Unravelling the Size and Temperature Dependence of Exciton

Figure 1. TEM images of colloidal ZnSe QDs with diameters of 4.0 ± 0.3 (a), 5.7 ± 0.4 (b), and 7.5 ..... CdTe, and PbSe QDs and by coupling to the l...
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Article pubs.acs.org/JPCC

Unravelling the Size and Temperature Dependence of Exciton Lifetimes in Colloidal ZnSe Quantum Dots Joren Eilers, Jacobine van Hest, Andries Meijerink, and Celso de Mello Donega* Condensed Matter and Interfaces, Debye Institute for Nanomaterials Science, Utrecht University, P.O. Box 80 000, 3508 TA Utrecht, Netherlands S Supporting Information *

ABSTRACT: We report on the temperature dependence of the band-edge photoluminescence decay of organically capped colloidal ZnSe quantum dots (QDs) in the size range from 4.0 to 7.5 nm. A similar trend is observed for all investigated sizes: the decay time is short (∼5 ns) above 20 K and increases sharply below 20 K, eventually reaching a constant value (270−400 ns) at sufficiently low temperatures (