Synthesis of nitrogen-doped epitaxial graphene via plasma-assisted method: Role of the graphene–substrate interaction

• Published in: Surface science 2016-01, Vol.643, p.214-221
• Main Authors: Orlando, Fabrizio, Lacovig, Paolo, Dalmiglio, Matteo, Baraldi, Alessandro, Larciprete, Rosanna, Lizzit, Silvano
• Format: Article
• Language: English
• Subjects: Annealing; Carbon; Fingerprints; Functionalization; Graphene; Iridium; Networks; Nitrogen atoms; Nitrogen doping; Synthesis; X-rays; XPD; XPS
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2015.06.017

Functionalization of graphene by substitution of carbon with nitrogen atoms is a promising way to tailor its electronic properties, but a good control over the heteroatomic configuration in the graphene network is most often a difficult task. In this paper, the synthesis of N-doped graphene by nitrogen plasma treatment of graphene/Ir(111) is presented. The formation of substitutional, pyrrolic and pyridinic nitrogen is analyzed by means of X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD). The graphene–Ir interaction is suggested to control the variation in the relative concentration of the nitrogen species. Annealing of the sample also leads to modifications of the nitrogen species incorporated in the graphene layer. Furthermore, the connection of the substitutional nitrogen arrangement with its corresponding spectroscopic fingerprint is unequivocally confirmed by XPD measurements, which give also a direct insight on the local geometry of the nitrogen atoms incorporated in the carbon network. [Display omitted] •N-doped graphene was synthesized by nitrogen plasma treatment of GR/Ir(111).•Graphitic, pyrrolic and pyridinic-N species were identified by fast HR-XPS and XPD.•The GR–Ir interaction modulates the relative concentration of the N species.•Graphitic-N concentration increases upon annealing and for decoupled GR.•Graphitic n-doping is about three times larger (modulus) than the pyridinic p-doping.