Effect of transport coherence on trapping: Quantum-yield calculations for excitons in molecular crystals

On the basis of a general transport formalism and two models of the trapping interaction, a description of Frenkel exciton transport in molecular crystals doped with traps is given in terms of an exact calculation. The analysis is directed particularly at the coherence question. The observables calculated are the quantum yields (explicitly) and the time-dependent luminescence intensities (to quadraturesj. It is shown that the neglect of coherence in interpretations of yield experiments leads to an underestimation of the exciton diffusion constant, and a prescription for evaluating the extent of coherence from bulk quenching observations is suggested.