First-principles study on strain engineered SnS monolayer

Electronic properties of two-dimensional materials can be tuned with applied strain due to their ultrathin and flexible characteristics. In this work, we have performed first-principles calculations based on Density Functional Theory (DFT) to study the structural and electronic properties of SnS monolayer. SnS is semiconducting in nature with an indirect bandgap of 1.3815 eV. The electronic responses of the SnS monolayer to strain are found to be sensitive and anisotropic because of its puckered structure. It can be turned into a direct bandgap material with the applied strain and the bandgap is tunable within the energy range of 0.8752 eV to 1.7911 eVe It also experiences repeated indirect-direct bandgap transitions due to tensile uniaxial and biaxial strains. The carrier effective masses in the SnS monolayer are less sensitive to uniaxial strain but deviates a lot due to biaxial strain. In the region of direct transition, the electron and hole effective mass of strain engineered SnS monolayer varies from 0.19mo to 0.24m₀ and 0.25mo to 0.36m₀, respectively. These intriguing properties make SnS monolayer a promising two-dimensional material for electronic and optoelectronic devices.