Adhesion and electronic structure of graphene on hexagonal boron nitride substrates

Abstract

We investigate the adsorption of graphene sheets on h-BN substrates by means of first-principles calculations in the framework of adiabatic connection fluctuation-dissipation theory in the random phase approximation. We obtain adhesion energies for different crystallographic stacking configurations and show that the interlayer bonding is due to long-range van der Waals forces. The interplay of elastic and adhesion energies is shown to lead to stacking disorder and moiré structures. Band structure calculations reveal substrate induced mass terms in graphene which change their sign with the stacking configuration. The dispersion, absolute band gaps and the real space shape of the low energy electronic states in the moiré structures are discussed. We find that the absolute band gaps in the moiré structures are at least an order of magnitude smaller than the maximum local values of the mass term. Our results are in agreement with recent STM experiments.

Optical properties of bulk semiconductors and graphene/boron nitride: The Bethe-Salpeter equation with derivative discontinuity-corrected density functional energies

“…57 The ground state electronic properties, including the role of dispersive forces, and the band structure have been studied. 57,58 Below we investigate the optical properties of the graphene/h-BN interface and assess the quality of the GLLBSC for such a two-dimensional structure.…”

“…Recent RPA calculations found this structure and adsorption distance to be the most stable. 58 Figure 4 shows the band structure of graphene/h-BN. For the LDA band structure (dotted lines), a small band gap of 31 meV opens at the K point.…”

Flat bands with Berry curvature in multilayer graphene

“…Hence we obtained the bandstructure in the reduced zone. Although the bandstructure contains Z 2 = 56 2 = 3136 conduction bands per spin and valley, only the lowest conduction band is flat, and is separated from the higher bands by an energy scale of order λ, where the gap may be estimated from the DFT calculations in [28], and is of order 10meV . Meanwhile, the bandgap ∆ between conduction and valence bands can be externally controlled using gates, and may be made as large as desired.…”

Observation of an intrinsic bandgap and Landau level renormalization in graphene/boron-nitride heterostructures

“…The coupling between graphene and h-BN results in a periodic moiré superlattice potential due to a 1.8% lattice mismatch 8 , which gives rise to superlattice minibands and new Dirac points near the edges of the superlattice Brillouin zone [8][9][10][11][12]14 . Furthermore, the local sublattice symmetry of graphene is broken owing to different local potentials produced by boron and nitrogen atoms [17][18][19] (Fig. 1b), inducing a local bandgap 18,19 .…”

“…In particular, graphene/h-BN heterostructures have shown great potentials for band structure engineering of graphene [8][9][10][11][12][13][14][15][16][17][18][19][20] including inducing a bandgap 11,13,[15][16][17][18][19][20] (Fig. 1a), which is of great fundamental [21][22][23][24] and technological 25 interest.…”