Turning electronic performance and Schottky barrier of graphene/β-Si3N4 (0001) heterostructure by external strain and electric field

Abstract Graphene-based van der Waals (vdW) heterostructures have currently emerged as a promising application in the construction of next-generation electronic and optoelectronic devices. In this present contribution, through the comprehensive first-principle calculations, the electronic characteristics along with the Schottky barrier of graphene/β-silicon nitride(0001) heterostructure are theoretically investigated, considering external strain and electric fields effects. The results concluded that the electronic performance of both the graphene monolayer and β-Si3N4(0001) surface are perfectly maintained in the heterostructure on account of a weak interlayer vdW force between them. Furthermore, the graphene/β-Si3N4 (0001) heterostructure forms a p-type Schottky contact with the SBH of 0.72 eV, which can be modified by using normal strain or perpendicular electric field. It is found that the heterostructure still maintains a p-type Schottky contact when the interlayer spacing from 2.2 A to 4.4 A or when the applied positive electric field is smaller than 0.2 V/A. Most importantly, a transformation from the p-type Schottky contact to Ohmic one is observed in the heterostructure at an electric field of +0.2 V/A. The above results are expected to provide a practical guidance for designing and fabrication of the novel nanoelectronic devices based on graphene/β-Si3N4 vdW heterostructure.