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Alignment of Heptagonal Diimide and Triazine Enables Narrowband Pure‐Blue Organic Light‐Emitting Diodes with Low Efficiency Roll‐Off.
- Source :
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Angewandte Chemie International Edition . 11/27/2023, Vol. 62 Issue 48, p1-7. 7p. - Publication Year :
- 2023
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Abstract
- The endeavor to develop high‐performance narrowband blue organic light‐emitting diodes (OLEDs) with low efficiency roll‐off represents an attractive challenge. Herein, we introduce a hetero‐acceptor design strategy centered around the heptagonal diimide (BPI) building block to create an efficient thermally activated delayed fluorescence (TADF) sensitizer. The alignment of a twisted BPI unit and a planar diphenyltriazine (TRZ) fragment imparts remarkable exciton dynamic properties to 26tCz‐TRZBPI, including a fast radiative decay rate (kR) of 1.0×107 s−1 and a swift reverse intersystem crossing rate (kRISC) of 1.8×106 s−1, complemented by a slow non‐radiative decay rate (kNR) of 6.0×103 s−1. Consequently, 26tCz‐TRZBPI facilitates the fabrication of high‐performance narrowband pure‐blue TADF‐sensitized fluorescence OLEDs (TSF‐OLEDs) with a maximum external quantum efficiency (EQEmax) of 24.3 % and low efficiency roll‐off even at a high brightness level of 10000 cd m−2 (EQE10000: 16.8 %). This showcases a record‐breaking external quantum efficiency at a high luminance level of 10000 cd m−2 for narrowband blue TSF‐OLEDs. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14337851
- Volume :
- 62
- Issue :
- 48
- Database :
- Academic Search Index
- Journal :
- Angewandte Chemie International Edition
- Publication Type :
- Academic Journal
- Accession number :
- 173760429
- Full Text :
- https://doi.org/10.1002/anie.202312297