Structural stability and the electrical and optical properties of chalcogen (O, S, and Te) doped tetragonal ZnSe monolayers under high pressure

Abstract

In this study, the structural, electrical and optical properties of pure tetragonal ZnSe monolayers and chalcogen doped ZnSe monolayers have been investigated for changes under pressure based on the first-principles approach. According to the relationship of free energy and the cell volume with pressure, the pressure range in which each phase undergoes a structural phase transition is determined, indicating its structural stability characteristics. In the presence of pressure, the band gap type of each substance changes and eventually undergoes a semiconductor to metallic transition. Under high pressure, the positions of the absorption peaks of all phases are significantly red shifted. The pressure in the stable pressure range leads to the infrared absorption characteristics of the pure ZnSe monolayer, and the S and Te doped ZnSe monolayers exhibit visible absorption characteristics.