Vacancy control in acene blends links exothermic singlet fission to coherence.

ABSTRACT: The fission of singlet excitons into triplet pairs in organic materials holds great technological promise, but the rational application of this phenomenon is hampered by a lack of understanding of its complex photophysics. Here, we use the controlled introduction of vacancies by means of spacer molecules in tetracene and pentacene thin films as a tuning parameter complementing experimental observables to identify the operating principles of different singlet fission pathways. Time-resolved spectroscopic measurements in combination with microscopic modelling enables us to demonstrate distinct scenarios, resulting from different singlet-to-triplet pair energy alignments. For pentacene, where fission is exothermic, coherent mixing between the photoexcited singlet and triplet-pair states is pr

SUBMITTER: Zeiser C 

PROVIDER: S-EPMC8390483 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature