LOCALIZED STATES MODEL OF GeS2 GLASSES BASED ON ELECTRONIC STATES OF GenSm CLUSTERS CALCULATED BY USING TD-DFT METHOD

Abstract

The first-principles calculation based on time dependent – density functional theory (TDDFT) reveals the origin of the molecular electronic structure and its connection to the localized states of the g-GeS2(Ti). The band gaps computed for GenSm clusters representing the local structures and their correlation to the experimental band gaps of g-GexS100-x together with possible model of band-tail states of g-GeS2 have been discussed. According to the observed results we propose to consider the band-gap states of g-exS100-x as superposition of electronic states of GenSm clusters. The type and concentration of these clusters are compositionally-dependent and influenced by technological conditions used for glass preparation.