Recombination in quantum dot ensembles

We have calculated recombination rates of an inhomogeneous ensemble of 10⁶ dots by summing localized recombination rates at individual dots, with occupation of dot states in the inhomogeneous distribution specified by Fermi Dirac statistics. We assign the same single dot recombination lifetime (1 ns) to all recombination processes to reveal the effect of localization on the overall rates. For the simplest system of the ground states alone deep state, radiative and Auger recombination processes depend in a similar manner upon the population of electrons in the ground states Consequently the light-current curves for the ground state are approximately linear and are not sensitive to the dominant non-radiative process. When excited states are included Auger recombination becomes dominant at high ensemble populations due to the higher degeneracy assigned to the excited states. While the form of the light-current curves of the total dot system do depend upon the dominant recombination process, an analysis based on power law relations with respect to the ensemble electron population are not appropriate.