Graphene on the C-terminated SiC (000 ̄1) surface: An ab initio study

International audienceThe atomic and electronic structures of a graphene layer on top of the (2 × 2) reconstruction of the SiC (000 ̄1) surface are studied from ab initio calculations. At variance with the (0001) face, no C bufferlayer is found here. Si adatoms passivate the substrate surface so that the very first C layer presents a linear dispersion characteristic of graphene. A small graphene-substrate interaction remains in agreement with scanning tunneling experiments (F.Hiebel et al. Phys. Rev. B 78 153412 (2008)). The stacking geometry has little influence on the interaction which explains the rotational disorder observed on this face