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Sun Y, Xu Z, Wang Y, Niu Z, Xu Z, Li S, Wang W, Liu Y. Enhanced performance of thermally activated delayed fluorescent light emitting diodes by optimized host polarity. OPTICS EXPRESS 2024; 32:17942-17952. [PMID: 38858962 DOI: 10.1364/oe.522090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 04/17/2024] [Indexed: 06/12/2024]
Abstract
The interaction between the intrinsic polarity of the host material and the TADF guest material affects charge injection and transport, exciton formation, charge recombination, and emission mechanisms. Therefore, understanding and controlling the interaction between the intrinsic polarity of the host material and the TADF guest material is very important to realize efficient TADF-OLED devices. This study investigated the molecular interaction between different polar host materials and a thermally activated delayed fluorescence material (DMAc-PPM). It has been found that interaction between the host and guest (π-π stacking interaction, multiple CH/π contacts) greatly influence the molecular transition dipole moment orientation of the guest. And the OLED devices based on the strong polar host (DPEPO) exhibited the highest EQEmax and lowest luminescence intensity, while devices using the weaker polar hosts mCP and CBP achieved higher luminance and lower EQEmax. Then, the strong polar host DPEPO was mixed with the weaker polar hosts CBP and mCP, respectively. The devices prepared based on the mixed-host DPEPO: mCP showed a 2.2 times improvement in EQEmax from 6.3% to 20.1% compared to the single-host mCP. The devices prepared based on the mixed-host DPEPO: CBP showed a 3.1 times improvement in luminance intensity from 1023 cd/m2 to 4236 cd/m2 compared to the single host of DPEPO. This suggests that optimizing the polarity of host materials has the potential to enhance the performance of solution prepared OLED devices.
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Jang HJ, Lee JY. Key Factor Managing the Horizontal Emitting Dipole Orientation of a Thermally Activated Delayed Fluorescence Emitter in a Mixed Host. ACS APPLIED MATERIALS & INTERFACES 2022; 14:54907-54913. [PMID: 36453592 DOI: 10.1021/acsami.2c20210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Horizontal emitting dipole orientation (EDO) of thermally activated delayed fluorescence (TADF) molecules in a mixed host was studied by altering the host materials and host composition of the mixed host to gain insight into the important parameter of the host governing the EDO of TADF emitters. Five different host materials were combined with 1,3-bis(carbazol-9-yl)benzene (mCP), demonstrating that the host-dopant interaction is crucial to the absolute value of the horizontal EDO of the TADF emitters, whereas the glass transition temperature (Tg) is the important parameter determining the EDO dependence upon host composition. The mixed host of mCP with a high Tg host maintained high horizontal EDO in the mCP poor host composition, while that of mCP with a low Tg host showed average horizontal EDO of two hosts. Therefore, the combination of a high Tg n-type host enabling a strong host-dopant interaction with the p-type host with the usage of the n-type-host-rich composition is effective to achieve high horizontal EDO in the mixed-host-based TADF emitting layer.
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Affiliation(s)
- Ho Jin Jang
- School of Chemical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi 16419, Korea
| | - Jun Yeob Lee
- School of Chemical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi 16419, Korea
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Wang S, Zhu Z, Shi C, Li S, Liu Y, Zhang D, Wang Q, Zhao L, Wang W, Dong X. Enhanced performance of solution-processed OLEDs by altering the molecular transition dipole moment orientation of emission layers. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2022; 271:120933. [PMID: 35104742 DOI: 10.1016/j.saa.2022.120933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 12/17/2021] [Accepted: 01/17/2022] [Indexed: 06/14/2023]
Abstract
Transition dipole moment orientation is one of the crucial factors, which can enhance the performance of organic light-emitting diodes (OLEDs). In this work, the transition dipole moment orientation of the host-guest emission layers (EMLs) prepared by solution method annealed at different temperatures were systematically studied by analyzing the angle-dependent PL spectrum. When the EMLs of 2DPAc-MPM (20 wt%): DPEPO was annealed at the temperature of 115 °C, the photoluminescence quantum yield (PLQY) was enhanced to 78%±3.5%, and the vertical dipole ratio was reduced to 0.34. The lower vertical orientation of transition dipoles is conducted to improve the electron and hole mobility, which was testified by the hole and electron only devices. The lower vertical dipole ratio, higher PLQY and carrier mobility together enhanced the performance of solution processed OLEDs.
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Affiliation(s)
- Shuai Wang
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China
| | - Zhongchang Zhu
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China
| | - Chaojun Shi
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China
| | - Shuhong Li
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China.
| | - Yunlong Liu
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China
| | - Dong Zhang
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China
| | - Qingru Wang
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China
| | - Ling Zhao
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China
| | - Wenjun Wang
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China.
| | - Xiaochen Dong
- School of Physical Science and Information Technology, Liaocheng University, Shandong 252059, China; Shandong Provincial Key Laboratory of Optical Communication Science and Technology, Shandong 252059, China; Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM), School of Physical and Mathematical Sciences, Nanjing Tech University (NanjingTech), Nanjing 211800, China
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Otero-Martínez C, Ye J, Sung J, Pastoriza-Santos I, Pérez-Juste J, Xia Z, Rao A, Hoye RLZ, Polavarapu L. Colloidal Metal-Halide Perovskite Nanoplatelets: Thickness-Controlled Synthesis, Properties, and Application in Light-Emitting Diodes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2107105. [PMID: 34775643 DOI: 10.1002/adma.202107105] [Citation(s) in RCA: 47] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 11/09/2021] [Indexed: 05/20/2023]
Abstract
Colloidal metal-halide perovskite nanocrystals (MHP NCs) are gaining significant attention for a wide range of optoelectronics applications owing to their exciting properties, such as defect tolerance, near-unity photoluminescence quantum yield, and tunable emission across the entire visible wavelength range. Although the optical properties of MHP NCs are easily tunable through their halide composition, they suffer from light-induced halide phase segregation that limits their use in devices. However, MHPs can be synthesized in the form of colloidal nanoplatelets (NPls) with monolayer (ML)-level thickness control, exhibiting strong quantum confinement effects, and thus enabling tunable emission across the entire visible wavelength range by controlling the thickness of bromide or iodide-based lead-halide perovskite NPls. In addition, the NPls exhibit narrow emission peaks, have high exciton binding energies, and a higher fraction of radiative recombination compared to their bulk counterparts, making them ideal candidates for applications in light-emitting diodes (LEDs). This review discusses the state-of-the-art in colloidal MHP NPls: synthetic routes, thickness-controlled synthesis of both organic-inorganic hybrid and all-inorganic MHP NPls, their linear and nonlinear optical properties (including charge-carrier dynamics), and their performance in LEDs. Furthermore, the challenges associated with their thickness-controlled synthesis, environmental and thermal stability, and their application in making efficient LEDs are discussed.
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Affiliation(s)
- Clara Otero-Martínez
- CINBIO, Universidade de Vigo, Materials Chemistry and Physics Group, Department of Physical Chemistry, Campus Universitario Lagoas, Marcosende, Vigo, 36310, Spain
- CINBIO, Universidade de Vigo, Deparment of Physical Chemistry, Campus Universitario Lagoas, Marcosende, Vigo, 36310, Spain
- Galicia Sur Health Research Institute (IIS Galicia Sur). SERGAS-UVIGO, Vigo, 36310, Spain
| | - Junzhi Ye
- Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Jooyoung Sung
- Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge, CB3 0HE, UK
- Department of Emerging Materials Science, DGIST, Daegu, 42988, Republic of Korea
| | - Isabel Pastoriza-Santos
- CINBIO, Universidade de Vigo, Deparment of Physical Chemistry, Campus Universitario Lagoas, Marcosende, Vigo, 36310, Spain
- Galicia Sur Health Research Institute (IIS Galicia Sur). SERGAS-UVIGO, Vigo, 36310, Spain
| | - Jorge Pérez-Juste
- CINBIO, Universidade de Vigo, Deparment of Physical Chemistry, Campus Universitario Lagoas, Marcosende, Vigo, 36310, Spain
- Galicia Sur Health Research Institute (IIS Galicia Sur). SERGAS-UVIGO, Vigo, 36310, Spain
| | - Zhiguo Xia
- School of Physics and Optoelectronics, State Key Laboratory of Luminescent Materials and Devices and Guangdong Provincial Key Laboratory of Fiber Laser Materials and Applied Techniques, South China University of Technology, Guangzhou, Guangdong, 510641, P. R. China
| | - Akshay Rao
- Cavendish Laboratory, University of Cambridge, 19 JJ Thomson Avenue, Cambridge, CB3 0HE, UK
| | - Robert L Z Hoye
- Department of Materials, Imperial College London, Exhibition Road, London, SW7 2AZ, UK
| | - Lakshminarayana Polavarapu
- CINBIO, Universidade de Vigo, Materials Chemistry and Physics Group, Department of Physical Chemistry, Campus Universitario Lagoas, Marcosende, Vigo, 36310, Spain
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Li LK, Au-Yeung CC, Tang MC, Lai SL, Cheung WL, Ng M, Chan MY, Yam VWW. Design and synthesis of yellow- to red-emitting gold(III) complexes containing isomeric thienopyridine and thienoquinoline moieties and their applications in operationally stable organic light-emitting devices. MATERIALS HORIZONS 2022; 9:281-293. [PMID: 34473166 DOI: 10.1039/d1mh00821h] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A new class of yellow- to red-emitting carbazolylgold(III) complexes containing isomeric thienopyridine or thienoquinoline moieties in the cyclometalating ligand has been designed and synthesized, which showed high photoluminescence quantum yields of over 80% in solid-state thin films. The isomeric effect and extended π-conjugation of the N-heterocycles have been found to remarkably perturb the photophysical, electrochemical and electroluminescence properties of the gold(III) complexes. In particular, the operational lifetimes of organic light-emitting devices based on that incorporated with thieno[2,3-c]pyridine are almost three orders of magnitude longer than that incorporated with thieno[3,2-c]pyridine. This has led to long device operational stability with a LT70 value of up to 63 200 h at a luminance of 100 cd m-2 and a long half-lifetime of 206 800 h, as well as maximum external quantum efficiencies of up to 8.6% and 14.5% in the solution-processed and vacuum-deposited devices, respectively. This work provides insights into the development of robust and highly luminescent gold(III) complexes and the identification of stable molecular motifs for designing efficient emitters.
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Affiliation(s)
- Lok-Kwan Li
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Cathay Chai Au-Yeung
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Man-Chung Tang
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Shiu-Lun Lai
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Wai-Lung Cheung
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Maggie Ng
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Mei-Yee Chan
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
| | - Vivian Wing-Wah Yam
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong.
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Tenopala-Carmona F, Lee OS, Crovini E, Neferu AM, Murawski C, Olivier Y, Zysman-Colman E, Gather MC. Identification of the Key Parameters for Horizontal Transition Dipole Orientation in Fluorescent and TADF Organic Light-Emitting Diodes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2100677. [PMID: 34338351 DOI: 10.1002/adma.202100677] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 04/21/2021] [Indexed: 06/13/2023]
Abstract
In organic light-emitting diodes (OLEDs), horizontal orientation of the emissive transition dipole moment (TDM) can improve light outcoupling efficiency by up to 50% relative to random orientation. Therefore, there have been extensive efforts to identify drivers of horizontal orientation. The aspect ratio of the emitter molecule and the glass-transition temperature (Tg ) of the films are currently regarded as particularly important. However, there remains a paucity of systematic studies that establish the extent to which these and other parameters control orientation in the wide range of emitter systems relevant for state-of-the-art OLEDs. Here, recent work on molecular orientation of fluorescent and thermally activated delayed fluorescent emitters in vacuum-processed OLEDs is reviewed. Additionally, to identify parameters linked to TDM orientation, a meta-analysis of 203 published emitter systems is conducted and combined with density-functional theory calculations. Molecular weight (MW) and linearity are identified as key parameters in neat systems. In host-guest systems with low-MW emitters, orientation is mostly influenced by the host Tg , whereas the length and MW of the emitter become more relevant for systems involving higher-MW emitters. To close, a perspective of where the field must advance to establish a comprehensive model of molecular orientation is given.
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Affiliation(s)
- Francisco Tenopala-Carmona
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
- Humboldt Centre for Nano- and Biophotonics, Department of Chemistry, University of Cologne, Greinstr. 4-6, 50939, Köln, Germany
| | - Oliver S Lee
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Ettore Crovini
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Ana M Neferu
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Caroline Murawski
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
| | - Yoann Olivier
- Unité de Chimie Physique Théorique et Structurale & Laboratoire de Physique du Solide, Namur Institute of Structured Matter, Université de Namur, Rue de Bruxelles, 61, Namur, 5000, Belgium
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Malte C Gather
- Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, St Andrews, KY16 9SS, UK
- Humboldt Centre for Nano- and Biophotonics, Department of Chemistry, University of Cologne, Greinstr. 4-6, 50939, Köln, Germany
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Hinojosa ARC, de Souza SP, Alves TV, dos Santos ITO, Silva EO, Gonçalves IL, Merlo AA, Junkes CF, Bechtold IH, Vieira AA. Shining rings: The effect of the rigid core and benzazole heterocycles on the properties of luminescent calamitic liquid crystals. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116614] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Balijapalli U, Lee Y, Karunathilaka BSB, Tumen‐Ulzii G, Auffray M, Tsuchiya Y, Nakanotani H, Adachi C. Tetrabenzo[
a
,
c
]phenazine Backbone for Highly Efficient Orange–Red Thermally Activated Delayed Fluorescence with Completely Horizontal Molecular Orientation. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202106570] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Umamahesh Balijapalli
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
| | - Yi‐Ting Lee
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
| | - Buddhika S. B. Karunathilaka
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
| | - Ganbaatar Tumen‐Ulzii
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
| | - Morgan Auffray
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
| | - Youichi Tsuchiya
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
| | - Hajime Nakanotani
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
- International Institute for Carbon Neutral Energy Research, (WPI-I2CNER) Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
- International Institute for Carbon Neutral Energy Research, (WPI-I2CNER) Kyushu University 744 Motooka, Nishi Fukuoka 819-0395 Japan
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Balijapalli U, Lee YT, Karunathilaka BSB, Tumen-Ulzii G, Auffray M, Tsuchiya Y, Nakanotani H, Adachi C. Tetrabenzo[a,c]phenazine Backbone for Highly Efficient Orange-Red Thermally Activated Delayed Fluorescence with Completely Horizontal Molecular Orientation. Angew Chem Int Ed Engl 2021; 60:19364-19373. [PMID: 34155775 DOI: 10.1002/anie.202106570] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Indexed: 11/09/2022]
Abstract
Three thermally activated delayed fluorescence (TADF) molecules, namely PQ1, PQ2, and PQ3, are composed of electron-accepting (A) tetrabenzo[a,c]phenazine (TBPZ) and electron-donating (D) phenoxazine (PXZ) units are designed and characterized. The combined effects of planar acceptor manipulation and high steric hindrance between D and A units endow high molecular rigidity that suppresses nonradiative decay of the excitons with improved photoluminescence quantum yields (PLQYs). Particularly, the well-aligned excited states involving a singlet and a triplet charge-transfer excited states and a localized excited triplet state in PQ3 enhances the reverse intersystem crossing rate constant (kRISC ) with a short delay lifetime (τd ). The orange-red OLED based on PQ3 displays a maximum external EL quantum efficiency (EQE) of 27.4 % with a well-suppressed EL efficiency roll-off owing to a completely horizontal orientation of the transition dipole moment in the film state.
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Affiliation(s)
- Umamahesh Balijapalli
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Yi-Ting Lee
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Buddhika S B Karunathilaka
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Ganbaatar Tumen-Ulzii
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Morgan Auffray
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Youichi Tsuchiya
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Hajime Nakanotani
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan.,International Institute for Carbon Neutral Energy Research, (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan.,International Institute for Carbon Neutral Energy Research, (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi, Fukuoka, 819-0395, Japan
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Vieira AA, Farias G, Costa WC, Eccher J, Bechtold IH, Durola F, Bock H. Nematic Triphenyltriazine Triesters and the Induction of the Columnar Mesophase by Fluorine Substitution. Chemistry 2021; 27:9003-9010. [PMID: 33871125 DOI: 10.1002/chem.202005456] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Indexed: 11/06/2022]
Abstract
Whereas their para homologs are not mesogenic, the disk-shaped triphenyltriazine meta-trialkylesters obtained via trimerization of 3-cyanobenzoic alkylester, which are configurationally more flexible, exhibit a monotropic nematic mesophase. Introduction of fluorine atoms into the alkyl chains or into the phenyl moieties leads to the appearance of an enantiotropic columnar mesophase. If fluorine is introduced both in the chains and in the phenyl moieties, only a monotropic mesophase remains. Fluorination of either the alkyl chains or the aromatic core, but not both, appears thus as a simple means of inducing or stabilizing columnar self-assembly in disk-shaped systems. As the homeotropically alignable columnar mesophase can thus be made to persist at room temperature, as energies higher than 3 eV of the first excited triplet state are computed in agreement with the value reported for the parent arene, and as they are not fluorescent themselves, these compounds are of promise as aligning host matrices for blue-emitting TADF devices with improved light outcoupling. Dilution of a columnar with a nonmesogenic homolog induces the nematic state, indicating that the nanoscopic make-up of both mesophases is closely related.
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Affiliation(s)
- André A Vieira
- Instituto de Química, Universidade Federal da Bahia, 40170-115, Salvador, BA, Brazil
| | - Giliandro Farias
- Departamento de Química, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - Wallison C Costa
- Departamento de Física, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - Juliana Eccher
- Departamento de Física, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - Ivan H Bechtold
- Departamento de Física, Universidade Federal de Santa Catarina, 88040-900, Florianópolis, SC, Brazil
| | - Fabien Durola
- Centre de Recherche Paul Pascal, CNRS & Université de Bordeaux 115 av. Schweitzer, 33600, Pessac, France
| | - Harald Bock
- Centre de Recherche Paul Pascal, CNRS & Université de Bordeaux 115 av. Schweitzer, 33600, Pessac, France
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De Nicola A, Correa A, Giunchi A, Muccioli L, D'Avino G, Kido J, Milano G. Bidimensional H‐Bond Network Promotes Structural Order and Electron Transport in BPyMPMs Molecular Semiconductor. ADVANCED THEORY AND SIMULATIONS 2021. [DOI: 10.1002/adts.202000302] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Antonio De Nicola
- Frontier Center for Organic Materials (FROM) Yamagata University 4‐3‐16 Jonan Yonezawa Yamagata 992‐8510 Japan
| | - Andrea Correa
- Dipartment of Chemistry University of Naples Federico II Complesso di Monte S. Angelo Napoli 80126 Italy
| | - Andrea Giunchi
- Department of Industrial Chemistry “Toso Montanari” University of Bologna Bologna 40136 Italy
| | - Luca Muccioli
- Department of Industrial Chemistry “Toso Montanari” University of Bologna Bologna 40136 Italy
| | - Gabriele D'Avino
- Grenoble Alpes University CNRS Grenoble INP Institut Néel 25 Rue des Martyrs Grenoble 38042 France
| | - Junji Kido
- Frontier Center for Organic Materials (FROM) Yamagata University 4‐3‐16 Jonan Yonezawa Yamagata 992‐8510 Japan
| | - Giuseppe Milano
- Frontier Center for Organic Materials (FROM) Yamagata University 4‐3‐16 Jonan Yonezawa Yamagata 992‐8510 Japan
- Department of Chemistry and Biology “Adolfo Zambelli” University of Salerno Fisciano 84084 Italy
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Tang MC, Li LK, Lai SL, Cheung WL, Ng M, Wong CY, Chan MY, Yam VWW. Design Strategy Towards Horizontally Oriented Luminescent Tetradentate-Ligand-Containing Gold(III) Systems. Angew Chem Int Ed Engl 2020; 59:21023-21031. [PMID: 32754992 DOI: 10.1002/anie.202006911] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Indexed: 11/08/2022]
Abstract
Phosphorescent dopants are promising candidates for organic light-emitting diodes (OLEDs). Although it has been established that the out-coupling efficiency and overall performances of vacuum-deposited OLEDs can be significantly improved by a horizontal orientation of the dopants, no horizontally oriented gold(III) complexes have been reported to date. Herein, a novel class of tetradentate C^C^N^N ligand-containing gold(III) complexes with a preferential horizontal orientation successfully generated through a one-pot reaction is reported. These complexes demonstrate high photoluminescence quantum yields of 70 % and a high horizontal dipole ratio of 0.87 in solid-state thin films. Green-emitting OLEDs based on these complexes operate with a maximum external quantum efficiency of 20.6 % with an estimated out-coupling efficiency of around 30 %. A promising device stability has been achieved in the vacuum-deposited OLEDs, with operational half-lifetimes of around 37 500 h at 100 cd m-2 .
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Affiliation(s)
- Man-Chung Tang
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Lok-Kwan Li
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Shiu-Lun Lai
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Wai-Lung Cheung
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Maggie Ng
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Chun-Yin Wong
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Mei-Yee Chan
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
| | - Vivian Wing-Wah Yam
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
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Tang M, Li L, Lai S, Cheung W, Ng M, Wong C, Chan M, Yam VW. Design Strategy Towards Horizontally Oriented Luminescent Tetradentate‐Ligand‐Containing Gold(III) Systems. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Man‐Chung Tang
- Institute of Molecular Functional Materials and Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Lok‐Kwan Li
- Institute of Molecular Functional Materials and Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Shiu‐Lun Lai
- Institute of Molecular Functional Materials and Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Wai‐Lung Cheung
- Institute of Molecular Functional Materials and Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Maggie Ng
- Institute of Molecular Functional Materials and Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Chun‐Yin Wong
- Institute of Molecular Functional Materials and Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Mei‐Yee Chan
- Institute of Molecular Functional Materials and Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong P. R. China
| | - Vivian Wing‐Wah Yam
- Institute of Molecular Functional Materials and Department of Chemistry The University of Hong Kong Pokfulam Road Hong Kong P. R. China
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