Nano Archive

Exciton storage by Mn2+ in colloidal Mn2+-doped CdSe quantum dots

Beaulac, Remi and Archer, Paul I. and van Rijssel, Jos and Meijerink, Andries and Gamelin, Daniel R. (2008) Exciton storage by Mn2+ in colloidal Mn2+-doped CdSe quantum dots. NANO LETTERS, 8 (9). pp. 2949-2953.

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Official URL: http://pubs.acs.org/doi/abs/10.1021/nl801847e

Abstract

Colloidal Mn2+-doped CdSe quantum dots showing long excitonic photoluminescence decay times of up to τexc = 15 μs at temperatures over 100 K are described. These decay times exceed those of undoped CdSe quantum dots by 103 and are shown to arise from the creation of excitons by back energy transfer from excited Mn2+ dopant ions. A kinetic model describing thermal equilibrium between Mn2+ 4T1 and CdSe excitonic excited states reproduces the experimental observations and reveals that, for some quantum dots, excitons can emit with near unity probability despite being 100 meV above the Mn2+ 4T1 state. The effect of Mn2+ doping on CdSe quantum dot luminescence at high temperatures is thus completely opposite from that at low temperatures described previously.

Item Type:Article
Subjects:Physical Science > Nano objects
Physical Science > Quantum phenomena
ID Code:6384
Deposited By:IoN
Deposited On:06 Aug 2009 16:14
Last Modified:06 Aug 2009 16:14

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