title: Electronic structure of epitaxial graphene layers on SiC: effect of the substrate.
abstract: A strong substrate-graphite bond is found in the first all-carbon layer by density functional theory calculations and x-ray diffraction for few graphene layers grown epitaxially on SiC. This first layer is devoid of graphene electronic properties and acts as a buffer layer. The graphene nature of the film is recovered by the second carbon layer grown on both the (0001) and (0001[over]) 4H-SiC surfaces. We also present evidence of a charge transfer that depends on the interface geometry. Hence the graphene is doped and a gap opens at the Dirac point after three Bernal stacked carbon layers are formed.
authors.affiliation: Institut Néel, CNRS-UJF, BP 166, 38042 Grenoble Cedex 9, France.
authors.forename: F
authors.initials: F
authors.lastname: Varchon
authors.forename: R
authors.initials: R
authors.lastname: Feng
authors.forename: J
authors.initials: J
authors.lastname: Hass
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: B Ngoc
authors.initials: BN
authors.lastname: Nguyen
authors.forename: C
authors.initials: C
authors.lastname: Naud
authors.forename: P
authors.initials: P
authors.lastname: Mallet
authors.forename: J-Y
authors.initials: JY
authors.lastname: Veuillen
authors.forename: C
authors.initials: C
authors.lastname: Berger
authors.forename: E H
authors.initials: EH
authors.lastname: Conrad
authors.forename: L
authors.initials: L
authors.lastname: Magaud