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Meng G, Zhou J, Han XS, Zhao W, Zhang Y, Li M, Chen CF, Zhang D, Duan L. B-N Covalent Bond Embedded Double Hetero-[n]helicenes for Pure Red Narrowband Circularly Polarized Electroluminescence with High Efficiency and Stability. Adv Mater 2024; 36:e2307420. [PMID: 37697624 DOI: 10.1002/adma.202307420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/22/2023] [Indexed: 09/13/2023]
Abstract
Chiral B/N embedded multi-resonance (MR) emitters open a new paradigm of circularly polarized (CP) organic light-emitting diodes (OLEDs) owing to their unique narrowband spectra. However, pure-red CP-MR emitters and devices remain exclusive in literature. Herein, by introducing a B-N covalent bond to lower the electron-withdrawing ability of the para-positioned B-π-B motif, the first pair of pure-red double hetero-[n]helicenes (n = 6 and 7) CP-MR emitter peaking 617 nm with a small full-width at half-maximum of 38 nm and a high photoluminescence quantum yield of ≈100% in toluene is developed. The intense mirror-image CP light produced by the enantiomers is characterized by high photoluminescence dissymmetry factors (gPL ) of +1.40/-1.41 × 10-3 from their stable helicenes configuration. The corresponding devices using these enantiomers afford impressive CP electroluminescence dissymmetry factors (gEL ) of +1.91/-1.77 × 10-3 , maximum external quantum efficiencies of 36.6%/34.4% and Commission Internationale de I'Éclairage coordinates of (0.67, 0.33), exactly satisfying the red-color requirement specified by National Television Standards Committee (NTSC) standard. Notably a remarkable long LT95 (operational time to 95% of the initial luminance) of ≈400 h at an initial brightness of 10,000 cd m-2 is also observed for the same device, representing the most stable CP-OLED up to date.
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Affiliation(s)
- Guoyun Meng
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Jianping Zhou
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Xu-Shuang Han
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Wenlong Zhao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yuewei Zhang
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Meng Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Chuan-Feng Chen
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Dongdong Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Lian Duan
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
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