title: Tunable doping of graphene by using physisorbed self-assembled networks.
abstract: One current key challenge in graphene research is to tune its charge carrier concentration, i.e., p- and n-type doping of graphene. An attractive approach in this respect is offered by controlled doping via well-ordered self-assembled networks physisorbed on the graphene surface. We report on tunable n-type doping of graphene using self-assembled networks of alkyl-amines that have varying chain lengths. The doping magnitude is modulated by controlling the density of the strong n-type doping amine groups on the surface. As revealed by scanning tunneling and atomic force microscopy, this density is governed by the length of the alkyl chain which acts as a spacer within the self-assembled network. The modulation of the doping magnitude depending on the chain length was demonstrated using Raman spectroscopy and electrical measurements on graphene field effect devices. This supramolecular functionalization approach offers new possibilities for controlling the properties of graphene and other two-dimensional materials at the nanoscale.
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be.
authors.forename: Roald
authors.initials: R
authors.lastname: Phillipson
authors.affiliation: KU Leuven, Department of Metallurgy and Materials Engineering, Kasteelpark Arenberg 44, B-3001 Leuven, Belgium and imec, Kapeldreef 75, B-3001 Leuven, Belgium. Stefan.DeGendt@imec.be.
authors.forename: César J
authors.initials: CJ
authors.lastname: Lockhart de la Rosa
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be.
authors.forename: Joan
authors.initials: J
authors.lastname: Teyssandier
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be.
authors.forename: Peter
authors.initials: P
authors.lastname: Walke
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be.
authors.forename: Deepali
authors.initials: D
authors.lastname: Waghray
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Fujita
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be.
authors.forename: Jinne
authors.initials: J
authors.lastname: Adisoejoso
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be.
authors.forename: Kunal S
authors.initials: KS
authors.lastname: Mali
authors.affiliation: imec, Kapeldreef 75, B-3001 Leuven, Belgium. Stefan.DeGendt@imec.be.
authors.forename: Inge
authors.initials: I
authors.lastname: Asselberghs
authors.affiliation: imec, Kapeldreef 75, B-3001 Leuven, Belgium. Stefan.DeGendt@imec.be.
authors.forename: Cedric
authors.initials: C
authors.lastname: Huyghebaert
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be and RIES, Hokkaido University, Sapporo, 001-0020, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Uji-I
authors.affiliation: imec, Kapeldreef 75, B-3001 Leuven, Belgium. Stefan.DeGendt@imec.be and KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Design and Synthesis, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
authors.forename: Stefan
authors.initials: S
authors.lastname: De Gendt
authors.affiliation: KU Leuven-University of Leuven, Department of Chemistry, Division of Molecular Imaging and Photonics, Celestijnenlaan 200F, B-3001 Leuven, Belgium. steven.defeyter@kuleuven.be.
authors.forename: Steven
authors.identifier: http://orcid.org/0000-0002-0909-9292
authors.initials: S
authors.lastname: De Feyter