Proposal of graphene band-gap enhancement via heterostructure of graphene with boron nitride in vertical stacking scheme.

Since the discovery of graphene and other two-dimensional (2D) materials in recent years, heterostructures composed of multilayered 2D materials have attracted immense research interest. This is mainly due to the potential prospects of the heterostructures for basic and applied applications related to the emerging technology of energy-efficient optoelectronic devices. In particular, heterostructures of graphene with 2D materials of similar structure have been proposed to open up the band gap to tune the transport properties of graphene for a variety of technological applications. In this paper, we propose a heterostructure scheme of band-gap engineering and modification of the electronic band structure of graphene via the heterostructure of graphene-boron nitride (GBN) based on first-principles calculations. For a comparative analysis of the properties of the proposed GBN heterostructure, we employ Kohn-Sham density functional theory (DFT) using local density and generalized gradient approximations within Perdew-Burke-Ernzehof parameterization. To account for weak interlayer van der Waals interactions, we employ the semi-empirical dispersion-corrected DFT scheme of Grimme, called the DFT-D2 approximation. In the vertical stacking arrangement of boron-nitride-doped graphene with hexagonal boron nitride, we predict a band-gap opening of 1.12 eV which, to our knowledge, is the largest value attained for this kind of system. The impact of interlayer spacing on the band-gap opening arising from the interlayer coupling effect is also analyzed. The band-gap enhancement supports the widely proposed promise of GBN heterostructure in design of high-performance optoelectronic devices such as field-effect transistors for potential applications.