Berlin 2012 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 81: Graphene: Transport incl. Spin Physics and Magnetic Fields I
HL 81.5: Talk
Thursday, March 29, 2012, 16:00–16:15, ER 270
Temperature Dependent Magnetotransport Studies of Graphene on GaAs — •Nils Gayer, Karen Peters, and Wolfgang Hansen — Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Germany
We utilize temperature dependent magnetotransport measurements to investigate the electronic properties of graphene on (001)-GaAs. Our substrates contain a Si-doped GaAs backgate grown by means of molecular beam epitaxy. The investigated graphene flakes were prepared by mechanical cleavage of natural graphite. We were able to determine the number of layers of the graphene flakes by using Raman spectroscopy.
Shubnikov-de Haas oscillations in the longitudinal resistance allow for determination of the charge carrier densities and subsequently the carrier mobilities. The gate-voltage dependency of the resistance suggests that the samples are p-doped. The observed weak localization enables the extraction of the temperature dependent dephasing time τφ. The temperature dependency reveals diffusive electron-electron scattering to be the phase breaking process.