The room temperature dynamics of single fluorescent dye molecules adsorbed on dry surfaces was investigated with submillisecond time resolution. Rapid turn-on and off events that satisfy stochastic statistics of quantum jumps were observed. These jumps were most likely intersystem crossing transitions to the triplet state, individually resolved due to the extended triplet state lifetime τoff in the dry condition. Saturation study of such single molecules confirmed the extended τoff. Distributions in intersystem crossing yield YISC and in τoff, probably due to different local environment, were measured. Moreover, individual molecules exhibited abrupt changes in τoff and YISC, correlated with spectral changes of the molecular emission.
|Number of pages||5|
|Journal||Chemical Physics Letters|
|State||Published - 6 Jun 1997|
Bibliographical noteFunding Information:
This research was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under US Department of Energy, Contract No. DE-AC03-76SF00098 and by the Office of Naval Research, Contract No. N00014-95-F-0099.