Relative stability of 6H-SiC(0001) surface terminations and formation of graphene overlayers by Si evaporation
Preprint, 2010

We present density functional theory (DFT) calculations for 6H-SiC{0001} surfaces with different surface stackings, terminations and reconstructions. We compare the relative stability of different (0001) and different (000-1) surfaces in terms of their surface free energies. Removing surface and subsurface Si atoms, we simulate the formation of graphene and graphene-like overlayers by Si evaporation. We find that overlayers with a different nature of bonding are preferred at the two non-equivalent surface orientations. At (0001), a chemically bonded, highly strained and buckled film is predicted. At (000-1), a van der Waals (vdW) bonded overlayer is preferred. We quantify the vdW binding and show that it can have a doping effect on electron behavior in the overlayer.


Jochen Rohrer

Chalmers, Applied Physics, Electronics Material and Systems

Per Hyldgaard

Chalmers, Applied Physics, Electronics Material and Systems

Areas of Advance

Nanoscience and Nanotechnology


Materials Science

Subject Categories

Other Engineering and Technologies not elsewhere specified

Condensed Matter Physics

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Innovation and entrepreneurship

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