Berlin 2015 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 24: Focus Session: Functional Semiconductor Nanowires II (organized by HL)

TT 24.12: Talk

Monday, March 16, 2015, 18:30–18:45, EW 201

Charge transport along GaAs nanowires: Surface conductivity and band bending — •Stefan Korte¹, Matthias Steidl², Weihong Zhao², Werner Prost³, Felix Lüpke¹, Vasily Cherepanov¹, Bert Voigtländer¹, Peter Kleinschmidt², and Thomas Hannappel² — ¹Peter Grünberg Institut (PGI-3), Forschungszentrum Jülich, 52425 Jülich, Germany, and JARA-Fundamentals of Future Information Technology — ²Photovoltaics Group, Institute for Physics, Technische Universität Ilmenau, 98684 Ilmenau, Germany — ³CeNIDE and Center for Semiconductor Technology and Optoelectronics, University of Duisburg-Essen, 47057 Duisburg, Germany

Using a multi-tip STM as nanoprober to explore the electrical transport properties of freestanding p-doped GaAs nanowires, we revealed a highly increased resistivity in the nanowire base, which caused bad contact to the substrate. This high resistance can be explained by a charge carrier depletion through the whole nanowire cross section due to Fermi level pinning at surface states. To explore this, Zn-doped GaAs nanowires were grown by Au-assisted metal-organic vapor-phase epitaxy (MOVPE) in the vapor-liquid-solid growth mode with different growth procedures. We measured and analyzed I/V characteristics and resistance profiles to understand the conduction mechanisms and band bending along these nanowires.