▎ 摘　　要

The structural stability and electronic properties of monolayer and bilayer graphene with SnS hybrid heterostructures are studied by using the first-principle methods. The intrinsic electronic properties of SnS and graphene are preserved, and p-type Schottky contacts with the significantly small barrier height are formed in the van der Waals (vdW) heterostructures. In the graphene/SnS (G/S) heterostructure, the p-type Schottky contacts can be changed to Ohmic contacts by decreasing the interlayer distance, and it is also turned to n-type Schottky contacts by applying external electric field. However, the Schottky barrier of graphene/SnS/graphene (G/S/G) heterostructure is insensitive to the external electric field. Moreover, in the SnS/graphene/graphene (S/G/G) heterostructure, the external electric field can easily induce the transition from p-type to n-type Schottky contacts, then to Ohmic contacts. These studies provide a promising route to design new graphene-based vdW heterostructures and explore its potential applications in electronic and optoelectronic devices. (C) 2016 Elsevier Ltd. All rights reserved.