Triplet exciton trapping by dislocations in anthracene

Dislocations have been produced in anthracene crystals by plastic bending. The triplet exciton trapping characteristics have been obtained from a study of the temperature dependence of the triplet decay rate and delayed fluorescence intensity. The results indicate that only one kind of trap with depth 0.3 eV is introduced by the plastic bending. This trap can be removed by annealing the crystal for l h at 443°K. The trapping rate constant is three orders of magnitude smaller than expected for diffusion-limited trapping.