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O: Fachverband Oberflächenphysik
O 60: Poster Session IV (Solid/liquid interfaces; Semiconductors; Oxides and insulators; Graphene; Plasmonics and nanooptics; Electronic Structure; Surface chemical reactions; Heterogeneous catalysis)
O 60.45: Poster
Wednesday, March 16, 2011, 17:30–21:00, P4
Mechanically stacked 1 nm thick carbon nanosheets: 2D layered materials with tunable optical, chemical and electrical properties — Christoph Nottbohm1, Andrey Turchanin1, André Beyer1, Rainer Stosch2, •Matthias Büenfeld1, Andreas Winter1, and Armin Gölzhäuser1 — 1Physik supramolekularer Systeme und Oberflächen, Fakultät für Physik, Universität Bielefeld — 2Physikalisch-Technische Bundesanstalt, Braunschweig
Carbon nanosheets are mechanically stable free-standing two-dimensional materials with a thickness of ~1 nm and well defined physical and chemical properties. They are made by radiation induced cross-linking of aromatic self-assembled monolayers. Here we present a route to the scalable fabrication of multilayer nanosheets with tunable electrical, optical and chemical properties. Stacks up to five nanosheets with sizes of ~1 cm2 on oxidized silicon were studied. Their optical characteristics were investigated by optical microscopy, UV/Vis reflection spectroscopy and model calculations. Their chemical composition was studied by X-ray photoelectron spectroscopy. The samples were then annealed in ultra high vacuum at various temperatures up to 1100 K. A subsequent investigation by Raman, X-ray photoelectron and UV/Vis reflection spectroscopy as well as by electrical four-point probe measurements demonstrates that the layered nanosheets transform into nanocrystalline graphene. This structural transformation is accompanied by changes in the optical properties and electrical conductivity and opens up a new path for the fabrication of ultrathin functional conductive coatings.