We have developed a model for the temperature dependence of the concentration quenching of luminescent materials, and have applied this model to YAG:Ce. This model of concentration quenching is based on an assumption in which, following excitation of an activator ion, there is energy migration via non-radiative energy transfer among similar ions, finally ending at a "killer" site. The temperature dependence of a single ion-ion energy transfer process is assumed to be determined solely by the overlap of the emission and absorption bands of the donor and acceptor ions. Using our previous results to calculate the temperature dependence of this overlap function, we propose a model for calculating the effect of concentration quenching on the lifetime of the luminescent ion. This model has two parameters, one of which is the average number of energy transfer jumps that occur before reaching a killer site. In the case of YAG:Ce, we show that the observed temperature dependence of the Ce lifetime at various concentrations can be explained satisfactorily using this model.
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