The barrier–cluster model applied to chalcogenide glasses

The aim of this article is to familiarize the readers with barrier–cluster model of the non-crystalline semiconductors, which is based on the assumption that in non-crystalline semiconductors, there exist micro-regions separated from each other by potential barriers. We suppose that these micro-regions in chalcogenide glasses are created by closed clusters. This model allows explanation not only of a number of important optical and electrical features of chalcogenide glasses, but also the results of X-ray structure measurements and ESR experiments. This concept gives a new look at the density of states within the forbidden band and at the exponential tails of the optical absorption.