Dresden 2009 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 28: Electronic Properties I
MM 28.1: Vortrag
Mittwoch, 25. März 2009, 10:15–10:30, IFW D
The Tuneable Electron Mobility in Charged Indium Tin Oxide Thin Films — •Subho Dasgupta, Maya Lukas, Robert Kruk, and Horst Hahn — Institute for Nanotechnology, Forschungszentrum Karlsruhe GmbH, P.O. Box 3640, D-76021 Karlsruhe, Germany
This study aims at the quantitative understanding of the change in electronic transport upon surface charging in nanoparticulate and nanocrystalline conducting oxide. Previously, we demonstrated a device with a metallic conducting channel made of Indium Tin Oxide (ITO) nanoparticles which exhibits an on/off ratio of 2×103 [1]. To find the mechanism of such a large change in conductivity, we prepared nanocrystalline ITO thin films of a few nanometers thickness as a model system. It was observed that an increase in the Sn-doping level near the grain boundaries results in a local variation in the screening length upon charging. This variation is considered to be equivalent to an increase in the surface roughness resulting in the disruption of the conducting paths. It is concluded that primarily a change in the scattering probability is causing the high value of variation in transport properties for highly-doped semiconductors like ITO.
[1] S. Dasgupta, S. Gottschalk, R. Kruk, H. Hahn, Nanotechnology 19 (2008) 435203