Energy Transfer in Doped Organic Crystals

Abstract

This paper summarizes the results we have obtained in studying energy transfer in doped organic crystals as a function of temperature, dopent concentration, sample size, method of crystal growth and method of excitation. Neither the theory of energy transfer by exciton diffusion nor the theory of long range resonance energy transfer can adequately explain the experimental observations. We also show that the predictions of exciton diffusion do not agree with the observed fluorescence rise times reported previously by other workers. Unsuccessful attempts to fit the data with a theory of exciton diffusion in two dimensions are also reported.