A Phenomenological Model for Decay Process of Long-Persistent Phosphorescence

A sum of two or more exponential decay functions is empirically adopted nowadays to analyze the decay curve of long-persistent phosphor.However,the fitting parameters of this empirical model lack well-defined physical meanings,especially when the number of exponential decay function is greater than two.We propose a phenomenological model to describe the decay curve oflong-persistent phosphor based on an analysis of the relationship between carrier concentration and light-emitting intensity.This model has a few fitting parameters with well-defined physical meanings as compared to the current empirical one.With this model,we quantitatively analyze the decay processes of typical long-persistent phosphors of SrAl_(2)O_(4):Eu,Dy and obtain reasonable fitting results.