Compositional and Thickness Effects on the Optical Properties of Zinc– Doped Selenium–Antimony Thin Films

Abstract

Chalcogenide system of antimony (Sb)-selenium (Se)-zinc (Zn) system is a promisingsemiconductor for phase change memory devices due to its thermal stability and low powerconsumption. The study investigated the effect of film thickness and zinc content on the opticalproperties of thermally evaporated Sb10Se90-xZnx (x = 0, 5, 10 & 15 at. %) thin films. It was foundthat transmittance (T~ 85-40%) and optical band gap energy (Eopt ~ 1.60 eV – 1.22 eV) decreasedbut absorption coefficient (α~0.840–2.031  104 cm–1) increased with increase in zinc content.Furthermore, as the film thickness increased from 53  5 nm to 286  10 nm, transmittancedecreased but band gap energy increased due to zinc defects and localized states in the Sb 10Se90-xZnx system.