Abstract

An ultrapure deep-blue multi-resonance-induced thermally activated delayed fluorescence material (DOB2-DABNA-A) is designed and synthesized. Benefiting from a fully resonating extended helical π-conjugated system, this compound has a small ΔEST value of 3.6 meV and sufficient spin–orbit coupling to exhibit a high-rate constant for reverse intersystem crossing (kRISC = 1.1 × 106 s–1). Furthermore, an organic light-emitting diode employing DOB2-DABNA-A as an emitter is fabricated; it exhibits ultrapure deep-blue emission at 452 nm with a small full width at half maximum of 24 nm, corresponding to Commission Internationale de l’Éclairage (CIE) coordinates of (0.145, 0.049). The high kRISC value reduces the efficiency roll-off, resulting in a high external quantum efficiency (EQE) of 21.6% at 1000 cd m–2.

The realization of a BT.2020 blue emitter is challenging due to the spectral redshift associated with π-extension. Here, the authors report a multi-resonance thermally activated delayed fluorescence emitter, exhibiting ultrapure deep-blue narrow emission and CIEy ≤ 0.05 exceeding 20% efficiency.

Details

Title
Highly efficient multi-resonance thermally activated delayed fluorescence material toward a BT.2020 deep-blue emitter
Author
Ochi, Junki 1   VIAFID ORCID Logo  ; Yamasaki, Yuki 2 ; Tanaka, Kojiro 1 ; Kondo, Yasuhiro 3 ; Isayama, Kohei 3 ; Oda, Susumu 4 ; Kondo, Masakazu 5 ; Hatakeyama, Takuji 1   VIAFID ORCID Logo 

1  Kyoto University, Department of Chemistry, Graduate School of Science, Kyoto, Japan (GRID:grid.258799.8) (ISNI:0000 0004 0372 2033) 
2  Kwansei Gakuin University, Department of Chemistry, Graduate School of Science and Technology, Sanda, Japan (GRID:grid.258777.8) (ISNI:0000 0001 2295 9421) 
3  Ltd., SK JNC Japan Co., Chiba, Japan (GRID:grid.452325.7) 
4  Toyo University, Department of Applied Chemistry, Graduate School of Science and Engineering, Saitama, Japan (GRID:grid.265125.7) (ISNI:0000 0004 1762 8507) 
5  Ltd., JNC Co., Chiba, Japan (GRID:grid.452325.7) 
Pages
2361
Publication year
2024
Publication date
2024
Publisher
Nature Publishing Group
e-ISSN
20411723
Source type
Scholarly Journal
Language of publication
English
DOI
https://doi.org/10.1038/s41467-024-46619-8
ProQuest document ID
3030960412
Copyright
© The Author(s) 2024. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.