Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 37: Quantum Dots and Wires: Optical Properties III

HL 37.6: Vortrag

Mittwoch, 24. März 2010, 10:45–11:00, H15

Dependence of spectral diffusion on excitation mechanisms in InGaAs/GaAs quantum dots — •Irina Ostapenko¹, Jan Amaru Töfflinger¹, Murat Öztürk¹, Erik Stock¹, Sven Rodt¹, Till Warming¹, Paola Atkinson^2,3, Oliver G. Schmidt², and Dieter Bimberg¹ — ¹Institut für Festkörperphysik, TU Berlin, Hardenbergstr. 36, 10623 Berlin, Germany — ²Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstrasse 20, 01069 Dresden — ³Max-Planck-Institut für Festkörperforschung, Heisenbergstr. 1, 70569 Stuttgart, Germany

The discrete energy levels and sharp luminescence lines of self organized quantum dots (QDs) allow the development of new nano-photonic devices such as emitters of entangled or single photons. Fluctuating fields in the sample may cause a spectral diffusion (jitter) of the lines: their energetic positions shift and the intensities vary. If the characteristic jitter timescale is smaller than the integration time of a given application, the luminescence line is inhomogeneously broadened which might hinder the use of single QD-based devises. Therefore the understanding of the intrinsic mechanisms of jitter is essential for the realization of such devices. Here we compare the spectral diffusion of the same QDs under optical and, what is more substantial for real applications, electrical excitation conditions in electro-, cathode- and micro-photoluminescence experiments. The key element is an electrically driven device with a low density of QDs and the possibility to probe the same QD with different excitation methods.