Interactions in stanene centred van der Waals trilayers structures of boron-nitride and graphene: effect of mirror symmetry on electronic interactions

Dispersion-corrected density functional theory was used to investigate structures consisting of a stanene layer sandwiched between atomically-thin boron nitride and graphene. The parameters controlling the mirror symmetry, lattice rotation and stacking sequences were varied systematically to generate fifteen candidate trilayers. Two types of structural buckling occur in the heterostructures depending on whether the lattice vectors are co-aligned or non-collinear. The configurations with the honeycomb lattices rotated by π/6 with respect to the stanene generally have lower binding energy. In the majority of the trilayers, the electronic structures deviate strongly from the band structures of the isolated components. The boron nitride/stanene/boron nitride structure is identified as a special case where stanene has an electronic structure that is not perturbed by interlayer interactions and resembles the ideal monolayer form. For the other candidate structures, however, interlayer interactions drive significant modifications in the electronic structure thus indicating emergent features that go beyond the pure van der Waals description. (paper)