Unusual enhancement of dye luminescence by exciton resonance of J-Aggregates

Abstract In this study, we report an effective excitation energy transfer from J-aggregates to exciton traps (specially selected dye molecules) located within different polymer layers by Forster resonance energy transfer mechanism. With an increase in the distance d between the layer of J-aggregates and that of the exciton traps, the intensity of the traps luminescence reaches a maximum at the certain spacer layer thickness, instead of a gradual decrease according to the Forster law ~ d−6, and then drops down. Moreover, the decay time of the traps luminescence synchronously changes, reaching its maximum at the maximum of the traps luminescence. The observed effect takes place for different types of J-aggregates and exciton traps and even at the direct excitation into the traps absorption band. Despite that, the critical distance between J-aggregates and exciton traps, at which the maximum of the traps luminescence and its highest decay time are observed, was nearly the same for all J-aggregates – exciton traps pairs.