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HL: Fachverband Halbleiterphysik
HL 12: Quantum Dots and Wires: Arsenides
HL 12.3: Talk
Monday, March 14, 2011, 12:30–12:45, POT 151
Dynamic and directional modulation of the optical emission of individual GaAs nanowires using surface acoustic waves — •Jörg B. Kinzel1, Daniel Rudolph2, Gerhard Abstreiter2, Jonathan J. Finley2, Gregor Koblmüller2, Achim Wixforth1, and Hubert J. Krenner1 — 1Lehrstuhl für Experimentalphysik 1, Universität Augsburg, Germany — 2Walter Schottky Institut, Technische Universität München, Germany
The influence of surface acoustic waves (SAW) on the optical emission of individual GaAs nanowires (NW) is investigated by micro photoluminescence (µ-PL) spectroscopy at low temperatures. In time-integrated experiments we observe a pronounced quenching of the NW emission as the amplitude of the SAW is increased. This quenching is maximum for SAW propagation along the NW axis and minimum in a perpendicular arrangement. This observation can be readily understood by a SAW-induced break-up of electron-hole pairs which is suppressed for the perpendicular configuration since the NW diameter ∼ 50−100 nm is significantly smaller the SAW wavelength ∼ 5 µ m By introducing a tunable phase relation between the exciting laser pulse and the radio frequency signal exciting the SAW we observe a clear oscillation of the PL signal. In addition, time-correlated single photon counting (TCSPC) spectroscopy proves that this effect arises from a dynamic modulation of the NW emission with the frequency of the SAW.