1
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Wu X, Wang CH, Ni S, Wu CC, Lin YD, Qu HT, Wu ZH, Liu D, Yang MZ, Su SJ, Zhu W, Chen K, Jiang ZC, Yang SD, Hung WY, Chou PT. Multiple Enol-Keto Isomerization and Excited-State Unidirectional Intramolecular Proton Transfer Generate Intense, Narrowband Red OLEDs. J Am Chem Soc 2024; 146:24526-24536. [PMID: 39177295 PMCID: PMC11378290 DOI: 10.1021/jacs.4c07364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/24/2024]
Abstract
A novel series of excited-state intramolecular proton transfer (ESIPT) emitters, namely, DPNA, DPNA-F, and DPNA-tBu, endowed with dual intramolecular hydrogen bonds, were designed and synthesized. In the condensed phase, DPNAs exhibit unmatched absorption and emission spectral features, where the minor 0-0 absorption peak becomes a major one in the emission. Detailed spectroscopic and dynamic approaches conclude fast ground-state equilibrium among enol-enol (EE), enol-keto (EK), and keto-keto (KK) isomers. The equilibrium ratio can be fine-tuned by varying the substitutions in DPNAs. Independent of isomers and excitation wavelength, ultrafast ESIPT takes place for all DPNAs, giving solely KK tautomer emission maximized at >650 nm. The spectral temporal evolution of ESIPT was resolved by a state-of-the-art technique, namely, the transient grating photoluminescence (TGPL), where the rate of EK* → KK* is measured to be (157 fs)-1 for DPNA-tBu, while a stepwise process is resolved for EE* → EK* → KK*, with a rate of EE* → EK* of (72 fs)-1. For all DPNAs, the KK tautomer emission shows a narrowband emission with high photoluminescence quantum yields (PLQY, ∼62% for DPNA in toluene) in the red, offering advantages to fabricate deep-red organic light-emitting diodes (OLED). The resulting OLEDs give high external quantum efficiency with a spectral full width at half-maximum (FWHM) as narrow as ∼40 nm centered at 666-670 nm for DPNAs, fully satisfying the BT. 2020 standard. The unique ESIPT properties and highly intense tautomer emission with a small fwhm thus establish a benchmark for reaching red narrowband organic electroluminescence.
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Affiliation(s)
- Xiugang Wu
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou 213164, China
| | - Chih-Hsing Wang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Songqian Ni
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou 213164, China
| | - Chi-Chi Wu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yan-Ding Lin
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Hao-Ting Qu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Zong-Hsien Wu
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Denghui Liu
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Ming-Zhou Yang
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou 213164, China
| | - Shi-Jian Su
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Weiguo Zhu
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou 213164, China
| | - Kai Chen
- Robinson Research Institute, Faculty of Engineering, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Zi-Cheng Jiang
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Shang-Da Yang
- Institute of Photonics Technologies, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Wen-Yi Hung
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
- Center for Emerging Material and Advanced Devices, National Taiwan University, Taipei 10617, Taiwan
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2
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Cai X, Pan Y, Li C, Li L, Pu Y, Wu Y, Wang Y. Nitrogen-Embedding Strategy for Short-Range Charge Transfer Excited States and Efficient Narrowband Deep-Blue Organic Light Emitting Diodes. Angew Chem Int Ed Engl 2024; 63:e202408522. [PMID: 38828837 DOI: 10.1002/anie.202408522] [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: 04/05/2024] [Revised: 06/02/2024] [Accepted: 06/03/2024] [Indexed: 06/05/2024]
Abstract
The development of deep-blue organic light-emitting diodes (OLEDs) featuring high efficiency and narrowband emission is of great importance for ultrahigh-definition displays with wide color gamut. Herein, based on the nitrogen-embedding strategy for modifying the short range charge transfer excited state energies of multi-resonance (MR) thermally activated delayed fluorescence (TADF) emitters, we introduce one or two nitrogen atoms into the central benzene ring of a versatile boron-embedded 1,3-bis(carbazol-9-yl)benzene skeleton. This approach resulted in the stabilization of the highest occupied molecular orbital energy levels and the formation of intramolecular hydrogen bonds, and thus systematic hypsochromic shifts and narrowing spectra. In toluene solution, two heterocyclic-based MR-TADF molecules, Py-BN and Pm-BN, exhibit deep-blue emissions with high photoluminescence quantum yields of 93 % and 94 %, and narrow full width at half maximum of 14 and 13 nm, respectively. A deep-blue hyperfluorescent OLED based on Py-BN exhibited a maximum external quantum efficiency of 27.7 % and desired color purity with Commission Internationale de L'Eclairage (CIE) coordinates of (0.150, 0.052). These results demonstrate the significant potential for the development of deep blue narrowband MR-TADF emitters.
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Affiliation(s)
- Xinliang Cai
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, Changchun, P. R. China
| | - Yue Pan
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, School of Life Science, Jilin University, 130012, Changchun, P. R. China
| | - Chenglong Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, Changchun, P. R. China
- Chongqing Research Institute, Jilin University, 401120, Chongqing, P. R. China
| | - Linjie Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, Changchun, P. R. China
| | - Yexuan Pu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, Changchun, P. R. China
| | - Youwei Wu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, Changchun, P. R. China
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, 130012, Changchun, P. R. China
- Jihua Hengye Electronic Materials CO. LTD., 528200, Foshan, Guangdong Province, P. R. China
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3
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Wang H, Cheng YC, Fan XC, Chen DY, Xiong X, Hao XY, Shi YZ, Yu J, Huang D, Chen JX, Wang K, Zhang XH. Efficient solution-processable OLEDs near BT.2020 red standard enabled by a multiresonant emitter. Sci Bull (Beijing) 2024:S2095-9273(24)00557-7. [PMID: 39129116 DOI: 10.1016/j.scib.2024.08.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2024] [Revised: 06/14/2024] [Accepted: 07/30/2024] [Indexed: 08/13/2024]
Affiliation(s)
- Hui Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China
| | - Ying-Chun Cheng
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China
| | - Xiao-Chun Fan
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China
| | - Dong-Yang Chen
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China
| | - Xin Xiong
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China
| | - Xiao-Yao Hao
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China
| | - Yi-Zhong Shi
- School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215123, China
| | - Jia Yu
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China
| | - Da Huang
- Suzhou Institute of Renewable Energy and Photoelectronics, Suzhou 215101, China
| | - Jia-Xiong Chen
- School of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006, China.
| | - Kai Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China; Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou 215123, China.
| | - Xiao-Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou 215123, China; Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215123, China.
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Feng Y, Xu Y, Qu C, Wang Q, Ye K, Liu Y, Wang Y. Structurally Tunable Donor-Bridge-Fluorophore Architecture Enables Highly Efficient and Concentration-Independent Narrowband Electroluminescence. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2403061. [PMID: 38782371 DOI: 10.1002/adma.202403061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/05/2024] [Indexed: 05/25/2024]
Abstract
Luminescent materials with narrowband emission have extraordinary significance for developing ultrahigh-definition display. B-N-containing multiple resonance thermally activated delayed fluorescence (MR-TADF) materials are strong contenders. However, their device performances pervasively encounter detrimental aggregation-caused quenching effect that is highly vulnerable to doping concentration, complicating device fabrication. Therefore, constructing highly efficient and concentration-independent MR-TADF emitters is of pragmatic importance for improving device controllability and reproducibility, simplifying manufacturing procedures, and conserving production costs. Here, by systematic arrangement of donor triphenylamine and fluorophore BNCz on distinct bridges, a spatial confinement strategy has been developed with a donor-bridge-fluorophore architecture. Structurally fine modulation and progressive evolution to construct molecular entities with congested steric hindrance effect that can suppress intermolecular interactions without substantially affecting the luminescence tone of fluorophore BNCz, resulting in highly efficient and concentration-independent narrowband emitters; through isomer engineering, two isomers BN-PCz-TPA and TPA-PCz-BN with different crystal stacking patterns are synthesized by altering the connection mode between triphenylamine and BNCz. As a result, BN-PCz-TPA-based device showcases maximum external quantum efficiency (EQE) of 36.3% with narrow full-width at half-maximum of 27 nm at 10 wt% doping concentration. Even at 20 wt% doping concentration, the maximum EQE remains at 32.5% and the emission spectrum is almost unchanged.
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Affiliation(s)
- Yu Feng
- 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
| | - Cheng Qu
- 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
| | - Kaiqi Ye
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yu Liu
- 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 Laboratory, 28 Huandao South Road, Foshan, Guangdong Province, 528200, P. R. China
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5
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Li L, Li J, Guo L, Xu Y, Bi Y, Pu Y, Zheng P, Chen XK, Wang Y, Li C. A multi-resonance emitter with five-membered thiophene as the π-core enables efficient, narrowband and reduced efficiency roll-off OLEDs. Chem Sci 2024; 15:11435-11443. [PMID: 39055010 PMCID: PMC11268511 DOI: 10.1039/d4sc02899f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 06/18/2024] [Indexed: 07/27/2024] Open
Abstract
Efficient, narrowband multi-resonance thermally activated delayed fluorescence (MR-TADF) emitters have recently sparked significant interest in high-resolution organic light-emitting diode (OLED) displays. However, almost all the progress in MR-TADF materials has been accomplished using a six-membered ring as the π-core to date. Herein, we present the first example of a five-membered ring π-core-based MR-TADF emitter named Th-BN developed by introducing thiophene instead of hexagonal benzene as the π-core. The introduction of thiophene significantly enhances intramolecular charge transfer intensity and the spin-orbit coupling matrix elements but does not change the intrinsic MR properties. As a result, Th-BN exhibits a narrowband green emission at 512 nm, with a high luminous efficiency of 97%, a narrow full-width at half maximum of 41 nm/0.20 eV, and a rapid reverse intersystem crossing rate of 18.7 × 104 s-1, which is 10 times higher than that of its benzenoid counterpart DtBuCzB. The corresponding green OLEDs based on Th-BN achieve excellent electroluminescence performance with an external quantum efficiency (EQE) of 34.6% and a reduced efficiency roll-off with an EQE of 26.8% at a high luminance of 1000 cd m-2.
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Affiliation(s)
- Linjie Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University Changchun 130012 P. R. China
| | - Jiaqi Li
- Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University Suzhou 215123 P. R. China
| | - Lixiao Guo
- 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
| | - Yifan Bi
- 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
| | - Pingping Zheng
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University Changchun 130012 P. R. China
| | - Xian-Kai Chen
- Institute of Functional Nano and Soft Materials (FUNSOM), Soochow University Suzhou 215123 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
| | - 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
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6
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Hayakawa M, Tang X, Ueda Y, Eguchi H, Kondo M, Oda S, Fan XC, Iswara Lestanto GN, Adachi C, Hatakeyama T. "Core-Shell" Wave Function Modulation in Organic Narrowband Emitters. J Am Chem Soc 2024; 146:18331-18340. [PMID: 38900500 DOI: 10.1021/jacs.4c02598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Efficient red-green-blue primary luminescence with an extraordinarily narrow band and durability is crucial for advanced display applications. Recently, the emergence of multiple-resonance (MR) from short-range atomic interactions has been shown to induce extremely narrow spectral widths in pure organic emitters. However, achieving wide-range color tuning without compromising color purity remains a persistent challenge for MR emitters. Herein, the concept of electronic donor/acceptor "core-shell" modulation is proposed within a boron/nitrogen (B/N) MR skeleton, enabling the rational utilization of intramolecular charge transfer to facilitate wavelength shift. The dense B atoms localized at the center of the molecule effectively compress the electron density and stabilize the lowest unoccupied molecular orbital wave function. This electron-withdrawing core is embedded with peripheral electron-donating atoms. Consequently, doping a single B atom into a deep-blue MR framework led to a profound bathochromic shift from 447 to 624 nm (∼0.8 eV) while maintaining a narrow spectral width of 0.10 eV in this pure-red emitter. Notably, organic light-emitting diodes assisted by thermally activated delayed fluorescence molecules achieved superb electroluminescent stability, with an LT99 (99% of the initial luminance) exceeding 400 h at an initial luminance of 1000 cd m-2, approaching commercial-level performance without the assistance of phosphors.
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Affiliation(s)
- Masahiro Hayakawa
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
| | - Xun Tang
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Yuta Ueda
- Department of Chemistry, Graduate School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Hayato Eguchi
- Department of Chemistry, Graduate School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan
| | - Masakazu Kondo
- JNC Co., Ltd. 5-1 Goi Kaigan, Ichihara, Chiba 290-8551, Japan
| | - Susumu Oda
- Department of Applied Chemistry, Graduate School of Science and Engineering, Toyo University, 2100 Kujirai, Kawagoe, Saitama 350-8585, Japan
| | - Xiao-Chun Fan
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Gerardus N Iswara Lestanto
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Takuji Hatakeyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502, Japan
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Dong J, Xu Y, Wang S, Miao J, Li N, Huang Z, Yang C. A diphenylphosphine oxide decorated multi-resonance TADF emitter for narrowband green electroluminescence with an EQE of 32.4. Chem Commun (Camb) 2024; 60:6789-6792. [PMID: 38868985 DOI: 10.1039/d4cc01672f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2024]
Abstract
A new narrowband thermally activated delayed fluorescence emitter, PhCzBN-PO, was developed by incorporating the diphenylphosphine oxide (DPPO) group into a multi-resonance core. The unique properties of DPPO enabled PhCzBN-PO to achieve pure green emission and a nonplanar structure. The resulting electroluminescent devices achieved high external quantum efficiencies up to 32.4% with extremely low efficiency roll-off and pure-green emission with Commission Internationale de L'Eclairage (CIE) coordinates of (0.24, 0.67).
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Affiliation(s)
- Junjie Dong
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, P. R. China.
| | - Yulin Xu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, P. R. China.
| | - Shuni Wang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, P. R. China.
| | - Jingsheng Miao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, P. R. China.
| | - Nengquan Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, P. R. China.
| | - Zhongyan Huang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, P. R. China.
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, P. R. China.
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8
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Ni F, Huang Y, Qiu L, Yang C. Synthetic progress of organic thermally activated delayed fluorescence emitters via C-H activation and functionalization. Chem Soc Rev 2024; 53:5904-5955. [PMID: 38717257 DOI: 10.1039/d3cs00871a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2024]
Abstract
Thermally activated delayed fluorescence (TADF) emitters have become increasingly prominent due to their promising applications across various fields, prompting a continuous demand for developing reliable synthetic methods to access them. This review aims to highlight the progress made in the last decade in synthesizing organic TADF compounds through C-H bond activation and functionalization. The review begins with a brief introduction to the basic features and design principles of TADF emitters. It then provides an overview of the advantages and concise development of C-H bond transformations in constructing TADF emitters. Subsequently, it summarizes both transition-metal-catalyzed and non-transition-metal-promoted C-H bond transformations used for the synthesis of TADF emitters. Finally, the review gives an outlook on further challenges and potential directions in this field.
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Affiliation(s)
- Fan Ni
- National Engineering Lab of Special Display Technology, State Key Lab of Advanced Display Technology, Academy of Opto-Electronic Technology, Intelligent Interconnected Systems Laboratory of Anhui, Anhui Province Key Laboratory of Measuring Theory and Precision Instrument, School of Instrument Science and Optoelectronic Engineering, Hefei University of Technology, Hefei, Anhui 230009, P. R. China.
| | - Yipan Huang
- National Engineering Lab of Special Display Technology, State Key Lab of Advanced Display Technology, Academy of Opto-Electronic Technology, Intelligent Interconnected Systems Laboratory of Anhui, Anhui Province Key Laboratory of Measuring Theory and Precision Instrument, School of Instrument Science and Optoelectronic Engineering, Hefei University of Technology, Hefei, Anhui 230009, P. R. China.
| | - Longzhen Qiu
- National Engineering Lab of Special Display Technology, State Key Lab of Advanced Display Technology, Academy of Opto-Electronic Technology, Intelligent Interconnected Systems Laboratory of Anhui, Anhui Province Key Laboratory of Measuring Theory and Precision Instrument, School of Instrument Science and Optoelectronic Engineering, Hefei University of Technology, Hefei, Anhui 230009, P. R. China.
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, Guangdong 518060, P. R. China.
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9
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Li P, Bai F. A Thorough Examination of the Variables Affecting the Quantum Efficiency of Radiative Decay of Trichlorotriphenylmethyl Radicals. J Phys Chem A 2024; 128:4279-4287. [PMID: 38752807 DOI: 10.1021/acs.jpca.4c01779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Fluorescence quantum efficiency is determined by the competition between radiation and nonradiation processes of the excited states. Understanding the factors affecting the radiation and nonradiative decay rates is of great significance for the design of luminescent materials. The excitation state deactivation mechanisms of singlet and triplet states have been extensively studied, providing a comprehensive understanding of the processes involved in the relaxation of these states. However, research on free radical systems involving doublet states is relatively scarce. Therefore, in this study, radiation and nonradiative decay rates and the mechanism of a series of trichlorotriphenylmethyl-based radicals were investigated theoretically. The results indicate that the relative rotations of electron donor and acceptor, as well as the internal rotations of trichlorotriphenylmethyl moiety, play important roles in energy dissipation through nonradiative channels. The effect of a solid-state environment on the radiation and nonradiative decay rates of radicals was investigated using a combination of quantum mechanics and molecular mechanics methods. The results indicate that the solid-state environment restricts the expansion of the conjugated system in the excited state of radicals, leading to a slight decrease in radiative decay rate. In addition, the solid-state environment reduces the reorganization energy and also affects the adiabatic excitation energy of radicals. The reduction in reorganization energy results in a decrease in nonradiative rate, while the opposite effect is observed for adiabatic excitation energy. The nonradiative rate of radicals in a solid-state environment is thus inflected by a combination of molecular geometric structure relaxation and ground-excited state energy gap.
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Affiliation(s)
- Pengyuan Li
- International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry and College of Chemistry, Jilin University, Changchun 130021, P. R. China
| | - Fuquan Bai
- International Joint Research Laboratory of Nano-Micro Architecture Chemistry, Institute of Theoretical Chemistry and College of Chemistry, Jilin University, Changchun 130021, P. R. China
- State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, P. R. China
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10
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Park JY, Kwon NY, Koh CW, Park SH, Kang MJ, Kwak H, Park CY, Chae WS, Hong CS, Park S, Cho MJ, Choi DH. Precision-Engineered Medium-Sized Molecular Host and Emitter for Ensuring Consistent Performance in Solution-Processed Narrowband OLEDs. ACS APPLIED MATERIALS & INTERFACES 2024; 16:16553-16562. [PMID: 38570940 DOI: 10.1021/acsami.3c18848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
In this study, two novel multiple resonance (MR) emitters, DtCzBN and Cy-DtCzBN, were designed based on the well-known BCzBN structure and synthesized for narrowband solution-processed organic light-emitting diodes (OLEDs). Cy-DtCzBN possesses a dimeric V-shaped structure formed by coupling two individual DtCzBN units via a nonconjugated cyclohexane linker. When compared with DtCzBN, Cy-DtCzBN, as a medium-sized molecule, was found to maintain the optical and photophysical properties of the corresponding monomeric unit, DtCzBN, but exhibits high thermal stability, excellent solubility, and good film-forming ability. Additionally, solution-processed OLEDs were fabricated by using two sets of molecules: one set of small molecular hosts and emitters (i.e., mCP and DtCzBN) and the other set of medium-sized molecular hosts and emitters (i.e., Cy-mCP and Cy-DtCzBN). Notably, devices using medium-sized molecular hosts and emitters exhibited similar optical and photophysical properties but showed significantly improved reproducibility and thermal stability compared with those based on small molecular hosts and emitters. Our current study provides some insights into molecular design strategies for thermally stable hosts and emitters, which are highly suitable for solution-processed OLEDs.
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Affiliation(s)
- Jin Young Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Na Yeon Kwon
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Chang Woo Koh
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Su Hong Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Min Ji Kang
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Haeun Kwak
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Chae Yeong Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Weon-Sik Chae
- Daegu Center, Korea Basic Science Institute, 80 Daehakro, Bukgu, Daegu 41566, Republic of Korea
| | - Chang Seop Hong
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Sungnam Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
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11
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Du M, Mai M, Zhang D, Duan L, Zhang Y. Stereo effects for efficient synthesis of orange-red multiple resonance emitters centered on a pyridine ring. Chem Sci 2024; 15:3148-3154. [PMID: 38425532 PMCID: PMC10901515 DOI: 10.1039/d3sc06470k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Accepted: 01/16/2024] [Indexed: 03/02/2024] Open
Abstract
Despite theoretical difficulties, we herein demonstrate an effective strategy for the inaugural synthesis of an orange-red multiple resonance (MR) emitter centered on a pyridine ring via stereo effects. Compared to conventional benzene-centered materials, the pyridine moiety in the novel MR material acts as a co-acceptor. This results in a significant spectral redshift and a narrower spectrum, as well as an improved photoluminescence quantum yield (PLQY) due to the formation of intramolecular hydrogen bonds. As envisioned, the proof-of-concept emitter Py-Cz-BN exhibits bright orange-red emission peaking at 586 nm with a small full width at half maximum (FWHM) of 0.14 eV (40 nm), exceeding both the wavelength and FWHM achieved with benzene-centered BBCz-Y. Benefiting from high PLQYs (>92%) and suppressed chromophore interactions, the optimized organic light-emitting diodes achieved high maximum external quantum efficiencies of 25.3-29.6%, identical small FWHMs of 0.18 eV (54 nm), and long lifetimes over a wide range of dopant concentrations (1-15 wt%). The performance described above demonstrates the effectiveness of this molecular design and synthesis strategy in constructing high performance long-wavelength MR emitters.
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Affiliation(s)
- Mingxu Du
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University Beijing 100084 P. R. China
- Laboratory of Flexible Electronics Technology, Tsinghua University Beijing 100084 P. R. China
| | - Minqiang Mai
- 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
- Laboratory of Flexible Electronics Technology, 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
- Laboratory of Flexible Electronics Technology, Tsinghua University Beijing 100084 P. R. China
| | - Yuewei Zhang
- Laboratory of Flexible Electronics Technology, Tsinghua University Beijing 100084 P. R. China
- Applied Mechanics Lab, School of Aerospace Engineering, Tsinghua University Beijing 100084 P. R. China
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12
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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] [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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13
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Mamada M, Hayakawa M, Ochi J, Hatakeyama T. Organoboron-based multiple-resonance emitters: synthesis, structure-property correlations, and prospects. Chem Soc Rev 2024; 53:1624-1692. [PMID: 38168795 DOI: 10.1039/d3cs00837a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Boron-based multiple-resonance (MR) emitters exhibit the advantages of narrowband emission, high absolute photoluminescence quantum yield, thermally activated delayed fluorescence (TADF), and sufficient stability during the operation of organic light-emitting diodes (OLEDs). Thus, such MR emitters have been widely applied as blue emitters in triplet-triplet-annihilation-driven fluorescent devices used in smartphones and televisions. Moreover, they hold great promise as TADF or terminal emitters in TADF-assisted fluorescence or phosphor-sensitised fluorescent OLEDs. Herein we comprehensively review organoboron-based MR emitters based on their synthetic strategies, clarify structure-photophysical property correlations, and provide design guidelines and future development prospects.
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Affiliation(s)
- Masashi Mamada
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
| | - Masahiro Hayakawa
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
| | - Junki Ochi
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
| | - Takuji Hatakeyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
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14
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Meng G, Zhou J, Han XS, Zhao W, Zhang Y, Li M, Chen CF, Zhang D, Duan L. B-N Covalent Bond Embedded Double Hetero-[n]helicenes for Pure Red Narrowband Circularly Polarized Electroluminescence with High Efficiency and Stability. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2307420. [PMID: 37697624 DOI: 10.1002/adma.202307420] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/22/2023] [Indexed: 09/13/2023]
Abstract
Chiral B/N embedded multi-resonance (MR) emitters open a new paradigm of circularly polarized (CP) organic light-emitting diodes (OLEDs) owing to their unique narrowband spectra. However, pure-red CP-MR emitters and devices remain exclusive in literature. Herein, by introducing a B-N covalent bond to lower the electron-withdrawing ability of the para-positioned B-π-B motif, the first pair of pure-red double hetero-[n]helicenes (n = 6 and 7) CP-MR emitter peaking 617 nm with a small full-width at half-maximum of 38 nm and a high photoluminescence quantum yield of ≈100% in toluene is developed. The intense mirror-image CP light produced by the enantiomers is characterized by high photoluminescence dissymmetry factors (gPL ) of +1.40/-1.41 × 10-3 from their stable helicenes configuration. The corresponding devices using these enantiomers afford impressive CP electroluminescence dissymmetry factors (gEL ) of +1.91/-1.77 × 10-3 , maximum external quantum efficiencies of 36.6%/34.4% and Commission Internationale de I'Éclairage coordinates of (0.67, 0.33), exactly satisfying the red-color requirement specified by National Television Standards Committee (NTSC) standard. Notably a remarkable long LT95 (operational time to 95% of the initial luminance) of ≈400 h at an initial brightness of 10,000 cd m-2 is also observed for the same device, representing the most stable CP-OLED up to date.
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Affiliation(s)
- Guoyun Meng
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Jianping Zhou
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Xu-Shuang Han
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Wenlong Zhao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yuewei Zhang
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Meng Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Chuan-Feng Chen
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Dongdong Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
| | - Lian Duan
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, 100084, P. R. China
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15
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Wang Q, Huang T, Qu Y, Song X, Xu Y, Wang Y. Frontier Molecular Orbital Engineering of Aromatic Donor Fusion: Modularly Constructing Highly Efficient Narrowband Yellow Electroluminescence. ACS APPLIED MATERIALS & INTERFACES 2024; 16:4948-4957. [PMID: 38235687 DOI: 10.1021/acsami.3c14514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
The development of high-performance multiple resonance thermally activated delayed fluorescence (MR-TADF) materials with narrowband yellow emission is highly critical for various applications in industries, such as the automotive, aerospace, and microelectronic industries. However, the modular construction approaches to expeditiously access narrowband yellow-emitting materials is relatively rare. Here, a unique molecular design concept based on frontier molecular orbital engineering (FMOE) of aromatic donor fusion is proposed to strategically address this issue. Donor fusion is a modular approach with a "leveraging effect"; through direct polycyclization of donor attached to the MR parent core, it is facile to achieve red-shifted emission by a large margin. As a result, two representative model molecules, namely BN-Cz and BN-Cb, have been constructed successfully. The BN-Cz- and BN-Cb-based sensitized organic light-emitting diodes (OLEDs) exhibit bright yellow emission with peaks of 560 and 556 nm, full-width at half-maxima (fwhm's) of 49 and 45 nm, Commission Internationale de L'Eclairage coordinates of (0.44, 0.55) and (0.43, 0.56), and maximum external quantum efficiencies (EQEs) of 32.9% and 29.7%, respectively. The excellent optoelectronic performances render BN-Cz and BN-Cb one of the most outstanding yellow-emitting MR-TADF materials.
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Affiliation(s)
- Qingyang Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Tingting Huang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Yupei Qu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Xiaoxian Song
- 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
| | - Yincai Xu
- 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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16
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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] [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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17
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Wang Y, Li Z, Bai Y, Wang Y. Increasing the Light Extraction Efficiency of Organic Light-Emitting Devices by Electrochemically Corroded Patterned Substrates. MICROMACHINES 2023; 15:67. [PMID: 38258187 PMCID: PMC10821355 DOI: 10.3390/mi15010067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/20/2023] [Accepted: 12/27/2023] [Indexed: 01/24/2024]
Abstract
A substrate with microstructure can increase the light extraction efficiency of OLEDs. However, the present preparation methods for micro- and nanostructures are not suited for broad-area manufacturing. In this research, we suggested an electrochemical etching approach to patterning Si substrates and effectively generated a vast area of micro-/nanostructures on the surface of Si. We created OLEDs using this patterned substrate. It was discovered through this study that when the current density is 100 mA/cm2, the brightness increases by 1.67 times and the efficiency increases by 1.43 times, over a planar equivalent. In the future, this electrochemical etching process for patterned silicon substrates might give rise to a new approach to the large-scale manufacture of microstructured silicon substrates.
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Affiliation(s)
- Yang Wang
- School of Electronic Information Engineering, Changchun University of Science and Technology, Changchun 130022, China
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18
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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] [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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19
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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] [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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20
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Gogoulis AT, Hojo R, Bergmann K, Hudson ZM. Red-Shifted Emission in Multiple Resonance Thermally Activated Delayed Fluorescent Materials through Malononitrile Incorporation. Org Lett 2023; 25:7791-7795. [PMID: 37862585 DOI: 10.1021/acs.orglett.3c02858] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
Multiple resonance thermally activated delayed fluorescent (MR-TADF) materials offer higher color purity than conventional TADF materials but suffer from aggregation-caused quenching (ACQ) and rarely exhibit red emission. Herein, two malononitrile-substituted emitters are synthesized from a quinolino[3,2,1-de]acridine-5,9-dione (QAO) MR-TADF precursor. Both materials maintain MR-TADF, while they display red-shifted fluorescence. They also overcome ACQ, displaying enhanced emission upon aggregation in solution and forming red-emissive J-aggregates in the solid state with photoluminescent quantum yields of 9 and 11%.
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Affiliation(s)
- Athan T Gogoulis
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Ryoga Hojo
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Katrina Bergmann
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
| | - Zachary M Hudson
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, Canada V6T 1Z1
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21
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Wang Y, Tian Y, Gao Y, Guo Z, Xue Z, Han Y, Yang W, Ma X. Resolving the Photophysics of Nitrogen-Embedded Multiple Resonance Emitters: Origin of Color Purity and Emitting Efficiency. J Phys Chem Lett 2023; 14:9665-9676. [PMID: 37870971 DOI: 10.1021/acs.jpclett.3c02245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The emerging nitrogen-embedded multiple resonance (MR) emitters with an indolo[3,2,1-jk] carbazole (ICz) unit have exhibited promising performance for high-resolution organic light-emitting diode (OLED) devices, while the underlying photophysics has been rarely reported. In this work, the optical spectra, color purity, and emitting efficiency of ICz-based MR emitters were investigated by using electronic structure and thermal vibration correlation function (TVCF) calculations. Unlike B-N MR emitters, the high color purity of investigated ICz-based MR emitters was mainly contributed by considerable structural rigidity, which also greatly affects the radiative decay rate and fluorescence quantum yield of the S1 state. For the majority of investigated emitters, potential reverse intersystem crossing (RISC) channels (T1 → S1 and T2 → S1) are limited by thermally inaccessible ΔEST* or insufficient spin-orbital coupling (SOC), which can be distinguished by the calculated temperature-dependent RISC rate pattern. We provided a systematic photophysical picture for ICz-based MR emitters that might be interesting for the OLED design and application community.
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Affiliation(s)
- Yaxin Wang
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
| | - Yiran Tian
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
| | - Yixuan Gao
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
| | - Zilong Guo
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
| | - Zheng Xue
- Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China
| | - Yandong Han
- Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China
| | - Wensheng Yang
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
- Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China
| | - Xiaonan Ma
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
- Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China
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22
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Liao C, Chen B, Xie Q, Li X, Liu H, Wang S. A Breakthrough in Solution-Processed Ultra-Deep-Blue HLCT OLEDs: A Record External Quantum Efficiency Exceeding 10% Based on Novel V-Shaped Emitters. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2305310. [PMID: 37523270 DOI: 10.1002/adma.202305310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/28/2023] [Indexed: 08/02/2023]
Abstract
It is always a great challenge to achieve high-efficiency solution-processed ultra-deep-blue organic light-emitting diodes (OLEDs) with the Commission Internationale de l'Eclairage (CIE) 1931 chromaticity coordinates matching the blue primary of Rec. International Telecommunication Union-Radiocommunication BT.2100, which specifies high dynamic range television image parameters. Inspired by hybrid local and charge transfer (HLCT) excited state emitters improving exciton utilization through high-lying reverse intersystem crossing, here, a series of high-performance blue emitters by a V-shaped symmetric donor (D)-π-acceptor (A)-π-D design strategy are developed. Here, the large torsions and unstable bonds of D-A structures can be improved through π bridges, and also the conjugation length and donor groups can be easily adjusted. The obtained emitters merit excellent photophysical and electrochemical properties, thermal stability, solution processibility, and HLCT excited state excellence. Results suggest that the OLEDs based on the obtained blue emitters all achieve high maximum external quantum efficiency (EQEmax ) of more than 8% with very low efficiency roll-off. In particular, the device based on 4',5'-bis(4-(9H-carbazol-9-yl)phenyl)spiro[fluorene-9,2'-imidazole] exhibits a satisfactory ultra-deep-blue emission (CIEx , y = 0.1579, 0.0387) and a record-high EQEmax (10.40%) among solution-processed HLCT OLEDs, which is very close to the record EQEmax of devices by vacuum vapor deposition technology.
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Affiliation(s)
- Chuanxin Liao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Bo Chen
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Qi Xie
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Xianggao Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Hongli Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Shirong Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
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23
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Fan X, Hao X, Huang F, Yu J, Wang K, Zhang X. RGB Thermally Activated Delayed Fluorescence Emitters for Organic Light-Emitting Diodes toward Realizing the BT.2020 Standard. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303504. [PMID: 37587784 PMCID: PMC10558656 DOI: 10.1002/advs.202303504] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 07/25/2023] [Indexed: 08/18/2023]
Abstract
With the surging demand for ultra-high-resolution displays, the International Telecommunication Union (ITU) announce the next-generation color gamut standard, named ITU-R Recommendation BT.2020, which not only sets a seductive but challenging milestone for display technologies but also urges researchers to recognize the importance of color coordinates. Organic light-emitting diodes (OLEDs) are an important display technology in current daily life, but they face challenges in approaching the BT.2020 standard. Thermally activated delayed fluorescence (TADF) emitters have bright prospects in OLEDs because they possess 100% theoretical exciton utilization. Thus, the development of TADF emitters emitting primary red (R), green (R), and blue (B) emission is of great significance. Here, a comprehensive overview of the latest advancements in TADF emitters that exhibit Commission Internationale de l'Éclairage (CIE) coordinates surpassing the National Television System Committee (NTSC) and approaching BT.2020 standards is presented. Rational strategies for molecular designs, as well as the resulting photophysical properties and OLED performances, are discussed to elucidate the underlying mechanisms for shifting the CIE coordinates of both donor-acceptor and multiple resonance (MR) typed TADF emitters toward the BT.2020 standard. Finally, the challenges in realization of the wide-color-gamut BT.2020 standard and the prospects for this research area are provided.
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Affiliation(s)
- Xiaochun Fan
- Institute of Functional Nano & Soft Materials (FUNSOM)Soochow UniversitySuzhouJiangsu215123P. R. China
| | - Xiaoyao Hao
- Institute of Functional Nano & Soft Materials (FUNSOM)Soochow UniversitySuzhouJiangsu215123P. R. China
| | - Feng Huang
- Institute of Functional Nano & Soft Materials (FUNSOM)Soochow UniversitySuzhouJiangsu215123P. R. China
| | - Jia Yu
- Institute of Functional Nano & Soft Materials (FUNSOM)Soochow UniversitySuzhouJiangsu215123P. R. China
- Jiangsu Key Laboratory of Advanced Negative Carbon TechnologiesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Kai Wang
- Institute of Functional Nano & Soft Materials (FUNSOM)Soochow UniversitySuzhouJiangsu215123P. R. China
- Jiangsu Key Laboratory of Carbon‐Based Functional Materials and DevicesSoochow UniversitySuzhouJiangsu215123P. R. China
| | - Xiaohong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM)Soochow UniversitySuzhouJiangsu215123P. R. China
- Jiangsu Key Laboratory of Advanced Negative Carbon TechnologiesSoochow UniversitySuzhouJiangsu215123P. R. China
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24
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Zou Y, He J, Li N, Hu Y, Luo S, Cao X, Yang C. Precisely regulating the double-boron-based multi-resonance framework towards pure-red emitters: high-performance OLEDs with CIE coordinates fully satisfying the BT. 2020 standard. MATERIALS HORIZONS 2023; 10:3712-3718. [PMID: 37403802 DOI: 10.1039/d3mh00800b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/06/2023]
Abstract
Here, we propose a new simple and effective strategy for designing pure-red multi-resonance (MR) emitters through precisely regulating the double-boron-based MR framework. The two designed emitters exhibit ultrapure red emission together with superb photophysical properties, and further enable high-performance, high color-purity red OLEDs.
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Affiliation(s)
- Yang Zou
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, People's Republic of China.
| | - Jiawei He
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, People's Republic of China.
| | - Nengquan Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, People's Republic of China.
| | - Yuxuan Hu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, People's Republic of China.
| | - Sai Luo
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, People's Republic of China.
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, People's Republic of China.
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518055, People's Republic of China.
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25
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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] [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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26
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Xie FM, Li HZ, Zhang K, Wang HY, Li YQ, Tang JX. Rational Multidimensional Shielded Multiple Resonance Emitter Suppresses Concentration Quenching and Spectral Broadening for Solution-Processed Organic Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2023; 15:39669-39676. [PMID: 37579002 DOI: 10.1021/acsami.3c07852] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Abstract
Thermally activated delayed fluorescence (TADF) emitters based on multiple resonance (MR) effects are promising for high-definition organic light-emitting diodes (OLEDs) with narrowband emission and high efficiency. However, they still face the challenges of aggregation-caused quenching (ACQ) and spectral broadening. Solution-processable MR-TADF emitters with an external quantum efficiency (EQE) of >20% and a full width at half-maximum (fwhm) of <30 nm have rarely been reported. To construct ACQ-resistant emitters without sacrificing color purity, the aggregation-induced MR-TADF material 6TBN with a rigid B,N-containing polycyclic aromatic hydrocarbon core and four carbazole substituents as well as 12 tert-butyl groups on the periphery is designed. The multidimensional shielded effect largely limits the ACQ, intermolecular interactions, and spectral broadening. Consequently, solution-processed OLEDs based on 6TBN exhibit a maximum EQE of 23.0% and high color purity with a fwhm of 25 nm. Furthermore, the nondoped device achieves a high efficiency (12.3%) and merely a slight widening of the fwhm to 27 nm. This work provides a feasible strategy to achieve MR-TADF materials with resistance to concentration quenching and high color purity.
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Affiliation(s)
- Feng-Ming Xie
- Macao Institute of Materials Science and Engineering (MIMSE), Faculty of Innovation Engineering, Macau University of Science and Technology, Taipa 999078, Macao, People's Republic of China
| | - Hao-Ze Li
- School of Physics and Electronic Science, East China Normal University, Shanghai 200062, People's Republic of China
| | - Kai Zhang
- Macao Institute of Materials Science and Engineering (MIMSE), Faculty of Innovation Engineering, Macau University of Science and Technology, Taipa 999078, Macao, People's Republic of China
| | - Han-Yang Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, People's Republic of China
| | - Yan-Qing Li
- School of Physics and Electronic Science, East China Normal University, Shanghai 200062, People's Republic of China
| | - Jian-Xin Tang
- Macao Institute of Materials Science and Engineering (MIMSE), Faculty of Innovation Engineering, Macau University of Science and Technology, Taipa 999078, Macao, People's Republic of China
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, People's Republic of China
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27
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Jing YY, Li N, Cao X, Wu H, Miao J, Chen Z, Huang M, Wang X, Hu Y, Zou Y, Yang C. Precise modulation of multiple resonance emitters toward efficient electroluminescence with pure-red gamut for high-definition displays. SCIENCE ADVANCES 2023; 9:eadh8296. [PMID: 37506207 PMCID: PMC10381944 DOI: 10.1126/sciadv.adh8296] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023]
Abstract
Multiple resonance (MR) compounds have garnered substantial attention for their prospective utility in wide color gamut displays. Nevertheless, developing red MR emitters with both high efficiency and saturated emission color remains demanding. We herein introduce a comprehensive strategy for spectral tuning in the red region by simultaneously regulating the π-conjugation and electron-donating strengths of a double boron-embedded MR skeleton while preserving narrowband characteristics. The proof-of-concept materials manifested emissions from orange-red to deep red, with bandwidths below 0.12 eV. The pure-red device based on CzIDBNO displayed superior color purity with CIE coordinates of (0.701, 0.298), approaching the Broadcast Television 2020 standard. In concert with high photoluminescence quantum yield and strong horizontal dipole orientation, CzIDBNO also achieved a maximum external quantum efficiency of 32.5% and a current efficiency of 20.2 cd A-1, outstripping prior reported organic light-emitting diodes (OLEDs) with CIEx exceeding 0.68. These findings offer a roadmap for designing high-performance emitters with exceptional color purity for future OLED material research advancements.
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Affiliation(s)
- Yan-Yun Jing
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
- College of Physics and Optoeletronic Engineering, Shenzhen University, Shenzhen, China
- Information Technology Research Institute, Shenzhen Institute of Information Technology, Shenzhen 518172, China
| | - Nengquan Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Han Wu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and 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 518060, China
| | - Zhanxiang Chen
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Manli Huang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xinzhong Wang
- Information Technology Research Institute, Shenzhen Institute of Information Technology, Shenzhen 518172, China
| | - Yuxuan Hu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Yang Zou
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
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