THEORY AND CALCULATION OF SINGLET EXCITATION-ENERGY TRANSFER IN MIXED MOLECULAR-CRYSTALS

A theoretical study of excitation energy transport among dipole-dipole interacting guests in mixed molecular crystals is carried out. To describe the temporal evolution of the excited state population, we derive a microscopic theory which treats an ensemble of dipole-dipole interacting guest molecules homogeneously distributed among two inequivalent sites of a host lattice. The theory is based on a generalized effective Hamiltonian accounting for intramolecular excited state depopulation and excitation energy transfer. The results are applied to the analysis of experimental data obtained from transient grating experiments in p-terphenyl:pentacene mixed molecular crystals. © 1995 American Institute of Physics.