Effects of external strain on electronic and optical properties of β-SnSe: a first-principle study

Abstract

Strain effects on magnetic and optical properties of β-SnSe have been investigated by the density functional theory (DFT) approach. Under the compressive strain, the band gap of β-SnSe disappears and becomes metal-like system. By comparison, under the tensile strain, the band gap firstly changes from 2.32 to 1.24 eV, and then it rises to 1.92 eV. We further find that the Sn-p and Se-p states at the bottom of conduction band contribute to the variations of the band structures. Moreover, due to the application of the external strain, the absorption strength in visible light might be enhanced.