Mechanisms of fluorescence decays of colloidal CdSe-CdS/ZnS quantum dots unraveled by time-resolved fluorescence measurement
2015 (English)In: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 17, no 41, 27588-27595 p.Article in journal (Refereed) Published
By narrowing the detection bandpass and increasing the signal-to-noise ratio in measuring the time-resolved fluorescence decay spectrum of colloidal CdSe-CdS/ZnS quantum dots (QDs), we show that directly after the photoexcitation, the fluorescence decay spectrum is characterized by a single exponential decay, which represents the energy relaxation of the photogenerated exciton from its initial high-energy state to the ground exciton state. The fluorescence decay spectrum of long decay time is in the form of beta/t(2), where beta is the radiative recombination time of the ground-state exciton and t is the decay time. Our findings provide us with a direct and quantitative link between fluorescence decay measurement data and fundamental photophysics of QD exciton, thereby leading to a novel way of applying colloidal QDs to study microscopic, physical and chemical processes in many fields including biomedicine.
Place, publisher, year, edition, pages
Royal Society of Chemistry, 2015. Vol. 17, no 41, 27588-27595 p.
Phonon Bottleneck, Cdte Nanocrystals, Energy-Transfer, Emission, Electron, Blinking, Relaxation, Nanoparticles, Microscopy, Lifetimes
Subatomic Physics Other Physics Topics Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:kth:diva-176997DOI: 10.1039/c5cp03109eISI: 000363193800038PubMedID: 26426293ScopusID: 2-s2.0-84944339303OAI: oai:DiVA.org:kth-176997DiVA: diva2:871694
FunderSwedish Research Council, 621-2011-4381Knut and Alice Wallenberg Foundation, KAW 2011.0218
QC 201511162015-11-162015-11-132016-09-02Bibliographically approved