at Google ScholarTitle data
Duda, Eimantas ; Hall, David ; Bagnich, Sergey ; Carpenter-Warren, Cameron L. ; Saxena, Rishabh ; Wong, Michael Y. ; Cordes, David B. ; Slawin, Alexandra M. Z. ; Beljonne, David ; Olivier, Yoann ; Zysman-Colman, Eli ; Köhler, Anna:
Enhancing Thermally Activated Delayed Fluorescence by Fine-Tuning the Dendron Donor Strength.
In: The Journal of Physical Chemistry B.
Vol. 126
(2022)
Issue 2
.
- pp. 552-562.
ISSN 1520-5207
DOI: https://doi.org/10.1021/acs.jpcb.1c05749
Abstract in another language
Thermally activated delayed fluorescence (TADF) relies on a small energy gap between the emissive singlet and the non-emissive triplet state, obtained by reducing the wavefunction overlap between donor and acceptor moieties. Efficient emission, however, requires maintaining a good oscillator strength, which is itself based on sufficient overlap of the wavefunctions between donor and acceptor moieties. We demonstrate an approach to subtly fine-tune the required wavefunction overlap by employing donor-dendrons of changing functionality. We use a carbazolyl-phthalonitrile based donor-acceptor core, 2CzPN, as a reference emitter, and progressively localize the hole density through substitution at the 3,6-positions of the carbazole donors (Cz) with further carbazole, (4-tert-butylphenyl)amine (tBuDPA) and phenoxazine (PXZ). Using detailed photoluminescence studies, complemented with Density Functional Theory (DFT) calculations, we show that this approach permits a gradual decrease of the singlet-triplet gap, ΔEST, from 300 meV to around 10 meV in toluene, yet we also demonstrate why a small ΔEST alone is not enough. While sufficient oscillator strength is maintained with the Cz- and tBuDPA-based donor dendrons, this is not the case for the PXZ-based donor dendron, where the wavefunction overlap is reduced too strongly. Overall, we find the donor-dendron extension approach allows successful fine-tuning of the emitter photoluminescence properties.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Additional notes: | PMID: 34995068 |
| Institutions of the University: | Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter > Chair Experimental Physics II - Optoelectronics of Soft Matter - Univ.-Prof. Dr. Anna Köhler Faculties Faculties > Faculty of Mathematics, Physics und Computer Science |
| Result of work at the UBT: | Yes |
| DDC Subjects: | 500 Science > 530 Physics |
| Date Deposited: | 17 Jan 2022 08:44 |
| Last Modified: | 08 Feb 2022 12:54 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/68363 |