▎ 摘　　要

Reducing the Schottky barrier to improve the electrical transport behavior of heterostructure remains a significant challenge in field-effect transistor. To address this issue, the electronic structures of a novel C6BN/graphene heterostructure under different interlayer spacings and external electric fields are investigated by the firstprinciples calculations. It is found that the monolayer C6BN and graphene can form a stable van der Waals heterostructure. The Schottky barrier height and contact types of the C6BN/graphene heterostructure can be efficiently modulated by varying interlayer spacing and applying electric field. Especially, the band alignment is more sensitive to the external electric field than the interlayer spacing. When the electric field varies from -1.0 to 0.8 V center dot angstrom- 1, the Schottky barrier height apparently changes about 0.1 to 0.2 eV with a 0.1 V center dot angstrom- 1 increase of the external electric field. In addition, the calculated work function show that the heterostructure contact has zero van der Waals tunneling potential barrier, hence when tuned into Ohmic regime, the contact is promising in achieving highly-efficient charge injection. Lastly, the plane-averaged charge density differences reveal that the interfacial charge transfer leads to a transformation in Fermi energy level, thus determining the height and type of Schottky barrier in the C6BN/graphene heterostructure. This work will provide promising approaches for the future design and development of C6BN/graphene-based field-effect transistors.