Influences of light intensity on fluorescence lifetime of nanorods and quantum dots

In this letter we investigate light-intensity dependence of the fluorescence lifetime for CdSe nanorods (NRs) and quantum dots (QDs) measured by time-correlated single photon counting techniques. We report extremely narrow lifetime distribution for NRs as the light intensity increases, although the change for QDs is not so pronounced. In addition, the averaged lifetimes for NRs and QDs all become shortened at higher light intensities. Some possible mechanisms for these effects are discussed. ? 2008 American Institute of Physics.