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O: Fachverband Oberflächenphysik
O 41: Graphene III
O 41.10: Vortrag
Mittwoch, 28. März 2012, 12:45–13:00, MA 041
Interaction of hydrogen with graphene on Silicon carbide: unraveling the interface structure — •Francois C. Bocquet1,2,4, Regis Bisson3, Thierry Angot3, and Jean-Marc Themlin1,2 — 1Aix-Marseille Université, IM2NP, France — 2CNRS, IM2NP (UMR 6242) F-13397 Marseille CEDEX 20, France — 3PIIM, UMR 6633 CNRS-Université de Provence, F-13397 Marseille CEDEX 20, France — 4Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany and JARA Fundamentals of Future Information Technology, 52425 Jülich, Germany
Since the stability of a single graphene layer has been discovered, much effort was devoted to the thermal growth of graphene over SiC. Recently, the reversible adsorption of atomic hydrogen on graphene was shown to induce drastic changes in electronic properties between clean, low [1] and high coverages [2]. Also, at high temperature, hydrogen penetrate beneath the buffer layer resulting in free-standing graphene [3]. We studied the buffer layer forming prior to graphene growth on SiC(0001) as well as a single-layer of free standing graphene obtained by hydrogen intercalation. By a subtle tuning of graphene electronic properties with hydrogen adsorption, High Resolution Electron Energy Loss Spectroscopy (HREELS) is allowed to probe below the graphene sheet. This reveals unambiguously the nature of the covalent bond between SiC and the buffer layer.
References [1] Bostwick, Phys. Rev. Lett., 103 (2009) 056404 [2] Elias, Science, 323 (2009) 610 [3] Riedl, Phys. Rev. Lett., 103 (2009) 246804