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Nonexponential Blinking Kinetics of Single CdSe Quantum Dots: A Universal Power Law Behavior



M Kuno, D P. Fromm, H F. Hamann, Alan Gallagher, David Nesbitt


We have studied the fluorescence intermittency of single CdSe quantum dots (17-29 radius) overcoated with ZnS. Optical measurements were made using a confocal microscope under epillumination conditions, with the 488 nm line of an Ar+ laser as the excitation source. This excitation was focused to a nearly diffraction-limited spot on the surface of a suprasil prism onto which the sample has been spin cast. Emission from the sample was collected through the same objective. The emission was then focused into a multimode fiber and directed to an avalanche photodiode (APD). Fluorescence intensity vs. time traces were obtained and integration times sampled. The net optical collection efficiencyof the system (i.e., number of fluorescence photons emitted versus photon counts registered on the APD) has been determined to be approximately 1-2%.
Journal of Chemical Physics
No. 7


blinking kinetics, fluorescence, intermittency, power law, quantum dot, single molecule


Kuno, M. , Fromm, D. , Hamann, H. , Gallagher, A. and Nesbitt, D. (2000), Nonexponential Blinking Kinetics of Single CdSe Quantum Dots: A Universal Power Law Behavior, Journal of Chemical Physics (Accessed April 18, 2024)
Created January 31, 2000, Updated October 12, 2021