Open AccessSpontaneous decay of CdSe / ZnS core-shell quantum dots at the air-dielectric interface
Author(s) -
Zhu Li,
Sarath Samudrala,
N. Stelmakh,
Michael Vasilyev
Publication year - 2012
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.20.003144
Subject(s) - quantum dot , dielectric , refractive index , materials science , spontaneous emission , optics , optoelectronics , nanosecond , condensed matter physics , physics , laser
We report measurements of the fluorescence decay times of CdSe/ZnS core-shell quantum dots at the air-dielectric interface for several dielectrics with different refractive indices. The results are in agreement with a simple theory that accounts for the impact of the refractive index on the density of states and magnitude of the vacuum field, as well as for the local-field correction inside the quantum dot. The results suggest that, by embedding the quantum dots into a high-index dielectric material, one can reduce the spontaneous decay time to sub-nanosecond scale while preserving high quantum efficiency.