Coupling effects of strain on structural transformation and bandgap engineering in SnS monolayer

Abstract

The anisotropy strain effects on black phosphorus and the IV–VI monolayer analogues have been widely investigated due to their potential applications in solar energy conversion and opto-electronics. Although the coupling effects of strain on structural and electronic properties might be important in flexible monolayer materials they were neglected in most cases. In this paper, we investigated the strain effect on the properties of SnS via strain induced potential energy surface and band profiles. Our first-principles calculations predict different types of low-dimensional phases under ununiformed biaxial strain of 19.09 N m⁻¹, with either strain induced semiconductor–metal transitions, indirect–direct bandgap transitions or negative Poisson's ratio. Our calculations suggest a new method to illuminate the strain effect beyond the axis direction, demonstrating that the coupling of strain effect plays an important role in the search for new properties for flexible materials and cannot be neglected.