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HL: Fachverband Halbleiterphysik
HL 68: Heterostructures and interfaces
HL 68.8: Talk
Wednesday, April 2, 2014, 16:45–17:00, POT 051
Investigation of interband dynamics in single InAs/GaAs quantum dots — •Daniel Stephan1,2, Jayeeta Bhattacharyya1, Manfred Helm1,2, Yongheng Huo3, Oliver Schmidt3, Armando Rastelli4, and Harald Schneider1 — 1Helmholtz-Zentrum Dresden-Rossendorf, Germany — 2Technische Universität Dresden, Germany — 3Leibniz Institute for Solid State Materials Research Dresden, Germany — 4Johannes Kepler Universität, Austria
We investigate the dynamics of inter-sublevel transitions in single InAs/GaAs self-assembled quantum dots (QDs). By using a micro-photoluminescence (PL) setup and low-density QD samples, we measure the PL emission from single QDs. The QDs is manipulated by a free-electron laser pulse tuned to the inter-sublevel transition energy, which excites carriers to a higher energy level, from which they decay non-radiatively back to the ground state. The PL is measured spectrally resolved, as well as time-resolved, employing time-correlated single photon counting. In time resolved measurements, the inter-sublevel dynamics causes quenching in the exponential PL decay. In contrast to previous studies on QD ensembles[1,2], the use of single dots eliminates effects such as inhomogeneous broadening and inter-dot transfer, providing a better understanding of inter-sublevel carrier dynamics.
[1] J. Bhattacharyya, et al., Applied Physics Letters 97, 031101 (2010).
[2] J. Bhattacharyya, et al., Applied Physics Letters 100, 152101 (2012).