Exciton radiative recombination in spherical CdS/CdSe/CdS quantum-well nanostructures

by Xu, J. F.; Xiao, M.; Battaglia, D.; Peng, X. G.

Photoluminescence (PL) and lifetimes of colloidal CdS/CdSe/CdS (core/well/shell) quantum-well (QW) nanostructures are investigated for different well thicknesses in the temperature range of 77-300 K. When the temperature increases, the PL intensity decreases continuously and PL peak shifts to lower energy side. The PL lifetimes for the 1-3 monolayer (ML) CdSe QWs increase with temperature and radiative recombination dominates the decay processes. The radiative lifetimes basically increase linearly with temperature, which indicates the existence of free two-dimensional excitons. For the 4 ML CdSe QW sample, the lifetime does not increase with temperature, showing more nonradiative processes due to more defect formation within the thicker QWs.

Journal
Applied Physics Letters
Volume
87
Issue
4
Year
2005
URL
https://dx.doi.org/10.1063/1.2001731
ISBN/ISSN
1077-3118; 0003-6951
DOI
10.1063/1.2001731