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Related papers: Graphene on metal surface: gap opening and n-dopin…

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Sufficiently large depletion region for photocarrier generation and separation is a key factor for two-dimensional material optoelectronic devices, but few device configurations has been explored for a deterministic control of a space…

When a gap of tunable size opens at the conic band intersections of graphene, the Berry phase does not vanish abruptly, but progressively decreases as the gap increases. The phase depends on the reciprocal-space path radius, i.e., for a…

Mesoscale and Nanoscale Physics · Physics 2015-11-05 Andrea Urru , Giulio Cocco , Vincenzo Fiorentini

We study the formation of epitaxial graphene on Ru(0001) using fast x-ray photoelectron spectroscopy during the growth process. The assignment of different C 1s and Ru 3d core level components and their evolution during the growth process…

The adhesion of graphene on slightly lattice-mismatched surfaces, for instance of hexagonal boron nitride (hBN) or Ir(111), gives rise to a complex landscape of sublattice symmetry-breaking potentials for the Dirac fermions. Whereas a gap…

Materials Science · Physics 2015-06-03 Carmine Ortix , Liping Yang , Jeroen van den Brink

To understand the band bending caused by metal contacts, we study the potential and charge density induced in graphene in response to contact with a metal strip. We find that the screening is weak by comparison with a normal metal as a…

Materials Science · Physics 2015-05-14 P. A. Khomyakov , A. A. Starikov , G. Brocks , P. J. Kelly

Doped graphene sheets are pseudochiral two-dimensional Fermi liquids with abnormal electron-electron interaction physics. We address graphene's Fermi liquid properties quantitatively using a microscopic random-phase-approximation theory and…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Marco Polini , Reza Asgari , Yafis Barlas , T. Pereg-Barnea , A. H. MacDonald

The effect of grain boundaries and wrinkles on the electrical properties of polycrystalline graphene is pronounced. Here we investigate the stitching between grains of polycrystalline graphene, specifically, overlapping of layers at the…

Materials Science · Physics 2014-06-09 Rahul Rao , Neal Pierce , Avetik R. Harutyunyan

We report on spectroscopy results from the mid- to far-infrared on wafer-scale graphene, grown either epitaxially on silicon carbide, or by chemical vapor deposition. The free carrier absorption (Drude peak) is simultaneously obtained with…

Mesoscale and Nanoscale Physics · Physics 2011-11-17 Hugen Yan , Fengnian Xia , Wenjuan Zhu , Marcus Freitag , Christos Dimitrakopoulos , Ageeth A. Bol , George Tulevski , Phaedon Avouris

An energy gap can be opened in the electronic spectrum of graphene by lifting its sublattice symmetry. In bilayers, it is possible to open gaps as large as 0.2 eV. However, these gaps rarely lead to a highly insulating state expected for…

The recent discovery of methods to isolate graphene, a one-atom-thick layer of crystalline carbon, has raised the possibility of a new class of nano-electronics devices based on the extraordinary electrical transport and unusual physical…

Mesoscale and Nanoscale Physics · Physics 2008-10-02 Xu Du , Ivan Skachko , Anthony Barker , Eva Y. Andrei

When combined with graphene, hexagonal boron nitride (h-BN) is an ideal substrate and gate dielectric with which to build metalh-BN|graphene field-effect devices. We use first-principles density functional theory (DFT) calculations for…

Materials Science · Physics 2011-11-11 Menno Bokdam , Petr A. Khomyakov , Geert Brocks , Zhicheng Zhong , Paul J. Kelly

Gap opening in graphene is usually discussed in terms of a semiconducting-like spectrum, where the appearance of a finite gap at the Dirac point is accompanied by a finite mass for the fermions. In this Letter we propose a gap scenario from…

Mesoscale and Nanoscale Physics · Physics 2008-10-03 L. Benfatto , E. Cappelluti

The interaction between a graphene layer and a hexagonal Boron Nitride (hBN) substrate induces lateral displacements and strains in the graphene layer. The displacements lead to the appearance of commensurate regions and the existence of an…

Mesoscale and Nanoscale Physics · Physics 2014-09-05 Pablo San-Jose , Ángel Gutiérrez , Mauricio Sturla , Francisco Guinea

High quality graphene nanoribbons (GNRs) grown by on-surface synthesis strategies with atomic precision can be controllably doped by inserting heteroatoms or chemical groups in the molecular precursors. Here, we study the electronic…

Using highly controlled coverages of graphene on SiC(0001), we have studied the structure of the first graphene layer that grows on the SiC interface. This layer, known as the buffer layer, is semiconducting. Using x-ray reflectivity and…

Materials Science · Physics 2017-11-22 M. Conrad , J. Rault , Y. Utsumi , Y. Garreau , A. Vlad , A. Coati , J. -P. Rueff , P. F. Miceli , E. H. Conrad

Graphene's linear dispersion relation and the attendant implications for bipolar electronics applications have motivated a range of experimental efforts aimed at producing p-n junctions in graphene. Here we report electrical transport…

The formation of graphene on the SiC(000-1) surface (the C-face of the {0001} surfaces) has been studied, utilizing both disilane and neon environments. In both cases, the interface between the graphene and the SiC is found to be different…

Mesoscale and Nanoscale Physics · Physics 2015-06-05 Guowei He , N. Srivastava , R. M. Feenstra

The dependence of the electric resistance R of nanoperforated graphene samples on the position of the Fermi level, which is varied by the gate voltage Vg, has been studied. Nanoperforation has been performed by irradiating graphene samples…

Graphene holds great promise for post-silicon electronics, however, it faces two main challenges: opening up a bandgap and finding a suitable substrate material. In principle, graphene on hexagonal boron nitride (hBN) substrate provides…

Mesoscale and Nanoscale Physics · Physics 2011-10-27 Neerav Kharche , Saroj K. Nayak

The 8-Pmmn borophene, a boron analogue of graphene, hosts tilted and anisotropic massless Dirac fermion quasiparticles owing to the presence of the distorted graphene-like sublattice. First-principles calculations show that the stacked…