Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 34: Poster Session I (Graphene; Plasmonics and nanooptics; Coherence and coherent control in nanophotonics and plasmonics)

O 34.15: Poster

Dienstag, 27. März 2012, 18:15–21:45, Poster E

Mechanical exfoliation of graphene in UHV — •Gerrit Begall, Oliver Ochedowski, and Marika Schleberger — Universität Duisburg-Essen, Duisburg, Germany

Our new approach to graphene preparation is mechanical exfoliation under UHV-conditions.

There are typically two ways of preparing graphene on an arbitrary substrate: The mechanical exfoliation (known as the scotch tape method) and the transfer of CVD-graphene (graphene grown on Ni by chemical vapor deposition), using a polymer which is dissolved later.

Both techniques are far from being perfect, regarding cleanliness of the samples and graphene properties. Scotch tapes, used in the mechanical exfoliation method, leave adhesives and there is usually water intercalated inbetween substrate and graphene. The quality of CVD-graphene is inferior to the quality of exfoliated graphene regarding its physical properties, since it consists of small domains. The chemicals involved in the transfer (acetone, PMMA) can be problematic as well.

With the possibilities of an UHV-system, we can prepare atomically clean substrates by sputtering and heating. After this cleaning, a graphenium-flake or a HOPG-crystal is pressed onto the sample. We plan to prepare graphene on Ni, Si (7x7) and SiO₂ surfaces. The results will be compared to classically prepared graphene.