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Han W, Liu J, Ran C, Huang Z, Gao G, You J, Bin Z. Alignment of Heptagonal Diimide and Triazine Enables Narrowband Pure-Blue Organic Light-Emitting Diodes with Low Efficiency Roll-Off. Angew Chem Int Ed Engl 2023; 62:e202312297. [PMID: 37815880 DOI: 10.1002/anie.202312297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 09/28/2023] [Accepted: 10/10/2023] [Indexed: 10/12/2023]
Abstract
The endeavor to develop high-performance narrowband blue organic light-emitting diodes (OLEDs) with low efficiency roll-off represents an attractive challenge. Herein, we introduce a hetero-acceptor design strategy centered around the heptagonal diimide (BPI) building block to create an efficient thermally activated delayed fluorescence (TADF) sensitizer. The alignment of a twisted BPI unit and a planar diphenyltriazine (TRZ) fragment imparts remarkable exciton dynamic properties to 26tCz-TRZBPI, including a fast radiative decay rate (kR ) of 1.0×107 s-1 and a swift reverse intersystem crossing rate (kRISC ) of 1.8×106 s-1 , complemented by a slow non-radiative decay rate (kNR ) of 6.0×103 s-1 . Consequently, 26tCz-TRZBPI facilitates the fabrication of high-performance narrowband pure-blue TADF-sensitized fluorescence OLEDs (TSF-OLEDs) with a maximum external quantum efficiency (EQEmax ) of 24.3 % and low efficiency roll-off even at a high brightness level of 10000 cd m-2 (EQE10000 : 16.8 %). This showcases a record-breaking external quantum efficiency at a high luminance level of 10000 cd m-2 for narrowband blue TSF-OLEDs.
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Affiliation(s)
- Weiguo Han
- Key Laboratory of Green Chemistry, Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China
| | - Junjie Liu
- Key Laboratory of Green Chemistry, Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China
| | - Chunhao Ran
- Key Laboratory of Green Chemistry, Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China
| | - Zhenmei Huang
- Key Laboratory of Green Chemistry, Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China
| | - Ge Gao
- Key Laboratory of Green Chemistry, Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China
| | - Jingsong You
- Key Laboratory of Green Chemistry, Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry, Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, People's Republic of China
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102
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Hao XL, Ren AM, Zhou L, Zhang H. Theoretical Research and Photodynamic Simulation of Aggregation-Induced Thermally Activated Delayed Fluorescence Materials for Organic Light-Emitting Diodes. J Phys Chem A 2023; 127:9771-9780. [PMID: 37948560 DOI: 10.1021/acs.jpca.3c06145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
The discovery and utilization of pure organic thermally activated delayed fluorescence (TADF) materials provide a major breakthrough in obtaining high-performance and low-cost organic light-emitting diodes (OLEDs). In spite of recent research progress in TADF emitters, highly efficient and stable TADF emitters in high-concentration solutions and in the solid state have been rarely reported, and most of them suffer from aggregation-induced quenching (ACQ). To resolve this issue, the aggregation-induced delayed fluorescence (AIDF) mechanism was studied in depth by the simulation of excited-state dynamic processes, and the effect of geometric modifications on optical properties was minutely investigated based on molecular modeling. TD-DFT calculations demonstrate that it is the key point for the transformation between prompt fluorescence and TADF to effectively regulate singlet-triplet energy difference and electron-vibration coupling by the aggregation effect. Then, excellent green and red TADF materials with very small singlet-triplet energy differences of 0.05 and 0.06 eV, high TADF quantum yields up to 57.53% and 39.19%, and suitable fluorescence lifetimes of 0.99 and 1.67 us, respectively, were designed and obtained, which demonstrate the potential application of these two TADF materials in OLEDs.
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Affiliation(s)
- Xue-Li Hao
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Ai-Min Ren
- Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | - Liang Zhou
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Hongjie Zhang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
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103
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Nair AG, Das A, Chathoth NE, Pratim Sarmah M, Anjukandi P. Chemical Tailoring Assisted non-TADF to TADF Switching in Carbazole-Benzophenone Emitter - An In-silico Investigation. Chemphyschem 2023; 24:e202300445. [PMID: 37608522 DOI: 10.1002/cphc.202300445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 08/22/2023] [Accepted: 08/22/2023] [Indexed: 08/24/2023]
Abstract
Organic light-emitting diodes (OLEDs) have become one of the most popular lighting technologies since they offer several advantages over conventional devices. In carbazole-benzophenone (CzBP) OLED devices, the polymeric form of the compound is previously reported to be Thermally Activated Delayed Fluorescence (TADF)-active (ΔEST ≈0.12 eV), while the monomer (CzBP) (ΔEST ≈0.39 eV) does not. The present study examines the effect of chemical tailoring on the optical and photophysical properties of CzBP using DFT and TDDFT methods. The introduction of a single -NO2 group or di-substitution (-NO2 , -COOH or -CN) in the selected LUMO region of the reference CzBP monomer significantly reduces ΔEST ≈0.01 eV, projecting these systems as potential TADF-active emitters. Furthermore, the chemical modification of CzBP-LUMO alters the two-step TADF mechanism (T1 →T2 →S1 ) in CzBP (ES₁ >ET2 >ET₁ ) to the Direct Singlet Harvesting (T1 →S1 ) mechanism (ET2 >ES₁ >ET₁ ), which has recently been identified in the fourth-generation OLED materials.
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Affiliation(s)
- Aparna G Nair
- Department of Chemistry, Indian Institute of Technology, Palakkad, Kerala, 678557, India
| | - Arathi Das
- Department of Chemistry, Pondicherry University, Kalapet, 605014, Puducherry, India
| | - Nayana Edavan Chathoth
- Department of Chemistry, Indian Institute of Technology, Palakkad, Kerala, 678557, India
| | - Manash Pratim Sarmah
- Department of Chemistry, Indian Institute of Technology, Palakkad, Kerala, 678557, India
| | - Padmesh Anjukandi
- Department of Chemistry, Indian Institute of Technology, Palakkad, Kerala, 678557, India
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104
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Bak JM, Song M, Shin I, Lim HN. A deconstruction-reconstruction strategy to access 1-naphthol derivatives: application to the synthesis of aristolactam scaffolds. Org Biomol Chem 2023; 21:8936-8941. [PMID: 37916683 DOI: 10.1039/d3ob01603j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
A deconstruction-reconstruction strategy for the synthesis of multisubstituted polycyclic aromatic hydrocarbons (PAHs) is delineated herein. The deconstruction step enables the synthesis of o-cyanomethylaroyl fluorides that are bifunctional substrates holding both a pro-nucleophile and an electrophile. The construction step involves a formal [4 + 2] benzannulation using o-cyanomethylaroyl fluorides and active methylenes. The utility of this synthetic method is also demonstrated by the synthesis of a tetracyclic aristolactam derivative.
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Affiliation(s)
- Jeong Min Bak
- Department of Chemistry, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk, 38541, Republic of Korea.
| | - Moonyeong Song
- Department of Fine Chemistry, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Republic of Korea
| | - Inji Shin
- Department of Fine Chemistry, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Republic of Korea
| | - Hee Nam Lim
- Department of Chemistry, Yeungnam University, 280 Daehak-Ro, Gyeongsan, Gyeongbuk, 38541, Republic of Korea.
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105
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Drwal D, Matousek M, Golub P, Tucholska A, Hapka M, Brabec J, Veis L, Pernal K. Role of Spin Polarization and Dynamic Correlation in Singlet-Triplet Gap Inversion of Heptazine Derivatives. J Chem Theory Comput 2023; 19:7606-7616. [PMID: 37864544 PMCID: PMC10653106 DOI: 10.1021/acs.jctc.3c00781] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Indexed: 10/23/2023]
Abstract
The new generation of proposed light-emitting molecules for organic light-emitting diodes (OLEDs) has raised considerable research interest due to its exceptional feature─a negative singlet-triplet (ST) gap violating Hund's multiplicity rule in the excited S1 and T1 states. We investigate the role of spin polarization in the mechanism of ST gap inversion. Spin polarization is associated with doubly excited determinants of certain types, whose presence in the wave function expansion favors the energy of the singlet state more than that of the triplet. Using a perturbation theory-based model for spin polarization, we propose a simple descriptor for prescreening of candidate molecules with negative ST gaps and prove its usefulness for heptazine-type molecules. Numerical results show that the quantitative effect of spin polarization decreases linearly with the increasing highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) exchange integral. Comparison of single- and multireference coupled-cluster predictions of ST gaps shows that the former methods provide good accuracy by correctly balancing the effects of doubly excited determinants and dynamic correlation. We also show that accurate ST gaps may be obtained using a complete active space model supplemented with dynamic correlation from multireference adiabatic connection theory.
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Affiliation(s)
- Daria Drwal
- Institute
of Physics, Lodz University of Technology, ul. Wolczanska 219, 90-924 Lodz, Poland
| | - Mikulas Matousek
- J.
Heyrovský Institute of Physical Chemistry, Academy of Sciences
of the Czech Republic, v.v.i., Dolejškova 3, 18223 Prague 8, Czech Republic
- Faculty
of Mathematics and Physics, Charles University, 12116 Prague, Czech Republic
| | - Pavlo Golub
- J.
Heyrovský Institute of Physical Chemistry, Academy of Sciences
of the Czech Republic, v.v.i., Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Aleksandra Tucholska
- Institute
of Physics, Lodz University of Technology, ul. Wolczanska 219, 90-924 Lodz, Poland
| | - Michał Hapka
- Faculty
of Chemistry, University of Warsaw, ul. L. Pasteura 1, 02-093 Warsaw, Poland
| | - Jiri Brabec
- J.
Heyrovský Institute of Physical Chemistry, Academy of Sciences
of the Czech Republic, v.v.i., Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Libor Veis
- J.
Heyrovský Institute of Physical Chemistry, Academy of Sciences
of the Czech Republic, v.v.i., Dolejškova 3, 18223 Prague 8, Czech Republic
| | - Katarzyna Pernal
- Institute
of Physics, Lodz University of Technology, ul. Wolczanska 219, 90-924 Lodz, Poland
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106
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Song XF, Peng LY, Chen WK, Gao YJ, Cui G. Theoretical studies on thermally activated delayed fluorescence of "carbene-metal-amide" Cu and Au complexes: geometric structures, excitation characters, and mechanisms. Phys Chem Chem Phys 2023; 25:29603-29613. [PMID: 37877743 DOI: 10.1039/d3cp03444e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
"Carbene-metal(I)-amide" (CMA) complexes have garnered significant attention due to their remarkable properties and potential TADF applications in organic electronics. However, the atomistic working mechanism is still elusive. Herein, we chose two CMA complexes, i.e., cyclic (alkyl)(amino) carbene-copper[gold](I)-carbazole (CAAC-Cu[Au]-Cz), and employed both DFT and TD-DFT methods, in combination with radiative and nonradiative rate calculations, to investigate geometric and electronic structures of these two complexes in the ground and excited states, including orbital compositions, electronic transitions, absorption and emission spectra, and the luminescence mechanism. It is found that the coplanar or perpendicular conformations are coexistent in the ground state (S0), the lowest excited singlet state (S1), and the triplet state (T1). Both the coplanar and perpendicular S1 and T1 states have similar ligand-to-ligand charge transfer (LLCT) character between CAAC and Cz, and some charge-transfer character between metal atoms and ligands, which is beneficial to minimize the singlet-triplet energy gaps (ΔEST) and increase the spin-orbit coupling (SOC). An interesting three-state (S0, S1, T1) model involving two regions (coplanar and perpendicular) is proposed to rationalize the experimental TADF phenomena in the CMA complexes. In addition to the coplanar ones, the perpendicular S1 and T1 states also play a role in promoting the repopulation of the coplanar S1 exciton, which is a primary source for the delayed fluorescence.
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Affiliation(s)
- Xiu-Fang Song
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, Chemistry College, Beijing Normal University, Beijing 100875, P. R. China.
| | - Ling-Ya Peng
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, Chemistry College, Beijing Normal University, Beijing 100875, P. R. China.
| | - Wen-Kai Chen
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, Chemistry College, Beijing Normal University, Beijing 100875, P. R. China.
| | - Yuan-Jun Gao
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, P. R. China.
| | - Ganglong Cui
- Key Laboratory of Theoretical and Computational Photochemistry, Ministry of Education, Chemistry College, Beijing Normal University, Beijing 100875, P. R. China.
- Hefei National Laboratory, Hefei 230088, China
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107
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Paredis S, Cardeynaels T, Brebels S, Deckers J, Kuila S, Lathouwers A, Van Landeghem M, Vandewal K, Danos A, Monkman AP, Champagne B, Maes W. Intramolecular locking and coumarin insertion: a stepwise approach for TADF design. Phys Chem Chem Phys 2023; 25:29842-29849. [PMID: 37888766 DOI: 10.1039/d3cp03695b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Three novel TADF (thermally activated delayed fluorescence) emitters based on the well-studied Qx-Ph-DMAC fluorophore are designed and synthesized. The photophysical properties of these materials are studied from a theoretical and experimental point of view, demonstrating the cumulative effects of multiple small modifications that combine to afford significantly improved TADF performance. First, an extra phenyl ring is added to the acceptor part of Qx-Ph-DMAC to increase the conjugation length, resulting in BQx-Ph-DMAC, which acts as an intermediate molecular structure. Next, an electron-deficient coumarin unit is incorporated to fortify the electron accepting ability, affording ChromPy-Ph-DMAC with red-shifted emission. Finally, the conjugated system is further enlarged by 'locking' the molecular structure, generating DBChromQx-DMAC with further red-shifted emission. The addition of the coumarin unit significantly impacts the charge-transfer excited state energy levels with little effect on the locally excited states, resulting in a decrease of the singlet-triplet energy gap. As a result, the two coumarin-based emitters show considerably improved TADF performance in 1 w/w% zeonex films when compared to the initial Qx-Ph-DMAC structure. 'Locking' the molecular structure further lowers the singlet-triplet energy gap, resulting in more efficient reverse intersystem crossing and increasing the contribution of TADF to the total emission.
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Affiliation(s)
- S Paredis
- Hasselt University, Institute for Materials Research (IMO-IMOMEC), Design & Synthesis of Organic Semiconductors (DSOS), Agoralaan 1, Diepenbeek 3590, Belgium.
- IMOMEC Division, IMEC, Wetenschapspark 1, Diepenbeek 3590, Belgium
- Energyville, Thorpark, Genk 3600, Belgium
| | - T Cardeynaels
- Hasselt University, Institute for Materials Research (IMO-IMOMEC), Design & Synthesis of Organic Semiconductors (DSOS), Agoralaan 1, Diepenbeek 3590, Belgium.
- IMOMEC Division, IMEC, Wetenschapspark 1, Diepenbeek 3590, Belgium
- Energyville, Thorpark, Genk 3600, Belgium
- University of Namur, Laboratory of Theoretical Chemistry, Theoretical and Structural Physical Chemistry Unit, Namur Institute of Structured Matter, Rue de Bruxelles 61, Namur 5000, Belgium
| | - S Brebels
- Hasselt University, Institute for Materials Research (IMO-IMOMEC), Design & Synthesis of Organic Semiconductors (DSOS), Agoralaan 1, Diepenbeek 3590, Belgium.
- IMOMEC Division, IMEC, Wetenschapspark 1, Diepenbeek 3590, Belgium
- Energyville, Thorpark, Genk 3600, Belgium
| | - J Deckers
- Hasselt University, Institute for Materials Research (IMO-IMOMEC), Design & Synthesis of Organic Semiconductors (DSOS), Agoralaan 1, Diepenbeek 3590, Belgium.
- IMOMEC Division, IMEC, Wetenschapspark 1, Diepenbeek 3590, Belgium
- Energyville, Thorpark, Genk 3600, Belgium
| | - S Kuila
- Durham University, Department of Physics, OEM Group, South Road, Durham DH1 3LE, UK.
| | - A Lathouwers
- Hasselt University, Institute for Materials Research (IMO-IMOMEC), Design & Synthesis of Organic Semiconductors (DSOS), Agoralaan 1, Diepenbeek 3590, Belgium.
- IMOMEC Division, IMEC, Wetenschapspark 1, Diepenbeek 3590, Belgium
- Energyville, Thorpark, Genk 3600, Belgium
| | - M Van Landeghem
- IMOMEC Division, IMEC, Wetenschapspark 1, Diepenbeek 3590, Belgium
- Energyville, Thorpark, Genk 3600, Belgium
- Hasselt University, Institute for Materials Research (IMO-IMOMEC), Organic Opto-Electronics (OOE), Wetenschapspark 1, Diepenbeek 3590, Belgium
| | - K Vandewal
- IMOMEC Division, IMEC, Wetenschapspark 1, Diepenbeek 3590, Belgium
- Energyville, Thorpark, Genk 3600, Belgium
- Hasselt University, Institute for Materials Research (IMO-IMOMEC), Organic Opto-Electronics (OOE), Wetenschapspark 1, Diepenbeek 3590, Belgium
| | - A Danos
- Durham University, Department of Physics, OEM Group, South Road, Durham DH1 3LE, UK.
| | - A P Monkman
- Durham University, Department of Physics, OEM Group, South Road, Durham DH1 3LE, UK.
| | - B Champagne
- University of Namur, Laboratory of Theoretical Chemistry, Theoretical and Structural Physical Chemistry Unit, Namur Institute of Structured Matter, Rue de Bruxelles 61, Namur 5000, Belgium
| | - W Maes
- Hasselt University, Institute for Materials Research (IMO-IMOMEC), Design & Synthesis of Organic Semiconductors (DSOS), Agoralaan 1, Diepenbeek 3590, Belgium.
- IMOMEC Division, IMEC, Wetenschapspark 1, Diepenbeek 3590, Belgium
- Energyville, Thorpark, Genk 3600, Belgium
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108
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Galindo JM, Tardío C, Saikia B, Van Cleuvenbergen S, Torres-Moya I. Recent Insights about the Role of Gels in Organic Photonics and Electronics. Gels 2023; 9:875. [PMID: 37998965 PMCID: PMC10670943 DOI: 10.3390/gels9110875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 10/31/2023] [Accepted: 11/02/2023] [Indexed: 11/25/2023] Open
Abstract
This review article provides an in-depth exploration of the role of gels in the fields of organic electronics and photonics, focusing on their unique properties and applications. Despite their remarkable potential, gel-based innovations remain relatively uncharted in these domains. This brief review aims to bridge the knowledge gap by shedding light on the diverse roles that gels can fulfil in the enhancement of organic electronic and photonic devices. From flexible electronics to light-emitting materials, we delve into specific examples of gel applications, highlighting their versatility and promising outcomes. This work serves as an indispensable resource for researchers interested in harnessing the transformative power of gels within these cutting-edge fields. The objective of this review is to raise awareness about the overlooked research potential of gels in optoelectronic materials, which have somewhat diminished in recent years.
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Affiliation(s)
- Josué M. Galindo
- Department of Chemistry, RCSI University of Medicine and Health Sciences, 123 St. Stephen’s Green, D02YN77 Dublin, Ireland;
| | - Carlos Tardío
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical Science and Technologies, University of Castilla-La Mancha-IRICA, 13071 Ciudad Real, Spain;
| | - Basanta Saikia
- Department of Chemistry, Molecular Imaging and Photonics, KULAK—KU Leuven, E. Sabbelaan 53, 8500 Kortrijk, Belgium; (B.S.); (S.V.C.)
| | - Stijn Van Cleuvenbergen
- Department of Chemistry, Molecular Imaging and Photonics, KULAK—KU Leuven, E. Sabbelaan 53, 8500 Kortrijk, Belgium; (B.S.); (S.V.C.)
| | - Iván Torres-Moya
- Department of Organic Chemistry, Faculty of Chemical Sciences, Campus of Espinardo, University of Murcia, 30010 Murcia, Spain
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109
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Wang Y, Tian Y, Gao Y, Guo Z, Xue Z, Han Y, Yang W, Ma X. Resolving the Photophysics of Nitrogen-Embedded Multiple Resonance Emitters: Origin of Color Purity and Emitting Efficiency. J Phys Chem Lett 2023; 14:9665-9676. [PMID: 37870971 DOI: 10.1021/acs.jpclett.3c02245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The emerging nitrogen-embedded multiple resonance (MR) emitters with an indolo[3,2,1-jk] carbazole (ICz) unit have exhibited promising performance for high-resolution organic light-emitting diode (OLED) devices, while the underlying photophysics has been rarely reported. In this work, the optical spectra, color purity, and emitting efficiency of ICz-based MR emitters were investigated by using electronic structure and thermal vibration correlation function (TVCF) calculations. Unlike B-N MR emitters, the high color purity of investigated ICz-based MR emitters was mainly contributed by considerable structural rigidity, which also greatly affects the radiative decay rate and fluorescence quantum yield of the S1 state. For the majority of investigated emitters, potential reverse intersystem crossing (RISC) channels (T1 → S1 and T2 → S1) are limited by thermally inaccessible ΔEST* or insufficient spin-orbital coupling (SOC), which can be distinguished by the calculated temperature-dependent RISC rate pattern. We provided a systematic photophysical picture for ICz-based MR emitters that might be interesting for the OLED design and application community.
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Affiliation(s)
- Yaxin Wang
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
| | - Yiran Tian
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
| | - Yixuan Gao
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
| | - Zilong Guo
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
| | - Zheng Xue
- Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China
| | - Yandong Han
- Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China
| | - Wensheng Yang
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
- Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China
| | - Xiaonan Ma
- Institute of Molecular Plus, Tianjin University, Tianjin 300072, P. R. China
- Engineering Research Center for Nanomaterials, Henan University, Kaifeng 475004, P. R. China
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110
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Liao C, Chen B, Xie Q, Li X, Liu H, Wang S. A Breakthrough in Solution-Processed Ultra-Deep-Blue HLCT OLEDs: A Record External Quantum Efficiency Exceeding 10% Based on Novel V-Shaped Emitters. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2305310. [PMID: 37523270 DOI: 10.1002/adma.202305310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 07/28/2023] [Indexed: 08/02/2023]
Abstract
It is always a great challenge to achieve high-efficiency solution-processed ultra-deep-blue organic light-emitting diodes (OLEDs) with the Commission Internationale de l'Eclairage (CIE) 1931 chromaticity coordinates matching the blue primary of Rec. International Telecommunication Union-Radiocommunication BT.2100, which specifies high dynamic range television image parameters. Inspired by hybrid local and charge transfer (HLCT) excited state emitters improving exciton utilization through high-lying reverse intersystem crossing, here, a series of high-performance blue emitters by a V-shaped symmetric donor (D)-π-acceptor (A)-π-D design strategy are developed. Here, the large torsions and unstable bonds of D-A structures can be improved through π bridges, and also the conjugation length and donor groups can be easily adjusted. The obtained emitters merit excellent photophysical and electrochemical properties, thermal stability, solution processibility, and HLCT excited state excellence. Results suggest that the OLEDs based on the obtained blue emitters all achieve high maximum external quantum efficiency (EQEmax ) of more than 8% with very low efficiency roll-off. In particular, the device based on 4',5'-bis(4-(9H-carbazol-9-yl)phenyl)spiro[fluorene-9,2'-imidazole] exhibits a satisfactory ultra-deep-blue emission (CIEx , y = 0.1579, 0.0387) and a record-high EQEmax (10.40%) among solution-processed HLCT OLEDs, which is very close to the record EQEmax of devices by vacuum vapor deposition technology.
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Affiliation(s)
- Chuanxin Liao
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Bo Chen
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Qi Xie
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Xianggao Li
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Hongli Liu
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
| | - Shirong Wang
- School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin, 300072, China
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111
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Naveen KR, Konidena RK, Keerthika P. Neoteric Advances in Oxygen Bridged Triaryl Boron-based Delayed Fluorescent Materials for Organic Light Emitting Diodes. CHEM REC 2023; 23:e202300208. [PMID: 37555789 DOI: 10.1002/tcr.202300208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/17/2023] [Indexed: 08/10/2023]
Abstract
Since their first demonstration, thermally activated delayed fluorescence (TADF) materials have been emerged as the most promising emitters because of their promising applications in optoelectronics, typified by organic light-emitting diodes (OLEDs). In which, the rigid oxygen bridged boron acceptor-featured (DOBNA) emitters have gained tremendous impetus for OLEDs, which is ascribed to their excellent external quantum efficiency (EQE). However, these materials often displayed severe efficiency roll-off and poor operational stability. Therefore, there needs to be a comprehensive understanding of the aspect of the molecular design and structure-property relationship. To the best of our knowledge, there is no detailed review on the structure-function outlook of DOBNA-based emitters emphasizing the effect of the nature of donor units, their number density, and substitution pattern on the physicochemical properties, excited state dynamics and OLED performance were reported. To fill this gap, herein we presented the recent advancements in DOBNA-based acceptor featured TADF materials by classifying them into several subgroups based on the molecular design i. e. donor-acceptor (D-A), D-A-D, A-D-A, and multi-resonant TADF (MR-TADF) emitters. The detailed design concepts, along with their respective physicochemical and OLED performances were summarized. Finally, the prospective of this class of materials in forthcoming OLED displays is also discussed.
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Affiliation(s)
- Kenkera Rayappa Naveen
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Rajendra Kumar Konidena
- Department of Chemistry, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur campus, Chennai, Tamil Nadu, 603203, India
| | - P Keerthika
- Department of Chemistry, Faculty of Engineering and Technology, SRM Institute of Science and Technology, Kattankulathur campus, Chennai, Tamil Nadu, 603203, India
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112
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Huang H, Li N, Fu S, Mo X, Cao X, Yin X, Yang C. Pure Polycyclic Aromatic Hydrocarbon Isomerides with Delayed Fluorescence and Anti-Kasha Emission: High-Efficiency Non-Doped Fluorescence OLEDs. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304204. [PMID: 37718390 PMCID: PMC10625133 DOI: 10.1002/advs.202304204] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 08/06/2023] [Indexed: 09/19/2023]
Abstract
Pure polycyclic aromatic hydrocarbons (PAHs) consisting solely of carbon-hydrogen or carbon-carbon bonds offer great potential for constructing durable and cost-effective emitters in organic electroluminescence devices. However, achieving versatile fluorescence characteristics in pure PAHs remains a considerable challenge, particularly without the inclusion of heteroatoms. Herein, an efficient approach is presented that involves incorporating non-six-membered rings into classical pyrene isomerides, enabling simultaneous achievement of full-color emission, delayed fluorescence, and anti-Kasha emission. Theoretical calculations reveal that the intensity and distribution of aromaticity/anti-aromaticity in both ground and excited states play a crucial role in determining the excited levels and fluorescence yields. Transient fluorescence measurements confirm the existence of thermally activated delayed fluorescence in pure PAHs. By utilizing these PAHs as emitting layers, electroluminescent spectra covering the entire visible region along with a maximum external quantum efficiency of 9.1% can be achieved, leading to the most exceptional results among non-doped pure hydrocarbon-based devices.
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Affiliation(s)
- Haoxin Huang
- Shenzhen Key Laboratory of New Information Display and Storage MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Nengquan Li
- Shenzhen Key Laboratory of New Information Display and Storage MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Shuguang Fu
- Shenzhen Key Laboratory of New Information Display and Storage MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Xuechao Mo
- Shenzhen Key Laboratory of New Information Display and Storage MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Xiaojun Yin
- Shenzhen Key Laboratory of New Information Display and Storage MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen518060P. R. China
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113
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Liu HW, He P, Li WT, Sun W, Shi K, Wang YQ, Mo QK, Zhang XY, Zhu SF. Catalyst-Oriented Design Based on Elementary Reactions (CODER) for Triarylamine Synthesis. Angew Chem Int Ed Engl 2023; 62:e202309111. [PMID: 37698233 DOI: 10.1002/anie.202309111] [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: 06/28/2023] [Revised: 09/09/2023] [Accepted: 09/12/2023] [Indexed: 09/13/2023]
Abstract
Recently, the application of computational tools to the rational design of catalysts has received considerable attention, but progress has been limited by the reliance on databases and because mechanistic data have been almost neglected. Herein, we report a new strategy for catalyst design, designated catalyst-oriented design based on elementary reactions (CODER), which fully utilizes mechanistic data, combines the strengths of computational tools and researcher experience. CODER enabled the development of extremely efficient Pd catalysts for C-N coupling, which markedly improved the efficiency of the synthesis of widely used triarylamine optoelectronic materials by enhancing the turnover numbers (up to 340000) to 1-3 orders of magnitude towards literature values.
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Affiliation(s)
- Hua-Wei Liu
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
| | - Peng He
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
| | - Wen-Tao Li
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
| | - Wei Sun
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
| | - Kai Shi
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
| | - You-Qin Wang
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
| | - Qian-Kun Mo
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
| | - Xin-Yu Zhang
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
| | - Shou-Fei Zhu
- Frontiers Science Center for New Organic Matters, State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, 94th Weijin Road, Tianjin, 300071, China
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114
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Ying A, Gong S. A Rising Star: Luminescent Carbene-Metal-Amide Complexes. Chemistry 2023; 29:e202301885. [PMID: 37431981 DOI: 10.1002/chem.202301885] [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: 06/13/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/12/2023]
Abstract
Coinage metal (gold, silver, and copper) complexes are attractive candidates to substitute the widely studied noble metal complexes, such as, iridium(III) and platinum(II), as luminescent materials in organic light-emitting diodes (OLEDs). However, the development of coinage metal complexes exhibiting high emission quantum yields and short exciton lifetimes is still a formidable challenge. In the past few years, coinage metal complexes featuring a carbene-metal-amide (CMA) motif have emerged as a new class of luminescent materials in OLEDs. Thanks to the coinage metal-bridged linear geometry, coplanar conformation, and the formation of excited states with dominant ligand-to-ligand charge transfer character and reduced metal d-orbital participation, most CMA complexes have high radiative rates via thermally activated delayed fluorescence. Currently, the family of CMA complexes have rapidly evolved and remarkable progresses in CMA-based OLEDs have been made. Here, a Concept article on CMA complexes is presented, with a focus on molecular design principles, the correlation between molecular structure/conformation and optoelectronic properties, as well as OLED performance. The future prospects of CMA complexes are also discussed.
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Affiliation(s)
- Ao Ying
- Hubei Key Lab on Organic and, Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, China
| | - Shaolong Gong
- Hubei Key Lab on Organic and, Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, China
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115
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Han P, Lin C, Xia E, Cheng J, Xia Q, Yang D, Qin A, Ma D, Tang BZ. Non-Doped Blue AIEgen-Based OLED with EQE Approaching 10.3 . Angew Chem Int Ed Engl 2023; 62:e202310388. [PMID: 37668100 DOI: 10.1002/anie.202310388] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/22/2023] [Accepted: 09/04/2023] [Indexed: 09/06/2023]
Abstract
Aggregation-induced emission (AIE) luminogens (AIEgens) are attractive for the construction of non-doped blue organic light-emitting diodes (OLEDs) owning to their high emission efficiency in the film state. However, the large internal inversion rate (kIC (Tn) ) between high-lying triplet levels (Tn ) and Tn-1 causes a huge loss of triplet excitons, resulting in dissatisfied device performance of these AIEgens-based non-doped OLEDs. Herein, we designed and synthesized a blue luminogen of DPDPB-AC by fusing an AIEgen of TPB-AC and a DMPPP, which feature hot exciton and triplet-triplet annihilation (TTA) up-conversion process, respectively. DPDPB-AC successfully inherits the AIE feature and excellent horizontal dipole orientation of TPB-AC. Furthermore, it owes smaller kIC (Tn) than TPB-AC. When DPDPB-AC was applied in OLED as non-doped emitting layer, an outstanding external quantum efficiency of 10.3 % and an exceptional brightness of 69311 cd m-2 were achieved. The transient electroluminescent measurements and steady-state dynamic analysis confirm that both TTA and hot exciton processes contribute to such excellent device performance. This work provides a new insight into the design of efficient organic fluorophores by managing high-lying triplet excitons.
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Affiliation(s)
- Pengbo Han
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Chengwei Lin
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Erhan Xia
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Jiawei Cheng
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Qing Xia
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Dezhi Yang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Anjun Qin
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, Center for Aggregation-Induced Emission, South China University of Technology, Guangzhou, 510640, China
| | - Ben Zhong Tang
- Center for Aggregation-Induced Emission, AIE Institute, South China University of Technology, Guangzhou, 510640, China
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Guangdong, 518172, China
- Hong Kong Branch of Chinese National Engineering Research Centre for Tissue Restoration and Reconstruction, The Hong Kong University of Science & Technology, Kowloon, 999077, Hong Kong, China
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116
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KIM S, YUMUŞAK Ç, IRIMIA CV, BEDNORZ M, YENEL E, KUŞ M, SARIÇİFTÇİ NS, SHIM BS, IRIMIA-VLADU M. Amplifying the dielectric constant of shellac by incorporating natural clays for organic field effect transistors (OFETs). Turk J Chem 2023; 47:1169-1182. [PMID: 38173751 PMCID: PMC10762868 DOI: 10.55730/1300-0527.3603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 10/31/2023] [Accepted: 10/11/2023] [Indexed: 01/05/2024] Open
Abstract
We demonstrate in this work the practical use of uniform mixtures of a bioresin shellac and four natural clays, i.e. montmorillonite, sepiolite, halloysite and vermiculate as dielectrics in organic field effect transistors (OFETs). We present a thorough characterization of their processability and film forming characteristic, surface characterization, elaborate dielectric investigation and the fabrication of field effect transistors with two classic organic semiconductors, i.e. pentacene and fullerene C60. We show that low operating voltage of approximately 4 V is possible for all the OFETs using several combinations of clays and shellac. The capacitance measurements show an improvement of the dielectric constant of shellac by a factor of 2, to values in excess of 7 in the uniform mixtures of sepiolite and montmorillonite with this bioresin.
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Affiliation(s)
- Sunwoo KIM
- Department of Chemical Engineering, Inha University,
South Korea
- Program in Biomedical Science & Engineering, Inha University,
South Korea
- Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Linz,
Austria
| | - Çiğdem YUMUŞAK
- Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Linz,
Austria
| | - Cristian Vlad IRIMIA
- Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Linz,
Austria
| | - Mateusz BEDNORZ
- Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Linz,
Austria
| | - Esma YENEL
- Department of Chemical Engineering, Konya Technical University, Konya,
Turkiye
| | - Mahmut KUŞ
- Department of Chemical Engineering, Konya Technical University, Konya,
Turkiye
| | - Niyazi Serdar SARIÇİFTÇİ
- Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Linz,
Austria
| | - Bong Sup SHIM
- Department of Chemical Engineering, Inha University,
South Korea
- Program in Biomedical Science & Engineering, Inha University,
South Korea
| | - Mihai IRIMIA-VLADU
- Linz Institute for Organic Solar Cells (LIOS), Institute of Physical Chemistry, Johannes Kepler University Linz, Linz,
Austria
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117
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Yang X, Xu S, Zhang Y, Zhu C, Cui L, Zhou G, Chen Z, Sun Y. Narrowband Pure Near-Infrared (NIR) Ir(III) Complexes for Solution-Processed Organic Light-Emitting Diode (OLED) with External Quantum Efficiency Over 16 . Angew Chem Int Ed Engl 2023; 62:e202309739. [PMID: 37626014 DOI: 10.1002/anie.202309739] [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: 07/09/2023] [Revised: 08/13/2023] [Accepted: 08/25/2023] [Indexed: 08/27/2023]
Abstract
Highly efficient near-infrared (NIR) emitters have significant applications in medical and optoelectronic fields, but the development stays a great challenge due to the energy gap law. Here, we report two NIR phosphorescent Ir(III) complexes which display emission peaks around 730 nm with a narrow full width at half maximum of only 43 nm. Therefore, pure NIR luminescence can be obtained without having a very long emission wavelength, thus alleviating the restriction of the energy gap law, and obtaining impressively high photoluminescence quantum yield up to 0.70. More importantly, the pure NIR organic light-emitting diode (OLED) fabricated by the solution-processed mothed shows outstanding device performance with the highest external quantum efficiency of 16.43 %, which sets a new record for solution-processed NIR-OLEDs based on different emitters. This work sheds light on the development of Ir(III) complexes with narrowband emissions as highly efficient pure NIR-emitters.
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Affiliation(s)
- 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
| | - Shipan Xu
- 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
| | - Yan Zhang
- School of Applied Physics and Materials, Wuyi University, Jiangmen, 529020, P. R. China
| | - 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
| | - Linsong Cui
- CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, 230026, 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
| | - Zhao Chen
- School of Applied Physics and Materials, Wuyi University, Jiangmen, 529020, 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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118
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Powley SL, Riley C, Cho HH, Le Phuoc N, Linnolahti M, Greenham N, Romanov AS. Highly phosphorescent carbene-metal-carboranyl complexes of copper(I) and gold(I). Chem Commun (Camb) 2023; 59:12035-12038. [PMID: 37729393 DOI: 10.1039/d3cc04091g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
New phosphorescent "carbene-metal-carboranyl" (CMC) Cu(I) and Au(I) complexes based on the diamidocarbene (DAC) ligand show up to 68% photoluminescence quantum yield and microsecond range lifetimes. CMC organic light emitting diodes (OLEDs) emit sky-blue and warm white electroluminescence.
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Affiliation(s)
- Samuel L Powley
- Department of Chemistry, The University of Manchester, Oxford Rd., Manchester, M13 9PL, UK.
| | - Charlotte Riley
- Department of Chemistry, The University of Manchester, Oxford Rd., Manchester, M13 9PL, UK.
| | - Hwan-Hee Cho
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HE, UK.
| | - Nguyen Le Phuoc
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, FI-80101 Joensuu, Finland.
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, Joensuu Campus, FI-80101 Joensuu, Finland.
| | - Neil Greenham
- Department of Physics, Cavendish Laboratory, Cambridge University, Cambridge CB3 0HE, UK.
| | - Alexander S Romanov
- Department of Chemistry, The University of Manchester, Oxford Rd., Manchester, M13 9PL, UK.
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119
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Poriel C, Rault-Berthelot J. Dihydroindenofluorenes as building units in organic semiconductors for organic electronics. Chem Soc Rev 2023; 52:6754-6805. [PMID: 37702538 DOI: 10.1039/d1cs00993a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2023]
Abstract
This review aims to discuss organic semiconductors constructed on dihydroindenofluorene positional isomers, which are key molecular scaffolds in organic electronics. Bridged oligophenylenes are key organic semiconductors that have allowed the development of organic electronic technologies. Dihydroindenofluorenes (DHIFs) belong to the family of bridged oligophenylenes constructed on a terphenyl backbone. They have proven to be very promising building blocks for the construction of highly efficient organic semiconductors for all OE devices, namely organic light emitting diodes (OLEDs), phosphorescent OLEDs, organic field-effect transistors (OFETs), solar cells, etc.
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Affiliation(s)
- Cyril Poriel
- UMR CNRS 6226-Université Rennes 1-ISCR-Campus de Beaulieu, 35042 Rennes, France.
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120
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Belyakov AV, Altova EP, Rykov AN, Sharanov PY, Shishkov IF, Romanov AS. The Equilibrium Molecular Structure of Cyclic (Alkyl)(Amino) Carbene Copper(I) Chloride via Gas-Phase Electron Diffraction and Quantum Chemical Calculations. Molecules 2023; 28:6897. [PMID: 37836740 PMCID: PMC10574683 DOI: 10.3390/molecules28196897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 09/24/2023] [Accepted: 09/29/2023] [Indexed: 10/15/2023] Open
Abstract
Copper-centered carbene-metal-halides (CMHs) with cyclic (alkyl)(amino) carbenes (CAACs) are bright phosphorescent emitters and key precursors in the synthesis of the highly promising class of the materials carbene-metal-amides (CMAs) operating via thermally activated delayed fluorescence (TADF). Aiming to reveal the molecular geometry for CMH phosphors in the absence of the intermolecular contacts, we report here the equilibrium molecular structure of the (CAAC)Cu(I)Cl (1) molecule in the gas-phase. We demonstrate that linear geometry around a copper atom shows no distortions in the ground state. The structure of complex 1 has been determined using the electron diffraction method, supported by quantum chemical calculations with RI-MP2/def2-QZVPP level of theory and compared with the crystal structure determined by X-ray diffraction analysis. Mean vibrational amplitudes, uij,h1, and anharmonic vibrational corrections (rij,e • rij,a) were calculated for experimental temperature T = 20 °C, using quadratic and cubic force constants, respectively. The quantum theory of atoms in molecules (QTAIM) and natural bond order (NBO) analysis of wave function at MN15/def2TZVP level of theory revealed two Cu…H, three H…H, and one three-center H…H…H bond paths with bond critical points. NBO analysis also revealed three-center, four-electron hyperbonds, (3c4e), [π(N-C) nπ(Cu) ↔ nπ(N) π(N-Cu)], or [N-C: Cu ↔ N: C-Cu] and nπ(Cu) → π(C-N)* hyperconjugation, that is the delocalization of the lone electron pair of Cu atom into the antibonding orbital of C-N bond.
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Affiliation(s)
| | - Ekaterina P. Altova
- Department of Chemistry, Moscow State University, 119992 Moscow, Russia; (E.P.A.); (P.Y.S.)
| | - Anatoliy N. Rykov
- Department of Chemistry, Moscow State University, 119992 Moscow, Russia; (E.P.A.); (P.Y.S.)
| | - Pavel Yu. Sharanov
- Department of Chemistry, Moscow State University, 119992 Moscow, Russia; (E.P.A.); (P.Y.S.)
| | - Igor F. Shishkov
- Department of Chemistry, Moscow State University, 119992 Moscow, Russia; (E.P.A.); (P.Y.S.)
| | - Alexander S. Romanov
- Department of Chemistry, University of Manchester, Oxford Rd., Manchester M13 9PL, UK
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121
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Wang B, Wang H, Hu Y, Waterhouse GIN, Lu S. Carbon Dot Based Multicolor Electroluminescent LEDs with Nearly 100% Exciton Utilization Efficiency. NANO LETTERS 2023; 23:8794-8800. [PMID: 37487142 DOI: 10.1021/acs.nanolett.3c02271] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
Carbon dots (CDs) are promising nanomaterials for next-generation lighting and displays due to their tunable bandgap, high photoluminescence quantum yield (PLQY), and high stability. However, the exciton utilization efficiency (EUE) of CD-based films can only reach 25%, fundamentally limiting their application in electroluminescent light-emitting diodes (LEDs). Improving the EUE is therefore of great significance. Herein, we developed composite films containing CDs and poly(9-vinylcarbazole) (PVK). The films were then used to construct a series of high-performance electroluminescent LEDs with tunable emission colors covering the blue to green regions as the concentration of CDs in the films increased, delivering a maximum external quantum efficiency and current efficiency of 2.62% and 5.11 cd/A, respectively. Theoretical calculations and experiments established that the excellent performance at low film PLQY was due to a hot exciton effect in the CDs, achieving nearly 100% EUE. This work provides new design strategies toward high-performance CD-based electroluminescent LEDs.
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Affiliation(s)
- Boyang Wang
- Green Catalysis Center and College of Chemistry, Zhengzhou University, Zhengzhou 450000, People's Republic of China
| | - Hongwei Wang
- Green Catalysis Center and College of Chemistry, Zhengzhou University, Zhengzhou 450000, People's Republic of China
| | - Yongsheng Hu
- School of Physics and Microelectronics, Zhengzhou University, Zhengzhou 450000, People's Republic of China
| | | | - Siyu Lu
- Green Catalysis Center and College of Chemistry, Zhengzhou University, Zhengzhou 450000, People's Republic of China
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122
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Wang Z, Ma L, Zhao H, Wan Y, Zhang XF, Li Y, Kuang Z, Xia A. Spin-orbit charge-transfer intersystem crossing in heavy-atom-free orthogonal covalent boron-dipyrromethene heterodimers. Phys Chem Chem Phys 2023; 25:24386-24394. [PMID: 37283300 DOI: 10.1039/d3cp01934a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Boron-dipyrromethene (BODIPY) derivatives are prospective organic-based triplet photosensitizers. Since the triplet generation yield of the parent BODIPY is low, heavy atoms are widely used to improve the triplet yield. However, the dimerization of BODIPYs can also significantly improve their ability to produce triplets. Through a comparative study of the triplet formation dynamics of two heavy-atom-free orthogonal covalent BODIPY heterodimers that differ in their dihedral angles, we have demonstrated that the mechanism of spin-orbit charge-transfer intersystem crossing (SOCT-ISC) promotes the triplet generation of BODIPY heterodimers in solution. Different from the general understanding of SOCT-ISC, the heterodimer with a smaller dihedral angle and low structural rigidity showed better triplet generation due to (a) the stronger inter-chromophoric interaction in the heterodimer, which promoted the formation of a solvent-stabilized charge-transfer (CT) state, (b) the more favorable energy level alignment with sizeable spin-orbit coupling strength, and (c) the balance between the stabilized singlet CT state and limited direct charge recombination to the ground state in a weakly polar solvent. The complete spectral characterization of the triplet formation dynamics clarified the SOCT-ISC mechanism and important factors affecting the triplet generation in BODIPY heterodimers.
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Affiliation(s)
- Zeming Wang
- State Key Laboratory of Information Photonic and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China.
| | - Lin Ma
- State Key Laboratory of Information Photonic and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China.
| | - Hongmei Zhao
- State Key Laboratory of Information Photonic and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China.
| | - Yan Wan
- College of Chemistry, Beijing Normal University, Beijing 100875, P. R. China
| | - Xian-Fu Zhang
- Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, Guangdong Province 518055, P. R. China.
| | - Yang Li
- State Key Laboratory of Information Photonic and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China.
| | - Zhuoran Kuang
- State Key Laboratory of Information Photonic and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China.
| | - Andong Xia
- State Key Laboratory of Information Photonic and Optical Communications, and School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China.
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123
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Hatanaka M, Kato H, Sakai M, Kariya K, Nakatani S, Yoshimura T, Inagaki T. Insights into the Luminescence Quantum Yields of Cyclometalated Iridium(III) Complexes: A Density Functional Theory and Machine Learning Approach. J Phys Chem A 2023; 127:7630-7637. [PMID: 37651718 DOI: 10.1021/acs.jpca.3c02179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Cyclometalated iridium(III) complexes have been used in various optical materials, including organic light-emitting diodes (OLEDs) and photocatalysts, and a deeper understanding and prediction of their luminescence quantum yields (LQYs) greatly aid in accelerating material design. In this study, we integrated density functional theory (DFT) calculations with machine learning (ML) techniques to extract factors controlling LQY. Although a substantial data set of Ir(III) complexes and their LQYs is indispensable for constructing accurate ML models to predict LQYs, generating this type of data set is challenging due to the complexities associated with ab initio calculations of LQYs. To address this issue, we investigated the nonradiative decay process of nine Ir(III) complexes emitting blue to green, each exhibiting varying experimental LQYs, by using DFT calculations. For all nine complexes, the quenching process was induced by the rotation of the single bond in one of the ligands, which converted the six-coordinate structure to the five-coordinate structure. Since the decay mechanism was common for the nine Ir(III) complexes, parameters correlated with LQYs could be used as objective variables instead of LQYs. Based on this idea, we collected a data set featuring Ir(III) complexes and the energy differences between their six- and five-coordinate triplet structures, which correlated with LQYs. We also constructed ML models using the calculated LQYs as the objective variables with the parameters from the ground-state calculations as explanatory variables. The analyses of the constructed model revealed that the LUMO energy of the ligand made the most significant negative contribution to LQY. This suggests that the potential energy surface of the metal-to-ligand charge transfer (MLCT) excited state, which stabilizes the six-coordinate structure, is reduced by decreasing the energy of the unoccupied orbitals.
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Affiliation(s)
- Miho Hatanaka
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Hiromoto Kato
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Minami Sakai
- Division of Materials Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, 8916-5 Takayama-cho, Ikokma, Nara 630-0192, Japan
| | - Kosuke Kariya
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Shunsuke Nakatani
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Takayoshi Yoshimura
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
| | - Taichi Inagaki
- Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan
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Omar Ö, Xie X, Troisi A, Padula D. Identification of Unknown Inverted Singlet-Triplet Cores by High-Throughput Virtual Screening. J Am Chem Soc 2023; 145:19790-19799. [PMID: 37639703 PMCID: PMC10510316 DOI: 10.1021/jacs.3c05452] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Indexed: 08/31/2023]
Abstract
Molecules where the energy of the lowest excited singlet state is found below the energy of the lowest triplet state (inverted singlet-triplet molecules) are extremely rare. It is particularly challenging to discover new ones through virtual screening because the required wavefunction-based methods are expensive and unsuitable for high-throughput calculations. Here, we devised a virtual screening approach where the molecules to be considered with advanced methods are pre-selected with increasingly more sophisticated filters that include the evaluation of the HOMO-LUMO exchange integral and approximate CASSCF calculations. A final set of 7 candidates (0.05% of the initial 15 000) were verified to possess inversion between singlet and triplet states with state-of-the-art multireference methods (MS-CASPT2). One of them is deemed of particular interest because it is unrelated to other proposals made in the literature.
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Affiliation(s)
- Ömer
H. Omar
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Xiaoyu Xie
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Alessandro Troisi
- Department
of Chemistry, University of Liverpool, Liverpool L69 7ZD, U.K.
| | - Daniele Padula
- Dipartimento
di Biotecnologie, Chimica e Farmacia, Università
di Siena, Via A. Moro
2, Siena 53100, Italy
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125
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Muthig AMT, Wieland J, Lenczyk C, Koop S, Tessarolo J, Clever GH, Hupp B, Steffen A. Towards Fast Circularly Polarized Luminescence in 2-Coordinate Chiral Mechanochromic Copper(I) Carbene Complexes. Chemistry 2023; 29:e202300946. [PMID: 37272620 DOI: 10.1002/chem.202300946] [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: 03/24/2023] [Revised: 05/15/2023] [Accepted: 06/02/2023] [Indexed: 06/06/2023]
Abstract
A series of chiral mechanochromic copper(I) cAAC (cAAC=cyclic (alkyl)(amino)carbene) complexes with a variety of amide ligands have been studied with regard to their photophysical and chiroptical properties to elucidate structure-property relationships for the design of efficient triplet exciton emitters exhibiting circularly polarized luminescence. Depending on the environment, which determines the excited state energies, either thermally activated delayed fluorescence (TADF) from 1/3 LLCT states or phosphorescence from 3 LLCT/LC states occurs. However, neither chiral moieties at the carbene nor at the carbazolate ligands provide detectable luminescence dissymmetries glum . An exception is [Cu(phenoxazinyl)(cAAC)], showing orange to deep red TADF with λmax =601-715 nm in solution, powders and in PMMA. In this case, the amide ligand can undergo distortions in the excited state. This design motif leads to the first linear, non-aggregated CPL-active copper(I) complex with glum of -3.4 ⋅ 10-3 combined with a high radiative rate constant of 6.7 ⋅ 105 s-1 .
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Affiliation(s)
- André M T Muthig
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Justin Wieland
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Carsten Lenczyk
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Stefan Koop
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Jacopo Tessarolo
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Guido H Clever
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Benjamin Hupp
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
| | - Andreas Steffen
- Department of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 6, 44227, Dortmund, Germany
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126
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Liu Q, Deng Y, Ren B, Lan X, Zhang Y, Guo R, Li C, Xiong G, Sun Y, Zhao Z. Unraveling the Position Effect of Spiroxanthene-Based n-Type Hosts for High-Performance TADF-OLEDs. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2517. [PMID: 37764546 PMCID: PMC10537283 DOI: 10.3390/nano13182517] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 09/04/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023]
Abstract
For developing high-performance organic light-emitting diodes (OLEDs) with thermally activated delayed fluorescent (TADF) emitters, the diphenyltriazine (TRZ) unit was introduced onto the 2'- and 3'-positions of xanthene moiety of spiro[fluorene-9,9'-xanthene] (SFX) to construct n-type host molecules, namely 2'-TRZSFX and 3'-TRZSFX. The outward extension of the TRZ unit, induced by the meta-linkage, resulted in a higher planarity between the TRZ unit and xanthene moiety in the corresponding 3'-TRZSFX. Additionally, this extension led to a perched T1 level, as well as a lower unoccupied molecular orbital (LUMO) level when compared with 2'-TRZSFX. Meanwhile, the 3'-TRZSFX molecules in the crystalline state presented coherent packing along with the interaction between TRZ units; the similar packing motif was spaced apart from xanthene moieties in the 2'-TRZSFX crystal. These endowed 3'-TRZSFX superior electron transport capacity in single-carrier devices relative to the 2'-TRZSFX-based device. Hence, the 3'-TRZSFX-based TADF-OLED showed remarkable electroluminescent (EL) performance under the operating luminance from turn-on to ca. 1000 cd·m-2 with a maximum external quantum efficiency (EQEmax) of 23.0%, thanks to its matched LUMO level with 4CzIPN emitter and better electron transport capacity. Interestingly, the 2'-TRZSFX-based device, with an EQEmax of 18.8%, possessed relatively low roll-off and higher efficiency when the operating luminance exceeded 1000 cd·m-2, which was attributed to the more balanced carrier transport under high operating voltage. These results were elucidated by the analysis of single-crystal structures and the measurements of single-carrier devices, combined with EL performance. The revealed position effect of the TRZ unit on xanthene moiety provides a more informed strategy to develop SFX-based hosts for highly efficient TADF-OLEDs.
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Affiliation(s)
- Qinglin Liu
- College of Science, Key Laboratory of Inorganic Molecule-Based Chemistry of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China; (Q.L.); (X.L.); (Y.Z.); (C.L.); (G.X.); (Y.S.)
| | - Yun Deng
- Frontiers Science Center for Flexible Electronics, Xi’an Institute of Flexible Electronics and Xi’an Institute of Biomedical Materials & Engineering, Northwestern Polytechnical University, Xi’an 710072, China;
| | - Baoyi Ren
- College of Science, Key Laboratory of Inorganic Molecule-Based Chemistry of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China; (Q.L.); (X.L.); (Y.Z.); (C.L.); (G.X.); (Y.S.)
| | - Xia Lan
- College of Science, Key Laboratory of Inorganic Molecule-Based Chemistry of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China; (Q.L.); (X.L.); (Y.Z.); (C.L.); (G.X.); (Y.S.)
| | - Yuehong Zhang
- College of Science, Key Laboratory of Inorganic Molecule-Based Chemistry of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China; (Q.L.); (X.L.); (Y.Z.); (C.L.); (G.X.); (Y.S.)
| | - Runda Guo
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China
- State Key Laboratory of Luminescent Materials and Devices, Key Laboratory of Luminescence from Molecular Aggregates of Guangdong Province, South China University of Technology, Guangzhou 510640, China;
| | - Chensheng Li
- College of Science, Key Laboratory of Inorganic Molecule-Based Chemistry of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China; (Q.L.); (X.L.); (Y.Z.); (C.L.); (G.X.); (Y.S.)
| | - Gang Xiong
- College of Science, Key Laboratory of Inorganic Molecule-Based Chemistry of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China; (Q.L.); (X.L.); (Y.Z.); (C.L.); (G.X.); (Y.S.)
| | - Yaguang Sun
- College of Science, Key Laboratory of Inorganic Molecule-Based Chemistry of Liaoning Province, Shenyang University of Chemical Technology, Shenyang 110142, China; (Q.L.); (X.L.); (Y.Z.); (C.L.); (G.X.); (Y.S.)
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices, Key Laboratory of Luminescence from Molecular Aggregates of Guangdong Province, South China University of Technology, Guangzhou 510640, China;
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127
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Sim JH, Kwon J, Chae H, Kim SB, Cho H, Lee W, Kim SH, Byun CW, Hahn S, Park DH, Yoo S. OLED catheters for inner-body phototherapy: A case of type 2 diabetes mellitus improved via duodenal photobiomodulation. SCIENCE ADVANCES 2023; 9:eadh8619. [PMID: 37656783 PMCID: PMC10854432 DOI: 10.1126/sciadv.adh8619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Accepted: 08/01/2023] [Indexed: 09/03/2023]
Abstract
Phototherapeutics has shown promise in treating various diseases without surgical or drug interventions. However, it is challenging to use it in inner-body applications due to the limited light penetration depth through the skin. Therefore, we propose an organic light-emitting diode (OLED) catheter as an effective photobiomodulation (PBM) platform useful for tubular organs such as duodenums. A fully encapsulated highly flexible OLED is mounted over a round columnar structure, producing axially uniform illumination without local hotspots. The biocompatible and airtight OLED catheter can operate in aqueous environments for extended periods, meeting the essential requirements for inner-body medical applications. In a diabetic Goto-Kakizaki (GK) rat model, the red OLED catheter delivering 798 mJ of energy is shown to reduce hyperglycemia and insulin resistance compared to the sham group. Results are further supported by the subdued liver fibrosis, illustrating the immense potential of the OLED-catheter-based internal PBM for the treatment of type 2 diabetes and other diseases yet to be identified.
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Affiliation(s)
- Jee Hoon Sim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Jinhee Kwon
- Digestive Disease Research Center, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
- Department of Medical Science, Asan Medical Institute of Convergence Science and Technology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Hyeonwook Chae
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Su-Bon Kim
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Hyunsu Cho
- Reality Display Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Republic of Korea
| | - Woochan Lee
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - So Hee Kim
- Digestive Disease Research Center, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Chun-Won Byun
- Reality Display Research Section, Electronics and Telecommunications Research Institute (ETRI), Daejeon, 34129, Republic of Korea
| | - Sangin Hahn
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Do Hyun Park
- Digestive Disease Research Center, Department of Internal Medicine, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Republic of Korea
| | - Seunghyup Yoo
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
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128
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Wu Y, Liu X, Liu J, Yang G, Han S, Yang D, Cao X, Ma D, Bin Z, You J. Geometry engineering of a multiple resonance core via a phenyl-embedded strategy toward highly efficient narrowband blue OLEDs. MATERIALS HORIZONS 2023; 10:3785-3790. [PMID: 37409621 DOI: 10.1039/d3mh00617d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/07/2023]
Abstract
The geometry of the molecular skeleton is of importance for the property regulation of organic electronic materials. Herein, we present a phenyl-embedded molecular design strategy to adjust the molecular curvature and achieve the improvement of blue multiple resonance (MR)-emitters. The introduction of a bridged phenyl contributes to a highly twisted saddle skeleton and the separation of frontier molecular orbitals, which are beneficial for the increase of photoluminescence quantum yield (PLQY) as well as the decrease of singlet-triplet energy gap (ΔEST). Consequently, hp-BQAO features an accelerated reverse intersystem crossing rate and suppressed non-radiative decay rate simultaneously, which enables the assembly of high-performance narrowband blue OLEDs with a record-high external quantum efficiency (EQE) of 24.1% for the blue OLED devices exploiting nitrogen-carbonyl-containing MR-emitters without sensitizers.
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Affiliation(s)
- Yimin Wu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Xiaoyu Liu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Junjie Liu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Ge Yang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Songyan Han
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Dezhi Yang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, People's Republic of China
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - Dongge Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, People's Republic of China
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Jingsong You
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
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129
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Khan AAT, Gobeze HB, Islam T, Arman HD, Schanze KS. Effect of bromine substitution on blue phosphorescent trans-(N-heterocyclic carbene)Pt(II) acetylide complexes. Dalton Trans 2023; 52:11535-11542. [PMID: 37540137 DOI: 10.1039/d3dt01483e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
N-heterocyclic carbene complexes of the type trans-(NHC)2PtII(CC-Ar)2 (where Ar = phenyl or substituted phenyl) are of interest as violet and blue phosphors. These complexes emit efficient phosphorescence in solution and in the solid state, and they have been applied as phosphors in organic light emitting diodes. This study explores the effect of bromine substitution on the trans-(NHC)2PtII(CC-Ar)2 chromophore through photophysical studies of a pair of complexes in which the phenyl groups feature either 3,5-dibromo- or 4-monobromo-substituents (IPt-DB and IPt-MB, respectively). The Br atoms were introduced as heavy atom(s) with the aim to enhance spin-orbit coupling and increase the radiative and non-radiative decay rates of the phosphorescent triplet state. Both IPt-MB and IPt-DB exhibit sky-blue phosphorescence in solution and in PMMA matrix. Interestingly, the emission quantum yield and lifetime of IPt-MB are substantially lower compared to IPt-DB in solution. This effect is attributed to a substantially larger non-radiative decay rate in the mono-bromo complex. Analysis of the photophysical data, combined with DFT and TD-DFT calculations, suggest that the difference in photophysical properties of the two complexes is related to the position of the Br-substituents on the phenyl acetylide rings. In short, in IPt-MB, the Br-substituents are located para-to the Pt-CC-unit, and this gives rise to stronger electron-vibrational coupling in the excited state, enhancing the rate of non-radiative decay.
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Affiliation(s)
- Amran A T Khan
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
| | - Habtom B Gobeze
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
| | - Tanjila Islam
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
| | - Hadi D Arman
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
| | - Kirk S Schanze
- Department of Chemistry, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, USA.
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130
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Liu JW, Tang X, Liu C, Zhou HC, Wang S, Kang HP, Li YH, Lai WY. Improved electroluminescence efficiency derived from functionalized decoration of 1,3,4-oxadiazole (OXD)-based Ir(III) complexes. Dalton Trans 2023; 52:11691-11697. [PMID: 37552532 DOI: 10.1039/d3dt01548c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
The performance of organic light emitting devices (OLEDs) fabricated using Ir(III) complexes bearing 1,3,4-oxadiazole (OXD)-based cyclometallic ligands still needs to be improved. In this work, Ir3+ was coordinated with a 2-(9,9-diethyl-9H-fluoren-2-yl)-1,3,4-oxadiazole (F-OXD) fragment, which was modified with various functionalized substituents, including fluorenyl, OXD and carbazolyl groups. Three complexes, named Ir-Flu, Ir-OXD and Ir-Cz, were synthesized successfully and their photophysical, electrochemical and electroluminescence properties were investigated in detail. All these complexes exhibited yellow-orange emission in solution and a distinct aggregation-induced phosphorescent emission (AIPE) phenomenon was observed. Monochrome OLEDs were fabricated using these phosphorescent dopants, and the turn-on voltage (V), luminance (L) and current efficiency (CE) showed significant improvement compared to analogous OXD-based Ir(III) complexes reported before. In particular, the device with Ir-OXD as the dopant achieved the highest maximum brightness of 25 014 cd m-2 and the lowest efficiency roll-off (42.6%) at the maximum luminance among all the devices. These results provided a proven strategy of functionalized decoration of OXD-based complexes to achieve superior luminous efficiency devices.
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Affiliation(s)
- Jia-Wei Liu
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
| | - Xiong Tang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
| | - Chang Liu
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
| | - Han-Chen Zhou
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
| | - Shi Wang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
| | - Hai-Peng Kang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
| | - Yong-Hua Li
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
| | - Wen-Yong Lai
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, Nanjing 210023, China.
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131
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Li X, Tu L, Gao M, Li A, Chen Y, Chi W, Zhang D, Duan L, Xie Y, Tang BZ, Li Z. Highly Efficient Blue Organic Light Emitting Diodes Based on Cyclohexane-Fused Quinoxaline Acceptor. J Phys Chem Lett 2023; 14:6982-6989. [PMID: 37523259 DOI: 10.1021/acs.jpclett.3c01629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Exploring blue organic light emitting diodes (OLED) is an important but challenging issue. Herein, to achieve blue-shifted emission, cyclohexane is fused to quinoxaline to weaken the electron-withdrawing ability and conjugation degree of the acceptor. As a result, blue to cyan fluorescent emitters of Me-DPA-TTPZ, tBu-DPA-TTPZ, and TPA-TTPZ were designed and synthesized with donors of diphenylamine and triphenylamine, which exhibit high photoluminescence quantum yields and good thermal stability. In OLEDs with emitters of TPA-TTPZ, the sensitized and nonsensitized devices demonstrate deep-blue (449 nm) and blue (468 nm) emission with maximum external quantum efficiency and CIE coordinates of 6.1%, (0.15, 0.10) and 5.1%, (0.17, 0.22), respectively, validating their potential as blue emitters in OLEDs.
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Affiliation(s)
- Xiaoning Li
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China
| | - Liangjing Tu
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China
| | - Mingxue Gao
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China
| | - Aisen Li
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University Binhai New City, Fuzhou 350207, China
| | - Yi Chen
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China
| | - Weijie Chi
- Department of Chemistry, School of Science, Hainan University, Haikou 570228, China
| | - Dongdong Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Lian Duan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing 100084, China
| | - Yujun Xie
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China
| | - Ben Zhong Tang
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Zhen Li
- Institute of Molecular Aggregation Science, Tianjin University, Tianjin 300072, China
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University Binhai New City, Fuzhou 350207, China
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan 430072, China
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132
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Suresh SM, Zhang L, Matulaitis T, Hall D, Si C, Ricci G, Slawin AMZ, Warriner S, Beljonne D, Olivier Y, Samuel IDW, Zysman-Colman E. Judicious Heteroatom Doping Produces High-Performance Deep-Blue/Near-UV Multiresonant Thermally Activated Delayed Fluorescence OLEDs. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2300997. [PMID: 37140188 DOI: 10.1002/adma.202300997] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 04/26/2023] [Indexed: 05/05/2023]
Abstract
Two multiresonant thermally activated delayed fluorescence (MR-TADF) emitters are presented and it is shown how further borylation of a deep-blue MR-TADF emitter, DIDOBNA-N, both blueshifts and narrows the emission producing a new near-UV MR-TADF emitter, MesB-DIDOBNA-N, are shown. DIDOBNA-N emits bright blue light (ΦPL = 444 nm, FWHM = 64 nm, ΦPL = 81%, τd = 23 ms, 1.5 wt% in TSPO1). The deep-blue organic light-emitting diode (OLED) based on this twisted MR-TADF compound shows a very high maximum external quantum efficiency (EQEmax ) of 15.3% for a device with CIEy of 0.073. The fused planar MR-TADF emitter, MesB-DIDOBNA-N shows efficient and narrowband near-UV emission (λPL = 402 nm, FWHM = 19 nm, ΦPL = 74.7%, τd = 133 ms, 1.5 wt% in TSPO1). The best OLED with MesB-DIDOBNA-N, doped in a co-host, shows the highest efficiency reported for a near-UV OLED at 16.2%. With a CIEy coordinate of 0.049, this device also shows the bluest EL reported for a MR-TADF OLED to date.
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Affiliation(s)
- Subeesh Madayanad Suresh
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Le Zhang
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
| | - Tomas Matulaitis
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - David Hall
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, 7000, Belgium
| | - Changfeng Si
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Gaetano Ricci
- Laboratory for Computational Modeling of Functional Materials, Namur Institute of Structured Matter, Université de Namur, Rue de Bruxelles, 61, Namur, 5000, Belgium
| | - Alexandra M Z Slawin
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Stuart Warriner
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, 7000, Belgium
| | - Yoann Olivier
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, 7000, Belgium
- Laboratory for Computational Modeling of Functional Materials, Namur Institute of Structured Matter, Université de Namur, Rue de Bruxelles, 61, Namur, 5000, Belgium
| | - Ifor D W Samuel
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
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133
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Jing YY, Li N, Cao X, Wu H, Miao J, Chen Z, Huang M, Wang X, Hu Y, Zou Y, Yang C. Precise modulation of multiple resonance emitters toward efficient electroluminescence with pure-red gamut for high-definition displays. SCIENCE ADVANCES 2023; 9:eadh8296. [PMID: 37506207 PMCID: PMC10381944 DOI: 10.1126/sciadv.adh8296] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 06/27/2023] [Indexed: 07/30/2023]
Abstract
Multiple resonance (MR) compounds have garnered substantial attention for their prospective utility in wide color gamut displays. Nevertheless, developing red MR emitters with both high efficiency and saturated emission color remains demanding. We herein introduce a comprehensive strategy for spectral tuning in the red region by simultaneously regulating the π-conjugation and electron-donating strengths of a double boron-embedded MR skeleton while preserving narrowband characteristics. The proof-of-concept materials manifested emissions from orange-red to deep red, with bandwidths below 0.12 eV. The pure-red device based on CzIDBNO displayed superior color purity with CIE coordinates of (0.701, 0.298), approaching the Broadcast Television 2020 standard. In concert with high photoluminescence quantum yield and strong horizontal dipole orientation, CzIDBNO also achieved a maximum external quantum efficiency of 32.5% and a current efficiency of 20.2 cd A-1, outstripping prior reported organic light-emitting diodes (OLEDs) with CIEx exceeding 0.68. These findings offer a roadmap for designing high-performance emitters with exceptional color purity for future OLED material research advancements.
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Affiliation(s)
- Yan-Yun Jing
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
- College of Physics and Optoeletronic Engineering, Shenzhen University, Shenzhen, China
- Information Technology Research Institute, Shenzhen Institute of Information Technology, Shenzhen 518172, China
| | - Nengquan Li
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Han Wu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Jingsheng Miao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Zhanxiang Chen
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Manli Huang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Xinzhong Wang
- Information Technology Research Institute, Shenzhen Institute of Information Technology, Shenzhen 518172, China
| | - Yuxuan Hu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Yang Zou
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China
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134
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Jiang C, Yoon S, Nguyen YH, Teets TS. Modular Imine Chelates with Variable Anionic Donors Promote Red Phosphorescence in Cyclometalated Iridium Complexes. Inorg Chem 2023. [PMID: 37410956 DOI: 10.1021/acs.inorgchem.3c01770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
The lack of red and deep-red emitting molecular phosphors with high photoluminescence quantum yields remains a significant fundamental challenge and has implications in optoelectronic technologies for color displays and other consumer products. In this work, we introduce a series of seven new red or deep-red emitting heteroleptic bis-cyclometalated iridium(III) complexes, supported by five different ancillary ligands (L^X) from the salicylaldimine and 2-picolinamide families. Previous work had shown that electron-rich anionic chelating "L^X" ligands can be effective in supporting efficient red phosphorescence, and the complementary approach described here, in addition to being synthetically simpler, offers two key advantages over the previous designs. First, the "L" and "X" functionalities can be independently tuned, providing excellent control over the electronic energy levels and excited-state dynamics. Second, these classes of L^X ligands can have beneficial impacts on the excited-state dynamics but do not significantly perturb the emission color profile. Cyclic voltammetry experiments show that the substituents on the L^X ligand impact the HOMO energy but have a minimal effect on the LUMO energy. Photoluminescence measurements reveal that all the compounds luminesce in the red or deep-red region as a function of the cyclometalating ligand and exhibit exceptionally high photoluminescence quantum yields (ΦPL), comparable or superior to the best-performing red-emitting iridium complexes.
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Affiliation(s)
- Chenggang Jiang
- University of Houston, Department of Chemistry, 3585 Cullen Blvd., Room 112, Houston, Texas 77204-5003, United States
| | - Sungwon Yoon
- University of Houston, Department of Chemistry, 3585 Cullen Blvd., Room 112, Houston, Texas 77204-5003, United States
| | - Yennie H Nguyen
- University of Houston, Department of Chemistry, 3585 Cullen Blvd., Room 112, Houston, Texas 77204-5003, United States
| | - Thomas S Teets
- University of Houston, Department of Chemistry, 3585 Cullen Blvd., Room 112, Houston, Texas 77204-5003, United States
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135
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Zhao T, Jiang S, Wang Y, Hu J, Lin FL, Meng L, Gao P, Chen XL, Lu CZ. Realizing High-Efficiency Orange-Red Thermally Activated Delayed Fluorescence Materials through the Construction of Intramolecular Noncovalent Interactions. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37315213 DOI: 10.1021/acsami.3c04117] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The development of highly efficient orange and red thermally activated delayed fluorescence (TADF) materials for constructing full-color and white organic light-emitting diodes (OLEDs) remains insufficient because of the formidable challenges in molecular design, such as the severe radiationless decay and the intrinsic trade-off between the efficiencies of radiative decay and reverse intersystem crossing (RISC). Herein, we design two high-efficiency orange and orange-red TADF molecules by constructing intermolecular noncovalent interactions. This strategy could not only ensure high emission efficiency via suppression of the nonradiative relaxation and enhancement of the radiative transition but also create intermediate triplet excited states to ensure the RISC process. Both emitters exhibit typical TADF characteristics, with a fast radiative rate and a low nonradiative rate. Photoluminescence quantum yields (PLQYs) of the orange (TPA-PT) and orange-red (DMAC-PT) materials reach up to 94 and 87%, respectively. Benefiting from the excellent photophysical properties and stability, OLEDs based on these TADF emitters realize orange to orange-red electroluminescence with high external quantum efficiencies reaching 26.2%. The current study demonstrates that the introduction of intermolecular noncovalent interactions is a feasible strategy for designing highly efficient orange to red TADF materials.
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Affiliation(s)
- Tianxiang Zhao
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou, Fuzhou, Fujian 350108, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shanshan Jiang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
| | - Yashu Wang
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
| | - Jiaxuan Hu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
| | - Fu-Lin Lin
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
| | - Lingyi Meng
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
| | - Peng Gao
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
| | - Xu-Lin Chen
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou, Fuzhou, Fujian 350108, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
| | - Can-Zhong Lu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
- Fujian Science & Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou, Fuzhou, Fujian 350108, China
- Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials, Xiamen Institute of Rare Earth Materials, Haixi Institutes, Chinese Academy of Sciences, Xiamen, Fujian 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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136
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Gawale Y, Ansari R, Naveen KR, Kwon JH. Forthcoming hyperfluorescence display technology: relevant factors to achieve high-performance stable organic light emitting diodes. Front Chem 2023; 11:1211345. [PMID: 37377883 PMCID: PMC10291061 DOI: 10.3389/fchem.2023.1211345] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
Over the decade, there have been developments in purely organic thermally activated delayed fluorescent (TADF) materials for organic light-emitting diodes (OLEDs). However, achieving narrow full width at half maximum (FWHM) and high external quantum efficiency (EQE) is crucial for real display industries. To overcome these hurdles, hyperfluorescence (HF) technology was proposed for next-generation OLEDs. In this technology, the TADF material was considered a sensitizing host, the so-called TADF sensitized host (TSH), for use of triplet excitons via the reverse intersystem crossing (RISC) pathway. Since most of the TADF materials show bipolar characteristics, electrically generated singlet and triplet exciton energies can be transported to the final fluorescent emitter (FE) through Förster resonance energy transfer (FRET) rather than Dexter energy transfer (DET). This mechanism is possible from the S1 state of the TSH to the S1 state of the final fluorescent dopant (FD) as a long-range energy transfer. Considering this, some reports are available based on hyperfluorescence OLEDs, but the detailed analysis for highly efficient and stable devices for commercialization was unclear. So herein, we reviewed the relevant factors based on recent advancements to build a highly efficient and stable hyperfluorescence system. The factors include an energy transfer mechanism based on spectral overlapping, TSH requirements, electroluminescence study based on exciplex and polarity system, shielding effect, DET suppression, and FD orientation. Furthermore, the outlook and future positives with new directions were discussed to build high-performance OLEDs.
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Affiliation(s)
| | | | | | - Jang Hyuk Kwon
- *Correspondence: Kenkera Rayappa Naveen, ; Jang Hyuk Kwon,
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137
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Phuoc NL, Brannan AC, Romanov AS, Linnolahti M. Tailoring Carbene-Metal-Amides for Thermally Activated Delayed Fluorescence: A Computationally Guided Study on the Effect of Cyclic (Alkyl)(amino)carbenes. Molecules 2023; 28:molecules28114398. [PMID: 37298874 DOI: 10.3390/molecules28114398] [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: 05/01/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023] Open
Abstract
Gold-centered carbene-metal-amides (CMAs) containing cyclic (alkyl)(amino)carbenes (CAACs) are promising emitters for thermally activated delayed fluorescence (TADF). Aiming at the design and optimization of new TADF emitters, we report a density functional theory study of over 60 CMAs with various CAAC ligands, systematically evaluating computed parameters in relation to photoluminescence properties. The CMA structures were primarily selected based on experimental synthesis prospects. We demonstrate that TADF efficiency of the CMA materials originates from a compromise between oscillator strength coefficients and exchange energy (ΔEST). The latter is governed by the overlap of HOMO and LUMO orbitals, where HOMO is localized on the amide and LUMO over the Au-carbene bond. The S0 ground and excited T1 states of the CMAs adopt approximately coplanar geometry of carbene and amide ligands, but rotate perpendicular in the excited S1 states, resulting in degeneracy or near-degeneracy of S1 and T1, accompanied by a decrease in the S1-S0 oscillator strength from its maximum at coplanar geometries to near zero at rotated geometries. Based on the computations, promising new TADF emitters are proposed and synthesized. Bright CMA complex (Et2CAAC)Au(carbazolide) is obtained and fully characterized in order to demonstrate that excellent stability and high radiative rates up to 106 s-1 can be obtained for the gold-CMA complexes with small CAAC-carbene ligands.
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Affiliation(s)
- Nguyen Le Phuoc
- Department of Chemistry, University of Eastern Finland, FI-80101 Joensuu, Finland
| | - Alexander C Brannan
- Department of Chemistry, University of Manchester, Oxford Rd., Manchester M13 9PL, UK
| | - Alexander S Romanov
- Department of Chemistry, University of Manchester, Oxford Rd., Manchester M13 9PL, UK
| | - Mikko Linnolahti
- Department of Chemistry, University of Eastern Finland, FI-80101 Joensuu, Finland
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138
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Zhang Y, Huang Z, Yang Y, Liu J, Tian Y, Bin Z, You J. Molecular engineering of locked alkyl aryl carbonyl-based thermally activated delayed fluorescence emitters via a cascade C-H activation process. Chem Sci 2023; 14:5125-5131. [PMID: 37206408 PMCID: PMC10189883 DOI: 10.1039/d3sc01298k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 04/18/2023] [Indexed: 05/21/2023] Open
Abstract
While diaryl ketones have drawn tremendous attention for the assembly of carbonyl-based thermally activated delayed fluorescence (TADF) emitters, alkyl aryl ketones are almost ignored. In this work, an efficient rhodium-catalyzed cascade C-H activation process of alkyl aryl ketones with phenylboronic acids has been developed for the concise construction of the α,α-dialkyl/aryl phenanthrone skeleton, which unlocks an opportunity to rapidly assemble a library of structurally nontraditional locked alkyl aryl carbonyl-based TADF emitters. Molecular engineering indicates that the introduction of a donor on the A ring enables the emitters to exhibit better TADF properties than those with a donor on the B ring. 2,6-Bis(9,9-dimethylacridin-10(9H)-yl)-10,10-diphenylphenanthren-9(10H)-one (2,6-DMAC-DPPO) with two donors on the A and B rings gives rise to superior organic light-emitting diode (OLED) performance with maximum external quantum efficiency and power efficiency as high as 32.6% and 123.5 lm W-1, respectively.
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Affiliation(s)
- Yunxi Zhang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 People's Republic of China
| | - Zhengmei Huang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 People's Republic of China
| | - Yudong Yang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 People's Republic of China
| | - Jiahui Liu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 People's Republic of China
| | - Yang Tian
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 People's Republic of China
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 People's Republic of China
| | - Jingsong You
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University 29 Wangjiang Road Chengdu 610064 People's Republic of China
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139
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Adranno B, Paterlini V, Smetana V, Bousrez G, Ovchinnikov A, Mudring AV. Enhanced stability and complex phase behaviour of organic-inorganic green-emitting ionic manganese halides. Dalton Trans 2023; 52:6515-6526. [PMID: 37186240 DOI: 10.1039/d2dt03817j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Light-emitting materials based on earth-abundant metals, such as manganese hold great promise as emitters for organic lighting devices. In order to apply such emitter materials and, in particular, to overcome the problem of self-quenching due to cross-relaxation, we investigated a series of tetrabromidomanganate ([MnBr4]2-) salts with bulky tetraalkylphosphonium counter cations [Pnnn]+, namely [Pnnnn]2[MnBr4] (n = 4 (1), 6 (2) and 8 (3)), which can be obtained by a straightforward reaction of the respective phosphonium bromide and MnBr2. Variation of the cation size allows control of the properties of the resulting ionic materials. 1 and 3 qualify as ionic liquids (ILs), where 1 features a melting point of 68 °C, and 3 is liquid at room temperature and even at very low temperatures. Furthermore, 1 and 2 show the formation of higher-ordered thermotropic mesophases. For 1 a transition to a thermodynamically metastable smectic liquid crystalline phase can be observed at room temperature upon reheating from the metastable glassy state; 2 appears to form a plastic crystalline phase at ∼63 °C, which persists up to the melting point of 235 °C. The photoemission is greatly affected by phase behaviour and ion dynamics. A photoluminescence quantum yield of 61% could be achieved, by balancing the increase in Mn2+-Mn2+ separation and reducing self-quenching through increasingly large organic cations which leads to adverse increased vibrational quenching. Compared to analogous ammonium compounds, which have been promoted as ̈inorganic hybrid perovskites̈, the phosphonium salts show superior performance, with respect to photoluminescent quantum yield and thermal and air/humidity stability. As the presented compounds are not sensitive to the atmosphere, in particular moisture, and show strong visible electroluminescence in the green region of light, they are important emitter materials for use in organic light-emitting devices.
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Affiliation(s)
- Brando Adranno
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, SE-10691 Stockholm, Sweden.
| | - Veronica Paterlini
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, SE-10691 Stockholm, Sweden.
| | - Volodymyr Smetana
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, SE-10691 Stockholm, Sweden.
- Intelligent Advanced Materials, Department of Biological & Chemical Engineering and iNANO, Aarhus University, 8000 Aarhus C, Denmark
| | - Guillaume Bousrez
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, SE-10691 Stockholm, Sweden.
- Intelligent Advanced Materials, Department of Biological & Chemical Engineering and iNANO, Aarhus University, 8000 Aarhus C, Denmark
| | - Alexander Ovchinnikov
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, SE-10691 Stockholm, Sweden.
| | - Anja-Verena Mudring
- Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, SE-10691 Stockholm, Sweden.
- Intelligent Advanced Materials, Department of Biological & Chemical Engineering and iNANO, Aarhus University, 8000 Aarhus C, Denmark
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140
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Yuan D, Liu W, Zhu X. Efficient and air-stable n-type doping in organic semiconductors. Chem Soc Rev 2023. [PMID: 37183967 DOI: 10.1039/d2cs01027e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Chemical doping of organic semiconductors (OSCs) enables feasible tuning of carrier concentration, charge mobility, and energy levels, which is critical for the applications of OSCs in organic electronic devices. However, in comparison with p-type doping, n-type doping has lagged far behind. The achievement of efficient and air-stable n-type doping in OSCs would help to significantly improve electron transport and device performance, and endow new functionalities, which are, therefore, gaining increasing attention currently. In this review, the issue of doping efficiency and doping air stability in n-type doped OSCs was carefully addressed. We first clarified the main factors that influenced chemical doping efficiency in n-type OSCs and then explain the origin of instability in n-type doped films under ambient conditions. Doping microstructure, charge transfer, and dissociation efficiency were found to determine the overall doping efficiency, which could be precisely tuned by molecular design and post treatments. To further enhance the air stability of n-doped OSCs, design strategies such as tuning the lowest unoccupied molecular orbital (LUMO) energy level, charge delocalization, intermolecular stacking, in situ n-doping, and self-encapsulations are discussed. Moreover, the applications of n-type doping in advanced organic electronics, such as solar cells, light-emitting diodes, field-effect transistors, and thermoelectrics are being introduced. Finally, an outlook is provided on novel doping ways and material systems that are aimed at stable and efficient n-type doped OSCs.
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Affiliation(s)
- Dafei Yuan
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- College of Materials Science and Engineering, Hunan University, Changsha, Hunan, 410082, P. R. China
| | - Wuyue Liu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
| | - Xiaozhang Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
- School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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141
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Madushani B, Mamada M, Goushi K, Nguyen TB, Nakanotani H, Kaji H, Adachi C. Multiple donor-acceptor design for highly luminescent and stable thermally activated delayed fluorescence emitters. Sci Rep 2023; 13:7644. [PMID: 37169821 PMCID: PMC10175249 DOI: 10.1038/s41598-023-34623-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 05/04/2023] [Indexed: 05/13/2023] Open
Abstract
A considerable variety of donor-acceptor (D-A) combinations offers the potential for realizing highly efficient thermally activated delayed fluorescence (TADF) materials. Multiple D-A type compounds are one of the promising families of TADF materials in terms of stability as well as efficiencies. However, those emitters are always composed of carbazole-based donors despite a wide choice of moieties used in linearly linked single D-A molecules. Herein, we developed a multiple D-A type TADF compound with two distinct donor units of 9,10-dihydro-9,9-dimethylacridine (DMAC) and carbazole as the hetero-donor design. The new emitter exhibits high photoluminescence quantum yield (PLQY) in various conditions including polar media blend and high concentrations. Organic light-emitting diodes (OLEDs) showed a reasonably high external quantum efficiency (EQE). In addition, we revealed that the multiple-D-A type molecules showed better photostability than the single D-A type molecules, while the operational stability in OLEDs involves dominant other factors.
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Affiliation(s)
- Bhagya Madushani
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Masashi Mamada
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan.
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
| | - Kenichi Goushi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Thanh Ba Nguyen
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Hajime Nakanotani
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Hironori Kaji
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, 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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142
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Xiao X, Lei B, Wu D, Bin Z. "Medium-ring" strategy enables high-performance narrowband pure-blue multi-resonance emitters: boost provided by a unique perpendicular geometry. Chem Commun (Camb) 2023; 59:6556-6559. [PMID: 37162403 DOI: 10.1039/d3cc01235b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The introduction of a heptagonal tribenzo[b,d,f]azepine (TBA) donor onto BCz-BN enabled the development of a pure-blue narrowband emitter, TBA-BCz-BN, and induced a significant blue shift of emission from 483 nm to 468 nm and a decrease in the singlet-triplet energy gap from 0.17 eV to 0.14 eV. The corresponding TBA-BCz-BN-based OLED exhibited a high external quantum efficiency of 30.8%.
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Affiliation(s)
- Xin Xiao
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Bowen Lei
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Di Wu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
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143
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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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144
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Yan J, Wang SF, Hsu CH, Shi EHC, Wu CC, Chou PT, Yiu SM, Chi Y, You C, Peng IC, Hung WY. Engineering of Cyano Functionalized Benzo[ d]imidazol-2-ylidene Ir(III) Phosphors for Blue Organic Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2023; 15:21333-21343. [PMID: 37074734 DOI: 10.1021/acsami.3c02671] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In this study, we designed and synthesized three series of blue emitting homoleptic iridium(III) phosphors bearing 4-cyano-3-methyl-1-phenyl-6-(trifluoromethyl)-benzo[d]imidazol-2-ylidene (mfcp), 5-cyano-1-methyl-3-phenyl-6-(trifluoromethyl)-benzo[d]imidazol-2-ylidene (ofcp), and 1-(3-(tert-butyl)phenyl)-6-cyano-3-methyl-4-(trifluoromethyl)-benzo[d]imidazol-2-ylidene (5-mfcp) cyclometalates, respectively. These iridium complexes exhibit intense phosphorescence in the high energy region of 435-513 nm in the solution state at RT, to which the relatively large T1 → S0 transition dipole moment is beneficial for serving as a pure emitter and an energy donor to the multiresonance thermally activated delayed fluorescence (MR-TADF) terminal emitters via Förster resonance energy transfer (FRET). The resulting OLEDs achieved true blue, narrow bandwidth EL with a max EQE of 16-19% and great suppression of efficiency roll-off with ν-DABNA and t-DABNA. We obtained the FRET efficiency up to 85% using titled Ir(III) phosphors f-Ir(mfcp)3 and f-Ir(5-mfcp)3 to achieve true blue narrow bandwidth emission. Importantly, we also provide analysis on the kinetic parameters involved in the energy transfer processes and, accordingly, propose feasible ways to improve the efficiency roll-off caused by the shortened radiative lifetime of hyperphosphorescence.
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Affiliation(s)
- Jie Yan
- Department of Materials Sciences and Engineering, Department of Chemistry, Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon Tong 999077 Hong Kong SAR, China
| | - Sheng Fu Wang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chao-Hsien Hsu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Emily Hsue-Chi Shi
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chi-Chi Wu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Shek-Man Yiu
- Department of Materials Sciences and Engineering, Department of Chemistry, Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon Tong 999077 Hong Kong SAR, China
| | - Yun Chi
- Department of Materials Sciences and Engineering, Department of Chemistry, Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon Tong 999077 Hong Kong SAR, China
| | - Caifa You
- Department of Materials Sciences and Engineering, Department of Chemistry, Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon Tong 999077 Hong Kong SAR, China
| | - I-Che Peng
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Wen-Yi Hung
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 20224, Taiwan
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145
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Chen D, Tenopala‐Carmona F, Knöller JA, Mischok A, Hall D, Madayanad Suresh S, Matulaitis T, Olivier Y, Nacke P, Gießelmann F, Laschat S, Gather MC, Zysman‐Colman E. Mesogenic Groups Control the Emitter Orientation in Multi-Resonance TADF Emitter Films. Angew Chem Int Ed Engl 2023; 62:e202218911. [PMID: 36760211 PMCID: PMC10947294 DOI: 10.1002/anie.202218911] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023]
Abstract
The use of thermally activated delayed fluorescence (TADF) emitters and emitters that show preferential horizontal orientation of their transition dipole moment (TDM) are two emerging strategies to enhance the efficiency of OLEDs. We present the first example of a liquid crystalline multi-resonance TADF (MR-TADF) emitter, DiKTa-LC. The compound possesses a nematic liquid crystalline phase between 80 °C and 110 °C. Importantly, the TDM of the spin-coated film shows preferential horizontal orientation, with an anisotropy factor, a, of 0.28, which is preserved in doped poly(vinylcarbazole) films. Green-emitting (λEL =492 nm) solution-processed OLEDs based on DiKTa-LC showed an EQEmax of 13.6 %. We thus demonstrate for the first time how self-assembly of a liquid crystalline TADF emitter can lead to the so-far elusive control of the orientation of the transition dipole in solution-processed films, which will be of relevance for high-performance solution-processed OLEDs.
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Affiliation(s)
- Dongyang Chen
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Francisco Tenopala‐Carmona
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - Julius A. Knöller
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Andreas Mischok
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - David Hall
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
- Laboratory for Chemistry of Novel MaterialsUniversity of MonsMonsBelgium
| | - Subeesh Madayanad Suresh
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Tomas Matulaitis
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Yoann Olivier
- Laboratory for Computational Modeling of Functional MaterialsNamur Institute of Structured MatterUniversité de NamurRue de Bruxelles 615000NamurBelgium
| | - Pierre Nacke
- Institut für Physikalische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Frank Gießelmann
- Institut für Physikalische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Sabine Laschat
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Malte C. Gather
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - Eli Zysman‐Colman
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
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146
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Naveen KR, Palanisamy P, Chae MY, Kwon JH. Multiresonant TADF materials: triggering the reverse intersystem crossing to alleviate the efficiency roll-off in OLEDs. Chem Commun (Camb) 2023; 59:3685-3702. [PMID: 36857643 DOI: 10.1039/d2cc06802h] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
The hunt for narrow-band emissive pure organic molecules capable of harvesting both singlet and triplet excitons for light emission has garnered enormous attention to promote the advancement of organic light-emitting diodes (OLEDs). Over the past decade, organic thermally activated delayed fluorescence (TADF) materials based on donor (D)/acceptor (A) combinations have been researched for OLEDs in wide color gamut (RGB) regions. However, due to the strong intramolecular charge-transfer (CT) state, they exhibit broad emission with full-width-at-half maximum (FWHM) > 70 nm, which deviates from being detrimental to achieving high color purity for future high-end display electronics such as high-definition TVs and ultra-high-definition TVs (UHDTVs). Recently, the new development in the sub-class of TADF emitters called multi-resonant TADF (MR-TADF) emitters based on boron/nitrogen atoms has attracted much interest in ultra-high definition OLEDs. Consequently, MR-TADF emitters are appeal to their potentiality as promising candidates in fabricating the high-efficient OLEDs due to their numerous advantages such as high photoluminescence quantum yield (PLQY), unprecedented color purity, and narrow bandwidth (FWHM ≤ 40 nm). Until now many MR-TADF materials have been developed for ultra-gamut regions with different design concepts. However, most MR-TADF-OLEDs showed ruthless external quantum efficiency (EQE) roll-off characteristics at high brightness. Such EQE roll-off characteristics were derived mainly from the low reverse intersystem crossing (kRISC) rate values. This feature article primarily focuses on the design strategies to improve kRISC for MR-TADF materials with some supportive strategies including extending charge delocalization, heavy atom introduction, multi-donor/acceptor utilization, and a hyperfluorescence system approach. Furthermore, the outlook and prospects for future developments in MR-TADF skeletons are described.
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Affiliation(s)
- Kenkera Rayappa Naveen
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Paramasivam Palanisamy
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Mi Young Chae
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| | - Jang Hyuk Kwon
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
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147
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Primrose WL, Mayder DM, Hojo R, Hudson ZM. Dibenzodipyridophenazines with Dendritic Electron Donors Exhibiting Deep-Red Emission and Thermally Activated Delayed Fluorescence. J Org Chem 2023; 88:4224-4233. [PMID: 36920272 DOI: 10.1021/acs.joc.2c02774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
The development of deep-red thermally activated delayed fluorescence (TADF) emitters is important for applications such as organic light-emitting diodes (OLEDs) and biological imaging. Design strategies for red-shifting emission include synthesizing rigid acceptor cores to limit nonradiative decay and employing strong electron-donating groups. In this work, three novel luminescent donor-acceptor compounds based on the dibenzo[a,c]dipyrido[3,2-h:20-30-j]-phenazine-12-yl (BPPZ) acceptor were prepared using dendritic carbazole-based donors 3,3″,6,6″-tetramethoxy-9'H-9,3':6',9″-tercarbazole (TMTC), N3,N3,N6,N6-tetra-p-tolyl-9H-carbazole-3,6-diamine (TTAC), and N3,N3,N6,N6-tetrakis(4-methoxyphenyl)-9H-carbazole-3,6-diamine (TMAC). Here, dimethoxycarbazole, ditolylamine, and bis(4-methoxyphenyl)amine were introduced at the 3,6-positions of carbazole to increase the strength of these donors and induce long-wavelength emission. Substituent effects were investigated with experiments and theoretical calculations. The emission maxima of these materials in toluene were found to be 562, 658, and 680 nm for BPPZ-2TMTC, BPPZ-2TTAC, and BPPZ-2TMAC, respectively, highlighting the exceptional strength of the TMAC donor, which pushes the emission into the deep-red region of the visible spectrum as well as into the biological transparency window (650-1350 nm). Long-lived emission lifetimes were observed in each emitter due to TADF in BPPZ-2TMC and BPPZ-2TTAC, as well as room-temperature phosphorescence in BPPZ-2TMAC. Overall, this work showcases deep-red emissive dendritic donor-acceptor materials which have potential as bioimaging agents with emission in the biological transparency window.
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Affiliation(s)
- William L Primrose
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Don M Mayder
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Ryoga Hojo
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Zachary M Hudson
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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148
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Dalmau D, Urriolabeitia EP. Luminescence and Palladium: The Odd Couple. Molecules 2023; 28:molecules28062663. [PMID: 36985639 PMCID: PMC10054068 DOI: 10.3390/molecules28062663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/06/2023] [Accepted: 03/08/2023] [Indexed: 03/18/2023] Open
Abstract
The synthesis, photophysical properties, and applications of highly fluorescent and phosphorescent palladium complexes are reviewed, covering the period 2018–2022. Despite the fact that the Pd atom appears closely related with an efficient quenching of the fluorescence of different molecules, different synthetic strategies have been recently optimized to achieve the preservation and even the amplification of the luminescent properties of several fluorophores after Pd incorporation. Beyond classical methodologies such as orthopalladation or the use of highly emissive ligands as porphyrins and related systems (for instance, biladiene), new concepts such as AIE (Aggregation Induced Emission) in metallacages or in coordination-driven supramolecular compounds (CDS) by restriction of intramolecular motions (RIM), or complexes showing TADF (Thermally Activated Delayed Fluorescence), are here described and analysed. Without pretending to be comprehensive, selected examples of applications in areas such as the fabrication of lighting devices, biological markers, photodynamic therapy, or oxygen sensing are also here reported.
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149
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Lei B, Huang Z, Li S, Liu J, Bin Z, You J. Medium-Ring Strategy Enables Multiple Resonance Emitters with Twisted Geometry and Fast Spin-Flip to Suppress Efficiency Roll-Off. Angew Chem Int Ed Engl 2023; 62:e202218405. [PMID: 36717355 DOI: 10.1002/anie.202218405] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/19/2023] [Accepted: 01/30/2023] [Indexed: 02/01/2023]
Abstract
Suppressing aggregation-caused quenching (ACQ) effect and reducing device efficiency roll-off are both crucial yet challenging for multi-resonance (MR) emitters. Herein, we put forward a medium-ring strategy to design efficient MR emitters that feature heptagonal tribenzo[b,d,f]azepine (TBA) donors. The highly twisted conformation enlarges the intermolecular distances between the MR-emitting cores, and thus suppresses ACQ effect. Meanwhile, the introduction of heptagonal donors enhances spin-orbital coupling, so as to accelerate reverse intersystem crossing (RISC) process. This medium-ring strategy gives rise to the first example of blue MR emitter that simultaneously possesses radiative decay rate as fast as 108 s-1 and RISC rate as fast as 106 s-1 . Accordingly, DTBA-B2N3 enables to assemble high-performance blue organic light-emitting diodes (OLEDs) with maximum external quantum efficiency (EQEmax ) of 30.9 % and alleviated efficiency roll-off (EQE1000 : 20.5 %).
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Affiliation(s)
- Bowen Lei
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Zhenmei Huang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Songtao Li
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Junjie Liu
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
| | - Jingsong You
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu, 610064, P. R. China
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Abstract
With the advent of a new era of smart-technology, the demand for more economic optoelectronic materials that do not compromise with efficiency is gradually on the rise. Organic semiconductors provide greener alternatives to the conventional inorganic ones, but encounter the challenge of balancing charge carrier mobility with processability in devices. Discotic liquid crystals (DLCs), a class of self-assembling soft organic materials, possess the perfect degree of order and dynamics to address this challenge. Providing unidimensional charge carrier pathways through their nanoscale columnar architecture, DLCs can behave as efficient charge transport systems across a wide range of optoelectronic devices. Moreover, DLCs are solution-processable, thus reducing the fabrication cost. In this article, we have discussed the approaches towards developing DLCs as semiconductors, focusing on their molecular design concepts, supramolecular structures and electronic properties in the context of their charge carrier mobilities.
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Affiliation(s)
- Ritobrata De
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector-81, SAS Nagar, Knowledge City, Manauli-140306, India.
| | - Santanu Kumar Pal
- Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Sector-81, SAS Nagar, Knowledge City, Manauli-140306, India.
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