title: Epitaxial graphene on SiC(0001): functional electrical microscopy studies and effect of atmosphere.
abstract: Surface potential distribution, V(CPD), and evolution of atmospheric adsorbates on few and multiple layers (FLG and MLG) of graphene grown on SiC(0001) substrate have been investigated by electrostatic and Kelvin force microscopy techniques at T = 20-120 °C. The change of the surface potential distribution, ΔV(CPD), between FLG and MLG is shown to be temperature dependent. The enhanced ΔV(CPD) value at 120 °C is associated with desorption of adsorbates at high temperatures and the corresponding change of the carrier balance. The nature of the adsorbates and their evolution with temperature are considered to be related to the process of adsorption and desorption of the atmospheric water on MLG domains. We demonstrate that both the nano- and microscale wettability of the material are strongly dependent on the number of graphene layers.
authors.affiliation: National Physical Laboratory, Teddington TW11 0LW, UK. olga.kazakova@npl.co.uk
authors.forename: O
authors.initials: O
authors.lastname: Kazakova
authors.forename: T L
authors.initials: TL
authors.lastname: Burnett
authors.forename: J
authors.initials: J
authors.lastname: Patten
authors.forename: L
authors.initials: L
authors.lastname: Yang
authors.forename: R
authors.initials: R
authors.lastname: Yakimova
mesh_terms: D001272:Atmosphere / Q000737:chemistry*; D017554:Carbon Compounds, Inorganic / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D008422:Materials Testing; D008854:Microscopy, Electron / Q000379:methods*; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D017655:Silicon Compounds / Q000737:chemistry*; D017155:Wettability
chemical_list: D017554:Carbon Compounds, Inorganic; D017655:Silicon Compounds; D006108:Graphite; C022088:silicon carbide