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Liu H, Wang Y, Zhao X, Song Y, Lin L, Fan J, Wang CK. Exploration of red and deep red Thermally activated delayed fluorescence molecules constructed via intramolecular locking strategy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 325:125110. [PMID: 39260238 DOI: 10.1016/j.saa.2024.125110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2024] [Revised: 08/12/2024] [Accepted: 09/06/2024] [Indexed: 09/13/2024]
Abstract
Red and deep red (DR) organic light-emitting diodes (OLEDs) have garnered increasing attention due to their widespread applications in display technology and lighting devices. However, most red OLEDs exhibit low luminescence efficiency, severely limiting their practical applications. To address this challenge, we theoretically design four novel TADF molecules with red and DR luminescence using intramolecular locking strategies building upon the experimental findings of DCN-DLB and DCN-DSP, and their crystal structures are predicted with the lower energy and higher packing density. The photophysical properties and luminescence mechanism of six molecules in toluene and crystal are clarified using the first principles calculation and thermal vibration correlation function (TVCF) method. The proposed design strategy is anticipated to offer several advantages: enhanced electron-donating capabilities, more rigid structures, longer emission wavelengths and higher luminescence efficiency. Specifically, we introduce oxygen atoms and nitrogen atoms as intramolecular locks, and the newly developed DCN-DBF and DCN-PHC have redshifted emission, narrow singlet-triplet energy gap (ΔEST), fast reverse intersystem crossing rate and enhanced photoluminescence quantum yield (PLQY). Notably, DCN-DBF achieves both long wavelength emission and high efficiency, with emission peaks at 598 nm and 587 nm corresponding to PLQY of 52.13 % and 43.42 % in toluene and crystal, respectively. Our work not only elucidates the relationship between molecular structures and photophysical properties, but also proposes feasible intramolecular locking design strategies and four promising red and DR TADF molecules, which could provide a valuable reference for the design of more efficient red and DR TADF emitters.
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Affiliation(s)
- Huanling Liu
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
| | - Yan Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
| | - Xin Zhao
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
| | - Yuzhi Song
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
| | - Lili Lin
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China
| | - Jianzhong Fan
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China; State Key Laboratory of Luminescent Materials and Devices, South China University of Technology
| | - Chuan-Kui Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
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Bai Z, Wang J, Zou P, Jiang R, Yang D, Ma D, Tang BZ, Zhao Z. Creating Efficient Red Thermally Activated Delayed Fluorescence Materials with Cyano-Substituted 11,12-Diphenyldipyrido[3,2-a:2',3'-c]phenazine Acceptors. Chemistry 2024; 30:e202303990. [PMID: 38060300 DOI: 10.1002/chem.202303990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/07/2023] [Accepted: 12/07/2023] [Indexed: 12/08/2023]
Abstract
Red luminescent materials are essential components for full color display and white lightening based on organic light-emitting diode (OLED) technology, but the extension of emission color towards red or deep red region generally leads to decreased photoluminescence and electroluminescence efficiencies. Herein, we wish to report two new luminescent molecules (2CNDPBPPr-TPA and 4CNDPBPPr-TPA) consisting of cyano-substituted 11,12-diphenyldipyrido[3,2-a:2',3'-c]phenazine acceptors and triphenylamine donors. As the increase of cyano substituents, the emission wavelength is greatly red-shifted and the reverse intersystem crossing process is promoted, resulting in strong red delayed fluorescence. Meanwhile, due to the formation of intramolecular hydrogen bonds, the molecular structures become rigidified and planarized, which brings about large horizontal dipole ratios. As a result, 2CNDPBPPr-TPA and 4CNDPBPPr-TPA can perform as emitters efficiently in OLEDs, furnishing excellent external quantum efficiencies of 28.8 % at 616 nm and 20.2 % at 648 nm, which are significantly improved in comparison with that of the control molecule without cyano substituents. The findings in this work demonstrate that the introduction of cyano substituents to the acceptors of delayed fluorescence molecules could be a facile and effective approach to explore high-efficiency red or deep red delayed fluorescence materials.
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Affiliation(s)
- Zhentao Bai
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Jianghui Wang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Peng Zou
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Ruming Jiang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Dezhi Yang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Ben Zhong Tang
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
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Diesing S, Zhang L, Zysman-Colman E, Samuel IDW. A figure of merit for efficiency roll-off in TADF-based organic LEDs. Nature 2024; 627:747-753. [PMID: 38538942 PMCID: PMC10972759 DOI: 10.1038/s41586-024-07149-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 02/01/2024] [Indexed: 04/01/2024]
Abstract
Organic light-emitting diodes (OLEDs) are a revolutionary light-emitting display technology that has been successfully commercialized in mobile phones and televisions1,2. The injected charges form both singlet and triplet excitons, and for high efficiency it is important to enable triplets as well as singlets to emit light. At present, materials that harvest triplets by thermally activated delayed fluorescence (TADF) are a very active field of research as an alternative to phosphorescent emitters that usually use heavy metal atoms3,4. Although excellent progress has been made, in most TADF OLEDs there is a severe decrease of efficiency as the drive current is increased, known as efficiency roll-off. So far, much of the literature suggests that efficiency roll-off should be reduced by minimizing the energy difference between singlet and triplet excited states (ΔEST) to maximize the rate of conversion of triplets to singlets by means of reverse intersystem crossing (kRISC)5-20. We analyse the efficiency roll-off in a wide range of TADF OLEDs and find that neither of these parameters fully accounts for the reported efficiency roll-off. By considering the dynamic equilibrium between singlets and triplets in TADF materials, we propose a figure of merit for materials design to reduce efficiency roll-off and discuss its correlation with reported data of TADF OLEDs. Our new figure of merit will guide the design and development of TADF materials that can reduce efficiency roll-off. It will help improve the efficiency of TADF OLEDs at realistic display operating conditions and expand the use of TADF materials to applications that require high brightness, such as lighting, augmented reality and lasing.
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Affiliation(s)
- S Diesing
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK
- Organic Semiconductor Centre, EaStCHEM, School of Chemistry, St Andrews, UK
| | - L Zhang
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK
- Organic Semiconductor Centre, EaStCHEM, School of Chemistry, St Andrews, UK
| | - E Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM, School of Chemistry, St Andrews, UK.
| | - I D W Samuel
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, UK.
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Jin YX, Chen ZQ, Zhang K, Yang CZ, Pan ZH, Ding L, Sun YQ, Wang CK, Fung MK, Fan J. Highly Efficient Luminescence from a Red Thermally Activated Delayed Fluorescence Emitter with Flexible Conformation of Ancillary Groups. Chemistry 2023; 29:e202301921. [PMID: 37470684 DOI: 10.1002/chem.202301921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/20/2023] [Accepted: 07/20/2023] [Indexed: 07/21/2023]
Abstract
Robust scaffolds were typically applied in thermally activated delayed fluorescence (TADF) molecules to suppress the non-radiative decay, trigger the fast spin-flipping, and enhance the light out-coupling efficiency. Herein, we disclosed for the first time the positive effect of flexible conformation of ancillary groups on the photophysical properties of TADF emitter. The red TADF emitter Ph-TPA with flexible conformation demonstrated small excited-state structural distortion and low reorganization energy compared to the counterpart Mc-TPA with a rigid macrocycle. Consequently, Ph-TPA showed an excellent photoluminescent quantum yield (PLQY) of 92 % and a state-of-the-art external quantum efficiency (EQE) of 30.6 % at 630 nm. This work could deepen our understanding of structure-property relationships of organic luminophores and help us to rationalize the design of efficient TADF materials.
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Affiliation(s)
- Yu-Xin Jin
- Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, China
| | - Zi-Qi Chen
- Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, China
| | - Kai Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology School of Physics and Electronics, Shandong Normal University, 250014, Jinan, China
| | - Chen-Zong Yang
- Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, China
| | - Ze-Hui Pan
- Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, China
| | - Lei Ding
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, 215009, China
| | - Yan-Qiu Sun
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu, 215009, China
| | - Chuan-Kui Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology School of Physics and Electronics, Shandong Normal University, 250014, Jinan, China
| | - Man-Keung Fung
- Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, China
| | - Jian Fan
- Institute of Functional Nano & Soft Materials (FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu, 215123, China
- State Key Laboratory of Structural Chemistry Fujian Institute of Research on Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 35002, China
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Hu J, Jiang S, Zhang D, Zhao T, Lin F, Meng L, Chen X, Lu C. Rational Design of Highly Efficient Orange-Red/Red Thermally Activated Delayed Fluorescence Emitters with Submicrosecond Emission Lifetimes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2300808. [PMID: 37279379 PMCID: PMC10427351 DOI: 10.1002/advs.202300808] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/15/2023] [Indexed: 06/08/2023]
Abstract
The development of orange-red/red thermally activated delayed fluorescence (TADF) materials with both high emission efficiencies and short lifetimes is highly desirable for electroluminescence (EL) applications, but remains a formidable challenge owing to the strict molecular design principles. Herein, two new orange-red/red TADF emitters, namely AC-PCNCF3 and TAC-PCNCF3, composed of pyridine-3,5-dicarbonitrile-derived electron-acceptor (PCNCF3) and acridine electron-donors (AC/TAC) are developed. These emitters in doped films exhibit excellent photophysical properties, including high photoluminescence quantum yields of up to 0.91, tiny singlet-triplet energy gaps of 0.01 eV, and ultrashort TADF lifetimes of less than 1 µs. The TADF-organic light-emitting diodes employing the AC-PCNCF3 as emitter achieve orange-red and red EL with high external quantum efficiencies of up to 25.0% and nearly 20% at doping concentrations of 5 and 40 wt%, respectively, both accompanied by well-suppressed efficiency roll-offs. This work provides an efficient molecular design strategy for developing high-performance red TADF materials.
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Affiliation(s)
- Jia‐Xuan Hu
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional MaterialsXiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian361021China
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
| | - Shanshan Jiang
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional MaterialsXiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian361021China
| | - Dong‐Hai Zhang
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional MaterialsXiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian361021China
| | - Tianxiang Zhao
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional MaterialsXiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian361021China
| | - Fu‐Lin Lin
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional MaterialsXiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian361021China
| | - Lingyi Meng
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional MaterialsXiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian361021China
| | - Xu‐Lin Chen
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional MaterialsXiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian361021China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of ChinaFuzhouFujian350108China
| | - Can‐Zhong Lu
- State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian350002China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional MaterialsXiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian361021China
- School of Physical Science and TechnologyShanghaiTech UniversityShanghai201210China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of ChinaFuzhouFujian350108China
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Wang H, Chen JX, Zhou L, Zhang X, Yu J, Wang K, Zhang XH. A dual-locked triarylamine donor enables high-performance deep-red/NIR thermally activated delayed fluorescence organic light-emitting diodes. MATERIALS HORIZONS 2023; 10:2997-3004. [PMID: 37194342 DOI: 10.1039/d3mh00445g] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Deep-red/near-infrared (DR/NIR) organic light-emitting diodes (OLEDs) have attracted a great deal of attention due to their widespread application fields, such as night-vision devices, optical communication, and information-secured displays. However, most DR/NIR OLEDs show low electroluminescence efficiencies, hampering their applications. Herein, we constructed a high-performance DR/NIR thermally activated delayed fluorescence (TADF) emitter based on an advanced dual-locked triarylamine donor (D) unit. Promisingly, such a novel D segment brings numerous advantages: a larger stereoscopic architecture, an enhanced electron-donating ability, and a stiffer molecular structure. In view of these features, the newly developed emitter DCN-DSP shows redshifted emission, a narrowed ΔEST, an enhanced PLQY value and aggregation-induced emission (AIE) properties, which allows for effectively alleviating concentration quenching compared to the control compound using a conventional triarylamine derivative as D units. The DCN-DSP-based OLEDs with modulated doping concentrations exhibit champion EQEs of 36.2% at 660 nm, 26.1% at 676 nm and 21.3% at 716 nm, which are record-high efficiencies among all TADF OLEDs in the similar emission ranges. This work realizes the efficiency breakthrough of DR/NIR TADF OLEDs, and such a promising molecular design approach may inspire even better DR/NIR TADF emitters in the future.
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Affiliation(s)
- Hui Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China.
| | - Jia-Xiong Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, Guangdong, 510006, P. R. China
| | - Lu Zhou
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China.
| | - Xi Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China.
| | - Jia Yu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China.
| | - Kai Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China.
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, 215123, Jiangsu, P. R. China
| | - Xiao-Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu 215123, P. R. China.
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, Jiangsu, P. R. China
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Wang XJ, Liu H, Zhang K, Yang D, Pan ZH, Wang CK, Fung MK, Ma D, Fan J. Using azaacene as an acceptor unit to construct an ultraefficient red fluorophore with an EQE over 40. MATERIALS HORIZONS 2023; 10:938-944. [PMID: 36598032 DOI: 10.1039/d2mh01322c] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Azaacenes, which have been known for a long time, are of scientific and practical importance in organic electronics. Azaacenes once shone as the luminophore in organic light-emitting diodes (OLEDs). However, due to the low exciton utilization efficiency and/or the aggregation induced quenching (ACQ) effect, N-heteroacene based OLEDs generally showed inferior device performance. In this work, azaacene has been revisited and applied as an acceptor for a red fluorophore (AZA-TPA), where the judicious connection pattern between donor and acceptor maximized the harvest of singlet and triplet excitons, resulting in a high photoluminescence efficiency of 94.6% in doped films (3 wt%). In addition, the linearly-fused polycyclic structure contributed to a high horizontal emitting dipole ratio (Θ‖ = 90%). As a result, an AZA-TPA-based OLED achieved an unprecedented external quantum efficiency of 41.30% at 610 nm. This work will pave a new path for the development of efficient N-heteroacene-based fluorophores.
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Affiliation(s)
- Xiao-Jing Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
| | - Han Liu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
| | - Kai Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Dezhi Yang
- Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.
| | - Ze-Hui Pan
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
| | - Chuan-Kui Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Man-Keung Fung
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
| | - Dongge Ma
- Institute of Polymer Optoelectronic Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.
| | - Jian Fan
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002, China
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8
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Yang CZ, Pan ZH, Zhang K, Tai JW, Wang CK, Ding L, Fung MK, Fan J. Intramolecular charge transfer effect for highly efficient deep red and near infrared thermally activated delayed fluorescence. MATERIALS HORIZONS 2023; 10:945-951. [PMID: 36598051 DOI: 10.1039/d2mh01015a] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Thermally activated delayed fluorescence (TADF) materials with emission in the deep red and near infrared (DR/NIR) region are underresearched due to the limited choice of strong donor/acceptor units. The current mainstream strategy for the design of DR/NIR TADFs is to increase the acceptor strength via the introduction of multiple sub-acceptor units, thereby narrowing the bandgap. In this work, the intramolecular charge transfer (ICT) effect was applied for the development of acceptor units to achieve efficient DR/NIR TADFs. The ICT effect within the acceptor unit enhanced the π-electron delocalization, lowered the LUMO and redshifted the emission wavelength. In addition, the fusion of the donor unit into the planar acceptor skeleton rigidified the molecular structure and reduced the non-radiative decay. This proof-of-concept study demonstrated that ICT is an undoubtedly effective strategy for the rational design of efficient DR/NIR TADFs.
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Affiliation(s)
- Chen-Zong Yang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
| | - Ze-Hui Pan
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
| | - Kai Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China.
| | - Jing-Wen Tai
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
| | - Chuan-Kui Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China.
| | - Lei Ding
- School of Chemistry and Life Sciences, Suzhou University of Science and Technology, Suzhou, Jiangsu 215009, China.
| | - Man-Keung Fung
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
| | - Jian Fan
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China.
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 35002, China
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Wang H, Chen JX, Fan XC, Cheng YC, Zhou L, Zhang X, Yu J, Wang K, Zhang XH. A TADF Emitter with Dual Para-Positioned Donors Enables OLEDs with Improved Efficiency and CIE Coordinates Close to the Rec. 2020 Red Standard. ACS APPLIED MATERIALS & INTERFACES 2023; 15:1685-1692. [PMID: 36579770 DOI: 10.1021/acsami.2c18219] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Developing red thermally activated delayed fluorescence (TADF) emitters concurrently with high efficiency and emission color close to the BT.2020 red standard is an ongoing challenge. Herein, we developed a new red TADF emitter BCN-TPA, in which two identical donors are attached at the para-positions of one fused phenyl ring in the acceptor framework. Such an arrangement mode can lead the donors with an obvious superimposed effect comparing the conventional arrangement with edge-capped donors on the acceptor. Thus, BCN-TPA yields enhanced overall donor strength with numerous superiorities, such as high oscillator strength and narrow singlet-triplet energy difference, thus giving rise to red-shifted emission with improved overall exciton utilization. In an organic light-emitting diode, BCN-TPA presents efficient deep-red electroluminescence with a maximum external quantum efficiency of 27.6% and a peak at 656 nm, corresponding to CIE coordinates of (0.686, 0.304), which are very close to the red primary in the BT.2020 standard. To the best of our knowledge, this is one of the topmost efficiencies in the field of deep-red TADF OLEDs. This work exemplifies an easy design principle for constructing high-performance deep-red TADF emitters, providing unique molecular-level insights toward improving color quality and elevating efficiency based on conventional D-A type molecular frameworks.
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Affiliation(s)
- Hui Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu215123, P. R. China
| | - Jia-Xiong Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou, Guangdong510006, P. R. China
| | - Xiao-Chun Fan
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu215123, P. R. China
| | - Ying-Chun Cheng
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu215123, P. R. China
| | - Lu Zhou
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu215123, P. R. China
| | - Xi Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu215123, P. R. China
| | - Jia Yu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu215123, P. R. China
| | - Kai Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu215123, P. R. China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, Jiangsu, P. R. China
| | - Xiao-Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu215123, P. R. China
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou, 215123, Jiangsu, P. R. China
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10
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Liu H, Zhang K, Zou H, Mu Q, Song Y, Lin L, Xu Y, Wang CK, Fan J. Controllable construction of red thermally activated delayed fluorescence molecules based on a spiro-acridine donor. Phys Chem Chem Phys 2023; 25:1032-1044. [PMID: 36537471 DOI: 10.1039/d2cp05084f] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Red and near-infrared (NIR) thermally activated delayed fluorescence (TADF) molecules show excellent potential applications in organic light-emitting diodes (OLEDs). Due to the lack of systematic studies on the relationship between molecular structures and luminescence properties, both the species and amounts of red and NIR TADF molecules are far from meeting the requirements for practical applications. Herein, four new efficient molecules (DQCN-2spAs, TPCN-2spAs, DPCN-2spAs and BPCN-2spAs) are proposed and their photophysical properties are theoretically predicted based on first-principles calculations and thermal vibration correlation function (TVCF) theory. The results show that all molecules exhibit red or NIR emissions and they have fast radiative decay rates and reverse intersystem crossing (RISC) rates, and the excellent TADF luminescence properties are predicted. Moreover, based on spiro-acridine (spAs) as the donor unit, the combination with different acceptors can change the dihedral angle between the ground state and the excited state, the bending degree of the donor is positively correlated with the reorganization energy, and this feature can have a great influence on the non-radiative process. Furthermore, based on these theoretical predictions, experimental verifications are performed and the synthesized BPCN-2spAs is confirmed to be an efficient NIR TADF molecule. Thus, the relationships between basic molecular structures and photophysical properties are revealed, a feasible design strategy is applied and four promising red and NIR TADF molecules are proposed. All these results could contribute to the development of red and NIR TADF emitters and OLEDs.
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Affiliation(s)
- Huanling Liu
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Kai Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Haipei Zou
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Qingfang Mu
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Yuzhi Song
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Lili Lin
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Yuanyuan Xu
- School of Science, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China
| | - Chuan-Kui Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
| | - Jianzhong Fan
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, Institute of Materials and Clean Energy, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China. .,Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates (South China University of Technology), Guangzhou 510640, China
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11
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Zhang K, Wang X, Zhang Q, Wu Z, Li X, Mu Q, Fan J, Wang CK, Lin L. Insights on isomeric emitters with thermally activated delayed fluorescence: Comparison between solvent and crystal state. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 278:121328. [PMID: 35537262 DOI: 10.1016/j.saa.2022.121328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 04/03/2022] [Accepted: 04/26/2022] [Indexed: 06/14/2023]
Abstract
Thermally activated delayed fluorescence (TADF) molecules with aggregation-induced emission (AIE) properties have attracted great attention in recent studies. In this study, three isomeric emitters DPAC-4PYPM, DPAC-TRZ and DPAC-6PYPM with TADF are studied in toluene and crystal with the combination of polarizable continuum model (PCM) and quantum mechanics and molecular mechanics (QM/MM) method. Results show that tiny difference of intramolecular interaction is induced due to the variation in the acceptor group, thus similar geometries and stacking patterns in crystal are obtained for three molecules. Our calculation also indicates that the energy diagram is quite different for three molecules in both toluene and crystal state, while the participation of higher triplet excited states provide additional decay channels for the reverse intersystem crossing (RISC) process, which favors the generation of TADF. In addition, the bending vibrations of the phenyl in the donor and the stretching vibrations of the C=C and C-H bonds are suppressed due to the intermolecular interactions in crystal state, thus block the excited-state energy consumption pathway. It indicates that all three molecules are typical AIE systems. Our calculation results agree with experimental measurements and provide more useful information for TADF emitters with AIE properties.
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Affiliation(s)
- Kai Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Xiaofei Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Qun Zhang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Zhimin Wu
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Xiaofang Li
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Qingfang Mu
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Jianzhong Fan
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China
| | - Chuan-Kui Wang
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China.
| | - Lili Lin
- Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, 250014 Jinan, China.
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12
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Jiang C, Miao J, Zhang D, Wen Z, Yang C, Li K. Acceptor-Donor-Acceptor π-Stacking Boosts Intramolecular Through-Space Charge Transfer towards Efficient Red TADF and High-Performance OLEDs. Research (Wash D C) 2022; 2022:9892802. [PMID: 35935129 PMCID: PMC9275096 DOI: 10.34133/2022/9892802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/01/2022] [Indexed: 11/18/2022] Open
Abstract
Organic push-pull systems featuring through-space charge transfer (TSCT) excited states have been disclosed to be capable of exhibiting thermally activated delayed fluorescence (TADF), but to realize high-efficiency long-wavelength emission still remains a challenge. Herein, we report a series of strongly emissive orange-red and red TSCT-TADF emitters having (quasi)planar and rigid donor and acceptor segments which are placed in close proximity and orientated in a cofacial manner. Emission maxima (λem) of 594−599 nm with photoluminescence quantum yields (PLQYs) of up to 91% and delayed fluorescence lifetimes of down to 4.9 μs have been achieved for new acceptor-donor-acceptor (A-D-A) molecules in doped thin films. The presence of multiple acceptors and the strong intramolecular π-stacking interactions have been unveiled to be crucial for the efficient low-energy TSCT-TADF emissions. Organic light-emitting diodes (OLEDs) based on the new A-D-A emitters demonstrated electroluminescence with maximum external quantum efficiencies (EQEs) of up to 23.2% for the red TSCT-TADF emitters. An EQE of 18.9% at the brightness of 1000 cd m−2 represents one of the highest values for red TADF OLEDs. This work demonstrates a modular approach for developing high-performance red TADF emitters through engineering through-space interactions, and it may also provide implications to the design of TADF emitter with other colours.
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Affiliation(s)
- Chenglin Jiang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Jingsheng Miao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
| | - Danwen Zhang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
| | - Zhenhua Wen
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
| | - Kai Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, China
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13
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Shang A, Zhao L, Li Z, Cheng Z, Jin H, Feng Z, Chen Z, Zhang H, Lu P. Rational Design of a Near-infrared Fluorescent Material with High Solid-state Efficiency, Aggregation-induced Emission and Live Cell Imaging Property. Chem Res Chin Univ 2022. [DOI: 10.1007/s40242-022-2046-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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14
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Yang H, Zhang M, Zhao J, Pu C, Lin H, Tao S, Zheng C, Zhang X. Improving Efficiency of Red Thermally Activated Delayed Fluorescence Emitter by Introducing
Quasi‐Degenerate
Orbital Distribution. CHINESE J CHEM 2022. [DOI: 10.1002/cjoc.202100776] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Hao‐Yu Yang
- School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu Sichuan 610054 China
| | - Ming Zhang
- School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu Sichuan 610054 China
- Institute of Functional Nano & Soft Materials (FUNSOM) Soochow University Suzhou Jiangsu 215123 China
| | - Jue‐Wen Zhao
- School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu Sichuan 610054 China
| | - Chun‐Peng Pu
- School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu Sichuan 610054 China
| | - Hui Lin
- School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu Sichuan 610054 China
| | - Si‐Lu Tao
- School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu Sichuan 610054 China
| | - Cai‐Jun Zheng
- School of Optoelectronic Science and Engineering University of Electronic Science and Technology of China Chengdu Sichuan 610054 China
| | - Xiao‐Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM) Soochow University Suzhou Jiangsu 215123 China
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15
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Zhang Y, Miao J, Xiong J, Li K, Yang C. Rigid Bridge‐Confined Double‐Decker Platinum(II) Complexes Towards High‐Performance Red and Near‐Infrared Electroluminescence. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202113718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Youming Zhang
- College of Materials Science and Engineering Shenzhen University Shenzhen 518055 P.R. China
| | - Jingsheng Miao
- College of Materials Science and Engineering Shenzhen University Shenzhen 518055 P.R. China
| | - Jinfan Xiong
- College of Materials Science and Engineering Shenzhen University Shenzhen 518055 P.R. China
| | - Kai Li
- College of Materials Science and Engineering Shenzhen University Shenzhen 518055 P.R. China
| | - Chuluo Yang
- College of Materials Science and Engineering Shenzhen University Shenzhen 518055 P.R. China
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16
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Ji SC, Jiang S, Zhao T, Meng L, Chen XL, Lu CZ. Efficient yellow and red thermally activated delayed fluorescence materials based on a quinoxaline-derived electron-acceptor. NEW J CHEM 2022. [DOI: 10.1039/d2nj01072k] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Highly efficient yellow and red organic light emitting-diodes are realized by employing thermally activated delayed fluorescence emitters based on a new quinoxaline-derived electron-acceptor.
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Affiliation(s)
- Si-Chao Ji
- College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, P. R. China
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare-earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, P. R. China
| | - Shanshan Jiang
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare-earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, P. R. China
- Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Materials, Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, P. R. China
| | - Tianxiang Zhao
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare-earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, P. R. China
- University of Chinese Academy of Sciences, P. R. China
| | - Lingyi Meng
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare-earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, P. R. China
- Jiangxi Provincial Key Laboratory of Functional Molecular Materials Chemistry, Department of Materials, Metallurgy and Chemistry, Jiangxi University of Science and Technology, Ganzhou 341000, P. R. China
| | - Xu-Lin Chen
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare-earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, P. R. China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian 350108, P. R. China
| | - Can-Zhong Lu
- College of Chemistry, Fuzhou University, Fuzhou, Fujian 350108, P. R. China
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, P. R. China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare-earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, P. R. China
- University of Chinese Academy of Sciences, P. R. China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China, Fuzhou, Fujian 350108, P. R. China
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17
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Jiang R, Wu X, Liu H, Guo J, Zou D, Zhao Z, Tang BZ. High-Performance Orange-Red Organic Light-Emitting Diodes with External Quantum Efficiencies Reaching 33.5% based on Carbonyl-Containing Delayed Fluorescence Molecules. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2104435. [PMID: 34923776 PMCID: PMC8787409 DOI: 10.1002/advs.202104435] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/17/2021] [Indexed: 06/14/2023]
Abstract
Developing orange to red purely organic luminescent materials having external quantum efficiencies (ηext s) exceeding 30% is challenging because it generally requires strong intramolecular charge transfer, efficient reverse intersystem crossing (RISC), high photoluminescence quantum yield (ΦPL ), and large optical outcoupling efficiency (Φout ) simultaneously. Herein, by introducing benzoyl to dibenzo[a,c]phenazine acceptor, a stronger electron acceptor, dibenzo[a,c]phenazin-11-yl(phenyl)methanone, is created and employed for constructing orange-red delayed fluorescence molecules with various acridine-based electron donors. The incorporation of benzoyl leads to red-shifted photoluminescence with accelerated RISC, reduced delayed lifetimes, and increased ΦPL s, and the adoption of spiro-structured acridine donors promotes horizontal dipole orientation and thus renders high Φout s. Consequently, the state-of-the-art orange-red organic light-emitting diodes are achieved, providing record-high electroluminescence (EL) efficiencies of 33.5%, 95.3 cd A-1 , and 93.5 lm W-1 . By referring the control molecule without benzoyl, it is demonstrated that the presence of benzoyl can exert significant positive effect over improving delayed fluorescence and enhancing EL efficiencies, which can be a feasible design for robust organic luminescent materials.
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Affiliation(s)
- Ruming Jiang
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Xing Wu
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Hao Liu
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Jingjing Guo
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Dijia Zou
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Ben Zhong Tang
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
- Shenzhen Institute of Aggregate Science and TechnologySchool of Science and EngineeringThe Chinese University of Hong KongShenzhenGuangdong518172China
- AIE InstituteGuangzhou Development DistrictHuangpuGuangzhou510530China
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18
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Hu X, Qin Y, Li Z, Gao H, Gao T, Liu G, Dong X, Tian N, Gu X, Lee CS, Wang P, Wang Y. Nearly 100% exciton utilization in highly efficient red OLEDs based on dibenzothioxanthone acceptor. CHINESE CHEM LETT 2021. [DOI: 10.1016/j.cclet.2021.12.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Zhang Y, Miao J, Xiong J, Li K, Yang C. Rigid Bridge-Confined Double-Decker Platinum(II) Complexes Towards High-Performance Red and Near-Infrared Electroluminescence. Angew Chem Int Ed Engl 2021; 61:e202113718. [PMID: 34734464 DOI: 10.1002/anie.202113718] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Indexed: 11/09/2022]
Abstract
A molecular design to high-performance red and near-infrared (NIR) organic light-emitting diodes (OLEDs) emitters remains demanding. Herein a series of dinuclear platinum(II) complexes featuring strong intramolecular Pt⋅⋅⋅Pt and π-π interactions has been developed by using N-deprotonated α-carboline as a bridging ligand. The complexes in doped thin films exhibit efficient red to NIR emission from short-lived (τ=0.9-2.1 μs) triplet metal-metal-to-ligand charge transfer (3 MMLCT) excited states. Red OLEDs demonstrate high maximum external quantum efficiencies (EQEs) of up to 23.3 % among the best PtII -complex-doped devices. The maximum EQE of 15.0 % and radiance of 285 W sr-1 m-2 for NIR OLEDs (λEL =725 nm) are unprecedented for devices based on discrete molecular emitters. Both red and NIR devices show very small efficiency roll-off at high brightness. Appealing operational lifetimes have also been revealed for the devices. This work sheds light on the potential of intramolecular metallophilicity for long-wavelength molecular emitters and electroluminescence.
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Affiliation(s)
- Youming Zhang
- College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P.R. China
| | - Jingsheng Miao
- College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P.R. China
| | - Jinfan Xiong
- College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P.R. China
| | - Kai Li
- College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P.R. China
| | - Chuluo Yang
- College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P.R. China
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20
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Cai Z, Wu X, Liu H, Guo J, Yang D, Ma D, Zhao Z, Tang BZ. Realizing Record-High Electroluminescence Efficiency of 31.5 % for Red Thermally Activated Delayed Fluorescence Molecules. Angew Chem Int Ed Engl 2021; 60:23635-23640. [PMID: 34459540 DOI: 10.1002/anie.202111172] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Indexed: 12/17/2022]
Abstract
Tailor-made red thermally activated delayed fluorescence (TADF) molecules comprised of an electron-withdrawing pyrazino[2,3-f][1,10]phenanthroline-2,3-dicarbonitrile core and various electron-donating triarylamines are developed. They can form intramolecular hydrogen-bonding, which is conducive to improving emission efficiency and promoting horizontal orientation and show near infrared (NIR) emissions (692-710 nm) in neat films and red delayed fluorescence (606-630 nm) with high photoluminescence quantum yields (73-90%) in doped films. They prefer horizontal orientation with large horizontal dipole ratios in films, rendering high optical out-coupling factors (0.39-0.41). Their non-doped OLEDs exhibit NIR lights (716-748 nm) with maximum external quantum efficiencies (ηext,max ) of 1.0-1.9%. And their doped OLEDs radiate red lights (606-648 nm) and achieve record-beating ηext,max of up to 31.5%. These new red TADF materials should have great potentials in display and lighting devices.
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Affiliation(s)
- Zheyi Cai
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Xing Wu
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Hao Liu
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Jingjing Guo
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Dezhi Yang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Ben Zhong Tang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China.,Shenzhen Institute of Aggregate Science and Technology, School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China.,AIE Institute, Guangzhou Development District, Huangpu, Guangzhou, 510530, China
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21
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Cai Z, Wu X, Liu H, Guo J, Yang D, Ma D, Zhao Z, Tang BZ. Realizing Record‐High Electroluminescence Efficiency of 31.5 % for Red Thermally Activated Delayed Fluorescence Molecules. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202111172] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Zheyi Cai
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Xing Wu
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Hao Liu
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Jingjing Guo
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Dezhi Yang
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
| | - Ben Zhong Tang
- State Key Laboratory of Luminescent Materials and Devices Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates South China University of Technology Guangzhou 510640 China
- Shenzhen Institute of Aggregate Science and Technology School of Science and Engineering The Chinese University of Hong Kong Shenzhen Guangdong 518172 China
- AIE Institute Guangzhou Development District, Huangpu Guangzhou 510530 China
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