Effects of electric field on Schottky barrier in graphene and hexagonal boron phosphide heterostructures

Abstract

Two dimensional graphene-based van der Waals heterostructures have attracted the interest of various researchers due to their unique properties. Based on the contact between metal electrodes and two dimensional materials has a substantial impact on the performance of electronic devices. The interfacial performance and Schottky contact performance with graphene and hexagonal boron phosphide (h-BP) vdW heterostructures are investigated using density functional theory calculations. We investigated eight energy-stable stacking configurations of multilayer graphene and h-BP vdW heterostructures. The different configurations of the h-BP/graphene vdW heterostructures all exhibit n-type Schottky contacts. The band structure of the h-BP in the heterostructures can be modulated under the influence of an external electric field (E field ), thus effectively manipulating the Schottky barrier height (SBH). The n-type SBH increases with the increasing positive E field and eventually the contact transforms into an Ohmic contact, while the Schottky contact transition from n-type to p-type occurs under the negative E field . The data demonstrate that modulating the electronic properties of hexagonal boron phosphide/graphere (h-BP/Gr) vdW heterostructures with E field is a promising approach, which can control the transition from Schottky to Ohmic contacts. The results can provide theoretical support for the design of controlled Schottky nanoelectronic devices. • 2D h-BP/Gr vdW heterostructures possesses a low n-type Schottky barrier height (0.15 eV–0.18 eV). • The transformate heterostructures can be transformed from an n-type Schottky contact to a p-type Schottky contact, then to an Ohmic contact. • The SBH of h-BP/Gr vdW heterostructures can be effectively regulated by an external electric field. • As the number of graphene layers increases the external electric field required for Schottky transition decreases.