Understanding the electronic properties, contact types and optical performances in graphene/InN heterostructure: Role of electric gating

In this work, we construct van der Waals heterostructure based on graphene and InN monolayer and analyze the interface, electronic and optical properties of formed heterostructure using first-principles calculations. Our results prove that the graphene/InN heterostructure is mainly contributed by the weak vdW interactions, which keep it feasible and thus it can be realized easily in recent experiment. Moreover, the intrinsic superior properties of both graphene and InN monolayers are well preserved in the graphene/InN heterostructure. In the graphene/InN heterostructure, InN layer becomes the electron-rich layer, while the graphene layer becomes the hole-rich layer, leading to the transportation of electrons from graphene to InN monolayer. The heterostructure possesses high performance absorption in the visible and near-infrared regions, revealing it is useful for acquiring efficient photocatalysts. The graphene/InN heterostructure at the equilibrium state form the n-type Schottky contact with a small of Schottky barrier height of 0.246 eV. More interestingly, our results predict that external electric fields can tune the graphene/InN heterostructure from n-type to p-type Schottky contact and to n-type Ohmic contact, demonstrating that such heterostructure is appreciate material for highly integrated devices, such as Schottky devices and Schottky diodes.