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HL: Fachverband Halbleiterphysik
HL 64: Poster II
HL 64.37: Poster
Donnerstag, 19. März 2020, 10:00–13:00, P1A
Interal photo-emission of electrons from a quantum dot — •Pia Lochner1, Jens Kerski1, Annika Kurzmann1, Andreas D. Wieck2, Arne Ludwig2, Martin Geller1, and Axel Lorke1 — 1Faculty of Physics and CENIDE, University of Duisburg-Essen, Germany — 2Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, Germany
Resonance fluorescence (RF) on excitonic transitions in confined quantum systems (like self-assembled quantum dots) is ideally free of any charge generation in the environment. The light field from the laser should only couple to the optical transitions. However, it as been shown recently that even under resonant excitation, free electrons can be generated in the environment by intra-band electron excitation from a nearby charge reservoir. These electrons can be captured by the dot and quench the exciton transition of the RF signal [1].
In this contribution, we demonstrate by time-resolved RF measurements on a single self-assembled quantum dot an internal photo-effect that emits electrons from the QD by an intraband excitation. The dot is in our sample only weakly-coupled to an electron reservoir with tunneling rates below 1/ms. We show a linear dependence of the optically-generated emission rate on the excitation intensity and use a rate equation model to deduce the involved rates. Our results demonstrate that also under resonant excitation, free electrons can be generated by an internal photo-effect that can influence the optical properties of a dot.
[1] A. Kurzmann, et al., APL 108, 263108 (2016).