Relationship between single quantum-dot intermittency and fluorescence intensity decays from collections of dots

We show that the slow dynamics of the fluorescence from a collection of colloidal quantum dots and the intermittency observed in single quantum dots are intimately related. This system illustrates the importance of uncovering dynamical behavior at the microscopic level for a proper understanding of ensemble phenomenology. We propose a model that introduces lower and upper bounds to the on- and off-time power-law distributions in single-nanocrystal quantum-dot (QD) fluorescence intermittency statistics. We use Monte Carlo simulations and analytical forms to quantitatively connect this single QD model to the fluorescence intensity decay to a steady state that is observed in collections of QD's. Inversely, we also show that experiments on collections of QD's can be used to directly obtain upper bounds to the single-QD fluorescence intermittency power-law statistics.