Photoinduced spectral diffusion and diffusion-controlled electron transfer reactions in fluorescence intermittency of quantum dots

An overview is given for the experimental and theoretical development on fluorescence intermittency (blinking) in semiconductor crystalline nanoparticles. We consider a model with photoinduced spectral diffusion and diffusion-controlled electron transfer processes as the underlying mechanism for intermittency in quantum dots. Depending on the frequency response of a dielectric medium, anomalous/normal diffusion in energy space leads to power-law intermittency for single quantum dots and quasi-stretched exponential decay in ensemble-averaged fluorescence intensity. Intricate relationship between single particle and ensemble behavior is discussed. Some kinetic and energetic parameters are linked to the temporal behavior of blinking statistics and ensemble fluorescence decay.