Effect of strains on electronic and optical properties of monolayer SnS: Ab-initio study

In this work, we consider the effect of biaxial epsilon(b) and uniaxial epsilon(ac/zz) strains on electronic properties and optical parameters of monolayer SnS using first-principles calculations. Our calculations show that the monolayer SnS is a semiconductor with an indirect energy gap of 1.63 eV at the equilibrium state. While an effect of tensile strains on bandgap is quite small, the bandgap of monolayer SnS depends strongly on the compressive strains, especially a semiconductor-metal phase transition is occurred due to the uniform compressive biaxial strain at -14% elongation. The optical spectra of the monolayer are high anisotropic, and the absorption coefficient of monolayer SnS tends to increase in the presence of compression strains, while the tensile strains reduce the absorption coefficient of the monolayer SnS. We believe that the phase transition and extraordinary optical properties of the strained monolayer SnS will make it become a useful material in nanoelectromechanical devices and optoelectronic applications.