Structural modification of Ge–Se amorphous films with the addition of Sb

Abstract

Extended X-ray absorption fine-structure (EXAFS) measurements were undertaken to understand the structural modification of amorphous Ge–Se films that occurs with the addition of Sb. We found that Ge–Ge bonds exist along with Ge–Se bonds in Ge-rich Ge–Se films. These bonds disappear with increasing Se content, to the extent that Ge–Se bonds predominate in stoichiometric GeSe2 films. When Ge is replaced by Sb, stable Sb–Se bonds are formed; concurrently, the proportion of Ge–Ge bonds is decreased at the expense of Ge–Se bonds. As a result, GeSbSe glasses have a more stable and stronger network structure.