<i>Ab Initio</i>Study of Graphene on SiC
<i>Ab Initio</i>Study of Graphene on SiC
Employing density-functional calculations we study single and double graphene layers on Si- and C-terminated 1x1-6H-SiC surfaces. We show that, in contrast with earlier assumptions, the first carbon layer is covalently bonded to the substrate and cannot be responsible for the graphene-type electronic spectrum observed experimentally. The characteristic spectrum of freestanding …