Nonequilibrium carrier dynamics in self-assembled InGaAs quantum dots

• Published in: Physica Status Solidi (b) Vol. 243; no. 10; pp. 2217 - 2223
• Main Authors: Wesseli, M., Ruppert, C., Trumm, S., Krenner, H. J., Finley, J. J., Betz, M.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.08.2006; WILEY‐VCH Verlag; Wiley
• Subjects: 78.47.+p; 78.67.Hc; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Exact sciences and technology; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Quantum dots; Nanoparticles; Gallium arsenides; Localized states; Interband transitions; Bleaching; Quantum dots; Self-assembled layers; Nanostructures; Absorption spectra; Ultrafast optics; Island structure; Indium arsenides
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200668006

Carrier dynamics in InGaAs/GaAs quantum dots is analyzed with highly sensitive femtosecond transmission spectroscopy. In a first step, measurements on a large ensemble of nanoislands reveal the dynamical electronic filling of quantum dots from the surrounding wetting layer. Most interestingly, we find a spin‐preserving phonon mediated scattering into fully localized states within a few picoseconds. Then, individual artificial atoms are isolated with metallic shadow masks. For the first time, a single self‐assembled quantum dot is addressed in an ultrafast transmission experiment. We find bleaching signals in the order of 10−5 that arise from individual interband transitions of one quantum dot. As a result, we have developed an ultrafast optical tool for both manipulation and read‐out of a single self‐assembled quantum dot. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)