Dielectric control of reverse intersystem crossing in thermally activated delayed fluorescence emitters.

ABSTRACT: Thermally activated delayed fluorescence enables organic semiconductors with charge transfer-type excitons to convert dark triplet states into bright singlets via reverse intersystem crossing. However, thus far, the contribution from the dielectric environment has received insufficient attention. Here we study the role of the dielectric environment in a range of thermally activated delayed fluorescence materials with varying changes in dipole moment upon optical excitation. In dipolar emitters, we observe how environmental reorganization after excitation triggers the full charge transfer exciton formation, minimizing the singlet-triplet energy gap, with the emergence of two (reactant-inactive) modes acting as a vibrational fingerprint of the charge transfer product. In contrast, the dielec

SUBMITTER: Gillett AJ 

PROVIDER: S-EPMC7613666 | biostudies-literature | 2022 Oct

REPOSITORIES: biostudies-literature