Triplet Exciton–Charge Carrier Interaction in Anthracene

The delayed fluorescence (DF) quenching of anthracene crystals caused by hole injection is investigated. The kinetics of DF and DF quenching due to triplet‐hole interaction are measured over a wide range of light intensities when the triplet exciton decay converts from unimolecular to bimolecular. The values of photoenhanced space‐charge‐limited current have provided the ratio of free to trapped hole concentrations in crystal. The increased role of triplet‐free hole interaction at high light intensity is shown. The rate constants of triplet‐trapped hole ((0.6 ± 0.2) × 10 −11 cm 3 s −1 ) and of triplet‐free hole ((2 ± 1) × × 10 −10 cm 3 s −1 ) interactions leading to triplet quenching are measured.