Parts | Days | Selection | Search | Downloads | Help
O: Fachverband Oberflächenphysik
O 60: Poster Session III (Methods: Atomic and electronic structure; Methods: electronic structure theory; Methods: Molecular simulations and statistical mechanics; Methods: Sanning probe techniques; Methods: other (experimental); Methods: other (theory) )
O 60.23: Poster
Wednesday, March 24, 2010, 17:45–20:30, Poster B2
Electronic characterisation of thin metallic films using Kelvin Probe Force Microscopy and 4-Point-Probe — •Oliver Ochedowski, Benedict Kleine Bußmann, Florian Meinerzhagen, and Marika Schleberger — Universität Duisburg-Essen, Lotharstrasse 1, 47057 Duisburg
We are investigating the electronic structure of thin metallic films, especially graphene on insulating substrates like siliconoxide. To achieve this, we are combining atomic force microscopy with Kelvin probe technology under UHV conditions and ex situ to map the surface contact potential of these films. This method, first utilized by M. Nonnenbacher, uses the measured force between between the tip and the sample as the control variable [1]: An ac voltage Umod between the tip and sample is modulated on a dc part UBias until the frequency shift due to electrostatic forces is minimized. As a result the difference in contact potentials can be mapped. We also measure the electrical surface resistance directly by using a four-point-probe mounted on a small micromanipulator. We present first test measurements under ambient conditions.
[1]M.Nonnenmacher, M.P. O Boyle, and H.K.Wickramasinghe Appl. Phys.Lett. 58 (25),2921-2923 (1991)