2D Hexagonal SnTe monolayer: a quasi direct band gap semiconductor with strain sensitive electronic and optical properties

The stability and electronic and optical properties of two-dimensional (2D) SnTe monolayer has been systematically studied by using first-principles calculations based on density functional theory. Our computations demonstrate that the predicted 2D SnTe monolayer is a stable quasi-direct semiconductor. Also, analysis of its electronic property shows that the ground state of this monolayer is a quasi-direct semiconductor with a band gap of ~2.00. This band gap can be effectively modulated by external strains. Investigation of optical properties shows that monolayer SnTe exhibits significant absorption and reflectivity in the ultraviolet region of the electromagnetic spectrum.