High Carrier Mobility and Controllable Electronic Property of the h-BN/SnSe2 Heterostructure

Building two-dimensional (2D) vertical van der Waalsheterostructures(vdWHs) is one of the effective methods to regulate the propertiesof single 2D materials. In this paper, we stack the hexagonal boronnitride (h-BN) monolayer (ML) on the SnSe2 ML to constructthe stable h-BN/SnSe2 vdWH, of which the crystal and electronicstructures, together with the optical properties, are also analyzedby the first-principles calculations. The results show that the h-BN/SnSe2 vdWH belongs to a type-I heterostructure with an indirectbandgap of 1.33 eV, in which the valence band maximum and conductionband minimum are both determined by the component SnSe2 ML. Interestingly, the h-BN/SnSe2 vdWH under the tensilestrain or electric field undergoes the transitions both from type-Ito type-II heterostructure and from the indirect to direct bandgapsemiconductor. In addition, the carrier mobility of the h-BN/SnSe2 heterostructure has a significant enhancement relative tothat of the SnSe2 ML, up to 10(4) cm(2) V-1 s(-1). Meanwhile, the h-BN/SnSe2 heterostructure presents the superb optical absorption andunique type-II hyperbolic property. Our findings will broaden thepotential applications of SnSe2 ML and provide theoreticalguidance for the related experimental studies.