10.1021/acs.joc.8b02187
https://zenodo.org/records/3675279
oai:zenodo.org:3675279
Patrycja Stachelek
Patrycja Stachelek
Durham University
Jonathan S. Ward
Jonathan S. Ward
Durham University
Paloma L. dos Santos
Paloma L. dos Santos
Durham University
Andrew Danos
Andrew Danos
Durham University
Marco Colella
Marco Colella
Durham University
Nils Haase
Nils Haase
Merck KGaA
Samuel J. Raynes
Samuel J. Raynes
Durham University
Andrei S. Batsanov
Andrei S. Batsanov
Durham University
Martin R. Bryce
Martin R. Bryce
Durham University
Andrew P. Monkman
Andrew P. Monkman
Durham University
Molecular Design Strategies for Color Tuning of Blue TADF Emitters
Zenodo
2019
TADF, photophysics, blue OLEDs, charge transfer, donor/acceptor tuning
2019-07-17
Creative Commons Attribution 4.0 International
New thermally activated delayed fluorescence (TADF) blue emitter molecules based on the known donor–acceptor–donor (D–A–D)-type TADF molecule, 2,7-bis(9,9-dimethylacridin-10-yl)-9,9-dimethylthioxanthene-S,S-dioxide (DDMA-TXO2), are reported. The motivation for the present investigation is via the use of rational molecular design, based on DDMA-TXO2, to elevate the organic light emitting diode (OLED) performance and obtain deeper blue color coordinates. To achieve this goal, the strength of the donor (D) unit and acceptor (A) units have been tuned with methyl substituents. The methyl functionality on the acceptor was also expected to modulate the D–A torsion angle in order to obtain a blue shift in the electroluminescence. The effect of regioisomeric structures has also been investigated. Herein, we report the photophysical, electrochemical, and single-crystal X-ray crystallography data to assist with the successful OLED design. The methyl substituents on the DDMA-TXO2 framework have profound effects on the photophysics and color coordinates of the emitters. The weak electron-donating methyl groups alter the redox properties of the D and A units and consequently affect the singlet and triplet levels but not the energy gap (ΔEST). By systematically manipulating all of the aforementioned factors, devices have been obtained with acceptor-substituted III with a maximum external quantum efficiency of 22.6% and Commission Internationale de l’Éclairage coordinates of (0.15, 0.18) at 1000 cd m–2.
European Commission
10.13039/501100000780
732013
Development of high-performance, hyperfluorescence OLEDs for use in display applications and solid state lighting