THEORY OF ELECTRIC-FIELD-INDUCED PHOTOLUMINESCENCE QUENCHING IN DISORDERED MOLECULAR-SOLIDS

The dynamics of excitons in disordered molecular solids is studied the oretically, taking into account migration between different sites, rec ombination, and dissociation into free charge carriers in the presence of an electric field. The theory is applied to interpret the results of electric-field-induced photoluminescence (PL) quenching experiments on molecularly doped polymers by Deussen et al. [Chem. Phys. 207, 147 (1996)]. Using an intermolecular dissociation mechanism, the dependen ce of the PL quenching on the electric-field strength and the dopant c oncentration, and the time evolution of the transient PL quenching can be well described. The results constitute additional proof of the dis tinct exciton dissociation mechanisms in conjugated polymer blends and molecularly doped polymers.