The growth of epitaxial graphene on SiC surfaces was accompanied by the evaporation of Si atoms during the growth process. The continuous loss of Si atoms takes place even after the surface graphene layers were formed. Understanding the atomic transport process involved was critical in establishing a growth mechanism to model and controlled the process. Using density functional theory, the potential energy variation was calculated and the diffusion of Si and C atoms on a single layer of graphene and between graphene sheets was studied. The results showed that Si atoms could move almost freely on graphene and between graphene layers, while C atoms had much larger diffusion barriers. This work provided a detailed description of the energetics of relevant processes in the growth of epitaxial graphene on SiC surfaces.

Diffusion of Si and C Atoms on and between Graphene Layers. Xian, L., Chou, M.Y.: Journal of Physics D: Applied Physics, 2012, 45[45], 455309