Effects of biaxial strain and local constant potential on electronic structure of monolayer SnSe

In this work, we use the modified Becke-Johnson exchange potential (mBJ) with the spin-orbit coupling effect (SOC) to study effects of biaxial strain and local constant potential on electronic structure of monolayer SnSe. Our results show the fundamental band gap size can be tuned via biaxial strain. Compressive strain (tensile strain) can narrow (enlarge) band gap and the compressive strain causes the transition from quasi-direct to indirect band gap. Moreover, by adding constant potential (CP) to atomic spheres we explore the effects on electronic and crystal structures. The results demonstrate that positive and negative CPs can narrow and enlarge band gap, respectively. At CP of 0.9 Ry, semiconductor-metal transition appears, and interestingly a new type of nearly linear dispersions occur at band edge. Our work is good for inspiring more experimental work and further theoretical research.

Automated summary

In this study, the electronic structure of monolayer SnSe under biaxial strain and constant potential was investigated using the modified Becke-Johnson exchange potential and spin-orbit coupling effect. The results showed that the band gap size can be tuned via biaxial strain and constant potential, with compressive strain leading to a transition from quasi-direct to indirect band gap. The findings have implications for further experimental and theoretical research in this area.