Raman Spectra of As2S3 in Bulk Glass and Amorphous Film Forms

Abstract

Structural changes induced by light and heat treatment in vacuum deposited amorphous chalcogenide films prepared by thermal evaporation methods with different rates have been investigated using Raman scattering. The changes in the Raman spectra of thermally evaporated amorphous As2S3 films after light treatment are interpreted in terms of rearrangement of bonding configurations of molecular species that exist just after depo sition. As the evaporation temperature or deposition rate is increased, irradiation with band-gap light and even more annealing of the films induces arsenic-enrichment and the formation of micro crystallites. The reversible photo-induced changes in annealed films involve negligible small change in bonding statistics. Discernable change occurs in the medium-range order.