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Dynamics of Excitons in Single Semiconductor Quantum Dots Probed by Time‐Resolved Optical Spectroscopy
Author(s) -
Regelman D.V.,
Dekel E.,
Gershoni D.,
Schoenfeld W.V.,
Petroff P.M.
Publication year - 2001
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/1521-3951(200103)224:2<343::aid-pssb343>3.0.co;2-z
Subject(s) - exciton , excitation , quantum dot , photoluminescence , spectroscopy , atomic physics , radiative transfer , spectral line , biexciton , coherence (philosophical gambling strategy) , emission spectrum , photoluminescence excitation , physics , molecular physics , optics , condensed matter physics , optoelectronics , quantum mechanics , astronomy
We resolve spatially, spectroscopically and temporally the photoluminescence emission from single self‐assembled In(Ga)As/GaAs quantum dots. The temporal evolution of the emission spectrum after pulsed excitation is measured for various excitation intensities at various ambient temperatures. The evolution of the spectrum with the increase in both steady state and pulse excitation intensities is measured as well. A multi‐exciton model is used for calculating the temporal and excitation intensity dependence of the measured spectra. The quantitative agreement between the measured and calculated spectra provides an unambiguous determination of the radiative lifetime of a single quantum dot exciton. This lifetime is 4–6 ns long and is temperature independent. The reduced spatial coherence between the confined exciton and the radiation electromagnetic field quantitatively explains this long radiative time.