Stepwise Molecular Engineering Toward High‐Performance Deep‐Blue Narrowband OLEDs: Rigidity as the Foundation, Symmetry as the Key
Abstract
ABSTRACT Developing high‐color‐purity deep‐blue emitters that meet the BT.2020 standard remains a critical challenge in organic light‐emitting diodes (OLEDs). Herein, a stepwise molecular engineering strategy for simultaneously accelerating reverse intersystem crossing rate ( k RISC ) and narrowing full‐width at half maxima (FWHM) is proposed for deep‐blue materials. By sequentially enhancing molecular rigidity, strengthening resonant strength, and completing molecular symmetry, a deep‐blue emitter (DBNDICz), constructed on modified diboron multiple‐resonance scaffold, is developed with peak of 452 nm, ultra‐narrow FWHM of 15 nm (0.08 eV) and k RISC of 3.0 × 10 5 s − 1 . The dominant υ 0‐0 transition character of DBNDICz produces a Commission Internationale de I’Éclairage (CIE) coordinates of (0.144, 0.060). Moreover, the expanded conjugated skeleton facilitates horizontal dipole orientation of 93%, leading to a high maximum external quantum efficiency (EQE max ) of 24.2% in bottom‐emitting OLEDs. Impressively, top‐emitting OLED achieves a record‐setting blue index of 514 cd A − 1 CIEy − 1 with CIE (0.146, 0.036) and EQE max of 45.2%, establishing a benchmark for state‐of‐the‐art deep‐blue devices. Additionally, an operational lifetime (LT 50 ) of 154.2 h is achieved in an anthracene‐based host. These results represent one of the best performances reported for deep‐blue OLEDs with CIEy≤ 0.06, providing a robust design paradigm for high‐performance narrowband deep‐blue TADF emitters.
Article Details
Authors (15)
Yitong Zeng
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Jun‐Tao Hu
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Guo‐Xi Yang
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Zhizhi Li
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Mingliang Xie
Dongguan VOLT‐AMP Optoelectronic Technology Co. Ltd Dongguan P. R. China
Xianjie Li
Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Zhihai Yang
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Yu Fu
Yongxia Ren
Shaofeng Chen
Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Xiangyi Cheng
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Mengke Li
Yuguang Ma
Junji Kido
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China
Shi‐Jian Su
Guangdong Basic Research Center of Excellence for Energy and Information Polymer Materials Institute of Polymer Optoelectronic Materials and Devices State Key Laboratory of Luminescent Materials and Devices South China University of Technology Guangzhou P. R. China