A model for steady-state luminescence of localized-state ensemble

A distribution function for localized carriers, f(E,T) = 1/(e(E − Ea)/kBT + τtr/τr), is obtained by solving a rate equation, in which electrical carriers' generation, thermal escape, recapture and radiative recombination are taken into account. Based on this distribution function, a model is developed for luminescence from localized-state ensemble with a Gaussian-type density of states. The model reproduces quantitatively all the anomalous temperature behaviors of localized-state luminescence. It reduces to the well-known band-tail and luminescence quenching models under certain approximations.