title: Charge transfer and electronic doping in nitrogen-doped graphene.
abstract: Understanding the modification of the graphene's electronic structure upon doping is crucial for enlarging its potential applications. We present a study of nitrogen-doped graphene samples on SiC(000) combining angle-resolved photoelectron spectroscopy, scanning tunneling microscopy and spectroscopy and X-ray photoelectron spectroscopy (XPS). The comparison between tunneling and angle-resolved photoelectron spectra reveals the spatial inhomogeneity of the Dirac energy shift and that a phonon correction has to be applied to the tunneling measurements. XPS data demonstrate the dependence of the N 1s binding energy of graphitic nitrogen on the nitrogen concentration. The measure of the Dirac energy for different nitrogen concentrations reveals that the ratio usually computed between the excess charge brought by the dopants and the dopants' concentration depends on the latter. This is supported by a tight-binding model considering different values for the potentials on the nitrogen site and on its first neighbors.
authors.affiliation: CARBON NAnostructures research Group (CARBONNAGe), University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Joucken
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot - Paris 7, Sorbonne Paris Cité, CNRS, UMR 7162 case courrier 7021, 75205 Paris 13, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Tison
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192 Gif sur Yvette Cedex, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Le Fèvre
authors.affiliation: Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192 Gif sur Yvette Cedex, France.|Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, UMR 8502 F-91405 Orsay, France.
authors.forename: Antonio
authors.initials: A
authors.lastname: Tejeda
authors.affiliation: UR1-SOLEIL/Synchrotron SOLEIL, L'Orme des Merisiers, Saint Aubin-BP 48, 91192 Gif sur Yvette Cedex, France.
authors.forename: Amina
authors.initials: A
authors.lastname: Taleb-Ibrahimi
authors.affiliation: The Georgia Institute of Technology, Atlanta, Georgia 30332-0430, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Conrad
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot - Paris 7, Sorbonne Paris Cité, CNRS, UMR 7162 case courrier 7021, 75205 Paris 13, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Repain
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot - Paris 7, Sorbonne Paris Cité, CNRS, UMR 7162 case courrier 7021, 75205 Paris 13, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Chacon
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot - Paris 7, Sorbonne Paris Cité, CNRS, UMR 7162 case courrier 7021, 75205 Paris 13, France.
authors.forename: Amandine
authors.initials: A
authors.lastname: Bellec
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot - Paris 7, Sorbonne Paris Cité, CNRS, UMR 7162 case courrier 7021, 75205 Paris 13, France.
authors.forename: Yann
authors.initials: Y
authors.lastname: Girard
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot - Paris 7, Sorbonne Paris Cité, CNRS, UMR 7162 case courrier 7021, 75205 Paris 13, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Rousset
authors.affiliation: CARBON NAnostructures research Group (CARBONNAGe), University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
authors.forename: Jacques
authors.initials: J
authors.lastname: Ghijsen
authors.affiliation: CARBON NAnostructures research Group (CARBONNAGe), University of Namur, 61 Rue de Bruxelles, 5000 Namur, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Sporken
authors.affiliation: Laboratoire d'Etude des Microstructures, ONERA-CNRS, BP 72, 92322 Châtillon Cedex, France.
authors.forename: Hakim
authors.initials: H
authors.lastname: Amara
authors.affiliation: Laboratoire d'Etude des Microstructures, ONERA-CNRS, BP 72, 92322 Châtillon Cedex, France.
authors.forename: François
authors.initials: F
authors.lastname: Ducastelle
authors.affiliation: Laboratoire Matériaux et Phénomènes Quantiques, UMR 7162, Université Paris Diderot - Paris 7, Sorbonne Paris Cité, CNRS, UMR 7162 case courrier 7021, 75205 Paris 13, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Lagoute