Safeguarding long-lived excitons from excimer traps in H-aggregated dye-assemblies.

ABSTRACT: The fate of perylene bisimide (PBI) H-aggregates as energy-harvesting materials depends on the ability to circumvent an extremely deleterious but efficient self-trapping process that scavenges the long-lived excitons to form deep excimeric traps. We present the first ever report of an ambient-stable, bright, steady-state photoluminescence (PL) from the long-lived exciton of an H-aggregated PBI crystal. The crystal structure reveals a rotationally displaced H-aggregated arrangement of PBI chromophores, in which transition from the lowest energy exciton state is partially allowed. Polarized absorption spectroscopy on single microcrystals confirms an unusually large exciton splitting of ∼1265 cm^-1 that stabilizes the lower exciton state, and inhibits excimer formation. A PL Mueller

SUBMITTER: Samanta S 

PROVIDER: S-EPMC7441499 | biostudies-literature | 2020 Jun

REPOSITORIES: biostudies-literature