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.

Författare

Jochen Rohrer

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Per Hyldgaard

Chalmers, Mikroteknologi och nanovetenskap (MC2), Elektronikmaterial och system

Styrkeområden

Nanovetenskap och nanoteknik

Produktion

Materialvetenskap

Ämneskategorier

Övrig annan teknik

Den kondenserade materiens fysik

Drivkrafter

Innovation och entreprenörskap