High optical/color contrast of Sb2Te thin film and its structural origin

Abstract

This work has investigated the optical/color contrast of Sb2Te phase change material and its structural volution. It is found that Sb2Te film possesses high optical/color contrast owing to its high discrepancy of refractive index and extinction coefficient between as-deposited and crystalline states. Raman spectra reveal that the enhanced Sb–Te bonds within two-dimensional Sb2Te3 plane is favorable for the high contrast of Sb2Te. The ab initio calculations further reveal that Sb2Te as-deposited phase has a complicated local motif owing to the excess Sb atoms. Moreover, analysis of the electronic structure of Sb2Te shows that the degree of electronic delocalization may in turn result in the large optical/color contrast of Sb2Te film. This work may provide a useful reference for future color display applications.