2007/04/30 by Gianluca Giovannetti, Petr A. Khomyakov, Geert Brocks +2 · 2 citations
Physics and Astronomy · #cond-mat.mtrl-sci #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.76.073103
published as Phys. Rev B. 76, 073103 (2007) · 5 pages, 4 figures, Phys. Rev. B, in press
arxiv created 2007/07/30 · arxiv updated 2015/05/12
We determine the electronic structure of a graphene sheet on top of a lattice-matched hexagonal boron nitride (h-BN) substrate using ab initio density functional calculations. The most stable configuration has one carbon atom on top of a boron atom, the other centered above a BN ring. The resulting inequivalence of the two carbon sites leads to the opening of a gap of 53 meV at the Dirac points of graphene and to finite masses for the Dirac fermions. Alternative orientations of the graphene sheet on the BN substrate generate similar band gaps and masses. The band gap induced by the BN surface can greatly improve room temperature pinch-off characteristics of graphene-based field effect transistors.