Impact of the Structural Properties of Graphene on SiC Surfaces on Their Electronic Applications: An Assessment
The structural properties of multilayer graphene, their stacking, and angular arrangement determine the electron dispersion relation around the K-point that is instrumental in the application of graphene-based devices in fast electronics. As revealed by transmission electron microscopy (TEM) studies, the structure on both sides is drastically different in many aspects including the attachment to a substrate, layer stacking, and thickness. The relation between these structural properties and the dispersion relations, including a possibility of its modication in functioning electronic devices is discussed using both tight-binding and density functional theory calculations. The extended defects, which are currently ubiquitous in synthesized graphene layers, are highly detrimental for the mobility of carriers. The inuence of local orientational disorder on the average electron transport properties is therefore discussed. The disorder is also related to the grain boundaries, composed of the chains of extended defects. The low-angle and high-angle boundaries and their relation to basic defects are elucidated using a structural analysis. The principal type of such defects is presented using TEM plan-view observations. The possible relation between various factors inducing defect creation, including a built-in strain and coalescence of the growing nuclei is discussed. Graphene growth on SiC, the creation of various stackings, and related creation of the extended defects is discussed.