Electronic structure of graphene on a reconstructed Pt(100) surface: Hydrogen adsorption, doping, and band gaps
| Autor: | Marco Bianchi, Louis Nilsson, Jill A. Miwa, Philip Hofmann, Liv Hornekær, Richard Balog, Søren Ulstrup |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Materials science
Low-energy electron diffraction Condensed matter physics Band gap Graphene Fermi level Binding energy Nanotechnology 02 engineering and technology 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials law.invention symbols.namesake law 0103 physical sciences symbols Saturation (graph theory) Scanning tunneling microscope 010306 general physics 0210 nano-technology Electronic band structure |
| Zdroj: | Physical Review B Ulstrup, S, Nilsson, L, Miwa, J A, Balog, R, Bianchi, M, Hornekær, L & Hofmann, P 2013, ' Electronic structure of graphene on a reconstructed Pt(100) surface : Hydrogen adsorption, doping, and band gaps ', Physical Review B-Condensed Matter and Materials Physics, vol. 88, no. 12 . https://doi.org/10.1103/PhysRevB.88.125425 |
| ISSN: | 1098-0121 |
| DOI: | 10.1103/PhysRevB.88.125425 |
| Popis: | We probe the structure and electronic band structure of graphene grown on a Pt(100) substrate using scanning tunneling microscopy, low energy electron diffraction, and angle-resolved photoemission spectroscopy. It is found that the graphene layer lacks a well-defined azimuthal orientation with respect to the substrate, causing a circular smearing of the $\ensuremath{\pi}$ band instead of a well-defined Dirac cone near the Fermi level. The graphene is found to be electron doped placing the Dirac point $\ensuremath{\sim}$0.45 eV below the Fermi level, and a gap of $0.15\ifmmode\pm\else\textpm\fi{}0.03$ eV is found at the Dirac point. We dose atomic hydrogen and monitor the coverage on the graphene by analyzing the impurity-induced broadening of the $\ensuremath{\pi}$-band width. Saturation of graphene on Pt(100) with hydrogen does not expand the band gap, but instead hydrogen-mediated broadening and rehybridization of the graphene $s{p}^{2}$ bonds into $s{p}^{3}$ leads to a complete disruption of the graphene $\ensuremath{\pi}$ band, induces a lifting of the Pt(100) reconstruction, and introduces a dispersing Pt state near the Fermi level. Deposition of rubidium on graphene on Pt(100) leads to further electron doping, pushing the Dirac point to a binding energy of $\ensuremath{\sim}$1.35 eV, and increasing the band gap to $0.65\ifmmode\pm\else\textpm\fi{}0.04$ eV. |
| Databáze: | OpenAIRE |
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