Regensburg 2016 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 48: Quantum Dots and Wires: Microcavities
HL 48.7: Vortrag
Mittwoch, 9. März 2016, 11:45–12:00, H15
Auger-recombination in a single self-assembled quantum dot: Quenching and broadening of the charged exciton — •Annika Kurzmann1, Arne Ludwig2, Andreas D. Wieck2, Axel Lorke1, and Martin Geller1 — 1Faculty of Physics and CENIDE, University of Duisburg-Essen, Lotharstraße 1, 47057 Duisburg, — 2Chair for Applied Solid State Physics, Ruhr-Universität Bochum, Universitätsstraße 150, 44780 Bochum, Germany
The Auger-recombination is a non-radiative process, where the electron-hole recombination energy is transferred to a third charge carrier. While this process was extensively studied in colloidal quantum dots [1], it was considered, unimportant for self-assembled quantum dots (QDs). Here, we show that in a single self-assembled QD the Auger recombination rate can directly be determined using time-resolved resonance fluorescence (RF) measurements. Furthermore, the Auger recombination quenches and broadens the charged exciton transition (two electrons and one hole).
The QD is embedded in a field-effect transistor, and the tunneling rate from the charge reservoir into the dot is about 1/µs. The measured Auger-recombination rate is of the same order of magnitude as this tunneling rate. This leads to an uncharged QD and a quenched RF signal. Our measurements show the relevance of the ratio between the Auger-recombination rate and the tunneling rate for the properties of the charged exciton transition. A model, based on rate equations, is in good agreement with our measurements.
[1] V. I. Klimov et al., Science 287, 1011 (2000)