title: Auger Recombination in Self-Assembled Quantum Dots: Quenching and Broadening of the Charged Exciton Transition.
abstract: In quantum dots (QDs), the Auger recombination is a nonradiative process in which the electron-hole recombination energy is transferred to an additional carrier. It has been studied mostly in colloidal QDs, where the Auger recombination time is in the picosecond range and efficiently quenches the light emission. In self-assembled QDs, on the other hand, the influence of Auger recombination on the optical properties is in general neglected, assuming that it is masked by other processes such as spin and charge fluctuations. Here, we use time-resolved resonance fluorescence to analyze the Auger recombination and its influence on the optical properties of a single self-assembled QD. From excitation-power-dependent measurements, we find a long Auger recombination time of about 500 ns and a quenching of the trion transition by about 80%. Furthermore, we observe a broadening of the trion transition line width by up to a factor of 2. With a model based on rate equations, we are able to identify the interplay between tunneling and Auger rate as the underlying mechanism for the reduced intensity and the broadening of the line width. This demonstrates that self-assembled QDs can serve as an ideal model system to study how the charge recapture process, given by the band-structure surrounding the confined carriers, influences the Auger process. Our findings are not only relevant for improving the emission properties of colloidal QD-based emitters and dyes, which have recently entered the consumer market, but also of interest for more visionary applications, such as quantum information technologies, based on self-assembled quantum dots.
authors.affiliation: Fakultät für Physik and CENIDE, Universität Duisburg-Essen , Lotharstraße 1, 47048 Duisburg, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Kurzmann
authors.affiliation: Chair of Applied Solid State Physics, Ruhr-Universität Bochum , Universitätsstr. 150, 44780 Bochum, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Ludwig
authors.affiliation: Chair of Applied Solid State Physics, Ruhr-Universität Bochum , Universitätsstr. 150, 44780 Bochum, Germany.
authors.forename: Andreas D
authors.initials: AD
authors.lastname: Wieck
authors.affiliation: Fakultät für Physik and CENIDE, Universität Duisburg-Essen , Lotharstraße 1, 47048 Duisburg, Germany.
authors.forename: Axel
authors.initials: A
authors.lastname: Lorke
authors.affiliation: Fakultät für Physik and CENIDE, Universität Duisburg-Essen , Lotharstraße 1, 47048 Duisburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Geller
keywords: Auger recombination; Quantum dot; line width; resonance fluorescence; trion