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Relaxation of Localized Excitons in CdSe/ZnSe Heterostructures Containing Quantum Islands of Different Sizes
Author(s) -
Wachter S.,
Dal Don B.,
Schmidt M.,
Baldauf M.,
Dinger A.,
Kurtz E.,
Klingshirn C.,
Kalt H.
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<437::aid-pssb437>3.0.co;2-j
Subject(s) - blueshift , exciton , photoluminescence , redshift , heterojunction , condensed matter physics , relaxation (psychology) , materials science , quantum dot , red shift , band gap , physics , molecular physics , optoelectronics , quantum mechanics , psychology , social psychology , galaxy
We report on localization dynamics of excitons in ensembles of self‐organized CdSe islands embedded in ZnSe. The experimental methods employed are temperature dependent, spatially‐resolved photoluminescence (μ‐PL), spatially‐integrated PL (macro‐PL), as well as time‐resolved PL (TRPL). We see the often observed non‐monotonous shift of the PL maximum with temperature which we can explain by a redistribution of the excitons amongst the islands. The measured shift is compared with the exact shift of the bandgap deduced from μ‐PL measurements and is found to depend strongly on island size and distribution. These transport processes are recovered in the temporal evolution of the PL. The decay time of the spectrally integrated PL reaches its maximum at exactly the same temperature at which the redshift of the macro‐PL turns into a blueshift.