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 promising semiconductor for phase change memory devices due to its thermal stability and low power consumption. The study investigated the effect of film thickness and zinc content on the optical properties of thermally evaporated Sb₁₀Se_90-xZn_x (x = 0, 5, 10 & 15 at. %) thin films. It was found that transmittance (T~ 85-40%) and optical band gap energy (E_opt ~ 1.60 eV – 1.22 eV) decreased but 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, transmittance decreased but band gap energy increased due to zinc defects and localized states in the Sb₁₀Se_90-xZn_x system.

Keywords: Selenium, phase change memory, localized states