Tunable electronic properties and Schottky barrier in a graphene/WSe2 heterostructure under out-of-plane strain and an electric field.

Abstract

Tuning the electrical transport behavior and reducing the Schottky barrier height of nanoelectronic devices remain a great challenge. To solve this issue, the electronic properties and Schottky barrier of the graphene/WSe2 heterostructure are investigated by the first-principles method under out-of-plane strain and an electric field. Our results show that the WSe2 monolayer and graphene could form a stable van der Waals heterostructure and the intrinsic electronic properties are well preserved. Furthermore, a transformation of a Schottky contact from the n-type to p-type occurs at d = 3.87 Å and E = +0.06 V Å-1. In addition, an ohmic contact is formed with E = -0.50, ±0.60 V Å-1. Lastly, the effective masses of electrons and holes are calculated to be 0.057m0 and -0.055m0 at the equilibrium state, respectively, indicating that the heterostructure has a high carrier mobility. Our research will provide promising approaches for the future design and development of graphene/WSe2 nano-field effect transistors.