Freiburg 2019 – scientific programme
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FM: Fall Meeting
FM 38: Enabling Technologies: Quantum Dots, Quantum Wires, Point Contacts and Excitonic Systems
FM 38.1: Talk
Tuesday, September 24, 2019, 14:00–14:15, 3043
Real-time detection of Auger recombination in a self-assembled quantum dot — •Pia Lochner1, Annika Kurzmann1, Jens Kerski1, Philipp Stegmann1, Jürgen König1, Rüdiger Schott2, Andreas D. Wieck2, Arne Ludwig2, Axel Lorke1, and Martin Geller1 — 1Faculty of Physics and CENIDE, University of Duisburg-Essen, Germany — 2Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Germany
Auger recombination is a non-radiative process, where the recombination energy of an electron hole pair is transferred to a third charge carrier. In colloidal quantum dots (QDs), this is a common effect, which quenches the radiative emission with recombination times in the order of ps [R. Vaxenburg, et al., Nano Lett. 15, 2092 (2015).]. In self-assembled QDs it has become possible to observe Auger recombination only recently, with recombination times in the order of µs [A. Kurzmann, et al., Nano Lett. 16, 3367 (2016).].
In this contribution, we use real-time measurements of the random telegraph signal [A. Kurzmann, et al., PRL, accepted (2019).] to investigate Auger recombination in a single self-assembled QD. This is coupled to a charge reservoir with a small tunneling rate in the order of ms-1. We are able to detect every single Auger recombination, as well as the "resetting" of the quantum dot to the singly charged state by single electron tunneling. By changing the laser power for resonant trion excitation, we can precisely tune the Auger rate while the tunneling rate remains constant and can thus determine the corresponding statistics of the processes.