Raman spectroscopic analysis of the Ge-As-S chalcogenide glass-forming system

The network-level structure of the GexAsyS100 − x − y glass family has been systematically investigated using Raman spectroscopy to probe the supported normal modes. More than 150 samples were melted in the ternary composition space, providing a detailed measure of the glass-forming region of the system. A Raman spectrum normalization is proposed which permits semi-quantitative evaluation of the glass structure across the composition space of interest. This normalization is employed to compare the network structures evidenced in the chalcogen-rich and -poor regions, as well as the so-called “molecular” region. Application to the in-situ study of structural changes during heat treatment is also demonstrated.