Carrier-Exciton Interactions in Crystalline Anthracene

Abstract

Quenching of delayed fluorescence by injected holes and electrons is observed when either monomolecular or bimolecular exciton processes afford the dominant exciton decay mechanism. With small triplet exciton densities, injected carriers reduce the triplet exciton lifetime, and hence the delayed fluorescence intensity. With high triplet exciton densities this effect is unimportant; however, the over-all triplet-triplet annihilation rate constant is found to increase while the singlet component of the annihilation rate constant decreases in the presence of charge carriers. These effects are discussed in terms of triplet pair formation and annihilation.