Size dependent oscillator strength of CdSe quantum dots determined by nanophotonic control

M. D. Leistikow, J. Johansen, A. J. Kettelarij, P. Lodahl, W. L. Vos

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Abstract

Control over spontaneous emission of quantum dots is important for many applications, especially as light sources in photonic materials and nanostructures. Colloidal CdSe quantum dots have recently generated enormous interest because of the tunability of their emission energy with particle diameter over the entire visible range. The strength of the interaction of a quantum dot with the light field is determined by the oscillator strength, making the oscillator strength a crucial parameter for successful inhibition and enhancement of spontaneous emission. This paper presents measurements of the oscillator strength and quantum efficiency of ensembles of colloidal CdSe quantum dots as a function of emission energy or equivalently quantum dot size. It is the first time the oscillator strength is determined from emission, giving highly accurate values that can be used to test theories. The total decay rate is measured as a function of normalised LDOS for different sizes of quantum dots in our ensemble. A linear relation between total decay rate and LDOS is found, as expected from Fermi's golden rule. The total decay rate increases with emission energy, in agreement with recent literature. This increase is mostly due to an increase in nonradiative decay rate. The oscillator strength is nearly independent on emission energy suggesting that the quantum dots are in the strong confinement regime.
Original languageEnglish
Title of host publicationEuropean Quantum Electronics Conference, EQEC 2009
PublisherOptical Society of America
ISBN (Print)9781424440801
DOIs
Publication statusPublished - 1 Jan 2009
Event11th European Quantum Electronics Conference, EQEC 2009 - Munich, Germany
Duration: 14 Jun 200919 Jun 2009
Conference number: 11
http://2009.cleoeurope.org/

Publication series

NameOptics InfoBase Conference Papers
ISSN (Electronic)2162-2701

Conference

Conference11th European Quantum Electronics Conference, EQEC 2009
Abbreviated titleEQEC 2009
CountryGermany
CityMunich
Period14/06/0919/06/09
Internet address

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Cite this

Leistikow, M. D., Johansen, J., Kettelarij, A. J., Lodahl, P., & Vos, W. L. (2009). Size dependent oscillator strength of CdSe quantum dots determined by nanophotonic control. In European Quantum Electronics Conference, EQEC 2009 (Optics InfoBase Conference Papers). Optical Society of America. https://doi.org/10.1109/CLEOE-EQEC.2009.5192115