Fluorescence decay time measurements in tetracene crystals

A dual exponential decay has been observed in the fluorescence of tetracene. A slow component with a decay time of 12 nsec dominates at low temperatures. The other component has a decay time of 0.8 nsec up to 230°K, where singlet fission begins and reduces the decay time to 0.3 nsec at 300°K. The efficiency of this fast component increases with temperature. The fast and slow components are assigned to different emitting species. © 1972.