Facile access to deep red/near-infrared emissive AIEgens for efficient non-doped OLEDs

Will W H Lee; Zheng Zhao; Yuanjing Cai; Zeng Xu; Ying Yu; Yu Xiong; Ryan T K Kwok; Yue Chen; Nelson L C Leung; Dongge Ma; Jacky W Y Lam; Anjun Qin; Ben Zhong Tang

doi:10.1039/c8sc01377b

Facile access to deep red/near-infrared emissive AIEgens for efficient non-doped OLEDs

Chem Sci. 2018 Jun 25;9(28):6118-6125. doi: 10.1039/c8sc01377b. eCollection 2018 Jul 28.

Authors

Will W H Lee¹, Zheng Zhao^{1

2}, Yuanjing Cai³, Zeng Xu³, Ying Yu¹, Yu Xiong², Ryan T K Kwok¹, Yue Chen³, Nelson L C Leung¹, Dongge Ma³, Jacky W Y Lam¹, Anjun Qin³, Ben Zhong Tang^{1

2

3}

Affiliations

¹ Department of Chemistry , Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , Institute of Molecular Functional Materials , Division of Life Science and Biomedical Engineering , State Key Laboratory of Nanoscience , The Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong , China . Email: tangbenz@ust.hk.
² HKUST-Shenzhen Research Institute , No. 9 Yuexing 1st RD, South Area, Hi-tech Park, Nanshan , Shenzhen 518057 , China.
³ NSFC Center for Luminescence from Molecular Aggregates , SCUT-HKUST Joint Research Laboratory , State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , China . Email: msdgma@scut.edu.cn.

Abstract

Notwithstanding the huge demand in bio-imaging and optoelectronics, the construction of highly emissive deep red/near infrared (DR/NIR) organic luminogens is still a big challenge because a narrow energy gap generally leads to low photoluminescence quantum yield. It is even more difficult to afford DR/NIR emitters in the solid state due to the aggregation caused quenching (ACQ) effect. In this work, we found that the direct attachment of a tetraphenylethylene substituted arylamine to the electron accepting 2,1,3-benzothiadiazole produces DR/NIR AIE luminogens with bright emission facilely and efficiently. And the emission wavelengths could be tuned from the red to the DR/NIR region by regulating the variety of the substituents. The long emission wavelength and high photoluminescence quantum yield of these AIEgens are ascribed to the effective intramolecular charge transfer and the suppressed intramolecular motion. Furthermore, non-doped OLEDs based on one of the AIEgens showed an EL emission at 684 nm with a large radiance of 5772 mW Sr^-1 m^-2 and an impressive external quantum efficiency (EQE) of 1.73%.