Excitation wavelength dependence of fluorescence intermittency in CdSe/ZnS core/shell quantum dots

Nano Lett. 2007 Dec;7(12):3869-74. doi: 10.1021/nl0714740. Epub 2007 Nov 10.

Abstract

Core/shell CdSe/ZnS quantum dot fluorescence-blinking statistics depend strongly on excitation wavelength. Excitation on the band gap (575 nm) results in inverse-power law "on" time distributions. However, distributions resulting from excitation above the band gap (525 nm) require a truncated power law and are 100 times less likely to display 10-s fluorescence. "Off" time statistics are insensitive to the excitation wavelength. The results may be explained by nonemissive trap states accessed with the higher-photon excitation energies.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Cadmium*
  • Kinetics
  • Quantum Theory
  • Selenium*
  • Spectrophotometry
  • Sulfur*
  • Zinc*

Substances

  • Cadmium
  • Sulfur
  • Selenium
  • Zinc