Dresden 2009 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 16: III-V semiconductors II

HL 16.6: Vortrag

Dienstag, 24. März 2009, 11:00–11:15, POT 151

Electrical conductivity in InN nanowires — •Florian Werner¹, Friederich Limbach², Michael Carsten¹, Christian Denker¹, Joerg Malindretos¹, and Angela Rizzi¹ — ¹IV. Physikalisches Institut, Georg-August-Universität Göttingen, Germany — ²Institut für Bio- und Nanosysteme (IBN-1), Forschungszentrum Jülich GmbH, Germany

Electrical conductance through InN nanowires strongly depends on their geometry and on the carrier distribution inside them. By measuring wires of different radii and lengths in a four-point probe geometry, quadratic contributions from the bulk and linear contributions from the surface can be distinguished. The linear contribution is attributed to a high density electron accumulation layer which had previously been confirmed by Raman and photoluminescence spectroscopy. The electron accumulation layer is demonstrated to dominate the conductance through wires with less than 55 nm in diameter, although the influence of the bulk conductance cannot be neglected even for small wires. Evidence of a thin surface layer of indium oxide is provided by X-ray core level photoemission spectroscopy. Therefore the electron accumulation layer is expected to form at the InN/In₂O₃ interface. The surface oxide forms a tunneling barrier between the contacts and the electron accumulation layer and therefore has a strong impact on the contact resistance.