Weerasinghe, R.W., Suresh, S.M., Hall, D. et al. (8 more authors) (2024) A Boron, Nitrogen, and Oxygen Doped π-Extended Helical Pure Blue Multiresonant Thermally Activated Delayed Fluorescent Emitter for Organic Light Emitting Diodes That Shows Fast kRISC Without the Use of Heavy Atoms. Advanced Materials, 36 (26). 2402289. ISSN 0935-9648
Abstract
Narrowband emissive multiresonant thermally activated delayed fluorescence (MR-TADF) emitters are a promising solution to achieve the current industry-targeted color standard, Rec. BT.2020-2, for blue color without using optical filters, aiming for high-efficiency organic light-emitting diodes (OLEDs). However, their long triplet lifetimes, largely affected by their slow reverse intersystem crossing rates, adversely affect device stability. In this study, a helical MR-TADF emitter (f-DOABNA) is designed and synthesized. Owing to its π-delocalized structure, f-DOABNA possesses a small singlet-triplet gap, ΔEST, and displays simultaneously an exceptionally faster reverse intersystem crossing rate constant, kRISC, of up to 2 × 10⁶ s⁻¹ and a very high photoluminescence quantum yield, ΦPL, of over 90% in both solution and doped films. The OLED with f-DOABNA as the emitter achieved a narrow deep-blue emission at 445 nm (full width at half-maximum of 24 nm) associated with Commission Internationale de l'Éclairage (CIE) coordinates of (0.150, 0.041), and showed a high maximum external quantum efficiency, EQEmax, of ≈20%.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2024 The Authors. Advanced Materials published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | blue emitter; boron; multiresonant thermally activated delayed fluorescence; organic light‐emitting diodes; reverse intersystem crossing |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Organic Chemistry (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 29 Apr 2024 13:32 |
Last Modified: | 07 Aug 2024 14:50 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/adma.202402289 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:211969 |