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Hua T, Li N, Huang Z, Zhang Y, Wang L, Chen Z, Miao J, Cao X, Wang X, Yang C. Narrowband Near-Infrared Multiple-Resonance Thermally Activated Delayed Fluorescence Emitters towards High-Performance and Stable Organic Light-Emitting Diodes. Angew Chem Int Ed Engl 2024; 63:e202318433. [PMID: 38148704 DOI: 10.1002/anie.202318433] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 12/21/2023] [Accepted: 12/22/2023] [Indexed: 12/28/2023]
Abstract
Multiple-resonance thermally activated delayed fluorescence (MR-TADF) materials are highly coveted for their high efficiency and narrowband emission in organic light-emitting diodes (OLEDs). Nevertheless, the development of near-infrared (NIR) MR-TADF emitters remains a formidable challenge. In this study, we design two new NIR MR-TADF emitters, PXZ-R-BN and BCz-R-BN, by embedding 10H-phenoxazine (PXZ) and 7H-dibenzo[c,g]carbazole (BCz) fragments to increase the electron-donating ability or extending π-conjugation on the framework of para-boron fusing polycyclic aromatic hydrocarbons (PAHs). Both compounds emit in the NIR region, with a full-width at half-maximum (FWHM) of 49 nm (0.13 eV) for PXZ-R-BN and 43 nm (0.11 eV) for BCz-R-BN in toluene. To sensitize the two NIR MR-TADF emitters in OLEDs, a new platinum complex, Pt-1, is designed as a sensitizer. The PXZ-R-BN-based sensitized OLEDs achieve a maximum external quantum efficiency (EQEmax ) of nearly 30 % with an emission band at 693 nm, and exceptional long operational stability with an LT97 (time to 97 % of the initial luminance) value of 39084 h at an initial radiance of 1000 mW sr-1 m-2 . The BCz-R-BN-based OLEDs reach EQEmax values of 24.2 % with an emission band at 713 nm, which sets a record value for NIR OLEDs with emission bands beyond 700 nm.
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Affiliation(s)
- Tao Hua
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Nengquan Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Zhongyan Huang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Youming Zhang
- Information Technology Research Institute, Shenzhen Institute of Information Technology, Shenzhen, 518172, P. R. China
| | - Lian Wang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Zhanxiang Chen
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Jingsheng Miao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Xinzhong Wang
- Information Technology Research Institute, Shenzhen Institute of Information Technology, Shenzhen, 518172, P. R. China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
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Liang L, Qu C, Fan X, Ye K, Zhang Y, Zhang Z, Duan L, Wang Y. Carbonyl- and Nitrogen-Embedded Multi-Resonance Emitter with Ultra-Pure Green Emission and High Electroluminescence Efficiencies. Angew Chem Int Ed Engl 2024; 63:e202316710. [PMID: 38061992 DOI: 10.1002/anie.202316710] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Indexed: 12/19/2023]
Abstract
Multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters with narrow emission spectra have garnered significant attention in future organic light-emitting diode (OLED) displays. However, current C=O/N-embedded MR-TADF systems still lack satisfactory performance in terms of electroluminescence bandwidths and external quantum efficiencies (EQEs). In this study, a C=O/N-embedded green MR-TADF emitter, featuring two acridone units incorporated in a sterically protected 11-ring fused core skeleton, is successfully synthesized through finely controlling the reaction selectivity. The superior combination of multiple intramolecular fusion and steric wrapping strategies in the design of the emitter not only imparts an extremely narrow emission spectrum and a high fluorescence quantum yield to the emitter but also mitigates aggregation-induced spectral broadening and fluorescence quenching. Therefore, the emitter exhibits leading green OLED performance among C=O/N-based MR-TADF systems, achieving an EQE of up to 37.2 %, a full width at half maximum of merely 0.11 eV (24 nm), and a Commission Internationale de l'Éclairage coordinate of (0.20, 0.73). This study marks a significant advance in the realization of ideal C=O/N-based MR-TADF emitters and holds profound implications for the design and synthesis of other MR-TADF systems.
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Affiliation(s)
- Lu Liang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Cheng Qu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Xiangyu Fan
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Kaiqi Ye
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yuewei Zhang
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Zuolun Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Lian Duan
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
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Tang X, Xie M, Lin Z, Mitrofanov K, Tsagaantsooj T, Lee YT, Kabe R, Sandanayaka ASD, Matsushima T, Hatakeyama T, Adachi C. A Rigid Multiple Resonance Thermally Activated Delayed Fluorescence Core Toward Stable Electroluminescence and Lasing. Angew Chem Int Ed Engl 2024; 63:e202315210. [PMID: 37991245 DOI: 10.1002/anie.202315210] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/08/2023] [Accepted: 11/20/2023] [Indexed: 11/23/2023]
Abstract
The investigation of organic light-emitting diodes (OLEDs) and organic laser devices with thermally activated delayed fluorescence (TADF) molecules is emerging due to the potential of harnessing triplets. In this work, a boron/nitrogen multiple-resonance TADF polycyclic framework fusing carbazole units (CzBNPh) was proposed. CzBNPh exhibited a narrowband emission (<30 nm), a unity photoluminescence quantum yield, and a fast radiative rate. Consequently, CzBNPh demonstrated a low distributed feedback (DFB) lasing threshold of 0.68 μJ cm-2 . Furthermore, the stimulated emission zone of CzBNPh was effectively separated from its singlet and triplet absorption, thereby minimizing the singlet-triplet annihilation under long-pulsed excitation ranging from 20 μs to 2.5 ms. Significantly, the enhanced rigid molecular conformation, thermal stability, and photo-stability resulted in improved lasing and electroluminescence stability compared to that of 5,9-diphenyl-5,9-diaza-13b-boranaphtho[3,2,1-de]anthracene (DABNA)-core. These findings indicate the potential of CzBN-core as a promising framework for achieving long-pulsed wave and electrically-pumped lasing in the future.
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Affiliation(s)
- Xun Tang
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Mingchen Xie
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Zesen Lin
- Organic Optoelectronics Unit, Okinawa Institute of Science and Technology, Graduate University, 1919-1 Tancha, Kunigami-gun, Okinawa, Onna-son, 904-0495, Japan
| | - Kirill Mitrofanov
- Organic Optoelectronics Unit, Okinawa Institute of Science and Technology, Graduate University, 1919-1 Tancha, Kunigami-gun, Okinawa, Onna-son, 904-0495, Japan
| | - Tuul Tsagaantsooj
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Yi-Ting Lee
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
- Department of Chemistry, Soochow University, 70 Linhsi Rd., Shihlin, Taipei, Taiwan
| | - Ryota Kabe
- Organic Optoelectronics Unit, Okinawa Institute of Science and Technology, Graduate University, 1919-1 Tancha, Kunigami-gun, Okinawa, Onna-son, 904-0495, Japan
| | - Atula S D Sandanayaka
- Department of Physical Sciences and Technologies, Faculty of Applied Sciences, Sabaragamuwa University of Sri Lanka, Belihuloya, 70140, Sri Lanka
| | - Toshinori Matsushima
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Takuji Hatakeyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa Oiwake-cho, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
- International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
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Xu Y, Wang Q, Cai X, Li C, Jiang S, Wang Y. Frontier Molecular Orbital Engineering: Constructing Highly Efficient Narrowband Organic Electroluminescent Materials. Angew Chem Int Ed Engl 2023; 62:e202312451. [PMID: 37724466 DOI: 10.1002/anie.202312451] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 09/18/2023] [Accepted: 09/19/2023] [Indexed: 09/20/2023]
Abstract
It is of great strategic significance to develop highly efficient narrowband organic electroluminescent materials that can be utilized to manufacture ultra-high-definition (UHD) displays and meet or approach the requirements of Broadcast Television 2020 (B.T.2020) color gamut standards. This motif poses challenges for molecular design and synthesis, especially for developing generality, diversity, scalability, and robustness of molecular structures. The emergence of multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters has ingeniously solved the problems and demonstrated bright application prospects in the field of UHD displays, sparking a research boom. This Minireview summarizes the research endeavors of narrowband organic electroluminescent materials, with emphasis on the tremendous contribution of frontier molecular orbital engineering (FMOE) strategy. It combines the outstanding advantages of MR framework and donor-acceptor (D-A) structure, and can achieve red-shift and narrowband emission simultaneously, which is of great significance in the development of long-wavelength narrowband emitters with emission maxima especially exceeding 500 nm. We hope that this Minireview would provide some inspiration for what could transpire in the future.
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Affiliation(s)
- Yincai Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Qingyang Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Xinliang Cai
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Chenglong Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Shimei Jiang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
- Jihua Hengye Electronic Materials CO. LTD., Foshan, 528200, Guangdong Province, P. R. China
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Luo S, Wang J, Li N, Song XF, Wan X, Li K, Yang C. Regulation of Multiple Resonance Delayed Fluorescence via Through-Space Charge Transfer Excited State towards High-Efficiency and Stable Narrowband Electroluminescence. Angew Chem Int Ed Engl 2023; 62:e202310943. [PMID: 37851366 DOI: 10.1002/anie.202310943] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 10/19/2023]
Abstract
B- and N-embedded multiple resonance (MR) type thermally activated delayed fluorescence (TADF) emitters usually suffer from slow reverse intersystem crossing (RISC) process and aggregation-caused emission quenching. Here, we report the design of a sandwich structure by placing the B-N MR core between two electron-donating moieties, inducing through-space charge transfer (TSCT) states. The proper adjusting of the energy levels brings about a 10-fold higher RISC rate in comparison with the parent B-N molecule. In the meantime, a high photoluminescence quantum yield of 91 % and a good color purity were maintained. Organic light-emitting diodes based on the new MR emitter achieved a maximum external quantum efficiency of 31.7 % and small roll-offs at high brightness. High device efficiencies were also obtained for a wide range of doping concentrations of up to 20 wt % thanks to the steric shielding of the B-N core. A good operational stability with LT95 of 85.2 h has also been revealed. The dual steric and electronic effects resulting from the introduction of a TSCT state offer an effective molecular design to address the critical challenges of MR-TADF emitters.
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Affiliation(s)
- Sai Luo
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, 518055, Shenzhen, P. R. China
| | - Junjie Wang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, 518055, Shenzhen, P. R. China
| | - Nengquan Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, 518055, Shenzhen, P. R. China
| | - Xiu-Fang Song
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, 518055, Shenzhen, P. R. China
| | - Xintong Wan
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, 518055, Shenzhen, P. R. China
| | - Kai Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, 518055, Shenzhen, P. R. China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, 518055, Shenzhen, P. R. China
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6
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Fan T, Zhu S, Cao X, Liang X, Du M, Zhang Y, Liu R, Zhang D, Duan L. Tailored Design of π-Extended Multi-Resonance Organoboron using Indolo[3,2-b]Indole as a Multi-Nitrogen Bridge. Angew Chem Int Ed Engl 2023; 62:e202313254. [PMID: 37806966 DOI: 10.1002/anie.202313254] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/02/2023] [Accepted: 10/03/2023] [Indexed: 10/10/2023]
Abstract
Extending the π-skeletons of multi-resonance (MR) organoboron emitters can feasibly modulate their optoelectronic properties. Here, we first adopt the indolo[3,2-b]indole (32bID) segment as a multi-nitrogen bridge and develop a high-efficiency π-extended narrowband green emitter. This moiety establishes not only a high-yield one-shot multiple Bora-Friedel-Crafts reaction towards a π-extended MR skeleton, but a compact N-ethylene-N motif for a red-shifted narrowband emission. An emission peak at 524 nm, a small full width at half maximum of 25 nm and a high photoluminescence quantum yield of 96 % are concurrently obtained in dilute toluene. The extended molecular plane also results in a large horizontal emitting dipole orientation ratio of 87 %. A maximum external quantum efficiency (EQE) of 36.6 % and a maximum power efficiency of 135.2 lm/W are thereafter recorded for the corresponding device, also allowing a low efficiency roll-off with EQEs of 34.5 % and 28.1 % at luminance of 1,000 cd/m2 and 10,000 cd/m2 , respectively.
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Affiliation(s)
- Tianjiao Fan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, 100084, Beijing, P. R. China
| | - Senqiang Zhu
- School of Chemistry and Molecular Engineering, Nanjing Tech University, 211816, Nanjing, China
| | - Xudong Cao
- Jiangsu Sunera Technology Co., Ltd, 214112, Wuxi, China
| | - Xiao Liang
- Jiangsu Sunera Technology Co., Ltd, 214112, Wuxi, China
| | - Mingxu Du
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, 100084, Beijing, P. R. China
| | - Yuewei Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, 100084, Beijing, P. R. China
| | - Rui Liu
- School of Chemistry and Molecular Engineering, Nanjing Tech University, 211816, Nanjing, China
| | - Dongdong Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, 100084, Beijing, P. R. China
| | - Lian Duan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, 100084, Beijing, P. R. China
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Zhang K, Wang X, Chang Y, Wu Y, Wang S, Wang L. Carbazole-Decorated Organoboron Emitters with Low-Lying HOMO Levels for Solution-Processed Narrowband Blue Hyperfluorescence OLED Devices. Angew Chem Int Ed Engl 2023; 62:e202313084. [PMID: 37775994 DOI: 10.1002/anie.202313084] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 09/28/2023] [Accepted: 09/29/2023] [Indexed: 10/01/2023]
Abstract
The hyperfluorescence has drawn great attention in achieving efficient narrowband emitting devices based on multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters. However, achieving efficient solution-processed pure blue hyperfluorescence devices is still a challenge, due to the unbalanced charge transport and serious exciton quenching caused by that the holes are easily trapped on the high-lying HOMO (the highest occupied molecular orbital) level of traditional diphenylamine-decorated emitters. Here, we developed two narrowband blue organoboron emitters with low-lying HOMO levels by decorating the MR-TADF core with weakly electron-donating carbazoles, which could suppress the hole trapping effect by reducing the hole traps between host and MR-TADF emitter from deep (0.40 eV) to shallow (0.14/0.20 eV) ones for facilitating hole transport and exciton formation, as well as avoiding exciton quenching. And the large dihedral angle between the carbazole and MR-TADF core makes the carbazole act as a steric hindrance to inhibit molecular aggregation. Accordingly, the optimized solution-processed pure blue hyperfluorescence devices simultaneously realize record external quantum efficiency of 29.2 %, narrowband emission with a full-width at half-maximum of 16.6 nm, and pure blue color with CIE coordinates of (0.139, 0.189), which is the best result for the solution-processed organic light-emitting diodes based on MR-TADF emitters.
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Affiliation(s)
- Kaiyuan Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022, Changchun, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, 230026, Hefei, P. R. China
| | - Xingdong Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022, Changchun, P. R. China
| | - Yufei Chang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022, Changchun, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, 230026, Hefei, P. R. China
| | - Yuliang Wu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022, Changchun, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, 230026, Hefei, P. R. China
| | - Shumeng Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022, Changchun, P. R. China
| | - Lixiang Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 130022, Changchun, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, 230026, Hefei, P. R. China
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Meng G, Zhou J, Huang T, Dai H, Li X, Jia X, Wang L, Zhang D, Duan L. B-N/B-O Contained Heterocycles as Fusion Locker in Multi-Resonance Frameworks towards Highly-efficient and Stable Ultra-Narrowband Emission. Angew Chem Int Ed Engl 2023; 62:e202309923. [PMID: 37584379 DOI: 10.1002/anie.202309923] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 08/10/2023] [Accepted: 08/11/2023] [Indexed: 08/17/2023]
Abstract
Fusing condensed aromatics into multi-resonance (MR) frameworks has been an exquisite strategy to modulate the optoelectronic properties, which, however, always sacrifices the small full width at half maxima (FWHM). Herein, we strategically embed B-N/B-O contained heterocycles as fusion locker into classical MR prototypes, which could enlarge the π-extension and alleviate the steric repulsion for an enhanced planar skeleton to suppress the high-frequency stretching/ scissoring vibrations for ultra-narrowband emissions. Sky-blue emitters with extremely small FWHMs of 17-18 nm are thereafter obtained for the targeted emitters, decreased by (1.4-1.9)-fold compared with the prototypes. Benefiting from their high photoluminescence quantum yields of >90 % and fast radiative decay rates of >108 s-1 , one of those emitters shows a high maximum external quantum efficiency of 31.9 % in sensitized devices, which remains 25.8 % at a practical luminance of 1,000 cd m-2 with a small FWHM of merely 19 nm. Notably a long operation half-lifetime of 1,278 h is also recorded for the same device, representing one of the longest lifetimes among sky-blue devices based on MR emitters.
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Affiliation(s)
- Guoyun Meng
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Jianping Zhou
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Tianyu Huang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Hengyi Dai
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Xiao Li
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Xiaoqin Jia
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Lu Wang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Dongdong Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Lian Duan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
- Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
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9
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Fan XC, Huang F, Wu H, Wang H, Cheng YC, Yu J, Wang K, Zhang XH. A Quadruple-Borylated Multiple-Resonance Emitter with para/meta Heteroatomic Patterns for Narrowband Orange-Red Emission. Angew Chem Int Ed Engl 2023; 62:e202305580. [PMID: 37431732 DOI: 10.1002/anie.202305580] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/12/2023]
Abstract
Hindered by spectral broadening issues with redshifted emission, long-wavelength (e.g., maxima beyond 570 nm) multiple resonance (MR) emitters with full width at half maxima (FWHMs) below 20 nm remain absent. Herein, by strategically embedding diverse boron (B)/nitrogen (N) atomic pairs into a polycyclic aromatic hydrocarbon (PAH) skeleton, we propose a hybrid pattern for the construction of a long-wavelength narrowband MR emitter. The proof-of-concept emitter B4N6-Me realized orange-red emission with an extremely small FWHM of 19 nm (energy unit: 70 meV), representing the narrowest FWHM among all reported long-wavelength MR emitters. Theoretical calculations revealed that the cooperation of the applied para B-π-N and para B-π-B/N-π-N patterns is complementary, which gives rise to both narrowband and redshift characteristics. The corresponding organic light-emitting diode (OLED) employing B4N6-Me achieved state-of-the-art performance, e.g., a narrowband orange-red emission with an FWHM of 27 nm (energy unit: 99 meV), an excellent maximum external quantum efficiency (EQE) of 35.8 %, and ultralow efficiency roll-off (EQE of 28.4 % at 1000 cd m-2 ). This work provides new insights into the further molecular design and synthesis of long-wavelength MR emitters.
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Affiliation(s)
- Xiao-Chun Fan
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Feng Huang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Hao Wu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Hui Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, Jiangsu, 215123, P. R. China
| | - Ying-Chun Cheng
- 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
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, 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 and Devices, Soochow University, Suzhou, Jiangsu, 215123, 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, Jiangsu, 215123, P. R. China
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10
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Wang X, Duan L, Zhang D. Indolocarbazole-Based Multiple-Resonance Molecules: an Emerging Class of Full-Color, Narrowband Emitters for Organic Light-Emitting Diodes. Chemistry 2023:e202300701. [PMID: 37119010 DOI: 10.1002/chem.202300701] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/23/2023] [Accepted: 04/24/2023] [Indexed: 04/30/2023]
Abstract
Narrowband emitters based on multiple resonance (MR) effect have shown great promises for applications in high-definition displays. Though most reported MR emitters adopt the boron- and nitrogen- doped triangulene-like skeleton following the design of the DABNA series, MR materials with the nitrogen-only indolocarbazole structures have recently emerged and demonstrated good color tunability from violet to deep red and impressive electroluminescence performances in terms of both efficiency and stability. Herein, we will summarize indolocarbazole-based MR materials in recent reports, with emphasis on their molecular design, synthesis, photophysical and electroluminescence properties as well as some future research directions to unlock the full potential of this fascinating class of materials.
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Affiliation(s)
- Xiang Wang
- Tsinghua University Department of Chemistry, chemistry, CHINA
| | - Lian Duan
- Tsinghua University, Chemistry, CHINA
| | - Dongdong Zhang
- Tsinghua University, Department of Chemistry, Room 114, Hetian Building, 100084, Beijing, CHINA
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11
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Chen H, Fan T, Zhao G, Zhang D, Li G, Jiang W, Duan L, Zhang Y. A Simple Molecular Design Strategy for Pure-Red Multiple Resonance Emitters. Angew Chem Int Ed Engl 2023; 62:e202300934. [PMID: 36918397 DOI: 10.1002/anie.202300934] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/16/2023]
Abstract
Though the flourishment of materials with multiple resonance (MR) in blue to green regions, red-emissive MR emitters are still rare in literatures, which definitely should be resolved for further applications. Herein, we report a simple molecular design strategy for the construction of pure-red MR emitters by conjugate charge transfer, which could greatly enhance the π-conjugation degree and charge-transfer property of the target molecule while maintaining the basic feature of MR, leading to a significant redshift of more than 128 nm compared to the selected parent MR core. The proof-of-concept emitter PPZ-BN exhibited a pure-red emission with a dominant peak at 613 nm and a small full-width-at-half-maximum of 0.16 eV (48 nm). The optimized organic light-emitting diode showed a high external quantum efficiency of 26.9%, a small efficiency roll-off, and an excellent operation stability (LT99) of more than 43 hours at an initial luminance of 10,000 cd/m2.
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Affiliation(s)
- Haowen Chen
- Southeast University, School of Chemistry and Engineering, CHINA
| | - Tianjiao Fan
- Tsinghua University, Department of Chemistry, CHINA
| | - Guimin Zhao
- Southeast University, School of Chemistry and Engineering, CHINA
| | | | | | - Wei Jiang
- Southeast University, School of Chemistry and Engineering, CHINA
| | - Lian Duan
- Tsinghua University, Chemistry, HeTian Building Dept. of Chemistry, Tsinghua University, Beijing, P. R. China, 100084, Beijing, CHINA
| | - Yuewei Zhang
- Tsinghua University, Laboratory of Flexible Electronics Technology, CHINA
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12
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Lei B, Huang Z, Li S, Liu J, Bin Z, You J. Medium-Ring Strategy Enables Multiple Resonance Emitters with Twisted Geometry and Fast Spin-Flip to Suppress Efficiency Roll-Off. Angew Chem Int Ed Engl 2023; 62:e202218405. [PMID: 36717355 DOI: 10.1002/anie.202218405] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/19/2023] [Accepted: 01/30/2023] [Indexed: 02/01/2023]
Abstract
Suppressing aggregation-caused quenching (ACQ) effect and reducing device efficiency roll-off are both crucial yet challenging for multi-resonance (MR) emitters. Herein, we put forward a medium-ring strategy to design efficient MR emitters that feature heptagonal tribenzo[b,d,f]azepine (TBA) donors. The highly twisted conformation enlarges the intermolecular distances between the MR-emitting cores, and thus suppresses ACQ effect. Meanwhile, the introduction of heptagonal donors enhances spin-orbital coupling, so as to accelerate reverse intersystem crossing (RISC) process. This medium-ring strategy gives rise to the first example of blue MR emitter that simultaneously possesses radiative decay rate as fast as 108 s-1 and RISC rate as fast as 106 s-1 . Accordingly, DTBA-B2N3 enables to assemble high-performance blue organic light-emitting diodes (OLEDs) with maximum external quantum efficiency (EQEmax ) of 30.9 % and alleviated efficiency roll-off (EQE1000 : 20.5 %).
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Affiliation(s)
- Bowen Lei
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Zhenmei Huang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Songtao Li
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Junjie Liu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Jingsong You
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
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13
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Wang Q, Xu Y, Huang T, Qu Y, Xue J, Liang B, Wang Y. Precisely Slight Regulation of Emission Maxima and Construction of Highly Efficient Electroluminescent Materials with High Color Purity. Angew Chem Int Ed Engl 2023; 62:e202301930. [PMID: 36898967 DOI: 10.1002/anie.202301930] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 03/01/2023] [Accepted: 03/10/2023] [Indexed: 03/12/2023]
Abstract
Advanced multiple resonance induced thermally activated delayed fluorescence (MR-TADF) emitters have emerged as a privileged motif for applications in organic light-emitting diodes (OLEDs), because they furnish highly tunable bandgap with emission ranges spanning the visible light region, and have the intrinsic properties of outstanding TADF characteristics and high color purity emission. One of the typical construction paradigms of MR-TADF molecule is based on polycyclization of MR parent core and a representative target model molecule BN-TP has been prepared. Herein, based on the unique nitrogen-atom embedding molecular engineering (NEME) strategy, a series of congeners of BN-TP, namely BN-TP-Nx (x = 1, 2, 3, 4), have been customized. The nitrogen-atom anchored at different position of triphenylene hexagonal lattice entails varying degrees of perturbation to the electronic structure. The newly-constructed emitters have demonstrated the precisely slight regulation of emission maxima of MR-TADF emitters to meet the actual industrial demand, and further enormously enriched the MR-TADF molecular reservoir. The BN-TP-N3-based OLED exhibits ultrapure green emission, with peak of 524 nm, full-width at half-maximum (FWHM) of 33 nm, Commission Internationale de L'Eclairage (CIE) coordinates of (0.23, 0.71), and maximum external quantum efficiency (EQE) of 37.3%.
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Affiliation(s)
| | - Yincai Xu
- Jilin University, College of Chemistry, CHINA
| | | | - Yupei Qu
- Jilin University, College of Chemistry, CHINA
| | - Jianan Xue
- Jilin University, College of Chemistry, CHINA
| | - Baoyan Liang
- Jihua Laboratory, Organic Electroluminescent Materials, CHINA
| | - Yue Wang
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun 130012, P. R. China, 130012, Changchun, CHINA
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14
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Cai X, Xu Y, Pan Y, Li L, Pu Y, Zhuang X, Li C, Wang Y. Solution-Processable Pure-Red Multiple Resonance-induced Thermally Activated Delayed Fluorescence Emitter for Organic Light-Emitting Diode with External Quantum Efficiency over 20 . Angew Chem Int Ed Engl 2023; 62:e202216473. [PMID: 36511099 DOI: 10.1002/anie.202216473] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 12/12/2022] [Accepted: 12/13/2022] [Indexed: 12/15/2022]
Abstract
Developing solution-processable red organic light-emitting diodes (OLEDs) with high color purity and efficiency based on multiple resonance thermally activated delayed fluorescence (MR-TADF) is a formidable challenge. Herein, by introducing auxiliary electron donor and acceptor moieties into the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) distributed positions of multiple resonance skeleton simultaneously, an effective strategy to obtain red MR-TADF emitters was represented. The proof-of-the-concept molecule BN-R exhibits a narrowband pure-red emission at 624 nm, with a high luminous efficiency of 94 % and a narrow bandwidth of 46 nm. Notably, the fabricated solution-processable pure-red OLED based on BN-R exhibits a state-of-the-art external quantum efficiency over 20 % with the Commission Internationale de I'Éclairage coordinates of (0.663, 0.337) and a long operational lifetime (LT50 ) of 1088 hours at an initial luminance of 1000 cd m-2 .
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Affiliation(s)
- Xinliang Cai
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yincai Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yue Pan
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, School of Life Science, Jilin University, Changchun, 130012, P. R. China
| | - Linjie Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yexuan Pu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Xuming Zhuang
- Jihua Laboratory, 28 Huandao South Road, Foshan, 528200, Guangdong Province, P. R. China
| | - Chenglong Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.,Chongqing Research Institute, Jilin University, Chongqing, 401120, P. R. China
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China.,Jihua Laboratory, 28 Huandao South Road, Foshan, 528200, Guangdong Province, P. R. China.,Jihua Hengye Electronic Materials CO. LTD., Foshan, 528200, Guangdong Province, P. R. China
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15
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Lv X, Miao J, Liu M, Peng Q, Zhong C, Hu Y, Cao X, Wu H, Yang Y, Zhou C, Ma J, Zou Y, Yang C. Extending the π-Skeleton of Multi-Resonance TADF Materials towards High-Efficiency Narrowband Deep-Blue Emission. Angew Chem Int Ed Engl 2022; 61:e202201588. [PMID: 35536106 DOI: 10.1002/anie.202201588] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Indexed: 11/05/2022]
Abstract
Multi-resonance TADF (MR-TADF) emitters are promising for high-resolution OLEDs, but the concurrent optimization of excited-state dynamics and color purity remains a tough challenge. Herein, three deep-blue MR-TADF compounds (BN1-BN3) featuring gradually enlarged ring-fused structures and increased rigidity are accessed by lithium-free borylation in high yields from the same precursor, with all the emitters possessing CIEy coordinates below 0.08. Structure-property investigations demonstrate a strategic improvement of the oscillator strength (fosc ) and acceleration of the reverse intersystem crossing (RISC) process by extending the π-skeleton, where BN3 realizes a maximum external quantum efficiency (EQE) of 37.6 % and reduced roll-off, thus showing the best efficiency reported for deep-blue TADF OLEDs. The internal regulation of the efficiency and color purity of these compounds validate the general effectiveness to achieve advanced deep-blue narrowband emitters with higher-order boron/nitrogen-based MR motifs.
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Affiliation(s)
- Xialei Lv
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Jingsheng Miao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Meihui Liu
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Qian Peng
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Cheng Zhong
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Yuxuan Hu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Han Wu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Yiyu Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Changjiang Zhou
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Jiazhi Ma
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Yang Zou
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
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16
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Zeng X, Wang X, Zhang Y, Meng G, Wei J, Liu Z, Jia X, Li G, Duan L, Zhang D. Nitrogen-Embedded Multi-Resonance Heteroaromatics with Prolonged Homogeneous Hexatomic Rings. Angew Chem Int Ed Engl 2022; 61:e202117181. [PMID: 35092123 DOI: 10.1002/anie.202117181] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Indexed: 01/15/2023]
Abstract
Nitrogen-containing polycyclic heteroaromatics have exhibited fascinating multi-resonance (MR) characteristics for efficient narrowband emission, but strategies to bathochromic shift their emissions while maintaining the narrow bandwidths remain exclusive. Here, homogeneous hexatomic rings are introduced into nitrogen-embedded MR skeletons to prolong the π-conjugation length for low-energy electronic transitions while retaining the non-bonding character of the remaining parts. The proof-of-the-concept emitters exhibit near unity photoluminescence quantum yields with peaks at 598 nm and 620 nm and small full-width-at-half-maximums of 28 nm and 31 nm, respectively. Optimal organic light-emitting diodes exhibit a high external quantum efficiency of 18.2 %, negligible efficiency roll-off, and ultra-long lifetime with negligible degradation at an initial luminance of 10 000 cd m-2 after 94 hours.
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Affiliation(s)
- Xuan Zeng
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.,Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Xiang Wang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Yuewei Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Guoyun Meng
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Jinbei Wei
- Beijing National Laboratory for Molecular Sciences, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China
| | - Ziyang Liu
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Xiaoqin Jia
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Guomeng Li
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Lian Duan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China.,Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Dongdong Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
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17
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Liu F, Cheng Z, Jiang Y, Gao L, Liu H, Liu H, Feng Z, Lu P, Yang W. Highly Efficient Asymmetric Multiple Resonance Thermally Activated Delayed Fluorescence Emitter with EQE of 32.8 % and Extremely Low Efficiency Roll-Off. Angew Chem Int Ed Engl 2022; 61:e202116927. [PMID: 35104385 DOI: 10.1002/anie.202116927] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Indexed: 01/01/2023]
Abstract
Multiple resonance thermally activated delayed fluorescence (MR-TADF) emitters show great potentials for high color purity organic light-emitting diodes (OLEDs). However, the simultaneous realization of high photoluminescence quantum yield (PLQY) and high reverse intersystem crossing rate (kRISC ) is still a formidable challenge. Herein, a novel asymmetric MR-TADF emitter (2Cz-PTZ-BN) is designed that fully inherits the high PLQY and large kRISC values of the properly selected parent molecules. The resonating extended π-skeleton with peripheral protection can achieve a high PLQY of 96 % and a fast kRISC of above 1.0×105 s-1 , and boost the performance of corresponding pure green devices with an outstanding external quantum efficiency (EQE) of up to 32.8 % without utilizing any sensitizing hosts. Remarkably, the device sufficiently maintains a high EQE exceeding 23 % at a high luminance of 1000 cd m-2 , representing the highest value for reported green MR-TADF materials at the same luminescence.
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Affiliation(s)
- Futong Liu
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Changchun, 130012, P. R. China
| | - Zhuang Cheng
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Changchun, 130012, P. R. China
| | - Yixuan Jiang
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Changchun, 130012, P. R. China
| | - Lei Gao
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Changchun, 130012, P. R. China
| | - Hanxuan Liu
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Changchun, 130012, P. R. China
| | - Hui Liu
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Changchun, 130012, P. R. China
| | - Zijun Feng
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Changchun, 130012, P. R. China
| | - Ping Lu
- Jilin University, State Key Laboratory of Supramolecular Structure and Materials, Department of Chemistry, Changchun, 130012, P. R. China
| | - Wensheng Yang
- Institute of Molecular Plus, Tianjin University, Tianjin, 300072, P. R. China
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