High Performance Narrowband Pure-red OLEDs with External Quantum Efficiencies up to 36.1% and Ultra-low Efficiency Roll-off

• Published in: Advanced materials (Weinheim) 2022-05, p.e2201442
• Main Authors: Zou, Yang, Hu, Jiahao, Yu, Mingxin, Miao, Jingsheng, Xie, Ziyang, Qiu, Yuntao, Cao, Xiaosong, Yang, Chuluo
• Format: Article
• Language: English
• ISSN: 1521-4095

High color-purity blue and green organic light-emitting diodes (OLEDs) have been resolved thanks to the development of B/N-based polycyclic multiple resonance (MR) emitters. However, due to the derivatization limit of B/N polycyclic structures, the design of red MR emitters remains challenging. Herein, we report a series of novel red MR emitters by para-positioning N-π-N, O-π-O, B-π-B pairs onto a benzene ring to construct a MR central core. These emitters can be facilely and modularly synthesized, allowing for easy fine-tuning of emission spectra by peripheral groups. Moreover, these red MR emitters display excellent photophysical properties such as near-unity photoluminescence quantum yield (PLQY), fast radiative decay rate (k ) up to 7.4 ⅹ 10 s , and most importantly, narrowband emission with full-width at half-maximum (FWHM) of 32 nm. Incorporating these MR emitters, pure red OLEDs sensitized by phosphor realize state-of-the-art device performances with external quantum efficiency (EQE) exceeding 36%, ultra-low efficiency roll-off (EQE remains as high as 25.1% at the brightness of 50000 cd m ), ultra-high brightness over 130000 cd m , together with good device lifetime. This article is protected by copyright. All rights reserved.