title: Evidence of nanocrystalline semiconducting graphene monoxide during thermal reduction of graphene oxide in vacuum.
abstract: As silicon-based electronics are reaching the nanosize limits of the semiconductor roadmap, carbon-based nanoelectronics has become a rapidly growing field, with great interest in tuning the properties of carbon-based materials. Chemical functionalization is a proposed route, but syntheses of graphene oxide (G-O) produce disordered, nonstoichiometric materials with poor electronic properties. We report synthesis of an ordered, stoichiometric, solid-state carbon oxide that has never been observed in nature and coexists with graphene. Formation of this material, graphene monoxide (GMO), is achieved by annealing multilayered G-O. Our results indicate that the resulting thermally reduced G-O (TRG-O) consists of a two-dimensional nanocrystalline phase segregation: unoxidized graphitic regions are separated from highly oxidized regions of GMO. GMO has a quasi-hexagonal unit cell, an unusually high 1:1 O:C ratio, and a calculated direct band gap of ∼0.9 eV.
authors.affiliation: Department of Physics and Laboratory for Surface Studies, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States.
authors.forename: Eric C
authors.initials: EC
authors.lastname: Mattson
authors.forename: Haihui
authors.initials: H
authors.lastname: Pu
authors.forename: Shumao
authors.initials: S
authors.lastname: Cui
authors.forename: Marvin A
authors.initials: MA
authors.lastname: Schofield
authors.forename: Sonny
authors.initials: S
authors.lastname: Rhim
authors.forename: Ganhua
authors.initials: G
authors.lastname: Lu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Nasse
authors.forename: Rodney S
authors.initials: RS
authors.lastname: Ruoff
authors.forename: Michael
authors.initials: M
authors.lastname: Weinert
authors.forename: Marija
authors.initials: M
authors.lastname: Gajdardziska-Josifovska
authors.forename: Junhong
authors.initials: J
authors.lastname: Chen
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Hirschmugl
mesh_terms: D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D006108:Graphite / Q000737:chemistry*; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D010316:Particle Size; D012666:Semiconductors; D013499:Surface Properties; D014618:Vacuum
chemical_list: D046911:Macromolecular Substances; D010087:Oxides; D006108:Graphite