Structural and electronic inhomogeneity for graphene grown on the C-face of SiC: Insights from ab initio calculations

The graphitization of the SiC(000 (1) over bar) plane, commonly referred to as the C-face of SiC, takes place through the sublimation and reorganization of surface atoms upon high-temperature annealing. Often, such reorganization gives rise to ordered atomic reconstructions over the ideally flat (000 (1) over bar) plane. In this article, we use the density functional theory to model graphene/SiC(000 (1) over bar) interfaces with an (1 x 1), (2 x 2) and (3 x 3) SiC periodicity. Our results indicate that the interface geometry can be crucial for both the stability and the electronic characteristics of the first graphitic layer, revealing a complex scenario of binding, doping and electronic correlations. We argue that the presence of more than one interface geometryat different areas of the same sample could be a reason for structural inhomogeneity and n- to p-type transitions. (C) 2013 Elsevier B.V. All rights reserved.