Electronic coupling and exciton energy transfer in CdTe quantum-dot molecules.
Stable dispersions of molecularlike aggregates of CdTe quantum dots are prepared by chemical cross-linking. Cryo-TEM images confirm the presence of cross-linked quantum dots and show that the size of the small aggregates can be controlled by the amount of cross-linker added. Optical measurements reveal two types of interdot interactions within these quantum-dot molecules: exciton energy transfer and electronic coupling. Quantitative information on the energy transfer rates in quantum-dot molecules is obtained by photoluminescence lifetime measurements. The degree of electronic coupling is dependent on the size of the quantum dots, which is supported by quantum mechanical calculations.
Koole
Rolf
R
Debye Institute, Condensed Matter and Interfaces, Utrecht University, P.O. Box 80 000, 3508 TA Utrecht, The Netherlands. r.koole@phys.uu.nl
Liljeroth
Peter
P
de Mello Donega
Celso
C
Vanmaekelbergh
Daniël
D
Meijerink
Andries
A