title: Structural and electronic properties of graphene nanoflakes on Au(111) and Ag(111).
abstract: We investigate the electronic properties of graphene nanoflakes on Ag(111) and Au(111) surfaces by means of scanning tunneling microscopy and spectroscopy as well as density functional theory calculations. Quasiparticle interference mapping allows for the clear distinction of substrate-derived contributions in scattering and those originating from graphene nanoflakes. Our analysis shows that the parabolic dispersion of Au(111) and Ag(111) surface states remains unchanged with the band minimum shifted to higher energies for the regions of the metal surface covered by graphene, reflecting a rather weak interaction between graphene and the metal surface. The analysis of graphene-related scattering on single nanoflakes yields a linear dispersion relation E(k), with a slight p-doping for graphene/Au(111) and a larger n-doping for graphene/Ag(111). The obtained experimental data (doping level, band dispersions around EF, and Fermi velocity) are very well reproduced within DFT-D2/D3 approaches, which provide a detailed insight into the site-specific interaction between graphene and the underlying substrate.
authors.affiliation: Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Tesch
authors.affiliation: Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Leicht
authors.affiliation: Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany.
authors.forename: Felix
authors.initials: F
authors.lastname: Blumenschein
authors.affiliation: Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany.
authors.forename: Luca
authors.initials: L
authors.lastname: Gragnaniello
authors.affiliation: Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Fonin
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: Lukas Eugen
authors.initials: LE
authors.lastname: Marsoner Steinkasserer
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Paulus
authors.affiliation: Humboldt-Universität zu Berlin, Institut für Chemie, 10099 Berlin, Germany.
authors.forename: Elena
authors.initials: E
authors.lastname: Voloshina
authors.affiliation: IHP, Im Technologiepark 25, 15236 Frankfurt (Oder), Germany.
authors.forename: Yuriy
authors.initials: Y
authors.lastname: Dedkov