LAUSR

Abstract Here we present a comprehensive study on the electronic and optical properties of Ga2SSe monolayer under a biaxial strain using the density functional theory (DFT). We identified that Ga2SSe monolayer is an indirect semiconductor with an energy band gap of 2.04 eV at the equilibrium state. The energy band gap tends to decrease slowly when the large biaxial strains applied. It is of interest that the compression strain leads to an indirect–direct band gap transition at the strain of 2%. In addition, we demonstrate that the absorption begins in the visible region. While the absorption edge remains visible region under the effect of compression strain, the tensile strain leads to shifting the absorption edge to the near infrared region. Overall, the maximum peaks are positioned in the ultraviolet region. Hence, it can be said that Ga2SSe can be used in the ultraviolet detectors, or in the photoelectric devices. We have confidence in that the control of the optical and electronic properties of Ga2SSe monolayer by biaxial strain engineering can be beneficial in its application in optoelectronic and nanoelectronic devices.