Epitaxial graphene on SiC(000(1)over-bar): Stacking order and interfacial structure

The fundamental structural properties of multilayer epitaxial graphene (MEG) on C-face SiC(000 (1) over bar) were revealed in a straightforward manner using cross-sectional transmission electron microscopy (TEM) and scanning TEM (STEM). The AB-stacking and the azimuthal rotational disorder of the graphene layers were directly identified by selected area electron diffraction and high-resolution TEM. The directly interpretable STEM revealed that the interlayer spacing between the first graphene layer and the top SiC bilayer is substantially larger than that of the bulk graphite. Such a large interlayer spacing combined with the regional partially decomposed top bilayers of the SiC substrate provides a plausible explanation to the weak bonding between the MEG film and the SiC(000 (1) over bar) substrate. (C) 2012 American Institute of Physics. [doi:10.1063/1.3678021]