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Zhu C, Liu L, Yang X, Zhou G, Sun Y. The Molecular Design and Electroluminescent Performance of Near-Infrared (NIR) Iridium(III) Complexes Bearing Isoquinoline-, Phthalazine- and Phenazine-Based Ligands. Chemphyschem 2024; 25:e202400232. [PMID: 39031895 DOI: 10.1002/cphc.202400232] [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: 03/02/2024] [Revised: 06/20/2024] [Accepted: 06/20/2024] [Indexed: 07/22/2024]
Abstract
Near-infrared (NIR) light has characteristics of invisibility to human eyes, less background interference, low light scattering, and strong cell penetration. Therefore, NIR luminescent materials have significant applications in imaging, sensing, energy, information storage and display. The development of NIR luminescent materials thus has emerged as a highly dynamic area of research in the realm of contemporary materials. To date, NIR luminescent materials are roughly divided into inorganic materials and organic materials. Compared with inorganic materials, organic NIR luminescent materials have become a hot research topic in recent years due to their rich sources, easy control of structure, simple preparation process, low cost, and good film-forming properties. Among them, iridium(III) [Ir(III)] complexes exhibit excellent properties such as thermal stability, simple synthesis, easy color modulation, short excited state lifetimes, and high brightness, thus becoming one of the ideal luminescent material systems for preparing high-quality organic light-emitting diodes. Therefore, how to obtain Ir(III) complexes with NIR emission and high efficiency through molecular design is a necessary and promising research topic. This work reviews the research progress of representative NIR Ir(III) complexes bearing isoquinoline-, phenazine-, and phthalazine-based ligands reported in recent years and introduces the design strategies and electroluminescent performances of NIR Ir(III) complexes.
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Affiliation(s)
- Chengyun Zhu
- School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Lina Liu
- School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Xiaolong Yang
- School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Guijiang Zhou
- School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Yuanhui Sun
- School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Material Chemistry, Engineering Research Center of Energy Storage Materials and Devices, Ministry of Education, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
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2
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Mamada M, Yada S, Hayakawa M, Uchida R, Katagiri H, Hatakeyama T, Adachi C. Donor-only substituted benzene achieves thermally activated delayed fluorescence. Commun Chem 2024; 7:212. [PMID: 39294436 PMCID: PMC11410811 DOI: 10.1038/s42004-024-01301-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Accepted: 09/06/2024] [Indexed: 09/20/2024] Open
Abstract
Thermally activated delayed fluorescence (TADF) is a promising mechanism for harvesting triplet excitons in organic light-emitting diodes (OLEDs). The donor-acceptor (D-A) design is the most conventional strategy for developing efficient TADF emitters. A subsequently emerged approach, known as the multiple resonance (MR) effect, also employs electron-donating and electron-withdrawing functional groups. Thus, developing TADF materials has traditionally relied on ingenuity in selecting and combining two functional units. Here, we have realized a TADF molecule by utilizing only a carbazole donor moiety. This molecule is an unusual example in the family of TADF materials and offers better insight into the electronic structures in the excited states for luminescent materials.
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Affiliation(s)
- Masashi Mamada
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
| | - Sawako Yada
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Masahiro Hayakawa
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Ryota Uchida
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Hiroshi Katagiri
- Graduate School of Organic Materials Science, Yamagata University, Yonezawa, Yamagata, 992-8510, Japan
| | - Takuji Hatakeyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan.
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan.
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Qu YK, Zhou DY, Zheng Q, Zuo P, Che ZL, Liao LS, Jiang ZQ. Linearly Arranged Multi-π-Stacked Structure for Efficient Through-Space Charge-Transfer Emitters. Angew Chem Int Ed Engl 2024; 63:e202408712. [PMID: 38962896 DOI: 10.1002/anie.202408712] [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: 05/08/2024] [Revised: 06/24/2024] [Accepted: 07/02/2024] [Indexed: 07/05/2024]
Abstract
Noncovalent spatial interaction has become an intriguing and important tool for constructing optoelectronic molecules. In this study, we linearly attached three conjugated units in a multi π-stacked manner by using just one trident bridge based on indeno[2,1-b]fluorene. To achieve this structure, we improved the synthetic approach through double C-H activation, significantly simplifying the preparation process. Due to the proximity of the C10, C11, and C12 sites in indeno[2,1-b]fluorene, we derived two novel donor|acceptor|donor (D|A|D) type molecules, 2DMB and 2DMFB, which exhibited closely packed intramolecular stacking, enabling efficient through-space charge transfer. This molecular construction is particularly suitable for developing high-performance thermally activated delayed fluorescence materials. With donor(s) and acceptor(s) constrained and separated within this spatially rigid structure, elevated radiative transition rates, and high photoluminescence quantum yields were achieved. Organic light-emitting diodes incorporating 2DMB and 2DMFB demonstrated superior efficiency, achieving maximum external quantum efficiencies of 28.6 % and 16.2 %, respectively.
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Affiliation(s)
- Yang-Kun Qu
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China
| | - Dong-Ying Zhou
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China
| | - Qi Zheng
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China
| | - Peng Zuo
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China
| | - Zong-Lu Che
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China
| | - Liang-Sheng Liao
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China
- Macao Institute of Materials Science and Engineering, Macau University of Science and Technology, Taipa, 999078, Macau SAR, China
| | - Zuo-Quan Jiang
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, 215123, Jiangsu, PR China
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4
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Itsoponpan T, Wongkaew P, Prakanpo N, Sukthawee T, Suyoadsuk T, Promarak V. Deep Blue Emitter with a Combination of Hybridized Local and Charge Transfer Excited State and Aggregation-Induced Emission Features for Efficient Non-Doped OLED. Chempluschem 2024:e202400438. [PMID: 39116088 DOI: 10.1002/cplu.202400438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2024] [Revised: 07/30/2024] [Accepted: 08/08/2024] [Indexed: 08/10/2024]
Abstract
Herein, a deep blue emitter (PI-TPB-CN) with a synergistic effect of hybridized local and charge transfer excited state (HLCT) and aggregation-induced emission (AIE) properties is successfully designed and synthesized to improve the performance of deep blue organic light-emitting diodes (OLEDs). It is constructed using a 1,2,4,5-tetraphenylbenzene (TPB) as an π-conjugated AIE core being asymmetrically functionalized with a phenanthro[9,10-d]imidazole (PI) as a weak donor (D) and a benzonitrile (CN) as an acceptor (A), thereby formulating D-π-A type fluorophore. Its HLCT and AIE properties verified by theoretical calculations, solvatochromic effects, and transient photoluminescence decay experiments, bring about a strong blue emission (452 nm) with a high photoluminescence quantum yield of 74 % in the thin film. PI-TPB-CN is successfully employed as a blue emitter in OLEDs. Non-doped OLED with the structure of ITO/HAT-CN (6 nm)/NPB (30 nm)/TCTA (10 nm)/PI-TPB-CN (30 nm)/TPBi (40 nm)/LiF (1 nm)/Al (100 nm) demonstrates excellent electroluminescence (EL) performance with blue emission (451 nm) and maximum external quantum efficiency (EQEmax) of 7.38 %. The device with a thinner layer of PI-TPB-CN (20 nm) and TPBi (30 nm) exhibits a deeper blue emission (444 nm) with CIE coordinates of (0.156, 0.096), a low turn-on voltage of 3.0 V, and EQEmax of 6.45 %.
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Affiliation(s)
- Teerapat Itsoponpan
- Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong, 21210, Thailand
| | - Praweena Wongkaew
- Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong, 21210, Thailand
| | - Nipanan Prakanpo
- Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong, 21210, Thailand
| | - Trirath Sukthawee
- Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong, 21210, Thailand
| | - Taweesak Suyoadsuk
- Frontier Research Center, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong, 21210, Thailand
| | - Vinich Promarak
- Department of Materials Science and Engineering, School of Molecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan, Rayong, 21210, Thailand
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5
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Li P, Lai SL, Chen Z, Tang WK, Leung MY, Ng M, Kwok WK, Chan MY, Yam VWW. Achieving efficient and stable blue thermally activated delayed fluorescence organic light-emitting diodes based on four-coordinate fluoroboron emitters by simple substitution molecular engineering. Chem Sci 2024; 15:12606-12615. [PMID: 39118634 PMCID: PMC11304800 DOI: 10.1039/d3sc06989c] [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: 12/29/2023] [Accepted: 06/18/2024] [Indexed: 08/10/2024] Open
Abstract
Achieving both high efficiency and high stability in blue thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs) is challenging for practical displays and lighting. Here, we have successfully developed a series of sky-blue to pure-blue emitting donor-acceptor (D-A) type TADF materials featuring a four-coordinated boron with 2,2'-(pyridine-2,6-diyl)diphenolate (dppy) ligands, i.e.1-8. Synergistic engineering of substituents on the phenyl bridge as well as the electronic properties and the attached positions of heteroatom N-donors not only enables fine-tuning of the emission colors, but also modulates the nature and energies of their triplet excited states that are important for the reverse intersystem crossing (RISC). Particularly for the compound with two methyl substituents on the phenyl bridge (compound 8), RISC is significantly facilitated through the vibronic coupling of the energetically close-lying triplet charge transfer (3CT) and the triplet local excited (3LE) states, when compared to analogue 7. Efficient sky-blue to pure-blue OLEDs with electroluminescence peaks (λ EL) at 460-492 nm have been obtained, in which ca. five-fold higher external quantum efficiencies (EQEs) of 18.9% have been demonstrated by 8 than that by 7. Moreover, ca. thirty times longer device operational half-lifetimes (LT50) of 9113 hours for 8 than that for 7 as well as satisfactory LT50 reaching 26 643 hours for 6 at an initial luminance of 100 cd m-2 have also been demonstrated. To the best of our knowledge, these results represent one of the best high-performance blue OLEDs based on tetracoordinated boron TADF emitters. Moreover, the design strategy presented here has provided an attractive strategy for enhancing the device performance of blue TADF-OLEDs.
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Affiliation(s)
- Panpan Li
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
- Hong Kong Quantum AI Lab Limited 17 Science Park West Avenue Pak Shek Kok Hong Kong P. R. China
| | - Shiu-Lun Lai
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Ziyong Chen
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Wai Kit Tang
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Ming-Yi Leung
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
- Hong Kong Quantum AI Lab Limited 17 Science Park West Avenue Pak Shek Kok Hong Kong P. R. China
| | - Maggie Ng
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Wing-Kei Kwok
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
- Hong Kong Quantum AI Lab Limited 17 Science Park West Avenue Pak Shek Kok Hong Kong P. R. China
| | - Mei-Yee Chan
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
- Hong Kong Quantum AI Lab Limited 17 Science Park West Avenue Pak Shek Kok Hong Kong P. R. China
| | - Vivian Wing-Wah Yam
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong Pokfulam Road Hong Kong P. R. China
- Hong Kong Quantum AI Lab Limited 17 Science Park West Avenue Pak Shek Kok Hong Kong P. R. China
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6
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An RZ, Sun Y, Chen HY, Liu Y, Privitera A, Myers WK, Ronson TK, Gillett AJ, Greenham NC, Cui LS. Excited-State Engineering Enables Efficient Deep-Blue Light-Emitting Diodes Exhibiting BT.2020 Color Gamut. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2313602. [PMID: 38598847 DOI: 10.1002/adma.202313602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 04/01/2024] [Indexed: 04/12/2024]
Abstract
Organic luminescent materials that exhibit thermally activated delayed fluorescence (TADF) can convert non-emissive triplet excitons into emissive singlet states through a reverse intersystem crossing (RISC) process. Therefore, they have tremendous potential for applications in organic light-emitting diodes (OLEDs). However, with the development of ultra-high definition 4K/8K display technologies, designing efficient deep-blue TADF materials to achieve the Commission Internationale de l'Éclairage (CIE) coordinates fulfilling BT.2020 remains a significant challenge. Here, an effective approach is proposed to design deep-blue TADF molecules based on hybrid long- and short-range charge-transfer by incorporation of multiple donor moieties into organoboron multiple resonance acceptors. The resulting TADF molecule exhibits deep-blue emission at 414 nm with a full width at half maximum (FWHM) of 29 nm, together with a thousand-fold increase in RISC rate. OLEDs based on the champion material achieve a record maximum external quantum efficiency (EQE) of 22.8% with CIE coordinates of (0.163, 0.046), approaching the coordinates of the BT.2020 blue standard. Moreover, TADF-assisted fluorescence devices employing the designed material as a sensitizer exhibit an exceptional EQE of 33.1%. This work thus provides a blueprint for future development of efficient deep-blue TADF emitters, representing an important milestone towards meeting the blue color gamut standard of BT.2020.
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Affiliation(s)
- Rui-Zhi An
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yuqi Sun
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Hao-Yang Chen
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yuan Liu
- Key Laboratory of the Ministry of Education for Optoelectronic Measurement Technology and Instrument, Beijing Information Science & Technology University, No. 12 Xiaoying East Road, Beijing, 100192, China
| | - Alberto Privitera
- Department of Industrial Engineering and INSTM Research Unit, University of Florence, Via Santa Marta 3, Firenze, 50139, Italy
| | - William K Myers
- Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, University of Oxford, Oxford, OX1 3QR, UK
| | - Tanya K Ronson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Alexander J Gillett
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Neil C Greenham
- Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Lin-Song Cui
- Key Laboratory of Precision and Intelligent Chemistry, University of Science and Technology of China, Hefei, Anhui, 230026, China
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China
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Chen X, Sun L, Sukhanov AA, Doria S, Bussotti L, Zhao J, Xu H, Dick B, Voronkova VK, Di Donato M. Photophysics and photochemistry of thermally activated delayed fluorescence emitters based on the multiple resonance effect: transient optical and electron paramagnetic resonance studies. Chem Sci 2024; 15:10867-10881. [PMID: 39027280 PMCID: PMC11253189 DOI: 10.1039/d4sc02513j] [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: 04/16/2024] [Accepted: 05/31/2024] [Indexed: 07/20/2024] Open
Abstract
The photochemistry of two representative thermally activated delayed fluorescence (TADF) emitters based on the multiple resonance effect (MRE) (DABNA-1 and DtBuCzB) was studied. No significant TADF was observed in fluid solution, although the compounds have a long-lived triplet state (ca. 30 μs). We found that these planar boron molecules bind with Lewis bases, e.g., 4-dimethylaminopyridine (DMAP) or an N-heterocyclic carbene (NHC). A new blue-shifted absorption band centered at 368 nm was observed for DtBuCzB upon formation of the adduct; however, the fluorescence of the adduct is the same as that of the free DtBuCzB. We propose that photo-dissociation occurs for the DtBuCzB-DMAP adduct, which is confirmed by femtosecond transient absorption spectra, implying that fluorescence originates from DtBuCzB produced by photo-dissociation; the subsequent in situ re-binding was observed with nanosecdon transient absorption spectroscopy. No photo-dissociation was observed for the NHC adduct. Time-resolved electron paramagnetic resonance (TREPR) spectra show that the triplet states of DABNA-1 and DtBuCzB have similar zero field splitting (ZFS) parameters (D = 1450 MHz). Theoretical studies show that the slow ISC is due to small SOC and weak Herzberg-Teller coupling, although the S1/T1 energy gap is small (0.14 eV), which rationalizes the lack of TADF.
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Affiliation(s)
- Xi Chen
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology Dalian 116024 P. R. China
| | - Lei Sun
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Key Laboratory of Forestry Genetics & Biotechnology of Ministry of Education, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-Forest Biomass, College of Chemical Engineering, Nanjing Forestry University Nanjing 210037 P. R. China
- School of Chemistry and Chemical Engineering, Henan Normal University Xinxiang 453002 China
| | - Andrey A Sukhanov
- Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS Kazan 420029 Russia
| | - Sandra Doria
- LENS (European Laboratory for Non-Linear Spectroscopy) Via N. Carrara 1 50019 Sesto Fiorentino (FI) Italy
- ICCOM-CNR Via Madonna del Piano 10-12 50019 Sesto Fiorentino (FI) Italy
| | - Laura Bussotti
- LENS (European Laboratory for Non-Linear Spectroscopy) Via N. Carrara 1 50019 Sesto Fiorentino (FI) Italy
| | - Jianzhang Zhao
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, School of Chemical Engineering, Dalian University of Technology Dalian 116024 P. R. China
| | - Haijun Xu
- Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Key Laboratory of Forestry Genetics & Biotechnology of Ministry of Education, Jiangsu Provincial Key Lab for the Chemistry and Utilization of Agro-Forest Biomass, College of Chemical Engineering, Nanjing Forestry University Nanjing 210037 P. R. China
- School of Chemistry and Chemical Engineering, Henan Normal University Xinxiang 453002 China
| | - Bernhard Dick
- Lehrstuhl für Physikalische Chemie, Institut für Physikalische und Theoretische Chemie, Universität Regensburg Regensburg 93053 Germany
| | - Violeta K Voronkova
- Zavoisky Physical-Technical Institute, FRC Kazan Scientific Center of RAS Kazan 420029 Russia
| | - Mariangela Di Donato
- LENS (European Laboratory for Non-Linear Spectroscopy) Via N. Carrara 1 50019 Sesto Fiorentino (FI) Italy
- ICCOM-CNR Via Madonna del Piano 10-12 50019 Sesto Fiorentino (FI) Italy
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8
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Zhang W, Li S, Gong Y, Zhang J, Zhou Y, Kong J, Fu H, Zhou M. Aggregation Enhanced Thermally Activated Delayed Fluorescence through Spin-Orbit Coupling Regulation. Angew Chem Int Ed Engl 2024; 63:e202404978. [PMID: 38697945 DOI: 10.1002/anie.202404978] [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: 03/12/2024] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 05/05/2024]
Abstract
Integrating aggregation-induced emission (AIE) into thermally activated delayed fluorescence (TADF) emitters holds great promise for the advancement of highly efficient organic light emitting diodes (OLEDs). Despite recent advancements, a thorough comprehension of the underlying mechanisms remains imperative for the practical application of such materials. In this work, we introduce a novel approach aimed at modulating the TADF process by manipulating dynamic processes in excited states through aggregation effect. Our findings reveal that aggregation not only enhances both prompt and delayed fluorescence simultaneously but also imposes constraints on molecular reorientation. This constraint reinforces spin-orbit coupling and reduces the energy gap between singlets and triplets. These insights deepen our understanding of the fundamental mechanisms governing the aggregation effect on TADF materials and provide valuable guidance for the design of high-efficiency photoluminescent materials.
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Affiliation(s)
- Wei Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Shuai Li
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Yujie Gong
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Jiachen Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Yujie Zhou
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Jie Kong
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing, 100048, China
| | - Meng Zhou
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, 230026, China
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9
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Bae J, Imai-Imada M, Kim HS, Lee M, Imada H, Tsuchiya Y, Hatakeyama T, Adachi C, Kim Y. Visualization of Multiple-Resonance-Induced Frontier Molecular Orbitals in a Single Multiple-Resonance Thermally Activated Delayed Fluorescence Molecule. ACS NANO 2024; 18:17987-17995. [PMID: 38934571 DOI: 10.1021/acsnano.4c04813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
The spatial distribution and electronic properties of the frontier molecular orbitals (FMOs) in a thermally activated delayed fluorescence (TADF) molecule contribute significantly to the TADF properties, and thus, a detailed understanding and sophisticated control of the FMOs are fundamental to the design of TADF molecules. However, for multiple-resonance (MR)-TADF molecules that achieve spatial separation of FMOs by the MR effect, the distinctive distribution of these molecular orbitals poses significant challenges for conventional computational analysis and ensemble averaging methods to elucidate the FMOs' separation and the precise mechanism of luminescence. Therefore, the visualization and analysis of electronic states with the specific energy level of a single MR-TADF molecule will provide a deeper understanding of the TADF mechanism. Here, scanning tunneling microscopy/spectroscopy (STM/STS) was used to investigate the electronic states of the DABNA-1 molecule at the atomic scale. FMOs' visualization and local density of states analysis of the DABNA-1 molecule clearly show that MR-TADF molecules also have well-separated FMOs according to the internal heteroatom arrangement, providing insights that complement existing theoretical prediction methods.
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Affiliation(s)
- Jaehyun Bae
- Surface and Interface Science Laboratory (SISL), RIKEN, Wako, Saitama 351-0198, Japan
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
- Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Miyabi Imai-Imada
- Surface and Interface Science Laboratory (SISL), RIKEN, Wako, Saitama 351-0198, Japan
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama 332-0012, Japan
| | - Hyung Suk Kim
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
- Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Minhui Lee
- Surface and Interface Science Laboratory (SISL), RIKEN, Wako, Saitama 351-0198, Japan
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 118-8656, Japan
| | - Hiroshi Imada
- Surface and Interface Science Laboratory (SISL), RIKEN, Wako, Saitama 351-0198, Japan
| | - Youichi Tsuchiya
- 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, Kyoto, Sakyo 606-8502, Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
- Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
- International Institute for Carbon Neutral Energy Research (I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka 819-0395, Japan
| | - Yousoo Kim
- Surface and Interface Science Laboratory (SISL), RIKEN, Wako, Saitama 351-0198, Japan
- Department of Applied Chemistry, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 118-8656, Japan
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10
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Zhu Z, Wei X, Liang W. A theoretical investigation of benzothiadiazole derivatives for high efficiency OLEDs. J Comput Chem 2024; 45:1603-1613. [PMID: 38520729 DOI: 10.1002/jcc.27352] [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: 12/04/2023] [Revised: 03/07/2024] [Accepted: 03/12/2024] [Indexed: 03/25/2024]
Abstract
It is of great importance and worthy of efforts to give a clear structure-property relationship and microscopic mechanism of fluorescence emitters with high quantum yield. In this work, we perform a detailed computational investigation to give an explanation to the high efficiency of a fluorescence emitter XBTD-NPh based TADF sensitized fluorescence (TSF) OLEDs, and construct a symmetry structure DSBNA-BTD. Theoretical calculations show that XBTD-NPh is a long-time phosphorescent material at 77 K and TADF is attributed to the RISC of T1 to S1 state. For DSBNA-BTD, excitons arrived at T1 state comes to a large rate of nonradiatively path to the ground state, meaning it is may not be an efficient TADF molecule. For both molecules, the fast IC between T2 and T1 state results in that the hot exciton channel T1-Tn-S1 makes no contribution to the TADF.
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Affiliation(s)
- Zhiye Zhu
- Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, College of Chemical and Materials Engineering, Xuchang University, Henan, People's Republic of China
| | - Xiaoqing Wei
- Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, Institute of Surface Micro and Nano Materials, College of Chemical and Materials Engineering, Xuchang University, Henan, People's Republic of China
| | - Wanzhen Liang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian, People's Republic of China
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11
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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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12
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Park JY, Lee S, Bi JC, Lee JS, Hwang YH, Kang B, Seok J, Park S, Lim D, Park YW, Ju BK. Selective Enhancement of Viewing Angle Characteristics and Light Extraction Efficiency of Blue Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes through an Easily Tailorable Si 3N 4 Nanofiber Structure. ACS APPLIED MATERIALS & INTERFACES 2024; 16:27566-27575. [PMID: 38743438 DOI: 10.1021/acsami.4c00240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
We selectively improved the viewing angle characteristics and light extraction efficiency of blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) by tailoring a nanofiber-shaped Si3N4 layer, which was used as an internal scattering layer. The diameter of the polymer nanofibers changed according to the mass ratio of polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) in the polymer solution for electrospinning. The Si3N4 nanofiber (SNF) structure was fabricated by etching an Si3N4 film using the PAN/PMMA nanofiber as a mask, making it easier to adjust parameters, such as the diameter, open ratio, and height, even though the SNF structure was randomly shaped. The SNF structures exhibited lower transmittance and higher haze with increasing diameter, showing little correlation with their height. However, all the structures demonstrated a total transmittance of over 80%. Finally, by applying the SNF structures to the blue TADF OLEDs, the external quantum efficiency was increased by 15.6%. In addition, the current and power efficiencies were enhanced by 23.0% and 25.6%, respectively. The internal light-extracting SNF structure also exhibited a synergistic effect with the external light-extracting structure. Furthermore, when the viewing angle changed from 0° to 60°, the peak wavelength and CIE coordinate shift decreased from 20 to 6 nm and from 0.0561 to 0.0243, respectively. These trends were explained by the application of Snell's law to the light path and were ultimately validated through finite-difference time-domain simulations.
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Affiliation(s)
- Jun-Young Park
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Seungwon Lee
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Jian Cheng Bi
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Ji-Sung Lee
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Young Hyun Hwang
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Byeongwoo Kang
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Jiwon Seok
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Seonghyeon Park
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Dogi Lim
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
- Samsung Display Co., 1, Samsung-ro, Giheung-gu, Yongin-si, Gyeonggi-do 17113, Republic of Korea
| | - Young Wook Park
- Department of Semiconductor and Display Engineering, Sun Moon University Asan-si 31460, Republic of Korea
| | - Byeong-Kwon Ju
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, Seoul 02841, Republic of Korea
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13
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Franca L, Danos A, Saxena R, Kuila S, Stavrou K, Li C, Wedler S, Köhler A, Monkman AP. Exploring the Early Time Behavior of the Excited States of an Archetype Thermally Activated Delayed Fluorescence Molecule. J Phys Chem Lett 2024; 15:1734-1740. [PMID: 38323906 PMCID: PMC10875657 DOI: 10.1021/acs.jpclett.4c00030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 01/30/2024] [Accepted: 02/02/2024] [Indexed: 02/08/2024]
Abstract
Optical pump-probe techniques allow for an in-depth study of dark excited states. Here, we utilize them to map and gain insights into the excited states involved in the thermally activated delayed fluorescence (TADF) mechanism of a benchmark TADF emitter DMAC-TRZ. The results identify different electronic excited states involved in the key TADF transitions and their nature by combining pump-probe and photoluminescence measurements. The photoinduced absorption signals are highly dependent on polarity, affecting the transition oscillator strength but not their relative energy positions. In methylcyclohexane, a strong and vibronically structured local triplet excited state absorption (3LE → 3LEn) is observed, which is quenched in higher polarity solvents as 3CT becomes the lowest triplet state. Furthermore, ultrafast transient absorption (fsTA) confirms the presence of two stable conformers of DMAC-TRZ: (1) quasi-axial (QA) interconverting within 20 ps into (2) quasi-equatorial (QE) in the excited state. Moreover, fsTA highlights how sensitive excited state couplings are to the environment and the molecular conformation.
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Affiliation(s)
- Larissa
G. Franca
- Department
of Physics, Durham University, South Road, Durham DH13LE, United Kingdom
| | - Andrew Danos
- Department
of Physics, Durham University, South Road, Durham DH13LE, United Kingdom
| | - Rishabh Saxena
- Soft
Matter Optoelectronics and Bavarian Polymer Institute (BPS), University of Bayreuth, Universitätsstrasse 30, Bayreuth 95440, Germany
| | - Suman Kuila
- Department
of Physics, Durham University, South Road, Durham DH13LE, United Kingdom
| | - Kleitos Stavrou
- Department
of Physics, Durham University, South Road, Durham DH13LE, United Kingdom
| | - Chunyong Li
- Department
of Physics, Durham University, South Road, Durham DH13LE, United Kingdom
| | - Stefan Wedler
- Soft
Matter Optoelectronics and Bavarian Polymer Institute (BPS), University of Bayreuth, Universitätsstrasse 30, Bayreuth 95440, Germany
| | - Anna Köhler
- Soft
Matter Optoelectronics and Bavarian Polymer Institute (BPS), University of Bayreuth, Universitätsstrasse 30, Bayreuth 95440, Germany
| | - Andrew P. Monkman
- Department
of Physics, Durham University, South Road, Durham DH13LE, United Kingdom
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14
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Blazevicius D, Grigalevicius S. A Review of Benzophenone-Based Derivatives for Organic Light-Emitting Diodes. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:356. [PMID: 38392729 PMCID: PMC10892487 DOI: 10.3390/nano14040356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/06/2024] [Accepted: 02/09/2024] [Indexed: 02/24/2024]
Abstract
Organic light-emitting diodes (OLEDs) have garnered considerable attention in academic and industrial circles due to their potential applications in flat-panel displays and solid-state lighting technologies, leveraging the advantages offered by organic electroactive derivatives over their inorganic counterparts. The thin and flexible design of OLEDs enables the development of innovative lighting solutions, facilitating the creation of customizable and contoured lighting panels. Among the diverse electroactive components employed in the molecular design of OLED materials, the benzophenone core has attracted much attention as a fragment for the synthesis of organic semiconductors. On the other hand, benzophenone also functions as a classical phosphor with high intersystem crossing efficiency. This characteristic makes it a compelling candidate for effective reverse intersystem crossing, with potential in leading to the development of thermally activated delayed fluorescent (TADF) emitters. These emitting materials witnessed a pronounced interest in recent years due to their incorporation in metal-free electroactive frameworks and the capability to convert triplet excitons into emissive singlet excitons through reverse intersystem crossing (RISC), consequently achieving exceptionally high external quantum efficiencies (EQEs). This review article comprehensively overviews the synthetic pathways, thermal characteristics, electrochemical behaviour, and photophysical properties of derivatives based on benzophenone. Furthermore, we explore their applications in OLED devices, both as host materials and emitters, shedding light on the promising opportunities that benzophenone-based compounds present in advancing OLED technology.
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Affiliation(s)
- Dovydas Blazevicius
- Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu Plentas 19, LT50254 Kaunas, Lithuania
| | - Saulius Grigalevicius
- Department of Polymer Chemistry and Technology, Kaunas University of Technology, Radvilenu Plentas 19, LT50254 Kaunas, Lithuania
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15
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Zheng C, Deng J, Qi Y, Sun C, Cui D, Chen C, Zhu C, Wang S, Yuan J, Xie G, Li P, Chen R. Rational Design of Bipolar Host and Thermally Activated Delayed Fluorescence Materials in Donor-Acceptor Molecular Architecture: A Theoretical Study. J Phys Chem Lett 2024; 15:525-531. [PMID: 38194489 DOI: 10.1021/acs.jpclett.3c03068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Donor-acceptor (D-A) molecules have drawn massive attention recently in the design of high-performance materials, but the underlying reasons for the magic abilities of D-A architecture in building very different organic semiconductors are still unclear. Here, based on a series of experimentally bipolar host and thermally activated delayed fluorescence (TADF) molecules with the same donor but different acceptor units, it was found that TADF emitters have more effective charge transfer between donor and acceptor units than bipolar host molecules. More efficient conjugation effects between the donor and acceptor units of host materials were identified from the lower dihedral angles of the D-A structure, smaller and even negative charge transfer amount, shorter charge-transfer length, and larger hole-electron overlap extent. These findings with in-depth insights into different interaction models of donor and acceptor units shed important light on the molecular design of TADF emitters and bipolar materials in a D-A architecture.
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Affiliation(s)
- Chao Zheng
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Junyuan Deng
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Yuanyuan Qi
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Chengxi Sun
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Dongyue Cui
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Cailin Chen
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Chenxi Zhu
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Shuang Wang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Jie Yuan
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
- Engineering Technology Training Center, Nanjing Vocational University of Industry Technology, 1 Yangshan North Road, Nanjing 210023, China
| | - Gaozhan Xie
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Ping Li
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Runfeng Chen
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
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16
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Li H, Ren H, Wang J, Liu D, Li J. Cyano Decoration of π-Bridge to Boost Photoluminescence and Electroluminescence Quantum Yields of Triazine/Carbazole Based Blue TADF Emitter. Chemistry 2024; 30:e202303169. [PMID: 37965803 DOI: 10.1002/chem.202303169] [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: 09/28/2023] [Revised: 11/10/2023] [Accepted: 11/13/2023] [Indexed: 11/16/2023]
Abstract
In general, a large donor-acceptor dihedral angle is required to guarantee sufficient frontier molecular orbitals separation for thermally activated delayed fluorescence (TADF) emitters, which is intrinsically unfavorable for the radiative transition. We present a molecular design method favoring both reverse intersystem crossing (RISC) and radiative transitions even at a moderate D-A angle. A blue TADF emitter TrzBuCz-CN was designed with triazine/tert-butylcarbazole as donor/acceptor and cyano (CN) incorporated on the phenylene bridge. In comparison with the methyl decoration in similar way (TrzBuCz-Me), CN decoration reduced the D-A dihedral angle from 70° to 60°, which is intrinsically not favorable for sufficient FMO separation, but unexpectedly reduced the singlet and triplet energy gap (ΔEST ) and thus facilitated TADF feature by pulling down the lowest singlet state energy. While the reduced distorsion instead improved the HOMO-LUMO overlap and boosted the fluorescence quantum yield from 41 % to 94 %. The blue organic light-emitting diode of TrzBuCz-CN exhibited an external quantum efficiency of 13.7 % with emission peak at 466 nm, greatly superior to 6.0 % of TrzBuCz-Me. The result provides a feasible design strategy to facilitate both RISC and radiation processes by CN decoration of the linking bridge of TADF emitters.
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Affiliation(s)
- Huiting Li
- Key Laboratory of Natural Product Chemistry and Functional Molecular Synthesis, College of Chemistry and Materials, Inner Mongolia Minzu University, West Huolinhe Street, Tongliao, 028000, China
- Frontiers Science Center for Smart Materials, School of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian, 116024, China
| | - Huicai Ren
- Yantai Sunera Limited Liability Company, Yantai Economic and Technological Development Zone, No. 7 Shaoxing Road, Yantai, China
| | - Jiahui Wang
- Frontiers Science Center for Smart Materials, School of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian, 116024, China
| | - Di Liu
- Frontiers Science Center for Smart Materials, School of Chemistry, Dalian University of Technology, 2 Linggong Road, Dalian, 116024, China
| | - Jiuyan Li
- Shandong Laboratory of Advanced Materials and Green Manufacturing at Yantai, Yantai Economic and Technological Development Zone, 300 Changjiang Road, Yantai, China
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17
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Goll FD, Schelhorn A, Litvinas D, Tenopala-Carmona F, Kazak L, Jelezko F, Lambert C, Gather MC, Kuehne AJC, Ziener U. Revealing the Origin of Fast Delayed Fluorescence in a Donor Functionalized Bisterpyridine. Chemistry 2024; 30:e202303067. [PMID: 37902606 DOI: 10.1002/chem.202303067] [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: 09/21/2023] [Revised: 10/27/2023] [Accepted: 10/30/2023] [Indexed: 10/31/2023]
Abstract
A new carbazole-substituted bisterpyridine with pronounced delayed fluorescence is presented. While the molecular donor-acceptor-donor design suggests the origin of this to be thermally activated delayed fluorescence (TADF), results from various photophysical characterizations, OLED characteristics, temperature-dependent NMR spectroscopy, and DFT calculations all point against the involvement of triplet states. The molecule exhibits blue emission at about 440 nm with two or more fast decay channels in the lower nanosecond range in both solution and thin films. The delayed emission is proposed to be caused by rotational vibrational modes. We suggest that these results are generally applicable, especially for more complex molecules, and should be considered as alternative or competitive emissive relaxation pathways in the field of organic light emitting materials.
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Affiliation(s)
- Felix D Goll
- Institute of Organic Chemistry III -, Macromolecular Chemistry and Organic Materials, Ulm University, 89081, Ulm, Germany
| | - Andreas Schelhorn
- Institute of Organic Chemistry III -, Macromolecular Chemistry and Organic Materials, Ulm University, 89081, Ulm, Germany
| | - Džiugas Litvinas
- Humboldt Centre for Nano- and Biophotonics, Department of Chemistry, University of Cologne, Greinstraße 4-6, 50939, Köln, Germany
| | - Francisco Tenopala-Carmona
- Humboldt Centre for Nano- and Biophotonics, Department of Chemistry, University of Cologne, Greinstraße 4-6, 50939, Köln, Germany
| | - Lev Kazak
- Institute for Quantum Optics, Ulm University, 89081, Ulm, Germany
| | - Fedor Jelezko
- Institute for Quantum Optics, Ulm University, 89081, Ulm, Germany
| | - Christoph Lambert
- Institut für Organische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Malte C Gather
- Humboldt Centre for Nano- and Biophotonics, Department of Chemistry, University of Cologne, Greinstraße 4-6, 50939, Köln, Germany
- SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, KY16 9SS, St Andrews, Fife, UK
| | - Alexander J C Kuehne
- Institute of Organic Chemistry III -, Macromolecular Chemistry and Organic Materials, Ulm University, 89081, Ulm, Germany
| | - Ulrich Ziener
- Institute of Organic Chemistry III -, Macromolecular Chemistry and Organic Materials, Ulm University, 89081, Ulm, Germany
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18
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Wu Z, Zhang Q, Wang X, Zhang K, Li X, Li R, Song Y, Fan J, Wang CK, Lin L, Wang Z. Multi-resonance thermally activated delayed fluorescence molecules with intramolecular-lock: theoretical design and performance prediction. Phys Chem Chem Phys 2023; 25:24406-24416. [PMID: 37621260 DOI: 10.1039/d3cp02255b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Multi-resonance thermally activated delayed fluorescence (MR-TADF) molecules with narrow full width at half maximum (FWHM) have attracted much attention recently. In this work, 36 borane/amine (B/N) type MR-TADF molecules were theoretically designed by using an intramolecular-lock strategy and systematically studied based on first-principles calculations. It was found that intramolecular-lock at different positions and in different manners could induce different luminescent properties. The calculated oscillator strengths for PXZ-L2 and PTZ-L2 locking systems are weaker than that for 2DPABN (without intramolecular-lock), while the Cz-L1 and TMCZ-L1 locking could result in stronger oscillator strength. Though the calculated FWHM of all the systems with intramolecular-lock is higher than that of 2DPABN, the Cz, TMCz and DMAC locking at L1 or L2 would induce relatively small FWHM which is comparable to that of 2DPABN. Our calculation results indicate that intramolecular-lock could enhance the SOC values and decrease the energy gap between the first singlet excited state and the first triplet excited state, which is quite favorable to reverse intersystem crossing. The Cz, TMCz and DMAC locking systems could realize comparable and higher efficiency than 2DPABN, thus higher quantum efficiency could be obtained. Our calculation results indicate that the intramolecular-lock strategy is an effective method to realize the design of highly efficient MR-TADF emitters.
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Affiliation(s)
- Zhimin Wu
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Qun Zhang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Xiaofei Wang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Kai Zhang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Xiaofang Li
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Rui Li
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Yuzhi Song
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Jianzhong Fan
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Chuan-Kui Wang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Lili Lin
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
| | - Zhongjie Wang
- Shandong Key Laboratory of Medical Physics and Image Processing & Shandong Provincial Engineering and Technical Center of Light Manipulations, School of Physics and Electronics, Shandong Normal University, Jinan 250358, China.
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19
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Siddiqui I, Kumar S, Tsai YF, Gautam P, Shahnawaz, Kesavan K, Lin JT, Khai L, Chou KH, Choudhury A, Grigalevicius S, Jou JH. Status and Challenges of Blue OLEDs: A Review. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2521. [PMID: 37764550 PMCID: PMC10536903 DOI: 10.3390/nano13182521] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023]
Abstract
Organic light-emitting diodes (OLEDs) have outperformed conventional display technologies in smartphones, smartwatches, tablets, and televisions while gradually growing to cover a sizable fraction of the solid-state lighting industry. Blue emission is a crucial chromatic component for realizing high-quality red, green, blue, and yellow (RGBY) and RGB white display technologies and solid-state lighting sources. For consumer products with desirable lifetimes and efficiency, deep blue emissions with much higher power efficiency and operation time are necessary prerequisites. This article reviews over 700 papers covering various factors, namely, the crucial role of blue emission for full-color displays and solid-state lighting, the performance status of blue OLEDs, and the systematic development of fluorescent, phosphorescent, and thermally activated delayed fluorescence blue emitters. In addition, various challenges concerning deep blue efficiency, lifetime, and approaches to realizing deeper blue emission and higher efficacy for blue OLED devices are also described.
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Affiliation(s)
- Iram Siddiqui
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Sudhir Kumar
- Institute for Chemical and Bioengineering, ETH Zürich, 8093 Zürich, Switzerland
| | - Yi-Fang Tsai
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Prakalp Gautam
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Shahnawaz
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Kiran Kesavan
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Jin-Ting Lin
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Luke Khai
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Kuo-Hsien Chou
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Abhijeet Choudhury
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Saulius Grigalevicius
- Department of Polymer Chemistry and Technology, Kaunas University of Technology, LT-50254 Kaunas, Lithuania
| | - Jwo-Huei Jou
- Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan
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20
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Yu YJ, Song M, Meng XY, Qu YK, Wang XQ, Chen L, Yang SY, Zhou DY, Jiang ZQ, Liao LS. Design and Synthesis of Red Through-Space Charge Transfer Thermally Activated Delayed Fluorescence Emitters with Donor/Acceptor/Donor Stacking. Org Lett 2023; 25:6024-6028. [PMID: 37552571 DOI: 10.1021/acs.orglett.3c02168] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/10/2023]
Abstract
Red through-space charge transfer thermally activated delayed fluorescence (TSCT TADF) materials named SAF36DCPP and SAF27DCPP with sandwiched structures were synthesized. Single crystals indicated that the intramolecular C-H···π interactions play a vital role in rigidifying the sandwiched structure, which results in a fluorescence yield of 63% for SAF36DCPP compared to 40% for SAF27DCPP. Organic light-emitting diodes with SAF36DCPP as the emitter realized a maximum external quantum efficiency of 16.12%.
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Affiliation(s)
- You-Jun Yu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Min Song
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Xin-Yue Meng
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Yang-Kun Qu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Xue-Qi Wang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Long Chen
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Sheng-Yi Yang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Dong-Ying Zhou
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Zuo-Quan Jiang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
| | - Liang-Sheng Liao
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, P. R. China
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21
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Qiu W, Liu D, Li M, Cai X, Chen Z, He Y, Liang B, Peng X, Qiao Z, Chen J, Li W, Pu J, Xie W, Wang Z, Li D, Gan Y, Jiao Y, Gu Q, Su SJ. Confining donor conformation distributions for efficient thermally activated delayed fluorescence with fast spin-flipping. Nat Commun 2023; 14:2564. [PMID: 37142564 PMCID: PMC10160101 DOI: 10.1038/s41467-023-38197-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Accepted: 04/19/2023] [Indexed: 05/06/2023] Open
Abstract
Fast spin-flipping is the key to exploit the triplet excitons in thermally activated delayed fluorescence based organic light-emitting diodes toward high efficiency, low efficiency roll-off and long operating lifetime. In common donor-acceptor type thermally activated delayed fluorescence molecules, the distribution of dihedral angles in the film state would have significant influence on the photo-physical properties, which are usually neglected by researches. Herein, we find that the excited state lifetimes of thermally activated delayed fluorescence emitters are subjected to conformation distributions in the host-guest system. Acridine-type flexible donors have a broad conformation distribution or bimodal distribution, in which some conformers feature large singlet-triplet energy gap, leading to long excited state lifetime. Utilization of rigid donors with steric hindrance can restrict the conformation distributions in the film to achieve degenerate singlet and triplet states, which is beneficial to efficient reverse intersystem crossing. Based on this principle, three prototype thermally activated delayed fluorescence emitters with confined conformation distributions are developed, achieving high reverse intersystem crossing rate constants greater than 106 s-1, which enable highly efficient solution-processed organic light-emitting diodes with suppressed efficiency roll-off.
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Affiliation(s)
- Weidong Qiu
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - 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, P. R. China
| | - Mengke Li
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China.
| | - Xinyi Cai
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Zijian Chen
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Yanmei He
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | | | - Xiaomei Peng
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Zhenyang Qiao
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Jiting Chen
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Wei Li
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Junrong Pu
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Wentao Xie
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Zhiheng Wang
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
- Ji Hua Laboratory, Foshan, 528200, P. R. China
| | - Deli Li
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Yiyang Gan
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Yihang Jiao
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Qing Gu
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. 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, P. R. China.
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22
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Qian X, Chu F, Zhou W, Zheng Z, Chen X, Zhao Y. Design of Intramolecular Dihedral Angle between Electronic Donor and Acceptor in Thermally Activated Delayed Fluorescence Molecules. J Phys Chem Lett 2023; 14:3335-3342. [PMID: 36994861 DOI: 10.1021/acs.jpclett.3c00515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
In order to improve the exciton utilization efficiency (ηexc) of organic light-emitting materials, we addressed the ideal donor-acceptor dihedral angle (θD-A) in the TADF molecule by striking a balance between two photophysical processes. One is the conversion of triplet excitons into singlet excitons, and the other is the radiative process from a low-lying excited state to the ground state. Using a combination of first-principles calculations and molecular dynamics simulations, we investigated the impact of θD-A on the splitting energy and spin-orbit coupling between singlet and triplet excitons as well as the transition dipole moment for carbazole benzonitrile (CzBN) derivatives. By comparison with the reverse intersystem crossing rate (krISC), fluorescence emission rate (kr), and ηexc, we proposed a potential highest ηexc (of 94.4%) with the ideal θD-A of 77° for blue light CzBN derivatives; the calculated results have a good agreement with experimental measurement. The structure-efficiency physical connection between the molecular structure (θD-A) and efficiency provided an ideal parameter for a potential candidate for blue TADF-OLED materials.
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Affiliation(s)
- Xin Qian
- Faculty of Materials and Manufacturing, Faculty of Information Technology, Beijing University of Technology, Beijing 100124, P. R. China
| | - Feihong Chu
- Faculty of Materials and Manufacturing, Faculty of Information Technology, Beijing University of Technology, Beijing 100124, P. R. China
| | - Wencai Zhou
- Faculty of Materials and Manufacturing, Faculty of Information Technology, Beijing University of Technology, Beijing 100124, P. R. China
| | - Zilong Zheng
- Faculty of Materials and Manufacturing, Faculty of Information Technology, Beijing University of Technology, Beijing 100124, P. R. China
| | - Xiaoqing Chen
- Faculty of Materials and Manufacturing, Faculty of Information Technology, Beijing University of Technology, Beijing 100124, P. R. China
| | - Yi Zhao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, Fujian Provincial Key Lab of Theoretical and Computational Chemistry, and College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
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23
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Kumar V, Kaur P, Singh K. Julolidine based red emitting ESIPT/AIE active material showing luminescence beyond excimer emission: An "on-off" emission response to Cu 2. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 290:122239. [PMID: 36563439 DOI: 10.1016/j.saa.2022.122239] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/06/2022] [Accepted: 12/10/2022] [Indexed: 06/17/2023]
Abstract
A new julolidine-fluorene based excited state intramolecular proton transfer (ESIPT)/aggregate induced emission (AIE) active Schiff-base (JDF) has been synthesized and evaluated for its photophysical properties in solution and aggregated/solid states. The correlation between the emission behavior and the solid state crystal packing structure revealed the interplay of ESIPT coupled excimer reaction occurring in the solid state, which is one of the rare examples reported so far. For a comprehensive comparison, we synthesized a non-ESIPT methyl derivative (JDF-Me) of JDF capable of showing excimer emission only in the solid state. Further, JDF exhibits normal as well as keto emission in solution, upon addition of water, its poor solvent, that promotes aggregation, the fluorescence emission shows the preponderance of the excimer band in the low energy region. It was also interesting to note that in the solid state (thin films), JDF shows emission beyond the excimer emission, which is wavelength dependent. This is attributed to the formation of diverse clusters leading to the extended delocalization beyond excimers, and represents a clustering-triggered emission ascribing bright red color to the solid JDF. Such mélange of emission characteristics of JDF are responsible for the multicolor emission covering a broad range of electromagnetic spectrum, which is demonstrated by the confocal microscopy images of the JDF recorded in different states. Further, in its aggregated state, JDF recognized Cu2+ ions, selectively, manifested in the form of emission quenching via the interaction of Cu2+ ions with the oxygen and nitrogen atoms of JDF inhibiting the excimer formation.
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Affiliation(s)
- Virendra Kumar
- Department of Chemistry, Centre of Advanced Study, Guru Nanak Dev University, Amritsar 143005, India
| | - Paramjit Kaur
- Department of Chemistry, Centre of Advanced Study, Guru Nanak Dev University, Amritsar 143005, India.
| | - Kamaljit Singh
- Department of Chemistry, Centre of Advanced Study, Guru Nanak Dev University, Amritsar 143005, India.
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24
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Jiang D, Lu T, Du C, Liu F, Yan Z, Hu D, Shang A, Gao L, Lu P, Ma Y. Utilizing morpholine for purely organic room temperature phosphors. Sci China Chem 2023. [DOI: 10.1007/s11426-022-1507-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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25
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Yersin H, Czerwieniec R, Monkowius U, Ramazanov R, Valiev R, Shafikov MZ, Kwok WM, Ma C. Intersystem crossing, phosphorescence, and spin-orbit coupling. Two contrasting Cu(I)-TADF dimers investigated by milli- to micro-second phosphorescence, femto-second fluorescence, and theoretical calculations. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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26
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Liu Y, Yang J, Mao Z, Wang Y, Zhao J, Su SJ, Chi Z. Isomeric thermally activated delayed fluorescence emitters for highly efficient organic light-emitting diodes. Chem Sci 2023; 14:1551-1556. [PMID: 36794188 PMCID: PMC9906651 DOI: 10.1039/d2sc06335b] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 01/12/2023] [Indexed: 01/13/2023] Open
Abstract
The isomeric strategy is an important design concept in molecular design that has a non-negligible influence on molecular properties. Herein, two isomeric thermally activated delayed fluorescence (TADF) emitters (NTPZ and TNPZ) are constructed with the same skeleton consisting of an electron donor and electron acceptor but different connection sites. Systematic investigations show that NTPZ exhibits a small energy gap, large up-conversion efficiency, low non-radiative decay, and high photoluminescence quantum yield. Further theoretical simulations reveal that the excited molecular vibrations play a key role in regulating the non-radiative decays of the isomers. Therefore, an NTPZ based OLED achieves better electroluminescence performances, such as a higher external quantum efficiency of 27.5% compared to a TNPZ based OLED (18.3%). This isomeric strategy not only provides an opportunity to deeply understand the relationship between substituent locations and molecular properties, but also affords a simple and effective strategy to enrich TADF materials.
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Affiliation(s)
- Yanyan Liu
- PCFM Lab, GDHPPC Lab, Guangdong Engineering Technology Research Center for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of OEMT, School of Chemistry, Sun Yat-sen University Guangzhou 510275 China
| | - Jiaji Yang
- State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology Guangzhou 510640 China
| | - Zhu Mao
- Shenzhen Institute of Advanced Electronic Materials, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences Shenzhen 518055 China
| | - Yuyuan Wang
- PCFM Lab, GDHPPC Lab, Guangdong Engineering Technology Research Center for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of OEMT, School of Chemistry, Sun Yat-sen University Guangzhou 510275 China
| | - Juan Zhao
- School of Materials Science and Engineering, Sun Yat-sen University Guangzhou 510275 China
| | - Shi-Jian Su
- State Key Laboratory of Luminescent Materials and Devices, Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology Guangzhou 510640 China
| | - Zhenguo Chi
- PCFM Lab, GDHPPC Lab, Guangdong Engineering Technology Research Center for High-performance Organic and Polymer Photoelectric Functional Films, State Key Laboratory of OEMT, School of Chemistry, Sun Yat-sen University Guangzhou 510275 China
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27
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Lian M, Ye Z, Mu Y, Hu D, Liu Y, Zhang H, Ji S, Huo Y. Progress on Blue-Emitting Hot Exciton Materials. CHINESE J ORG CHEM 2023. [DOI: 10.6023/cjoc202207042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
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28
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Huang J, Hung H, Hsu K, Chen C, Lee P, Lin H, Lin B, Leung M, Chiu T, Lee J, Friend RH, Wu Y. Numerical Analysis and Optimization of a Hybrid Layer Structure for Triplet–Triplet Fusion Mechanism in Organic Light‐Emitting Diodes. ADVANCED THEORY AND SIMULATIONS 2022. [DOI: 10.1002/adts.202200633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jun‐Yu Huang
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering National Taiwan University Taipei 10617 Taiwan
- Cavendish Laboratory University of Cambridge Cambridge CB3 0HE UK
| | - Hsiao‐Chun Hung
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering National Taiwan University Taipei 10617 Taiwan
| | - Kung‐Chi Hsu
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering National Taiwan University Taipei 10617 Taiwan
| | - Chia‐Hsun Chen
- Department of Chemistry National Taiwan University Taipei 10617 Taiwan
| | - Pei‐Hsi Lee
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering National Taiwan University Taipei 10617 Taiwan
| | - Hung‐Yi Lin
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering National Taiwan University Taipei 10617 Taiwan
| | - Bo‐Yen Lin
- Department of Opto‐Electronic Engineering National Dong Hwa University Shoufeng Hualien 974301 Taiwan
| | - Man‐kit Leung
- Department of Chemistry National Taiwan University Taipei 10617 Taiwan
| | - Tien‐Lung Chiu
- Department of Electrical Engineering Yuan‐Ze University Taoyuan 32003 Taiwan
| | - Jiun‐Haw Lee
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering National Taiwan University Taipei 10617 Taiwan
| | | | - Yuh‐Renn Wu
- Graduate Institute of Photonics and Optoelectronics and Department of Electrical Engineering National Taiwan University Taipei 10617 Taiwan
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29
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Tu C, Huang W, Liang S, Wang K, Tian Q, Yan W. Combining machine learning and quantum chemical calculations for high-throughput virtual screening of thermally activated delayed fluorescence molecular materials: the impact of selection strategy and structural mutations. RSC Adv 2022; 12:30962-30975. [PMID: 36349007 PMCID: PMC9619240 DOI: 10.1039/d2ra05643g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/09/2022] [Indexed: 11/23/2022] Open
Abstract
In view of the theoretical importance and huge application potential of Thermally Activated Delayed Fluorescence (TADF) materials, it is of great significance to conduct High-Throughput Virtual Screening (HTVS) on compound libraries to find TADF candidate molecules. This research focuses on the computational design of pure organic TADF molecules. By combining machine learning and quantum chemical calculations, using cheminformatics tools, and introducing the concept of selection and mutation from evolutionary theory, we have designed a computational program for HTVS of TADF molecular materials, especially the impact of selection strategy and structural mutations on the results of HTVS was explored. An initial compound library (size = 103) constructed by enumeration of typical donors and acceptors was used to evolve by successively applying selection and 10 different structural mutations. And a group fingerprint similarity (ΔMSPR) index was proposed to account for the similarity between two compound libraries with comparable sizes. Based on the computed data, we have found that the mix of selection and mutations into the evolution map does have great impact on the HTVS results: (a) except the fast mutation Sub2, all the rest of the mutations can effectively concentrate 'good' molecules in a compound library, and hence give large material abundance (typically >0.8) for high mutation generations (n g ≥ 6). (b) The mean energy gap can exhibit a fast convergent trend toward very low values, hence the studied mutations (except Sub2) can cooperate very well with the studied DA substrates to generate optimal molecules, and the group fingerprint similarity can retain high enough values for large n g, which can be associated with the apparent convergence in molecular skeletons as n g increases. (c) The distribution of skeleton frequencies for a specific mutation is generally uneven with one dominant skeleton. The overall numbers of common and generic cores for all mutations are 11 and 7 as n g = 9. Hence, in a sense, the 'optimal' skeletons seem unique and useful in realizing low energy gaps. With these observations and the development of related HTVS software, we expect to provide insight and tools to the research community of HTVS of molecular (TADF) materials.
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Affiliation(s)
- Chunyun Tu
- School of Chemistry and Materials Engineering, Guiyang University Guiyang 550005 P. R. China +86-180-9605-0905
| | - Weijiang Huang
- School of Chemistry and Materials Engineering, Guiyang University Guiyang 550005 P. R. China +86-180-9605-0905
| | - Sheng Liang
- School of Mathematics and Information Science, Guiyang University Guiyang 550005 P. R. China
| | - Kui Wang
- School of Chemistry and Materials Engineering, Guiyang University Guiyang 550005 P. R. China +86-180-9605-0905
| | - Qin Tian
- School of Chemistry and Materials Engineering, Guiyang University Guiyang 550005 P. R. China +86-180-9605-0905
| | - Wei Yan
- School of Chemistry and Materials Engineering, Guiyang University Guiyang 550005 P. R. China +86-180-9605-0905
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30
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Highly Efficient Solution-Processed Blue Phosphorescent Organic Light-Emitting Diodes Based on Co-Dopant and Co-Host System. Molecules 2022; 27:molecules27206882. [PMID: 36296475 PMCID: PMC9611992 DOI: 10.3390/molecules27206882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/08/2022] [Accepted: 10/08/2022] [Indexed: 11/05/2022] Open
Abstract
The low-lying HOMO level of the blue emitter and the interfacial miscibility of organic materials result in inferior hole injection, and long exciton lifetime leads to triplet-triplet annihilation (TTA) and triplet-polaron annihilation (TPA), so the efficiencies of blue phosphorescent organic light-emitting diodes (PhOLEDs) are still unsatisfactory. Herein, we design co-host and co-dopant structures to improve the efficiency of blue PhOLEDs by means of solution processing. TcTa acts as hole transport ladder due to its high-lying HOMO level, and bipolar mCPPO1 helps to balance carriers’ distribution and weaken TPA. Besides the efficient FIr6, which acts as the dominant blue dopant, FCNIrPic was introduced as the second dopant, whose higher HOMO level accelerates hole injection and high triplet energy facilitates energy transfer. An interesting phenomenon caused by microcavity effect between anode and cathode was observed. With increasing thickness of ETL, peak position of electroluminescence (EL) spectrum red shifts gradually. Once the thickness of ETL exceeded 140 nm, emission peak blue-shifts went back to its original position. Finally, the maximum current efficiency (CE), power efficiency (PE), and external quantum efficiency (EQE) of blue phosphorescent organic light-emitting diode (PhOLED) went up to 20.47 cd/A, 11.96 lm/W, and 11.62%, respectively.
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31
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Gu Q, Chotard F, Eng J, Reponen APM, Vitorica-Yrezabal IJ, Woodward AW, Penfold TJ, Credgington D, Bochmann M, Romanov AS. Excited-State Lifetime Modulation by Twisted and Tilted Molecular Design in Carbene-Metal-Amide Photoemitters. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2022; 34:7526-7542. [PMID: 36032551 PMCID: PMC9404540 DOI: 10.1021/acs.chemmater.2c01938] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/25/2022] [Indexed: 06/15/2023]
Abstract
Carbene-metal-amides (CMAs) are an emerging class of photoemitters based on a linear donor-linker-acceptor arrangement. They exhibit high flexibility about the carbene-metal and metal-amide bonds, leading to a conformational freedom which has a strong influence on their photophysical properties. Herein we report CMA complexes with (1) nearly coplanar, (2) twisted, (3) tilted, and (4) tilt-twisted orientations between donor and acceptor ligands and illustrate the influence of preferred ground-state conformations on both the luminescence quantum yields and excited-state lifetimes. The performance is found to be optimum for structures with partially twisted and/or tilted conformations, resulting in radiative rates exceeding 1 × 106 s-1. Although the metal atoms make only small contributions to HOMOs and LUMOs, they provide sufficient spin-orbit coupling between the low-lying excited states to reduce the excited-state lifetimes down to 500 ns. At the same time, high photoluminescence quantum yields are maintained for a strongly tilted emitter in a host matrix. Proof-of-concept organic light-emitting diodes (OLEDs) based on these new emitter designs were fabricated, with a maximum external quantum efficiency (EQE) of 19.1% with low device roll-off efficiency. Transient electroluminescence studies indicate that molecular design concepts for new CMA emitters can be successfully translated into the OLED device.
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Affiliation(s)
- Qinying Gu
- Department
of Physics, Cavendish Laboratory, Cambridge
University, Cambridge CB3 0HF, U.K.
| | - Florian Chotard
- School
of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K.
| | - Julien Eng
- School
of Chemistry, Newcastle University, Bedson Building, Newcastle upon Tyne, NE1 7RU, U.K.
| | - Antti-Pekka M. Reponen
- Department
of Physics, Cavendish Laboratory, Cambridge
University, Cambridge CB3 0HF, U.K.
| | | | - Adam W. Woodward
- Department
of Chemistry, University of Manchester, Manchester, M13 9PL, U.K.
| | - Thomas J. Penfold
- School
of Chemistry, Newcastle University, Bedson Building, Newcastle upon Tyne, NE1 7RU, U.K.
| | - Dan Credgington
- Department
of Physics, Cavendish Laboratory, Cambridge
University, Cambridge CB3 0HF, U.K.
| | - Manfred Bochmann
- School
of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K.
| | - Alexander S. Romanov
- School
of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, U.K.
- Department
of Chemistry, University of Manchester, Manchester, M13 9PL, U.K.
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32
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Guo S, Liu W, Wu Y, Sun J, Li J, Jiang H, Zhang M, Wang S, Liu Z, Wang L, Wang H, Fu H, Yao J. Distinctive Excited State Symmetry Breaking Dynamics in Typical Donor-Acceptor-Donor Fluorophore: Strong Photoluminescence and Ultrafast Charge Separation from a Partial Charge Transfer State. J Phys Chem Lett 2022; 13:7547-7552. [PMID: 35948107 DOI: 10.1021/acs.jpclett.2c02342] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Understanding the structure-property relationships in organic semiconductors is crucial for controlling their photophysical properties and developing new optoelectronic materials. Quadrupolar molecules, donor-acceptor-donor (DAD), have attracted extensive attention in various optoelectronic applications. However, the systematic studies on the differences on photophysical properties between DAD and simple donor-acceptor (DA) chromophores are rarely reported. Herein we present a comparative study on the excited state dynamics of DA and DAD fluorescence systems using theoretical calculation and transient absorption spectroscopy. Results show that DA and DAD molecules exhibit similar excited state dynamics, which are attributed to the distinctive excited-state symmetry breaking (ESSB) phenomenon observed in a DAD system. The strong photoluminescence (PL) and ultrafast charge separation (CS) from an ESSB-induced partial charge transfer (CT) state were clearly detected in different solvent environments. These results not only offer insight into the excited state dynamics of the DAD fluorescence system but also provide some basic guidelines for designing new optoelectronic materials.
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Affiliation(s)
- Shaoting Guo
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Wen Liu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Yuling Wu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Jing Sun
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Jie Li
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Hongyu Jiang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Mengfan Zhang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Senhao Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Zuyuan Liu
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Long Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, College of Chemistry, Taiyuan University of Technology, Taiyuan 030024, China
| | - Hua Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Hongbing Fu
- Beijing Key Laboratory for Optical Materials and Photonic Devices, Department of Chemistry, Capital Normal University, Beijing 100048, China
| | - Jiannian Yao
- Beijing National Laboratory for Molecules Science (BNLMS), Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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33
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Lu C, Li N, Jin Y, Sun Y, Wang J. Physical Mechanisms of Intermolecular Interactions and Cross-Space Charge Transfer in Two-Photon BDBT-TCNB Co-Crystals. NANOMATERIALS (BASEL, SWITZERLAND) 2022; 12:2757. [PMID: 36014621 PMCID: PMC9414930 DOI: 10.3390/nano12162757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/06/2022] [Accepted: 08/09/2022] [Indexed: 06/15/2023]
Abstract
Co-crystal materials formed by stacking different molecules with weak interactions are a hot research topic. In this work, we theoretically investigate the intermolecular interactions and charge transfer properties of the supramolecular BDBT-TCNB co-crystal (BTC). The π-π bonds, hydrogen bonds, and S-N bonds in the BTC bind the BDBT and TCNB molecules together to form a highly ordered co-crystal and lead to the co-crystal's excellent two-photon absorption (TPA) properties. The intermolecular interactions of the BTC are discussed in detail by the independent gradient model based on Hirshfeld partition (IGMH), atoms in molecules (AIM), electrostatic overlay diagram, and symmetry-adapted perturbation theory (SAPT) energy decomposition; it is found that there is a strong interaction force along the stacking direction. The charge transfer properties of the one-photon absorption (OPA) and TPA of the BTC were investigated by charge density difference (CDD) and transition density matrix (TDM). It is found that the dominant charge transfer mode is the cross-space charge transfer along the stacking direction. Therefore, strong intermolecular interactions will promote intermolecular cross-space charge transfer. This work is of great significance for the design of organic optoelectronic supramolecular materials.
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Affiliation(s)
- Chen Lu
- College of Science, Liaoning Petrochemical University, Fushun 113001, China
| | - Ning Li
- College of Science, Liaoning Petrochemical University, Fushun 113001, China
| | - Ying Jin
- College of Science, Liaoning Petrochemical University, Fushun 113001, China
| | - Ying Sun
- Institute of Clean Energy Chemistry, Key Laboratory for Green Synthesis and Preparative Chemistry of Advanced Materials of Liaoning Province, College of Chemistry, Liaoning University, Shenyang 110036, China
| | - Jingang Wang
- College of Science, Liaoning Petrochemical University, Fushun 113001, China
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34
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Kelly D, Franca LG, Stavrou K, Danos A, Monkman AP. Laplace Transform Fitting as a Tool To Uncover Distributions of Reverse Intersystem Crossing Rates in TADF Systems. J Phys Chem Lett 2022; 13:6981-6986. [PMID: 35881847 PMCID: PMC9358706 DOI: 10.1021/acs.jpclett.2c01864] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/18/2022] [Indexed: 05/22/2023]
Abstract
Donor-acceptor (D-A) thermally activated delayed fluorescence (TADF) molecules are exquisitely sensitive to D-A dihedral angle. Although commonly simplified to an average value, these D-A angles nonetheless exist as distributions across the individual molecules embedded in films. The presence of these angle distributions translates to distributions in the rates of reverse intersystem crossing (krISC), observed as time dependent spectral shifts and multiexponential components in the emission decay, which are difficult to directly quantify. Here we apply inverse Laplace transform fitting of delayed fluorescence to directly reveal these distributions. Rather than a single average value, the crucial krISC rate is instead extracted as a density of rates. The modes and widths of these distributions vary with temperature, host environment, and intrinsic D-A torsional rigidity of different TADF molecules. This method gives new insights and deeper understanding of TADF host-guest interactions, as well as verifies future design strategies that target D-A bond rigidity.
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35
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Lee HL, Jeon SO, Kim I, Kim SC, Lim J, Kim J, Park S, Chwae J, Son WJ, Choi H, Lee JY. Multiple-Resonance Extension and Spin-Vibronic-Coupling-Based Narrowband Blue Organic Fluorescence Emitters with Over 30% Quantum Efficiency. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2202464. [PMID: 35762112 DOI: 10.1002/adma.202202464] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 06/03/2022] [Indexed: 06/15/2023]
Abstract
Achieving narrow-bandwidth emission and high external quantum efficiency (EQE) simultaneously is a challenge for next-generation blue-emitting organic light-emitting diodes (OLEDs). In this study, novel multiple-resonance thermally activated delayed fluorescence (MR-TADF) emitters are developed by fusing an indolocarbazole unit with two carbazole skeletons using para-oriented nitrogen atoms. The resulting rigid and planar π-system without electron-accepting atoms exhibits pure blue photoluminescence at 470 nm, reaching a 100% quantum yield with a full-width-at-half-maximum (FWHM) of 25 nm. Higher-level quantum chemistry calculations confirm an MR effect within the extended π-conjugation and an enhanced triplet-to-singlet crossover (104 s-1 ) through a reduced energy gap (ΔEST ) coupled with large spin-vibronic coupling mediated by low-lying triplet excited states. An OLED fabricated using the MR-TADF emitter with CIE color coordinates of (0.12, 0.16) exhibits a record high EQE of 30.9% and a small FWHM of 23 nm. With further optimization of the device structure, a high EQE of 33.8% is achieved without additional outcoupling enhancements owing to the near-perfect horizontal alignment of the emitting dipoles.
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Affiliation(s)
- Ha Lim Lee
- School of Chemical Engineering, Sungkyunkwan University 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi, 16419, Republic of Korea
| | - Soon Ok Jeon
- Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Suwon, Gyeonggi, 16678, Republic of Korea
| | - Inkoo Kim
- Innovation Center, Samsung Electronics, Hwaseong, 18448, Republic of Korea
| | - Seung Chan Kim
- School of Chemical Engineering, Sungkyunkwan University 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi, 16419, Republic of Korea
| | - Junseop Lim
- School of Chemical Engineering, Sungkyunkwan University 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi, 16419, Republic of Korea
| | - Joonghyuk Kim
- Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Suwon, Gyeonggi, 16678, Republic of Korea
| | - Sangho Park
- Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Suwon, Gyeonggi, 16678, Republic of Korea
| | - Jun Chwae
- Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Suwon, Gyeonggi, 16678, Republic of Korea
| | - Won-Joon Son
- Innovation Center, Samsung Electronics, Hwaseong, 18448, Republic of Korea
| | - Hyeonho Choi
- Samsung Advanced Institute of Technology, Samsung Electronics, 130 Samsung-ro, Suwon, Gyeonggi, 16678, Republic of Korea
| | - Jun Yeob Lee
- School of Chemical Engineering, Sungkyunkwan University 2066, Seobu-ro, Jangan-gu, Suwon, Gyeonggi, 16419, Republic of Korea
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36
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Highly Efficient Blue Thermally Activated Delayed Fluorescence Emitters Based on Multi-Donor Modified Oxygen-Bridged Boron Acceptor. Molecules 2022; 27:molecules27134048. [PMID: 35807295 PMCID: PMC9268263 DOI: 10.3390/molecules27134048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 06/21/2022] [Accepted: 06/22/2022] [Indexed: 12/10/2022] Open
Abstract
The employment of thermally activated delayed fluorescence (TADF) emitters is one of the most promising ways to realize the external quantum efficiency (EQE) of over 25% for organic light-emitting diodes (OLEDs). In addition, the TADF emitter based on oxygen-bridged boron (BO) fragment can maintain blue emission with high color purity. Herein, we constructed two blue TADF emitters, 3TBO and 5TBO, for OLEDs application. Both emitters consist of three donors linked at the oxygen-bridged boron acceptor. OLED devices based on 3TBO and 5TBO exhibited both high excellent device efficiency and high color purity with a maximum EQE; full-width at half-maximum (FWHM); and CIE coordinates of 17.3%, 47 nm, (0.120, 0.294), and 26.2%, 57 nm, (0.125, 0.275), respectively.
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37
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Yang SY, Qu YK, Liao LS, Jiang ZQ, Lee ST. Research Progress of Intramolecular π-Stacked Small Molecules for Device Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2104125. [PMID: 34595783 DOI: 10.1002/adma.202104125] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/18/2021] [Indexed: 06/13/2023]
Abstract
Organic semiconductors can be designed and constructed in π-stacked structures instead of the conventional π-conjugated structures. Through-space interaction (TSI) occurs in π-stacked optoelectronic materials. Thus, unlike electronic coupling along the conjugated chain, the functional groups can stack closely to facilitate spatial electron communication. Using π-stacked motifs, chemists and materials scientists can find new ways for constructing materials with aggregation-induced emission (AIE), thermally activated delayed fluorescence (TADF), circularly polarized luminescence (CPL), and room-temperature phosphorescence (RTP), as well as enhanced molecular conductance. Organic optoelectronic devices based on π-stacked molecules have exhibited very promising performance, with some of them exceeding π-conjugated analogues. Recently, reports on various organic π-stacked structures have grown rapidly, prompting this review. Representative molecular scaffolds and newly developed π-stacked systems could stimulate more attention on through-space charge transfer the well-known through-bond charge transfer. Finally, the opportunities and challenges for utilizing and improving particular materials are discussed. The previous achievements and upcoming prospects may provide new insights into the theory, materials, and devices in the field of organic semiconductors.
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Affiliation(s)
- Sheng-Yi Yang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, P. R. China
| | - Yang-Kun Qu
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, P. R. China
| | - Liang-Sheng Liao
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, P. R. China
- Macao Institute of Materials Science and Engineering, Macau University of Science and Technology, Taipa, Macau SAR, 999078, P. R. China
| | - Zuo-Quan Jiang
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, P. R. China
| | - Shuit-Tong Lee
- Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu, 215123, P. R. China
- Macao Institute of Materials Science and Engineering, Macau University of Science and Technology, Taipa, Macau SAR, 999078, P. R. China
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38
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Cheon HJ, Shin YS, Park NH, Lee JH, Kim YH. Boron-Based Multi-Resonance TADF Emitter with Suppressed Intermolecular Interaction and Isomer Formation for Efficient Pure Blue OLEDs. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2107574. [PMID: 35274463 DOI: 10.1002/smll.202107574] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/03/2022] [Indexed: 06/14/2023]
Abstract
Multi-resonance (MR) thermally activated delayed fluorescent (TADF) emitters are highly attractive due to their superior color purity as well as efficient light-harvesting ability from singlets and triplets. However, boron and nitrogen-based MR-TADF emitters suffer from their strong π-π interaction owing to their rigid flat cores. Herein, a boron-based multi-resonance blue TADF emitter with suppressed intermolecular interaction and isomer formation is developed through a simple synthetic process by introducing meta-xylene and meta-phenyphenyl groups to the core. The MR-TADF emitter, mBP-DABNA-Me, shows a narrowband blue emission with a peak at 467 nm, along with full width at half maximum of 28 nm, and photoluminescence quantum yield of 97%. Notably, highly efficient pure blue organic light-emitting diode (OLED) is realized using mBP-DABNA-Me, showing a maximum external quantum efficiency of 24.3% and a stable blue emission with a Commission Internationale de L'Eclairage coordinate of (0.124, 0.140). The color purity of the OLED is maintained at a high doping concentration of over 20%, attributed to the suppressed intermolecular interaction between the MR emitters.
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Affiliation(s)
- Hyung Jin Cheon
- Department of Chemistry and RIGET, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Youn-Seob Shin
- Department of Materials Science and Engineering, Inha University, Incheon, 22212, Republic of Korea
| | - Noh-Hwal Park
- 3D Convergence Center, Inha University, Incheon, 22212, Republic of Korea
| | - Jeong-Hwan Lee
- Department of Materials Science and Engineering, Inha University, Incheon, 22212, Republic of Korea
- 3D Convergence Center, Inha University, Incheon, 22212, Republic of Korea
| | - Yun-Hi Kim
- Department of Chemistry and RIGET, Gyeongsang National University, Jinju, 52828, Republic of Korea
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39
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Campbell E, Taladriz-Sender A, Paisley OI, Kennedy AR, Bush JT, Burley GA. A Chemo- and Regioselective Tandem [3 + 2]Heteroannulation Strategy for Carbazole Synthesis: Combining Two Mechanistically Distinct Bond-Forming Processes. J Org Chem 2022; 87:4603-4616. [PMID: 35302774 PMCID: PMC8981337 DOI: 10.1021/acs.joc.1c02943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
A modular approach to prepare tri-
and tetracyclic carbazoles by
a sequential [3 + 2]heteroannulation is described. First, optimization
of Pd-catalyzed Buchwald–Hartwig amination followed by C/N-arylation
in a one-pot process is established. Second, mechanistic analyses
identified the origins of chemo- and regioselective sequential control
of both bond-forming steps. Finally, the substrate scope is demonstrated
by the preparation of a range of tri- and tetracyclic carbazoles,
including expedient access to several natural products and anti-cancer
agents.
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Affiliation(s)
- Emma Campbell
- Department of Pure Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Andrea Taladriz-Sender
- Department of Pure Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Olivia I Paisley
- Department of Pure Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Alan R Kennedy
- Department of Pure Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, U.K
| | - Jacob T Bush
- GlaxoSmithKline, Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, U.K
| | - Glenn A Burley
- Department of Pure Applied Chemistry, University of Strathclyde, Thomas Graham Building, 295 Cathedral Street, Glasgow G1 1XL, U.K
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40
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Park EY, Shin S, Thangaraji V, Kim S, Lee J, Suh MC. Synthesis of indenocarbazole-based efficient deep-blue fluorescent emitter with a narrow emission band. J IND ENG CHEM 2022. [DOI: 10.1016/j.jiec.2021.11.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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41
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Zong W, Qiu W, Yuan P, Wang F, Liu Y, Xu S, Su SJ, Cao S. Thermally activated delayed fluorescence polymers for high-efficiency solution-processed non-doped OLEDs: Convenient synthesis by binding TADF units and host units to the pre-synthesized polycarbazole-based backbone via click reaction. POLYMER 2022. [DOI: 10.1016/j.polymer.2021.124468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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42
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Zhu A, Yu J, Zhou T, Zhang K, Qiu S, Ban X, Wang Y, Shen Z, Da S, Gao X. Rational design of multi-functional thermally activated delayed fluorescence emitters for both sensor and OLED applications. NEW J CHEM 2022. [DOI: 10.1039/d2nj00770c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Non-conjugated linking as a molecular design strategy to construct multifunctional structures to achieve the TADF feature and sensor properties in a single system.
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Affiliation(s)
- Aiyun Zhu
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
| | - Jianmin Yu
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
| | - Tao Zhou
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
| | - Kaizhi Zhang
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
| | - Suyu Qiu
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
| | - Xinxin Ban
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
- Jiangsu Key Laboratory of Function Control Technology for Advanced Materials, Lianyungang, Jiangsu, 222005, China
| | - Yuanchu Wang
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
| | - Zhouzhou Shen
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
| | - Shiji Da
- School of Environmental and Chemical Engineering, Jiangsu Ocean University, Lianyungang, Jiangsu, 222005, China
| | - Xuzhu Gao
- Department of Central Laboratory, The Second People's Hospital of Lianyungang City (Cancer Hospital of Lianyungang), Lianyungang, Jiangsu, 222005, China
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43
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Li J, Li T, Zhang M, Guo D, Zhang H. Rational designs of structurally similar TADF and HLCT emitters with benzo- or naphtho-carbazole units as electron donors. Phys Chem Chem Phys 2022; 24:25937-25949. [DOI: 10.1039/d2cp03500f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Structurally similar D–A type molecules with the combination of benzo- or naphtho-carbazole units as electron donors and tunable electron acceptors with different electron-withdrawing ability are designed to realize HLCT and TADF emissions.
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Affiliation(s)
- Jiaqi Li
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Tingyu Li
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Mingfan Zhang
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Dongxue Guo
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
| | - Houyu Zhang
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
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44
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Duan C, Xin Y, Wang Z, Zhang J, Han C, Xu H. High-efficiency hyperfluorescent white light-emitting diodes based on high-concentration-doped TADF sensitizer matrices via spatial and energy gap effects. Chem Sci 2021; 13:159-169. [PMID: 35059164 PMCID: PMC8694281 DOI: 10.1039/d1sc05753g] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 11/24/2021] [Indexed: 01/05/2023] Open
Abstract
Despite the success of monochromatic hyperfluorescent (HF) organic light-emitting diodes (OLEDs), high-efficiency HF white OLEDs (WOLEDs) are still a big challenge. Herein, we demonstrate HF WOLEDs with state-of-the-art efficiencies, featuring a quasi-bilayer emissive layer (EML) composed of an ultrathin (0.1 nm) blue fluorescence (FL) emitter (TBPe) layer and a layer of thermally activated delayed fluorescence (TADF) sensitizer matrix heavily doped with a yellow FL emitter (TBRb, 3%). Based on an asymmetric high-energy-gap TADF sensitizer host (PhCzSPOTz), such an “ultrathin blue emitting layer (UTBL)” strategy endowed the HF WOLEDs with a record power efficiency of ∼80 lm W−1, approaching the level of fluorescent tubes. Transient photoluminescence (PL) and electroluminescence (EL) kinetics demonstrate that the spatial separation of TBPe from the TADF sensitizer and TBRb, and the large energy gap between the latter two effectively suppress triplet leakage, in addition to suppressing triplet diffusion in the PhCzSPOTz matrix with anisotropic intermolecular interactions. These results provide a new insight into the exciton allocation process in HF white light-emitting systems. A thermally activated delayed fluorescence host was developed to realize high-efficiency fluorescence white organic light-emitting diodes (WOLED) through spatial and energy gap effects.![]()
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Affiliation(s)
- Chunbo Duan
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education & School of Chemistry and Material Science, Heilongjiang University 74 Xuefu Road Harbin 150080 P. R. China
| | - Ying Xin
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education & School of Chemistry and Material Science, Heilongjiang University 74 Xuefu Road Harbin 150080 P. R. China
| | - Zicheng Wang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education & School of Chemistry and Material Science, Heilongjiang University 74 Xuefu Road Harbin 150080 P. R. China
| | - Jing Zhang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education & School of Chemistry and Material Science, Heilongjiang University 74 Xuefu Road Harbin 150080 P. R. China
| | - Chunmiao Han
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education & School of Chemistry and Material Science, Heilongjiang University 74 Xuefu Road Harbin 150080 P. R. China
| | - Hui Xu
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education & School of Chemistry and Material Science, Heilongjiang University 74 Xuefu Road Harbin 150080 P. R. China
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New Unsymmetrically Substituted Benzothiadiazole-Based Luminophores: Synthesis, Optical, Electrochemical Studies, Charge Transport, and Electroluminescent Characteristics. Molecules 2021; 26:molecules26247596. [PMID: 34946679 PMCID: PMC8705470 DOI: 10.3390/molecules26247596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/24/2022] Open
Abstract
Three new benzothiadiazole (BTD)-containing luminophores with different configurations of aryl linkers have been prepared via Pd-catalyzed cross-coupling Suzuki and Buchwald–Hartwig reactions. Photophysical and electroluminescent properties of the compounds were investigated to estimate their potential for optoelectronic applications. All synthesized structures have sufficiently high quantum yields in film. The BTD with aryl bridged carbazole unit demonstrated the highest electrons and holes mobility in a series. OLED with light-emitting layer (EML) based on this compound exhibited the highest brightness, as well as current and luminous efficiency. The synthesized compounds are not only luminophores with a high photoluminescence quantum yield, but also active transport centers for charge carriers in EML of OLED devices.
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Crovini E, Zhang Z, Kusakabe Y, Ren Y, Wada Y, Naqvi BA, Sahay P, Matulaitis T, Diesing S, Samuel IDW, Brütting W, Suzuki K, Kaji H, Bräse S, Zysman-Colman E. Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode. Beilstein J Org Chem 2021; 17:2894-2905. [PMID: 34956408 PMCID: PMC8685574 DOI: 10.3762/bjoc.17.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 11/19/2021] [Indexed: 12/02/2022] Open
Abstract
In this work we showcase the emitter DICzTRZ in which we employed a twin-emitter design of our previously reported material, ICzTRZ. This new system presented a red-shifted emission at 488 nm compared to that of ICzTRZ at 475 nm and showed a comparable photoluminescence quantum yield of 57.1% in a 20 wt % CzSi film versus 63.3% for ICzTRZ. The emitter was then incorporated within a solution-processed organic light-emitting diode that showed a maximum external quantum efficiency of 8.4%, with Commission Internationale de l'Éclairage coordinate of (0.22, 0.47), at 1 mA cm-2.
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Affiliation(s)
- Ettore Crovini
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - Zhen Zhang
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
| | - Yu Kusakabe
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yongxia Ren
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yoshimasa Wada
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Bilal A Naqvi
- Experimental Physics IV, Institute of Physics, University of Augsburg, Universitätstrasse. 1, 86159 Augsburg, Germany
| | - Prakhar Sahay
- Experimental Physics IV, Institute of Physics, University of Augsburg, Universitätstrasse. 1, 86159 Augsburg, Germany
| | - Tomas Matulaitis
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - Stefan Diesing
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, UK
| | - Ifor D W Samuel
- Organic Semiconductor Centre, SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS, UK
| | - Wolfgang Brütting
- Experimental Physics IV, Institute of Physics, University of Augsburg, Universitätstrasse. 1, 86159 Augsburg, Germany
| | - Katsuaki Suzuki
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Hironori Kaji
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Stefan Bräse
- Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany
- Institute of Biological and Chemical Systems – Functional Molecular Systems (IBCS-FMS), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
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Noguchi Y. Exciton maps for thermally activated delayed fluorescence active/inactive carbazole benzonitrile derivatives. J Chem Phys 2021; 155:204302. [PMID: 34852472 DOI: 10.1063/5.0068402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The all-electron first-principles GW+Bethe-Salpeter method was applied to six carbazole benzonitrile (CzBN) derivatives, which were recently reported to be both thermally activated delayed fluorescence (TADF) active and inactive despite their singlet-triplet splittings being commonly around 0.2 eV. The present method successfully reproduced very similar photoabsorption spectra as experiments from the viewpoint of the peak positions and relative peak heights. We also performed exciton analysis with the exciton wave functions for several lowest singlet and triplet exciton states to reveal the details of the optical properties. We applied this to not only the present six CzBN derivatives but also 18 other TADF molecules and proposed a new exciton map to classify the molecules as the TADF active/inactive by using the exciton binding energy in the vertical axis and the ratio of electron and hole delocalization in the horizontal axis. Our results suggest two possible TADF mechanisms: spatially less localized hole states than the electron states where the exciton binding energy is proportional to the ratio of hole and electron delocalization and spatially more localized hole states than the electron states where the exciton binding energy should be large.
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Affiliation(s)
- Yoshifumi Noguchi
- Department of Applied Chemistry and Biochemical Engineering, Graduate School of Engineering, Shizuoka University, Johoku 3-5-1, Hamamatsu, Shizuoka 432-8561, Japan
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Singh PS, Badani PM, Kamble RM. Blue-orange emitting carbazole based donor-acceptor derivatives: Synthesis and studies of modulating acceptor unit on opto-electrochemical and theoretical properties. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113457] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Park J, Lim J, Lee JH, Jang B, Han JH, Yoon SS, Lee JY. Asymmetric Blue Multiresonance TADF Emitters with a Narrow Emission Band. ACS APPLIED MATERIALS & INTERFACES 2021; 13:45798-45805. [PMID: 34519492 DOI: 10.1021/acsami.1c11399] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In this study, we synthesized and characterized multiple resonance (MR) type blue thermally activated delayed fluorescence (TADF) emitters. Unlike many boron-based MR-TADF materials, the blue TADF emitters of this work had an asymmetric molecular structure with one boron, one oxygen, and one nitrogen. The aromatic units linked to the nitrogen were changed into diphenylamine, carbazole, dimethylacridine, and diphenylacridine to manage the light emission properties of the emitters. The TADF emitters exhibited a blue emission due to the weak electron-donating oxygen atom and the emission color was controlled by the aromatic unit connected to the nitrogen. The simple diphenylamine unit was effective in achieving real deep-blue emission for the BT2020 standard with a high external quantum efficiency (EQE), while the electron-rich nitrogen-based dimethylacridine and diphenylacridine accelerated the reverse intersystem crossing for high EQE and small EQE roll-off. Among the emitters, a diphenylamine-substituted emitter, 7-(tert-butyl)-9-phenyl-9H-5-oxa-9-aza-13b-boranaphtho[3,2,1-de]anthracene (B-O-dpa), showed a maximum external quantum efficiency of 16.3%, a small full width at half-maximum of 32 nm, and a real deep-blue color coordinate of (0.15, 0.05).
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Affiliation(s)
- Jinho Park
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
| | - Junseop Lim
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
| | - Jin Ho Lee
- Department of Chemistry, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
| | - Beomsu Jang
- Department of Chemistry, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
| | - Ju Hee Han
- Department of Chemistry, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
| | - Seung Soo Yoon
- Department of Chemistry, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
| | - Jun Yeob Lee
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do 16419, Korea
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50
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Abstract
We investigate a new strategy to enhance thermally activated delayed fluorescence (TADF) in organic light-emitting diodes (OLEDs). Given that the TADF rate of a molecule depends on its conformation, we hypothesize that there exists a conformation that maximizes the TADF rate. To test this idea, we use time-dependent density functional theory (TDDFT) to simulate the TADF rates of several TADF emitters while varying their geometries in a select subspace of internal coordinates. We find that geometric changes in this subspace can increase the TADF rate up to 3 orders of magnitude with respect to the minimum energy conformation, and the simulated TADF rate can even be brought into the submicrosecond time scales under the right conditions. Furthermore, the TADF rate enhancement can be maintained with a conformational energy that might be within the reach of modern synthetic chemistry. Analyzing the maximum TADF conformation, we extract a number of structural motifs that might provide a useful handle on the TADF rate of a donor-acceptor (DA) system. The incorporation of conformational engineering into the TADF technology could usher in a new paradigm of OLEDs.
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Affiliation(s)
- Changhae Andrew Kim
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Troy Van Voorhis
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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