Preservation of the Pt(100) surface reconstruction after growth of a continuous layer of graphene

a r t i c l e i n f o Scanning tunneling microscopy shows that a layer of graphene can be grown on the hex-reconstructed Pt (100) surface and that the reconstruction is preserved after growth. A continuous sheet of graphene can be grown across domain boundaries and step edges without loss of periodicity or change in direction. Density functional theory calculations on a simple model system support the observation that the graphene can have different rotation angles relative to the hex-reconstructed Pt surface. The graphene sheet direction can be changed by incorporating pentagon-heptagon defects giving rise to accommodation of edge disloca-tions. The defect formation energy and the induced buckling of the graphene have been characterized by DFT calculations. Graphene, a single atomic sheet of graphite, exhibits unique electronic , mechanical and thermal properties, which could be utilized in emerging areas such as graphene-based electronic devices [1,2]. Most important for the electronic device fabrication is the high mobility of the charge carriers that behave like massless Dirac fermions [3]. However , the production of high quality, large scale graphene by cost efficient routes needs further improvements [4-8]. The synthesis of graphene is currently pursued along two different, major directions [9,10]. Micromechanical or solvent based exfoliation of graphite (a top-down technique) may lead to isolated platelets of high-quality graphene, but the dimensions are typically limited to tens or hundreds of micrometers. The seminal paper igniting renewed interest in the properties of graphene was based on experiments performed on mechanically exfoliated graphene [11]. Epitaxial growth of graphene (a bottom-up technique) can be achieved along various routes. High temperature treatment of SiC wafers leads to thermal decomposition and the formation of a graphene surface layer [12]. By exposing appropriate metal crystals or metal foils to hydrocarbons at elevated temperature , large-area graphene can be formed by chemical vapour deposition (CVD). Segregation of carbon from the bulk may also play a significant role in the growth or perfection of epitaxial graphene on some metal surfaces. Growth of graphene (and graphite) on Pt single crystal surfaces by CVD and segregation was reported more than 40 years ago [13], and CVD growth has been achieved on many different metals which catalyze dehydrogenation of hydrocarbons [14]. Recently even large scale growth of graphene on foils of Cu, a fairly non-reactive metal for dehydrogena-tion reactions, was reported [7,8]. The quality of the graphene produced on many metals …