Structure of As-Se and As-P-Se glasses studied by Raman spectroscopy

The structure and the optical properties of bulk and thin films of the amorphous AsxSe100-x (x = 0, 28.6, 33, 40, 50 and 57.1) and AsxP4-xSe3 (x = 0, 1, 2, 3 and 4) chalcogenide systems have been studied in this work. Bulk samples we prepared from high purity elements, and thin films (d approximate to 1000 nm) were deposited by the vacuum thermal evaporation Both types of AsxSe100-x samples show long-term chemical stability. In the case of AsxP4-xSe3, especially the film chemical stability of as-prepared samples generally decreases with increasing phosphorus content. Structure of bulk an film samples has been determined by Raman spectroscopy as a function of exposure to light. It was found that exposure to halogen lamp light causes structural changes in short range order mainly in phosphorus containing films such that their structure approaches the structure of bulk samples of the same composition. In addition, the medium and/or Ion range structures are also affected by light, which then further contribute to the photo-induced changes in the optics properties of as-evaporated films. (C) 2003 Elsevier B.V. All rights reserved.