Tunable band alignment engineering in two-dimensional Janus SnSSe/phosphorene van der Waals heterostructures

Abstract

The band alignment affects the electronic properties and possible applications of van der Waals heterostructures (vdWHs). Here, we theoretically build two-dimensional (2D) Janus SnSSe/phosphorene vdWHs and explore the influences of external factors on the electronic properties of the vdWHs. The results identify that different interface patterns can lead to type III and type II vdWHs. Within a certain range, the weakened interlayer coupling or in-plane tensile strain can induce Se-interface vdWHs to change from intrinsic type II to type III, while S-interface vdWHs are robust. In addition, the positive electric field can adjust the vdWHs to exhibit type II, type III or type I characteristics, while the reverse electric field can only expand the tunneling window of type III vdWHs. This work suggests that interface-modified Janus SnSSe/phosphorene vdWHs possess potential applications in optoelectronic and tunneling FETs.

Keywords

• vdWHs
• Interface effect
• Band alignment