Chem. J. Chinese Universities ›› 2023, Vol. 44 ›› Issue (12): 20230274.doi: 10.7503/cjcu20230274

• Organic Chemistry • Previous Articles     Next Articles

High-efficiency Near-infrared Thermally Activated Delayed Fluorescence Based on Tetracyano Acceptor

WANG Xiaojing, LIU Yixia, LI Yang, YANG Chenzong, FUNG Mankeung(), FAN Jian()   

  1. Jiangsu Key Laboratory for Carbon?Based Functional Materials & Devices,Institute of Functional Nano & Soft Materials,Soochow University,Suzhou 215123,China
  • Received:2023-06-09 Online:2023-12-10 Published:2023-08-23
  • Contact: FUNG Mankeung E-mail:mkfung@suda.edu.cn;jianfan@suda.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(21871199)

Abstract:

The near-infrared thermally activated delayed fluorescence(TADF) material 11,12-bis[4-(diphenyla- min)phenyl]dipyrido[3,2-a:2',3'-c]phenazine-3,6,10,13-tetracarbonitrile(FCNPZ-TPA) was designed and synthesized with dipyridinophenazine as the acceptor unit and triphenylamine(TPA) as the donor unit. The introduction of four cyano groups into the acceptor unit increased its electron-withdrawing strength. Considering that tripheny-lamine is a strong electron-donating group, we successfully pushed the emission of FCNPZ-TPA into Near Infra(NIR) region via the incorporation of strong donor and strong acceptor. The steric hindrance between donor(D) and acceptor(A) led to a twisted D-A molecular configuration of FCNPZ-TPA, and thus achieving a small singlet-triplet energy gap(ΔEST). Due to the rigid molecular skeleton and small ΔEST, FCNPZ-TPA based organic light-emitting diode(OLED) exhibited a state-of-the-art maximum external quantum efficiency(EQE) of 8.01% at 742 nm when doped in the 4,4'-bis(N-carbazolyl)-1,1'-biphenyl.

Key words: Thermally activated delayed fluorescence, Near-infrared, Singlet-triplet energy gap, External quantum efficiency

CLC Number: 

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