Regensburg 2010 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 43: Graphene I
O 43.8: Vortrag
Mittwoch, 24. März 2010, 12:15–12:30, H31
Local work function of defective graphene probed by Kelvin Probe Force Microscopy — •Liang Yan1, Sasa Vinaji1, Christian Punckt2, Ilhan Aksay2, Hanna Bukowska3, Marika Schleberger3, Gerd Bacher1, and Wolfgang Mertin1 — 1Werkstoffe der Elektrotechnik & CeNIDE, Universität Duisburg-Essen, Bismarckstr. 81, 47057 Duisburg, Germany — 2Department of Chemical Engineering, Princeton University, Princeton, New Jersey, USA — 3Fakultät für Physik & CeNIDE, Universität Duisburg-Essen, 47057 Duisburg, Germany
Graphene is currently one of the hottest topics in research due to its unique properties. In particular for electronic applications, the influence of defects on its electronic properties such as work function is of great interest since it might be possible to taylor these properties by changing the type and density of defects. In this work we demonstrate local work function measurements on thermally exfoliated graphene on HOPG and on mechanically exfoliated graphene on SrTiO3 and SiO2 using Kelvin Probe Force Microscopy, which allows us to correlate the electronic properties with the topography of the defective areas. We find that in case of thermally exfoliated graphene, where the presence of defects and functional groups leads to wrinkling of the sheets, the work function at defective areas is increased compared to non-defective regions. In mechanically exfoliated graphene, a partial overflipping of the graphene layer is achieved by swift heavy ion bombardment, which results in a pronounced change of the local work function and thus in the electrical properties as compared to the non defective areas.