Growth and time-resolved photoluminescence study of self-organized CdSe quantum dots in ZnSe

Citation
E. Kurtz et al., Growth and time-resolved photoluminescence study of self-organized CdSe quantum dots in ZnSe, SUPERLATT M, 25(1-2), 1999, pp. 119-125
Citations number
10
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
SUPERLATTICES AND MICROSTRUCTURES
ISSN journal
07496036 → ACNP
Volume
25
Issue
1-2
Year of publication
1999
Pages
119 - 125
Database
ISI
SICI code
0749-6036(199901/02)25:1-2<119:GATPSO>2.0.ZU;2-H
Abstract
Employing two different growth methods: standard molecular beam epitaxy (MB E) and low-temperature atomic layer epitaxy (ALE) with subsequent annealing , we have obtained high-quality quantum dot structures consisting of CdSe e mbedded in ZnSe. Single dot emission lines are observed in micro-luminescen ce. The samples have been investigated by further optical methods including time-resolved photoluminescence under resonant excitation at 4.2 K. Distin ct properties of systems with three-dimensional confinement are observed su ch as the suppression of the interaction between isolated quantum dots (QDs ). In standard quantum wells tunneling/hopping processes generally lead to a pronounced red shift of the luminescence over time due to a lateral local ization of excitons in potential fluctuations. A much less pronounced red s hift is observed for the QDs reflecting only the different lifetimes of sin gle dots and higher excited states. The red shift completely vanishes under resonant excitation that selectively excites only a few QDs of the ensembl e in the layer. Typical behaviour is also observed from the halfwidth of th e quantum dot emission. (C) 1999 Academic Press.