied. An increase in the optical energy gap is observed after γγ-irradiation with an exposure dose higher than 100 kGy and up to 1050 kGy. The results of γγ-irradiation are discussed in terms of the structural aspects of Ge15Se82.5Ag2.5Ge15Se82.5Ag2.5 glass system. Photo-induced changes of the optical properties by UV-irradiation are also analyzed. The observed changes are associated with the interaction of the incident photon and the lone-pairs electrons which affects the band gap of the Ge15Se82.5Ag2.5Ge15Se82.5Ag2.5 system. The changes in band tail width of the localized state after irradiation with γγ or UV are found to have an opposite trend compared with the changes in the optical band gap. The X-ray structural characterization revealed the amorphous nature of the films before and after γγ and UV irradiation.