Dresden 2014 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 36: Posters: Bio/organic Molecules on Surfaces, Graphene, Solid/liquid interfaces, Metal Substrates, Electronic Structure Theory
O 36.41: Poster
Dienstag, 1. April 2014, 18:30–22:00, P1
HRTEM characterization of epitaxially grown graphene nanoribbons — Dennis Laube1, •Jens Baringhaus1, Atasi Chatterjee1, Eberhard Bugiel2, and Christoph Tegenkamp1 — 1Leibniz Universität Hannover, Institut für Festkörperphysik, 30167 Hannover, Germany — 2Leibniz Universität Hannover, Institut für Materialien und Bauelemente der Elektronik, 30167 Hannover, Germany
The fabrication of well-ordered graphene nanostructures is essential for any kind of graphene based device. Since standard lithography methods typically induce a large amount of defects at the edges the so produced nanostructures do not exhibit the theoretically expected transport behavior such as a width dependent bandgap (armchair edges) or ballistic transport (zig-zag edges). We use a three-stepped selective graphitization process on SiC mesa structures to grow graphene nanostructures directly in the desired shape to avoid any damaging post-processing. First, the mesa structure is patterned into the SiC substrate. In the second step, the substrate is heated at temperatures slightly below the graphitization temperature to induce a refacetting process of the mesa edges. In the last step, the sample is heated to 1350 ∘C for the graphitization which starts at the facets due to the much weaker bonding of silicon atoms. The fabrication process is monitored by means of high resolution TEM. Parameters such as the angle of the SiC facets (which predetermines the width of the nanostructure) were deduced. Finally, the graphene grown on the facets is studied with respect to local bonding as well as interface properties.