Evidence for a diffusion-controlled mechanism for fluorescence blinking of colloidal quantum dots
Abstract
Fluorescence blinking in nanocrystal quantum dots is known to exhibit power-law dynamics, and several different mechanisms have been proposed to explain this behavior. We have extended the measurement of quantum-dot blinking by characterizing fluctuations in the fluorescence of single dots over time scales from microseconds to seconds. The power spectral density of these fluctuations indicates a change in the power-law statistics that occurs at a time scale of several milliseconds, providing an important constraint on possible mechanisms for the blinking. In particular, the observations are consistent with the predictions of models wherein blinking is controlled by diffusion of the energies of electron or hole trap states.
Additional Information
© 2007 by The National Academy of Sciences of the USA. Contributed by Rudolph A. Marcus, July 2, 2007 (received for review May 19, 2007). Published online on August 24, 2007, 10.1073/pnas.0706164104. We thank Prof. Philippe Guyot-Sionnest for providing the QD samples and for valuable discussions, and Dr. Pavel Frantsuzov for helpful comments. This work was partially funded by National Science Foundation Grant CHE-0616663 (to N.F.S.), National Institutes of Health Grant R01GM67961 (to N.F.S.). The Center for Nanoscale Materials is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Contract DE-AC02-06CH11357. R.A.M. thanks the Office of Naval Research and the National Science Foundation for support. N.F.S. acknowledges the J.S. Guggenheim Foundation for a fellowship. Author contributions: M.P., N.F.S., and R.A.M. designed research; M.P., G.S., and R.A.M. performed research; M.P. analyzed data; and M.P., N.F.S., and R.A.M. wrote the paper. The authors declare no conflict of interest. This article contains supporting information online at www.pnas.org/cgi/content/full/0706164104/DC1.Attached Files
Published - PELpnas07.pdf
Supplemental Material - PELpnas07fig6.pdf
Supplemental Material - PELpnas07supptext.pdf
Files
Additional details
- PMCID
- PMC1964845
- Eprint ID
- 10072
- Resolver ID
- CaltechAUTHORS:PELpnas07
- Created
-
2008-04-10Created from EPrint's datestamp field
- Updated
-
2021-11-08Created from EPrint's last_modified field