Solution‐processed AIEgen NIR OLEDs with EQE Approaching 15

• Published in: Angewandte Chemie International Edition Vol. 61; no. 26; pp. e202204279 - n/a
• Main Authors: Yu, Ying, Xing, Hao, Liu, Dan, Zhao, Mengying, Sung, Herman H.‐Y., Williams, Ian D., Lam, Jacky W. Y., Xie, Guohua, Zhao, Zheng, Tang, Ben Zhong
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 27.06.2022; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Aggregation Induced Emission; Chemistry; Chemistry, Multidisciplinary; Emitters; Excitons; Medical imaging; Near Infrared; Near infrared radiation; Organic Light Emitting Diode; Organic light emitting diodes; Physical Sciences; Quantum efficiency; Science & Technology; Solution Process; Thermally Activated Delayed Fluorescence; Wavelength; AMPLIFIED SPONTANEOUS EMISSION; Aggregation Induced Emission; Organic Light Emitting Diode; MOBILITY; DEEP-RED; Near Infrared; ACTIVATED DELAYED FLUORESCENCE; EMITTERS; ORGANIC SEMICONDUCTORS; ELECTROLUMINESCENCE; Solution Process; LIGHT-EMITTING-DIODES; Thermally Activated Delayed Fluorescence; DEVICES; EFFICIENCY ROLL-OFF
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.202204279

Organic near‐infrared (NIR) luminogens have attracted intensive attention considering their vast potential applications in areas like bioimaging, organic light‐emitting diodes (OLEDs) and night‐vision telecommunication. However, organic NIR luminogens with high solid quantum efficiencies are scarce, limiting their applications. Here, we reported an electron‐deficient acceptor, BSM, based on dithiafulvalene and benzothiadiazole, which could work as a strong acceptor to produce highly efficient NIR emitters with aggregation‐induced emission (AIE) property. One of the AIEgens, TBSMCN emitted at 820 nm with a solid quantum yield of 10.7 %. When applied to solution‐processed OLEDs, an outstanding external quantum efficiency (EQE) of 9.4 % was achieved with a peak wavelength at 728 nm. Moreover, its non‐doped device could achieve an extraordinary EQE of 2.2 % peaking at 804 nm. In the further optimized configuration, when an extra sensitizer was added to harvest triplet excitons, the EQE unprecedentedly soared up to 14.3 % with a peak wavelength of 750 nm. A new acceptor core, obtained by fusing dithiafulvalene with benzothiadiazole, was utilized to construct near‐infrared AIEgen luminophores, in which TBSMCN emitted at 820 nm in the solid state and featured a high quantum yield of 10.7 %. The doped and non‐doped NIR OLEDs achieved excellent external quantum efficiencies of 14.3 % and 2.2 % peaking at 750 and 804 nm, respectively.