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First principles calculations of the geometric structure s and electronic properties of van der Waals heterostructure based on graphene, hexagonal boron nitride and molybdenum diselenide

Journal: Diamond & Related Materials
Author:  Khang D. Pham
Link: https://www.sciencedirect.com/science/article/pii/S0925963518303959
Abstract

In this work, by means of density functional theory, we systematically investigate the geometric structure and electronic properties of the vertical heterostructure by stacking graphene on top of single-layered hexagonal boron nitride and molybdenum diselenide (Gr/h-BN/MoSe2). Our results show that the interlayer coupling in the heterostructure is mainly governed by the weak van der Waals interactions. We find that in the heterostructure, a tiny band gap of 82 meV is opened around the Dirac K point of graphene due to sublattice symmetry breaking, and a minigap of 39 meV is opened between the π band of graphene and the vertical orbitals of MoSe2 due to their hybridization. This band gap opening in graphene makes it suitable for application in novel high-performance nanoeclectronic devices. Furthermore, the Gr/h-BN/MoSe2 heterostructure with inserting insulated h-BN layer forms an n-type Schottky contact with a small Schottky barrier height of 0.1 eV. These findings could provide helpful information for designing novel nanoelectronic devices by stacking graphene on top of single-layered h-BN and MoSe2.