title: Growth of semiconducting graphene on palladium.
abstract: We report in situ scanning tunneling microscopy studies of graphene growth on Pd(111) during ethylene deposition at temperatures between 723 and 1023 K. We observe the formation of monolayer graphene islands, 200-2000 A in size, bounded by Pd surface steps. Surprisingly, the topographic image contrast from graphene islands reverses with tunneling bias, suggesting a semiconducting behavior. Scanning tunneling spectroscopy measurements confirm that the graphene islands are semiconducting, with a band gap of 0.3 +/- 0.1 eV. On the basis of density functional theory calculations, we suggest that the opening of a band gap is due to the strong interaction between graphene and the Pd substrate. Our findings point to the possibility of preparing semiconducting graphene layers for future carbon-based nanoelectronic devices via direct deposition onto strongly interacting substrates.
authors.affiliation: Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095, USA.
authors.forename: Soon-Yong
authors.initials: SY
authors.lastname: Kwon
authors.forename: Cristian V
authors.initials: CV
authors.lastname: Ciobanu
authors.forename: Vania
authors.initials: V
authors.lastname: Petrova
authors.forename: Vivek B
authors.initials: VB
authors.lastname: Shenoy
authors.forename: Javier
authors.initials: J
authors.lastname: Bareño
authors.forename: Vincent
authors.initials: V
authors.lastname: Gambin
authors.forename: Ivan
authors.initials: I
authors.lastname: Petrov
authors.forename: Suneel
authors.initials: S
authors.lastname: Kodambaka
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods*; D006108:Graphite / Q000737:chemistry*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods; D010165:Palladium / Q000737:chemistry*; D010316:Particle Size; D012666:Semiconductors; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D010165:Palladium; D006108:Graphite