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HL: Fachverband Halbleiterphysik
HL 85: Poster Session II
HL 85.42: Poster
Thursday, March 17, 2011, 18:00–21:00, P4
Temperature dependent transport measurements in quasi-freestanding graphene on SiC(0001) — •Epaminondas Karaissaridis1, Sonja Weingart1, Claudia Bock1, Ulrich Kunze1, Florian Speck2, and Thomas Seyller2 — 1Werkstoffe und Nanoelektronik, Ruhr-Universität Bochum — 2Technische Physik, Friedrich-Alexander-Universität Erlangen-Nürnberg
We report on magneto- and ballistic transport measurements in 2D Hall bars and 1D orthogonal cross junctions fabricated from quasi-freestanding monolayer graphene on SiC(0001).
The investigated films are produced by conversion of the (6√3×6√3)R30∘ reconstruction into graphene via hydrogen intercalation [1].
The hole concentration of 6·1012 cm−2 and a mobility of 1900 cm2(Vs)−1 are derived from Hall effect measurements at 2D structures. These values are constant in a temperature range of 1.4 K≤ T ≤ 300 K and correspond to a constant mean free path of le ≈ 50 nm.
At T=1.4 K the bend resistance characteristic of the 1D orthogonal cross junctions (w = 50 nm) shows magnetic field dependent negative peaks indicating ballistic transport. As temperature is increased to T = 50 K a transition from the ballistic into the diffusive transport regime is observed. These results demonstrate that additional scattering in 1D systems plays an important role.
[1] F. Speck, et al., Mat. Sci. Forum 645-648, 629 (2010).