|
Authors
|
Cucchi, M. ; Matulaitis, T. ; Kukhta, N.A. ; Grazulevicius, J.V. ; Reineke, S. ; Scholz, R.
|
|
Title
|
Influence of the dielectric constant around an emitter on its delayed fluorescence
|
|
Date
|
23.10.2019
|
|
Number
|
57248
|
|
Abstract
|
The photophysical properties of emitting charge-transfer states are often reported to be profoundly influenced by the dielectric environment that surrounds the emitter. This poses a technological challenge because chromophores based on thermally activated delayed fluorescence used in organic light-emitting diodes feature a strong charge-transfer character of the emitting state, and their photophysics can be greatly altered by the properties of the host material in the emitting layer. In this work, three isomers with different degrees of steric hindrance against the rotation around the donor-acceptor connection are investigated. Furthermore, a continuous variation of the dielectric constant is achieved by our mixing two solvents, and the time-resolved fluorescence is analyzed to understand how the ratio of the delayed fluorescence to the prompt fluorescence varies. The computation of the excitonic structure in media of different dielectric constants using an optimally tuned range-separated hybrid functional allows us to precisely interpret the experimental results and to pinpoint the participation of a higher triplet in the reverse intersystem crossing as the key factor causing the peculiar increase of delayed fluorescence at low dielectric constant for one of the model compounds.
|
|
Publisher
|
Physical Review Applied
|
|
Wikidata
|
|
|
Citation
|
Physical Review Applied 12 (2019) 044021
|
|
DOI
|
https://doi.org/10.1103/PHYSREVAPPLIED.12.044021
|
|
Tags
|
|
