High Carrier Mobility and Controllable Electronic Property of the h-BN/SnSe<sub>2</sub> Heterostructure
Liang Tong, Chencheng Hu, Mengsi Lou, Zhiyan Feng, Dongbin Wang, Xiaolin Cai, Long Lin
Abstract
Building two-dimensional (2D) vertical van der Waals heterostructures (vdWHs) is one of the effective methods to regulate the properties of single 2D materials. In this paper, we stack the hexagonal boron nitride (h-BN) monolayer (ML) on the SnSe 2 ML to construct the stable h-BN/SnSe 2 vdWH, of which the crystal and electronic structures, together with the optical properties, are also analyzed by the first-principles calculations. The results show that the h-BN/SnSe 2 vdWH belongs to a type-I heterostructure with an indirect bandgap of 1.33 eV, in which the valence band maximum and conduction band minimum are both determined by the component SnSe 2 ML. Interestingly, the h-BN/SnSe 2 vdWH under the tensile strain or electric field undergoes the transitions both from type-I to type-II heterostructure and from the indirect to direct bandgap semiconductor. In addition, the carrier mobility of the h-BN/SnSe 2 heterostructure has a significant enhancement relative to that of the SnSe 2 ML, up to 10 4 cm 2 V –1 s –1 . Meanwhile, the h-BN/SnSe 2 heterostructure presents the superb optical absorption and unique type-II hyperbolic property. Our findings will broaden the potential applications of SnSe 2 ML and provide theoretical guidance for the related experimental studies.