Berlin 2012 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 66: Transport Properties III (Experiments)

HL 66.1: Vortrag

Mittwoch, 28. März 2012, 18:15–18:30, ER 164

Picosecond time-resolved photocurrents in GaAs nanowires — •Nadine Erhard¹, Leonhard Prechtel¹, Milan Padilla¹, Helmut Karl², Gerhard Abstreiter¹, Anna Fontcuberta³, and Alexander Holleitner¹ — ¹Walter Schottky Institut and Physik-Department, TU München, Am Coulombwall 4a, D-85748 Garching, Germany — ²Institute of Physics, University of Augsburg, D-86135 Augsburg, Germany — ³Laboratoire des Materiaux Semiconducteurs, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne, Switzerland

Conventional scanning photocurrent microscopy (SPCM) experiments on semiconductor nanowires are typically limited to timescales exceeding 10 ps. Yet, it is known from optical experiments that carrier relaxation and transport processes can occur on much faster timescales in semiconducting nanowires. We therefore apply a recently developed pump-probe photocurrent spectroscopy to investigate the photocurrent dynamics of p-doped GaAs nanowires with a picosecond time-resolution. Hereby, the ultrafast photocurrent response of the nanowire is sampled at a field probe in a stripline circuit. We discuss ultrafast thermoelectric, displacement, and carrier lifetime limited currents as well as the time-resolved transport of photogenerated holes.