The Important Role of Carbonyl in Accelerating Reverse Intersystem Crossing for Selenium‐Based Organoboron Narrowband Blue Emitters
Abstract
ABSTRACT Narrowband emissive polycyclic aromatic heterocycles (PAHs) featuring multiple resonance thermally‐activated delayed fluorescence (MR‐TADF) are capable of achieving high color purity with high exciton utilization efficiency via reverse intersystem crossing (RISC). However, thermally‐activated RISC remains the rate‐limiting step in MR‐TADF molecules due to the typically large singlet and triplet energy gap (Δ E ST ) and weak spin‐orbital coupling. To overcome this challenge, we introduce three carbonyl‐containing organoboron PAHs doped with selenium atoms (pSeXBNO, 1pSeXBN, and pSeXBN) for the first time. Introducing single or dual selenium‐embedded carbonyl heterocycles into the MR core enables significant orbital delocalization of carbonyls, resulting in small Δ E ST and ultrafast RISC rates of 7.5 × 10 6 s −1 for pSeXBNO, 1.5 × 10 7 s −1 for 1pSeXBN, and 4.8 × 10 7 s −1 for pSeXBN. The non‐sensitized OLED employing pSeXBN achieves an emission peak at 478 nm with a narrow bandwidth of 28 nm, along with a maximum external quantum efficiency (EQE) of 32.6% and retaining 28.4% at 1000 cd m −2 , representing state‐of‐the‐art performance for blue MR‐TADF materials. Moreover, bi‐color white OLED employing pSeXBN exhibits excellent performance with a maximum EQE of 30.9% and 23.2% retained at 1000 cd m −2 . These advances demonstrate the role of carbonyl here is of significant guidance in forwarding narrowband blue materials.
Article Details
Authors (20)
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
Yuling Chen
Zijian Chen
State Key Laboratory of Fine Chemicals, Frontiers Science Center for Smart Materials, School of Chemical Engineering
Suyu Liao
College of Chemistry and Chemical Engineering Key Laboratory for Preparation and Application of Ordered Structure Materials of Guangdong Province Shantou University Shantou P. R. China
Xinge Li
Sheng Liao
Department of Chemistry and Key Laboratory for Preparation and Application of Ordered Structural Materials of Guangdong Province, Shantou University 2 , Shantou 515063,
Denghui Liu
Guanwei Sun
Institute of Polymer Optoelectronic Materials and Devices Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials 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
Simin Jiang
School of Materials Science and Engineering
JunTao Hu
Yu Fu
Xuewei Nie
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
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
Tong Wang
Mengke Li
Ming‐De Li
School of Physics and Optoelectronic Engineering & Guangdong Provincial Key Laboratory of Sensing Physics and System Integration Applications Guangdong University of Technology Guangzhou Guangdong P.R. China
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