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Kwon NY, Kwak H, Kim HY, Park SH, Park JY, Kang MJ, Koh CW, Park S, Cho MJ, Choi DH. Effect of intramolecular energy transfer in a dual-functional molecular dyad on the performance of solution-processed TADF OLEDs. Chem Sci 2024; 15:12361-12368. [PMID: 39118616 PMCID: PMC11304526 DOI: 10.1039/d4sc02357a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 07/04/2024] [Indexed: 08/10/2024] Open
Abstract
This paper introduces the design concept of a dual-functional molecular dyad tailored specifically for solution-processable organic light-emitting diodes (OLEDs). Cy-tmCPBN, characterized by an asymmetric molecular dyad structure, integrates a host unit (tmCP) and a multiple-resonance (MR) emitter (CzBN) via a non-conjugated cyclohexane linker. Cy-tmCPBN exhibited efficient intramolecular energy transfers (EnTs) from tmCP to the CzBN unit, as confirmed by time-resolved fluorescence experiments. The fluorescence lifetime of the tmCP unit was approximately three times shorter in a highly diluted solution of Cy-tmCPBN than in a mixed solution of Cy-tmCP and Cy-CzBN. In addition, Cy-tmCPBN exhibited excellent solubility and film-forming ability, making it suitable for solution processing. Notably, OLEDs utilizing Cy-tmCPBN achieved over twice the brightness and improved external quantum efficiency of 12.3% compared to OLEDs using Cy-CzBN with the same concentration of CzBN in the emitting layer. The improved OLED performance can be explained by the increased EnT efficiency from Cy-tmCP to Cy-tmCPBN and the intramolecular EnT within Cy-tmCPBN. In our dual-functional dyad, incorporating both host and emitter units in an asymmetric molecular dyad structure, we induced a positive synergy effect with the host moiety, enhancing OLED performance through intramolecular EnT.
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Affiliation(s)
- Na Yeon Kwon
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Haeun Kwak
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Ha Yeon Kim
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Su Hong Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Jin Young Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Min Ji Kang
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Chang Woo Koh
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Sungnam Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Sciences, Korea University 145 Anam-ro, Seongbuk-gu Seoul 02841 Republic of Korea
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2
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Sugiyama R, Okada R, Noda T, Meguro N, Yoshida N, Hoshi K, Ohta H, Hayashi M, Sasabe H, Kido J. Highly Efficient Blue Fluorescent Organic Light-Emitting Devices Based on λ 5-Phosphinine Derivatives. Chemistry 2024; 30:e202304328. [PMID: 38332328 DOI: 10.1002/chem.202304328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/10/2024]
Abstract
Although λ5-phosphinine derivatives are known as a promising class of blue fluorescent emitters, those photoluminescent quantum yield (PLQY) values have been reached up to 92 %, however, only a few examples have been explored as an emitter for blue organic light-emitting device (OLED), and the external quantum efficiency (EQE) has been below 2.4 % so far. In this study, we newly developed two types of blue λ5-phosphinine derivatives namely CN-COCF3 and CO2Me-CHO, and investigated the photophysical properties in the solid states. The photophysical analyses in solid state films suggested that the strong electron-accepting nature of these λ5-phosphinine derivatives caused the inferior PLQY values, and the exciplex formation with the host and neighboring materials should be avoided to improve the device efficiency. By choosing suitable host and neighboring materials with deep ionization potentials, we successfully realized efficient blue fluorescent OLEDs with EQE of over 4 % and CIE (0.14, 0.18). This is among the best in λ5-phosphinine-based blue OLEDs so far.
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Affiliation(s)
- Ryo Sugiyama
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Riku Okada
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 790-8577, Matsuyama, Japan
| | - Taito Noda
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Naoki Meguro
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Naoto Yoshida
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Keigo Hoshi
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Hidetoshi Ohta
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 790-8577, Matsuyama, Japan
| | - Minoru Hayashi
- Department of Applied Chemistry, Graduate School of Science and Engineering, Ehime University, 790-8577, Matsuyama, Japan
| | - Hisahiro Sasabe
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Junji Kido
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
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3
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Sachnik O, Ie Y, Ando N, Tan X, Blom PWM, Wetzelaer GJAH. Single-Layer Organic Light-Emitting Diode with Trap-Free Host Beats Power Efficiency and Lifetime of Multilayer Devices. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2311892. [PMID: 38214416 DOI: 10.1002/adma.202311892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Indexed: 01/13/2024]
Abstract
Organic light-emitting diodes (OLEDs) employing a single active layer potentially offer a number of benefits compared to multilayer devices; reduced number of materials and deposition steps, potential for solution processing, and reduced operating voltage due to the absence of heterojunctions. However, for single-layer OLEDs to achieve efficiencies approaching those of multilayer devices, balanced charge transport is a prerequisite. This requirement excludes many efficient emitters based on thermally activated delayed fluorescence (TADF) that exhibit electron trapping, such as the green-emitting bis(4-(9,9-dimethylacridin-10(9H)-yl)phenyl)methanone (DMAC-BP). By employing a recently developed trap-free large band gap material as a host for DMAC-BP, nearly balanced charge transport is achieved. The single-layer OLED reaches an external quantum efficiency (EQE) of 19.6%, which is comparable to the reported EQEs of 18.9-21% for multilayer devices, but achieves a record power efficiency for DMAC-BP OLEDs of 82 lm W-1, clearly surpassing the reported multilayer power efficiencies of 52.9-59 lm W-1. In addition, the operational stability is greatly improved compared to multilayer devices and the use of conventional host materials in combination with DMAC-BP as an emitter. Next to the obvious reduction in production costs, single-layer OLEDs therefore also offer the advantage of reduced energy consumption and enhanced stability.
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Affiliation(s)
- Oskar Sachnik
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Yutaka Ie
- Department of Soft Nanomaterials, Nanoscience and Nanotechnology Center, The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Osaka, Ibaraki, 567-0047, Japan
| | - Naoki Ando
- Department of Soft Nanomaterials, Nanoscience and Nanotechnology Center, The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Osaka, Ibaraki, 567-0047, Japan
| | - Xiao Tan
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Paul W M Blom
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
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4
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Dong Q, He B, Qiao W, Zhu W, Duan P, Wang Y. A chiral bipolar host for efficient solution-processed circularly polarized OLEDs via a chirality energy transfer process. Chem Commun (Camb) 2024; 60:3421-3424. [PMID: 38441282 DOI: 10.1039/d3cc06148e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
Chiral bipolar hosts of (R/S)-L-2mCPCN are synthesized, which show high singlet/triplet energy levels and clear circularly polarized luminescence. Employing racemic phosphorescent and TADF materials as emitting guest molecules, solution-processable CP-OLEDs based on such chiral hosts are obtained with an EQEmax of 10.7% and |gEL| values of 5.0 × 10-3.
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Affiliation(s)
- Qiwei Dong
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, School of Materials Science & Engineering, Changzhou University, Changzhou 213164, China.
- School of Materials Engineering, Changzhou Vocational Institute of Industry Technology, Changzhou 213164, China
| | - Binghong He
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, School of Materials Science & Engineering, Changzhou University, Changzhou 213164, China.
| | - Wenjian Qiao
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, School of Materials Science & Engineering, Changzhou University, Changzhou 213164, China.
- ChinaZaozhuang Reinno Optoelectronic Information Co., Ltd, China
| | - Weiguo Zhu
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, School of Materials Science & Engineering, Changzhou University, Changzhou 213164, China.
| | - Pengfei Duan
- CAS Center for Excellence in Nanoscience CAS Key Laboratory of Nano system and Hierarchical Fabrication National Center for Nanoscience and Technology (NCNST), Beijing 100190, P. R. China
| | - Yafei Wang
- Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, School of Materials Science & Engineering, Changzhou University, Changzhou 213164, China.
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5
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Zheng C, Deng J, Qi Y, Sun C, Cui D, Chen C, Zhu C, Wang S, Yuan J, Xie G, Li P, Chen R. Rational Design of Bipolar Host and Thermally Activated Delayed Fluorescence Materials in Donor-Acceptor Molecular Architecture: A Theoretical Study. J Phys Chem Lett 2024; 15:525-531. [PMID: 38194489 DOI: 10.1021/acs.jpclett.3c03068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
Donor-acceptor (D-A) molecules have drawn massive attention recently in the design of high-performance materials, but the underlying reasons for the magic abilities of D-A architecture in building very different organic semiconductors are still unclear. Here, based on a series of experimentally bipolar host and thermally activated delayed fluorescence (TADF) molecules with the same donor but different acceptor units, it was found that TADF emitters have more effective charge transfer between donor and acceptor units than bipolar host molecules. More efficient conjugation effects between the donor and acceptor units of host materials were identified from the lower dihedral angles of the D-A structure, smaller and even negative charge transfer amount, shorter charge-transfer length, and larger hole-electron overlap extent. These findings with in-depth insights into different interaction models of donor and acceptor units shed important light on the molecular design of TADF emitters and bipolar materials in a D-A architecture.
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Affiliation(s)
- Chao Zheng
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Junyuan Deng
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Yuanyuan Qi
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Chengxi Sun
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Dongyue Cui
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Cailin Chen
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Chenxi Zhu
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Shuang Wang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Jie Yuan
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
- Engineering Technology Training Center, Nanjing Vocational University of Industry Technology, 1 Yangshan North Road, Nanjing 210023, China
| | - Gaozhan Xie
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Ping Li
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
| | - Runfeng Chen
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), School of Computer Science, Nanjing University of Posts and Telecommunications (NUPT), 9 Wenyuan Road, Nanjing 210023, China
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6
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Lu CH, Lin CY, Zeng SX, Chou YP, Chen CH, Liu YH, Lee JH, Wu CC, Wong KT. Engineering the Macrocyclic Donor Structures towards Deep-Blue Thermally Activated Delayed Fluorescence Emitters. ACS APPLIED MATERIALS & INTERFACES 2023; 15:35239-35250. [PMID: 37459567 DOI: 10.1021/acsami.3c05754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Deep-blue thermally activated delayed fluorescence (TADF) molecules present promising potential in organic light-emitting diodes (OLEDs), especially for display applications. Here, an efficient molecular engineering approach to modifying the donor or acceptor features of the D-π-A-configured TADF molecules for deep-blue emission is reported. By introducing oxygen and sulfone as a bridge unit onto the macrocyclic donor, two emitters, c-ON-MeTRZ and c-NS-MeTRZ, are synthesized and characterized, respectively. The reduced donor strength of c-ON-MeTRZ and c-NS-MeTRZ as compared to that of the model molecule c-NN-MeTRZ leads to blue-shifted emissions with high photoluminescence quantum yields (PLQYs) and retains TADF characters, while the new emitter c-NN-MePym with the most blue-shifted emission only exhibits a pure fluorescent nature because of the electron-accepting feature of pyrimidine that is insufficient for inducing the TADF property. In the presence of macrocyclic donors, these new emitters show high horizontal dipole ratios (Θ// = 85-89%), which are beneficial for improving the light out-coupling efficiency. Deep-blue TADF OLEDs incorporating c-ON-MeTRZ as an emitter doped in the mCPCN host achieves a high maximum external quantum efficiency (EQEmax) of 30.2% together with 1931 Commission Internationale de I'Eclairage (CIE) coordinates of (0.14, 0.13), while the counter device employing c-NS-MeTRZ as a dopant gives EQEmax of 15.4% and CIE coordinates of (0.14, 0.09). The EQEmax of c-ON-MeTRZ- and c-NS-MeTRZ-based devices can be significantly improved to 34.4 and 29.3%, respectively, with a polar host DPEPO, which stabilizes the charge transfer (CT) S1 state to give lower ΔEST for improving the reverse intersystem crossing process. The efficient TADF character, high PLQYs, and high anisotropic emission dipole ratios work together to render the superior electroluminescence (EL) efficiencies. Based on the detailed characterizations of physical properties, theoretical analyses, and comprehensive study on the corresponding devices, a clear structure-property-performance relationship has been successfully established to verify the effective molecular design strategy of modulating the macrocyclic donor characters for efficient deep-blue TADF emitters.
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Affiliation(s)
- Chen-Han Lu
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Chun-Yen Lin
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Shi-Xian Zeng
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yu-Pin Chou
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Chia-Hsun Chen
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Yi-Hung Liu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Jiun-Haw Lee
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Chung-Chih Wu
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Ken-Tsung Wong
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
- Institute of Atomic and Molecular Science, Academia Sinica, Taipei 10617, Taiwan
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7
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Kwon NY, Park SH, Koh CW, Park JY, Kang MJ, Baek HI, Youn J, Park S, Han CW, Cho MJ, Choi DH. Rational Molecular Design Strategy for Host Materials in Thermally Activated Delayed Fluorescence-OLEDs Suitable for Solution Processing. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37256769 DOI: 10.1021/acsami.3c01236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Herein, a novel core molecule for V-shaped host molecules was synthesized, wherein two carbazoles were directly linked to cyclohexane. Cy-mCP and Cy-mCBP hosts were also successfully prepared for solution-processable thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs). The Cy-mCP and Cy-mCBP molecules contained a cyclohexane linker directly linked to two small molecular hosts (mCP and mCBP), exhibiting twice the molecular weight while maintaining the basic properties of a single host molecule with improved film-forming ability and solubility in organic solvents. These host materials showed superior thermal stability and high glass transition temperatures compared to lower molecular weight hosts. Green TADF-OLEDs were prepared using the two host materials and 2,4,5,6-tetra(3,6-di-tert-butylcarbazol-9-yl)-1,3-dicyanobenzene (t4CzIPN) emitter, achieving device efficiencies similar to that of a low-molecular-weight host. However, after the incorporation of a V-shaped host, superior characteristics were observed in terms of the thermal stability and operational stability of the device. The synthesis of V-shaped molecules by directly linking two carbazoles to a cyclohexane linker is promising for the development of different hosts for solution-processable OLEDs.
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Affiliation(s)
- Na Yeon Kwon
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Su Hong Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Chang Woo Koh
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jin Young Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Min Ji Kang
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Heume Il Baek
- LG Display, E2 Block LG Science Park, 30, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Republic of Korea
| | - Junho Youn
- LG Display, E2 Block LG Science Park, 30, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Republic of Korea
| | - Sungnam Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Chang Wook Han
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
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8
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Sachnik O, Li Y, Tan X, Michels JJ, Blom PWM, Wetzelaer GJAH. Single-Layer Blue Organic Light-Emitting Diodes With Near-Unity Internal Quantum Efficiency. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023:e2300574. [PMID: 36914566 DOI: 10.1002/adma.202300574] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/09/2023] [Indexed: 05/09/2023]
Abstract
Efficient organic light-emitting diodes (OLEDs) commonly comprise a multilayer stack including charge-transport and charge- and exciton-blocking layers, to confine charge recombination to the emissive layer. Here, a highly simplified single-layer blue-emitting OLED is demonstrated based on thermally activated delayed fluorescence with the emitting layer simply sandwiched between ohmic contacts consisting of a polymeric conducting anode and a metal cathode. The single-layer OLED exhibits an external quantum efficiency of 27.7% with minor roll-off at high brightness. The internal quantum efficiency approaches unity, demonstrating that highly simplified single-layer OLEDs without confinement layers can achieve state-of-the-art performance, while greatly reducing the complexity of the design, fabrication, and device analysis.
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Affiliation(s)
- Oskar Sachnik
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Yungui Li
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Xiao Tan
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Jasper J Michels
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Paul W M Blom
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
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9
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Constructing high-efficiency orange-red thermally activated delayed fluorescence emitters by three-dimension molecular engineering. Nat Commun 2022; 13:7828. [PMID: 36535962 PMCID: PMC9763412 DOI: 10.1038/s41467-022-35591-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 12/12/2022] [Indexed: 12/24/2022] Open
Abstract
Preparing high-efficiency solution-processable orange-red thermally activated delayed fluorescence (TADF) emitters remains challenging. Herein, we design a series of emitters consisting of trinaphtho[3,3,3]propellane (TNP) core derivatized with different TADF units. Benefiting from the unique hexagonal stacking architecture of TNPs, TADF units are thus kept in the cavities between two TNPs, which decrease concentration quenching and annihilation of long-lived triplet excitons. According to the molecular engineering of TADF and host units, the excited states can further be regulated to effectively enhance spin-orbit coupling (SOC) processes. We observe a high-efficiency orange-red emission at 604 nm in one instance with high SOC value of 0.862 cm-1 and high photoluminescence quantum yield of 70.9%. Solution-processable organic light-emitting diodes exhibit a maximum external quantum efficiency of 24.74%. This study provides a universal strategy for designing high-performance TADF emitters through molecular packing and excited state regulation.
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10
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Yang Y, Wei J, Xiang‐YangLiu, Li R, Zhang Z. Novel
Ortho
‐Linkage Donor‐Acceptor Type Host Materials for Efficiently Red Phosphorescence Organic Light‐Emitting Diodes. ChemistrySelect 2022. [DOI: 10.1002/slct.202201647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Yong‐Jian Yang
- School of Environment and Chemical Engineering Jiangsu Ocean University, 59 Cangwu Road, Haizhou District Lianyungang 222005 P. R. China
| | - Jia‐Jia Wei
- School of Environment and Chemical Engineering Jiangsu Ocean University, 59 Cangwu Road, Haizhou District Lianyungang 222005 P. R. China
| | - Xiang‐YangLiu
- Wispo Advanced Materials (Suzhou) Co., Ltd. Suzhou Industrial Park (SIP) 200 Xingpu Road, Shengpu Street Suzhou 215126 P.R. China
| | - Runlai Li
- College of Polymer Science & Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065 P. R. China
| | - Zhen‐Ming Zhang
- School of Environment and Chemical Engineering Jiangsu Ocean University, 59 Cangwu Road, Haizhou District Lianyungang 222005 P. R. China
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11
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Francese T, Kundu A, Gygi F, Galli G. Quantum simulations of thermally activated delayed fluorescence in an all-organic emitter. Phys Chem Chem Phys 2022; 24:10101-10113. [PMID: 35416814 DOI: 10.1039/d2cp01147f] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigate the prototypical NAI-DMAC thermally activated delayed fluorescence (TADF) emitter in the gas phase- and high-packing fraction limits at finite temperature, by combining first principles molecular dynamics with a quantum thermostat to account for nuclear quantum effects (NQE). We find a weak dependence of the singlet-triplet energy gap (ΔEST) on temperature in both the solid and the molecule, and a substantial effect of packing. While the ΔEST vanishes in the perfect crystal, it is of the order of ∼0.3 eV in the molecule, with fluctuations ranging from 0.1 to 0.4 eV at 300 K. The transition probability between the HOMOs and LUMOs has a stronger dependence on temperature than the singlet-triplet gap, with a desirable effect for thermally activated fluorescence; such temperature effect is weaker in the condensed phase than in the molecule. Our results on ΔEST and oscillator strengths, together with our estimates of direct and reverse intersystem crossing rates, show that optimization of packing and geometrical conformation is critical to increase the efficiency of TADF compounds. Our findings highlight the importance of considering thermal fluctuations and NQE to obtain robust predictions of the electronic properties of NAI-DMAC.
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Affiliation(s)
- Tommaso Francese
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
| | - Arpan Kundu
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
| | - Francois Gygi
- Department of Computer Science, University of California, Davis, CA 95616, USA
| | - Giulia Galli
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA. .,Materials Science Division and Center for Molecular Engineering, Argonne National Laboratory, Lemont, IL 60439, USA.,Department of Chemistry, University of Chicago, Chicago, IL 60637, USA
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12
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Chen L, Chang Y, Shi S, Wang S, Wang L. Solution-processed white OLEDs with power efficiency over 90 lm W -1 by triplet exciton management with a high triplet energy level interfacial exciplex host and a high reverse intersystem crossing rate blue TADF emitter. MATERIALS HORIZONS 2022; 9:1299-1308. [PMID: 35195631 DOI: 10.1039/d1mh02060a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Solution-processed white organic light-emitting diodes (WOLEDs) have shown much lower device efficiency than their vacuum-deposited counterparts, due to the lack of triplet exciton management in a single-emissive-layer device structure, which will induce triplet-triplet annihilation (TTA) and triplet-polaron annihilation (TPA). Here, two kinds of solution-processed WOLEDs, including thermally activated delayed fluorescence (TADF)/phosphorescence hybrid WOLEDs and all-TADF WOLEDs, with high power efficiency are developed by using a high triplet energy level (T1) interfacial exciplex as a host and a high reverse intersystem crossing (RISC) rate TADF emitter as a blue dopant for triplet exciton management. The interfacial exciplex host with high T1 can ensure that triplet excitons transfer from the host to the blue emitter, and the blue TADF emitter with high RISC rate (1.15 × 107 s-1) can rapidly upconvert triplet excitons to singlet ones to avoid TTA and TPA. The solution-processed TADF/phosphorescence hybrid and all-TADF WOLEDs exhibit maximum external quantum efficiencies of 31.1% and 27.3%, together with maximum power efficiencies of 93.5 and 70.4 lm W-1, respectively, which are the record efficiencies for solution-processed WOLEDs, and quite comparable to those of most vacuum-deposited counterparts.
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Affiliation(s)
- Liang Chen
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Yufei Chang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Song Shi
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Shumeng Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
| | - Lixiang Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
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13
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Sebris A, Novosjolova I, Traskovskis K, Kokars V, Tetervenoka N, Vembris A, Turks M. Photophysical and Electrical Properties of Highly Luminescent 2/6-Triazolyl-Substituted Push-Pull Purines. ACS OMEGA 2022; 7:5242-5253. [PMID: 35187339 PMCID: PMC8851656 DOI: 10.1021/acsomega.1c06359] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Accepted: 01/13/2022] [Indexed: 06/14/2023]
Abstract
New push-pull N(9)-alkylated 6-piperidino-2-triazolylpurine and 2-piperidino-6-triazolylpurine derivatives are synthesized, and their optical and optoelectronic properties are comprehensively characterized with experimental and computational methods. The compounds possess intense violet or blue fluorescence with fluorescence quantum yields of up to 91% in solution and 40% in host-free films. Depending on their structural composition, the compounds have ionization energy in the range of 5.25-6.04 eV, electron affinity of 2.18-3.15 eV, and triplet energy of 2.52-2.95 eV. Due to the presence of hole-transporting purine and electron-transporting triazole fragments, compounds exhibit bipolar charge-transportation ability. Despite the favorable emissive properties of the studied push-pull purines, their electroluminescence in thin films is quenched owing to large current densities that are present even at a moderate driving voltage. This marks application directions related to a predominantly charge-transportation functionality as the most suitable for this compound class.
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Affiliation(s)
- Armands Sebris
- Faculty
of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, LV-1048 Riga, Latvia
| | - Irina Novosjolova
- Faculty
of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, LV-1048 Riga, Latvia
| | - Kaspars Traskovskis
- Faculty
of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, LV-1048 Riga, Latvia
| | - Valdis Kokars
- Faculty
of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, LV-1048 Riga, Latvia
| | - Natalija Tetervenoka
- Institute
of Solid State Physics, University of Latvia, Kengaraga Str. 8, LV-1063 Riga, Latvia
| | - Aivars Vembris
- Institute
of Solid State Physics, University of Latvia, Kengaraga Str. 8, LV-1063 Riga, Latvia
| | - Ma̅ris Turks
- Faculty
of Materials Science and Applied Chemistry, Riga Technical University, P. Valdena Str. 3, LV-1048 Riga, Latvia
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14
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Wu H, Wang G, Zhang D, Jin X, Luo X, Guo S, Zhou H, Miao Y, Huang J, Su J. Novel carbazole- and dioxino[2,3- b]pyrazine-based bipolar hosts for red PhOLEDs with a high brightness. NEW J CHEM 2022. [DOI: 10.1039/d2nj01951e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The target compounds offer new synthetic ideas for red bipolar host materials.
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Affiliation(s)
- Haifa Wu
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Guoliang Wang
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Daqing Zhang
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Xin Jin
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Xin Luo
- Shanghai Taoe Chemical Technology Co., Ltd, Shanghai, P. R. China
| | - Shiyan Guo
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Haitao Zhou
- Shanghai Taoe Chemical Technology Co., Ltd, Shanghai, P. R. China
| | - Yanqin Miao
- Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024, China
| | - Jinhai Huang
- Shanghai Taoe Chemical Technology Co., Ltd, Shanghai, P. R. China
| | - Jianhua Su
- Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, 130 Meilong Road, Shanghai 200237, P. R. China
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15
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Yi RH, Lei YC, Tseng YH, Lin YF, Cheng YC, Fang YC, Ho CY, Tsai WW, Chang CH, Lu CW. Imidazolyl-Phenylcarbazole-Based Host Materials and Their Use for Co-host Designs in Phosphorescent OLEDs. Chemistry 2021; 28:e202102966. [PMID: 34766387 DOI: 10.1002/chem.202102966] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Indexed: 01/18/2023]
Abstract
In recent years, owing to the demand for high-efficiency phosphorescent organic light-emitting devices (PhOLEDs), many studies have been conducted on the development of bipolar host materials. A series of imidazolyl-phenylcarbazole-based host materials, i. e., im-CzP, im-CzPCz, im-CzPtBu, and im-OCzP, were synthesized to obtain high-efficiency green and red-emitting PhOLEDs. With im-OCzP as the host, satisfactory peak efficiencies of 22.2 (77.0 cd A-1 and 93.1 lm W-1 ) and 14.1 % (9.0 cd A-1 and 10.1 lm W-1 ) could be obtained, respectively. To further improve the performance of the devices, an electron transport material, bis-4,6-(3,5-di-3-pyridylphenyl)-2-methylpyrimidine (B3PyMPM) was selected to construct a co-hosted system. The efficiency of im-OCzP combined with B3PyMPM forming co-hosts could also achieve high values of 23.0 (80.0 cd A-1 and 98.8 lm W-1 ) and 16.5 % (10.2 cd A-1 and 13.4 lm W-1 ) for green and red PhOLEDs, respectively. These results exhibited that the proposed bipolar hosts have great flexibility in adjusting the carrier balance of EML in OLEDs, demonstrating their ingenious design and high potential.
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Affiliation(s)
- Rong-Huei Yi
- Department of Applied Chemistry, Providence University, Taichung, 43301, Taiwan
| | - Ya-Chun Lei
- Department of Applied Chemistry, Providence University, Taichung, 43301, Taiwan
| | - Yeh-Hsiang Tseng
- Department of Electrical Engineering, Yuan Ze University, Chungli, 32003, Taiwan
| | - Yi-Fan Lin
- Department of Electrical Engineering, Yuan Ze University, Chungli, 32003, Taiwan
| | - Yen-Chia Cheng
- Department of Electrical Engineering, Yuan Ze University, Chungli, 32003, Taiwan
| | - Yu-Chuan Fang
- Department of Applied Chemistry, Providence University, Taichung, 43301, Taiwan
| | - Cheng-Yung Ho
- Department of Mechanical Engineering, Chung Yuan Christian University, Chungli, 32023, Taiwan
| | - Wei-Wen Tsai
- Electronics and Imaging, DuPont de Nemours, Inc., Newark, DE19713, USA
| | - Chih-Hao Chang
- Department of Electrical Engineering, Yuan Ze University, Chungli, 32003, Taiwan
| | - Chin-Wei Lu
- Department of Applied Chemistry, Providence University, Taichung, 43301, Taiwan
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16
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Singh PS, Badani PM, Kamble RM. Blue-orange emitting carbazole based donor-acceptor derivatives: Synthesis and studies of modulating acceptor unit on opto-electrochemical and theoretical properties. J Photochem Photobiol A Chem 2021. [DOI: 10.1016/j.jphotochem.2021.113457] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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17
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Wang L, Xiao H, Qu L, Song J, Zhou W, Zhou X, Xiang H, Xu ZX. Axially Chiral Bis-Cycloplatinated Binaphthalenes and Octahydro-Binaphthalenes for Efficient Circularly Polarized Phosphorescence in Solution-Processed Organic Light-Emitting Diodes. Inorg Chem 2021; 60:13557-13566. [PMID: 34409839 DOI: 10.1021/acs.inorgchem.1c01861] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A new series of axially chiral binuclear Pt(II) complexes with bridging ligands of binaphthalenes and octahydro-binaphthalenes and auxiliary ligands of β-diketones were designed and prepared. These complexes, identified by spectral and electrochemical methods and single-crystal X-ray diffraction, emit an orange-red phosphorescence with a quantum yield up to 21% and 70% in solution and solid, respectively, due to the effect of steric hindrance from bridging ligands and the 2,3-position extension of chiral axis planes. They can be used as emitters in solution-processed organic light-emitting diodes to achieve luminance efficiency, asymmetry factor, and external quantum efficiency up to 5.4 cd A-1, 3.0 × 10-3, and 3.1%, respectively. Moreover, the essential relationships between their chemical structures and luminescence quantum efficiency and asymmetry factor are discussed, which affords explicit insights for designing circularly polarized luminescent materials and devices.
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Affiliation(s)
- Lei Wang
- College of Chemistry, Sichuan University, Chengdu 610041, China
| | - Hui Xiao
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518000, China
| | - Lang Qu
- College of Chemistry, Sichuan University, Chengdu 610041, China
| | - Jintong Song
- College of Chemistry, Sichuan University, Chengdu 610041, China
| | - Weilan Zhou
- College of Chemistry, Sichuan University, Chengdu 610041, China
| | - Xiangge Zhou
- College of Chemistry, Sichuan University, Chengdu 610041, China
| | - Haifeng Xiang
- College of Chemistry, Sichuan University, Chengdu 610041, China
| | - Zong-Xiang Xu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518000, China
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18
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Chen YK, Jayakumar J, Hsieh CM, Wu TL, Liao CC, Pandidurai J, Ko CL, Hung WY, Cheng CH. Triarylamine-Pyridine-Carbonitriles for Organic Light-Emitting Devices with EQE Nearly 40. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2008032. [PMID: 34297444 DOI: 10.1002/adma.202008032] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 05/16/2021] [Indexed: 06/13/2023]
Abstract
Highly efficient thermally activated delayed fluorescence (TADF) molecules are in urgent demand for solid-state lighting and full-color displays. Here, the design and synthesis of three triarylamine-pyridine-carbonitrile-based TADF compounds, TPAPPC, TPAmPPC, and tTPAmPPC, are shown. They exhibit excellent photoluminescence quantum yields of 79-100% with small ΔEST values, fast reverse intersystem crossing (RISC), and high horizontal dipole ratios (Θ// = 86-88%) in the thin films leading to the enhancement of device light outcoupling. Consequently, a green organic light-emitting diode (OLED) based on TPAmPPC shows a high average external quantum efficiency of 38.8 ± 0.6%, a current efficiency of 130.1 ± 2.1 cd A-1 , and a power efficiency of 136.3 ± 2.2 lm W-1 . The highest device efficiency of 39.8% appears to be record-breaking among TADF-based OLEDs to date. In addition, the TPAmPPC-based device shows superior operation lifetime and high-temperature resistance. It is worth noting that the TPA-PPC-based materials have excellent optical properties and the potential for making them strong candidates for TADF practical application.
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Affiliation(s)
- Yi-Kuan Chen
- Department of Chemistry, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd., Hsinchu, 30013, Taiwan
| | - Jayachandran Jayakumar
- Department of Chemistry, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd., Hsinchu, 30013, Taiwan
| | - Chia-Min Hsieh
- Department of Chemistry, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd., Hsinchu, 30013, Taiwan
| | - Tien-Lin Wu
- Department of Chemistry, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd., Hsinchu, 30013, Taiwan
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Chun-Cheng Liao
- Department of Chemistry, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd., Hsinchu, 30013, Taiwan
| | - Jayabalan Pandidurai
- Department of Chemistry, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd., Hsinchu, 30013, Taiwan
| | - Chang-Lun Ko
- Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Wen-Yi Hung
- Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Chien-Hong Cheng
- Department of Chemistry, National Tsing Hua University, No. 101, Sec. 2, Kuang-Fu Rd., Hsinchu, 30013, Taiwan
- Department of Chemistry, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
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19
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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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20
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Patil B, Lade J, Sathe P, Tripathi A, Pownthurai B, Chetti P, Jadhav Y, Chaskar A. Combined experimental and density functional theory studies on novel 9‐(4/3/2‐cyanophenyl)‐9
H
‐carbazole‐3‐carbonitrile compounds for organic electronics. J PHYS ORG CHEM 2021. [DOI: 10.1002/poc.4207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Bhausaheb Patil
- National Centre for Nanosciences and Nanotechnology University of Mumbai Mumbai India
| | - Jatin Lade
- National Centre for Nanosciences and Nanotechnology University of Mumbai Mumbai India
| | - Pratima Sathe
- National Centre for Nanosciences and Nanotechnology University of Mumbai Mumbai India
| | - Anuj Tripathi
- Department of Chemistry National Institute of Technology Kurukshetra Haryana India
| | - B. Pownthurai
- National Centre for Nanosciences and Nanotechnology University of Mumbai Mumbai India
| | - Prabhakar Chetti
- Department of Chemistry National Institute of Technology Kurukshetra Haryana India
| | - Yogesh Jadhav
- National Centre for Nanosciences and Nanotechnology University of Mumbai Mumbai India
| | - Atul Chaskar
- National Centre for Nanosciences and Nanotechnology University of Mumbai Mumbai India
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21
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Li D, Li J, Liu D, Li W, Ko CL, Hung WY, Duan C. Highly Efficient Simple-Structure Sky-Blue Organic Light-Emitting Diode Using a Bicarbazole/Cyanopyridine Bipolar Host. ACS APPLIED MATERIALS & INTERFACES 2021; 13:13459-13469. [PMID: 33703891 DOI: 10.1021/acsami.0c20128] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Up to now, the most efficient blue phosphorescent organic light-emitting diode (PhOLED) was achieved with a maximum external quantum efficiency (ηext) of 34.1% by using an exciplex cohost. It still remains a challenge to obtain such high efficiencies using a single-host matrix. In this work, a highly efficient sky-blue PhOLED is successfully fabricated using a newly developed bipolar host material, namely 5-(2-(9H-[3,9'-bicarbazol]-9-yl)phenyl)nicotinonitrile (o-PyCNBCz), which realizes a ηext of 29.4% at a practical luminance of 100 cd m-2 and a maximum ηext of 34.6% (at 23 cd m-2). The present device is characterized by simple configuration with a single host and single emitting layer. o-PyCNBCz also reveals high efficiency of 28.2% (94.8 cd A-1) when used as the host for green PhOLED. Under identical conditions, o-PyCNBCz always outperforms than its isomer 3-PyCNBCz (5-(9-phenyl-9H-[3,9'-bicarbazol]-6-yl)nicotinonitrile) in terms of more balanced charge transportation, higher photoluminescent quantum yields of over 90%, and higher horizontal orientation ratio of the emitting dipole for the host-dopant films, which finally lead to its superior performance in PhOLEDs. It is observed that all these merits of o-PyCNBCz benefit from its ortho-linking style of carbazole (p-type unit) and cyanopyridine (n-type unit) on the phenylene bridge and the resultant molecular conformation.
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Affiliation(s)
- Deli Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Jiuyan Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Di Liu
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Wei Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Chang-Lun Ko
- Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 202, Taiwan
| | - Wen-Yi Hung
- Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 202, Taiwan
| | - Chunhui Duan
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
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22
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Kunz SV, Cole CM, Baumann T, Sonar P, Yambem SD, Blasco E, Barner-Kowollik C, Blinco JP. Emissive semi-interpenetrating polymer networks for ink-jet printed multilayer OLEDs. Polym Chem 2021. [DOI: 10.1039/d1py00794g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Solution-processing of multi-layered Organic Light Emitting Diodes (OLEDs) remains challenging. Herein, we introduce a facile blending process of emitting polymers with photoreactive polymer strands, allowing for the generation of solvent resistant emissive layers.
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Affiliation(s)
- Susanna V. Kunz
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, 4000 QLD, Australia
| | - Cameron M. Cole
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, 4000 QLD, Australia
| | - Thomas Baumann
- Cynora GmbH, Werner-von-Siemens-Straße 2-6, 76646 Bruchsal, Germany
| | - Prashant Sonar
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, 4000 QLD, Australia
| | - Soniya D. Yambem
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, 4000 QLD, Australia
| | - Eva Blasco
- Institute of Organic Chemistry, Heidelberg University, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
- Centre for Advanced Materials, Heidelberg University, Im Neuenheimer Feld 225, 69120 Heidelberg, Germany
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Christopher Barner-Kowollik
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, 4000 QLD, Australia
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - James P. Blinco
- Centre for Materials Science, School of Chemistry and Physics, Queensland University of Technology (QUT), 2 George Street, Brisbane, 4000 QLD, Australia
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23
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Wu HJ, Chang CC. Fabrication of Double Emission Enhancement Fluorescent Nanoparticles with Combined PET and AIEE Effects. Molecules 2020; 25:molecules25235732. [PMID: 33291763 PMCID: PMC7731327 DOI: 10.3390/molecules25235732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 11/18/2022] Open
Abstract
The major challenge in the fabrication of fluorescent silica nanoparticles (FSNs) based on dye-doped silica nanoparticles (DDSNs) is aggregation-caused fluorescence quenching. Here, we constructed an FSN based on a double emission enhancement (DEE) platform. A thio-reactive fluorescence turn-on molecule, N-butyl-4-(4-maleimidostyryl)-1,8-naphthalimide (CS), was bound to a silane coupling agent, (3-mercaptopropyl)-trimethoxysilane (MPTMS), and the product N-butyl-4-(3-(trimethoxysilyl-propylthio)styryl)-1,8-naphthalimide (CSP) was further used to fabricate a core–shell nanoparticle through the Stöber method. We concluded that the turn-on emission by CSP originated from the photoinduced electron transfer (PET) between the maleimide moiety and the CSP core scaffold, and the second emission enhancement was attributed to the aggregation-induced emission enhancement (AIEE) in CSP when encapsulated inside a core–shell nanoparticle. Thus, FSNs could be obtained through DEE based on a combination of PET and AIEE effects. Systematic investigations verified that the resulting FSNs showed the traditional solvent-independent and photostable optical properties. The results implied that the novel FSNs are suitable as biomarkers in living cells and function as fluorescent visualizing agents for intracellular imaging and drug carriers.
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Affiliation(s)
- Hsing-Ju Wu
- Research Assistant Center, Show Chwan Memorial Hospital, Changhua 500, Taiwan;
- Department of Biology, National Changhua University of Education, Changhua 500, Taiwan
| | - Cheng-Chung Chang
- Graduate Institute of Biomedical Engineering, National Chung Hsing University, No.145, Xing Da Road, Taichung 402, Taiwan
- Intelligent Minimally-Invasive Device Center, National Chung Hsing University, No.145, Xing Da Road, Taichung 402, Taiwan
- Correspondence: ; Tel.: +886-4-22840734
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24
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Mai VTN, Ahmad V, Mamada M, Fukunaga T, Shukla A, Sobus J, Krishnan G, Moore EG, Andersson GG, Adachi C, Namdas EB, Lo SC. Solid cyclooctatetraene-based triplet quencher demonstrating excellent suppression of singlet-triplet annihilation in optical and electrical excitation. Nat Commun 2020; 11:5623. [PMID: 33159048 PMCID: PMC7648636 DOI: 10.1038/s41467-020-19443-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 10/13/2020] [Indexed: 11/24/2022] Open
Abstract
Triplet excitons have been identified as the major obstacle to the realisation of organic laser diodes, as accumulation of triplet excitons leads to significant losses under continuous wave (CW) operation and/or electrical excitation. Here, we report the design and synthesis of a solid-state organic triplet quencher, as well as in-depth studies of its dispersion into a solution processable bis-stilbene-based laser dye. By blending the laser dye with 20 wt% of the quencher, negligible effects on the ASE thresholds, but a complete suppression of singlet-triplet annihilation (STA) and a 20-fold increase in excited-state photostability of the laser dye under CW excitation, were achieved. We used small-area OLEDs (0.2 mm2) to demonstrate efficient STA suppression by the quencher in the nanosecond range, supported by simulations to provide insights into the observed STA quenching under electrical excitation. The results demonstrate excellent triplet quenching ability under both optical and electrical excitations in the nanosecond range, coupled with excellent solution processability.
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Affiliation(s)
- Van T N Mai
- Centre for Organic Photonics & Electronics, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Viqar Ahmad
- Centre for Organic Photonics & Electronics, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Masashi Mamada
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Nishi, Fukuoka, 819-0395, Japan
- JST, ERATO, Adachi Molecular Exciton Engineering Project c/o Centre for Organic Photonics and Electronics Research (OPERA), Kyushu University, Nishi, Fukuoka, 819-0395, Japan
- Academia-Industry Molecular Systems for Devices Research and Education Centre (AIMS), Kyushu University, Nishi, Fukuoka, 819-0395, Japan
| | - Toshiya Fukunaga
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Nishi, Fukuoka, 819-0395, Japan
- JST, ERATO, Adachi Molecular Exciton Engineering Project c/o Centre for Organic Photonics and Electronics Research (OPERA), Kyushu University, Nishi, Fukuoka, 819-0395, Japan
| | - Atul Shukla
- Centre for Organic Photonics & Electronics, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Jan Sobus
- Centre for Organic Photonics & Electronics, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Gowri Krishnan
- Flinders Institute for Nanoscale Science and Technology, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5042, Australia
| | - Evan G Moore
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Gunther G Andersson
- Flinders Institute for Nanoscale Science and Technology, Flinders University, Sturt Road, Bedford Park, Adelaide, SA 5042, Australia
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Nishi, Fukuoka, 819-0395, Japan.
- JST, ERATO, Adachi Molecular Exciton Engineering Project c/o Centre for Organic Photonics and Electronics Research (OPERA), Kyushu University, Nishi, Fukuoka, 819-0395, Japan.
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, Nishi, Fukuoka, 819-0395, Japan.
| | - Ebinazar B Namdas
- Centre for Organic Photonics & Electronics, The University of Queensland, Brisbane, QLD 4072, Australia.
- School of Mathematics and Physics, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Shih-Chun Lo
- Centre for Organic Photonics & Electronics, The University of Queensland, Brisbane, QLD 4072, Australia.
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
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25
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Xiang Y, Li P, Gong S, Huang YH, Wang CY, Zhong C, Zeng W, Chen Z, Lee WK, Yin X, Wu CC, Yang C. Acceptor plane expansion enhances horizontal orientation of thermally activated delayed fluorescence emitters. SCIENCE ADVANCES 2020; 6:6/41/eaba7855. [PMID: 33036963 PMCID: PMC7546701 DOI: 10.1126/sciadv.aba7855] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 08/21/2020] [Indexed: 05/26/2023]
Abstract
Manipulating orientation of organic emitters remains a formidable challenge in organic light-emitting diodes (OLEDs). Here, expansion of the acceptor plane of thermally activated delayed fluorescence (TADF) emitters was demonstrated to selectively modulate emitting dipole orientation. Two proof-of-the-concept molecules, PXZPyPM and PXZTAZPM, were prepared by introducing a planar 2-phenylpyridine or 2,4,6-triphenyl-1,3,5-triazine substituent into a prototypical molecule (PXZPM) bearing a pyrimidine core and two phenoxazine donors. This design approach suppressed the influence of substituents on electronic structures and associated optoelectronic properties. Accordingly, PXZPyPM and PXZTAZPM preserved almost the same excited states and similar emission characteristics as PXZPM. The expanded acceptor plane of PXZPyPM and PXZTAZPM resulted in a 15 to 18% increase in horizontal ratios of emitting dipole orientation. PXZPyPM supported its green device exhibiting an external quantum efficiency of 33.9% and a power efficiency of 118.9 lumen per watt, competitive with the most efficient green TADF OLEDs reported so far.
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Affiliation(s)
- Yepeng Xiang
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, P. R. China
- Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Pan Li
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Shaolong Gong
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, P. R. China.
| | - Yu-Hsin Huang
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Chun-Yu Wang
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Cheng Zhong
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, P. R. China
| | - Weixuan Zeng
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, P. R. China
| | - Zhanxiang Chen
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, P. R. China
| | - Wei-Kai Lee
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan
| | - Xiaojun Yin
- Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, P. R. China
| | - Chung-Chih Wu
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei 10617, Taiwan.
| | - Chuluo Yang
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan 430072, P. R. China.
- Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, P. R. China
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26
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Sasabe H, Chikayasu Y, Ohisa S, Arai H, Ohsawa T, Komatsu R, Watanabe Y, Yokoyama D, Kido J. Molecular Orientations of Delayed Fluorescent Emitters in a Series of Carbazole-Based Host Materials. Front Chem 2020; 8:427. [PMID: 32528932 PMCID: PMC7262557 DOI: 10.3389/fchem.2020.00427] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 04/23/2020] [Indexed: 11/24/2022] Open
Abstract
Molecular orientation is one of the most crucial factors to boost the efficiency of organic light-emitting devices. However, active control of molecular orientation of the emitter molecule by the host molecule is rarely realized so far, and the underlying mechanism is under discussion. Here, we systematically investigated the molecular orientations of thermally activated delayed fluorescence (TADF) emitters in a series of carbazole-based host materials. Enhanced horizontal orientation of the TADF emitters was achieved. The degree of enhancement observed was dependent on the host material used. Consequently, our results indicate that π-π stacking, CH/n (n = O, N) weak hydrogen bonds, and multiple CH/π contacts greatly induce horizontal orientation of the TADF emitters in addition to the molecular shape anisotropy. Finally, we fabricated TADF-based organic light-emitting devices with an external quantum efficiency (ηext) of 26% using an emission layer with horizontal orientation ratio (Θ) of 79%, which is higher than that of an almost randomly oriented emission layer with Θ of 62% (ηext = 22%).
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Affiliation(s)
- Hisahiro Sasabe
- Research Center for Organic Electronics (ROEL), Yamagata University, Yamagata, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, Yamagata, Japan
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
| | - Yuki Chikayasu
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
| | - Satoru Ohisa
- Research Center for Organic Electronics (ROEL), Yamagata University, Yamagata, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, Yamagata, Japan
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
| | - Hiroki Arai
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
| | - Tatsuya Ohsawa
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
| | - Ryutaro Komatsu
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
| | - Yuichiro Watanabe
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
| | - Daisuke Yokoyama
- Research Center for Organic Electronics (ROEL), Yamagata University, Yamagata, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, Yamagata, Japan
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
| | - Junji Kido
- Research Center for Organic Electronics (ROEL), Yamagata University, Yamagata, Japan
- Frontier Center for Organic Materials (FROM), Yamagata University, Yamagata, Japan
- Department of Organic Materials Science, Graduate School of Organic Materials Science, Yamagata University, Yamagata, Japan
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27
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Yang CY, Lee KH, Lee JY. Zig-Zag Type Molecular Design Strategy of N-Type Hosts for Sky-Blue Thermally-Activated Delayed Fluorescence Organic Light-Emitting Diodes. Chemistry 2020; 26:2429-2435. [PMID: 31769095 DOI: 10.1002/chem.201904477] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Indexed: 11/06/2022]
Abstract
N-type hosts for long lifetime in sky-blue thermally-activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) were investigated by synthesizing four hosts with zig-zag-type backbone structure for high triplet energy. The four hosts had two CN units at different positions of the zig-zag-type backbone structure and two dibenzofuran units through either the 2 or 4-position of dibenzofuran. The position of the CN unit was controlled at the meta and para-positions in the zig-zag-type backbone to study the relationship between material parameters and lifetime of the TADF OLEDs. It was revealed that the meta-orientation of the CN units in the backbone was advantageous to extend device lifetime of the sky-blue TADF OLEDs.
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Affiliation(s)
- Chang Yoon Yang
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Seobu-ro, Suwon, Gyeonggi, 16419, Korea
| | - Kyung Hyung Lee
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Seobu-ro, Suwon, Gyeonggi, 16419, Korea
| | - Jun Yeob Lee
- School of Chemical Engineering, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Seobu-ro, Suwon, Gyeonggi, 16419, Korea
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28
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Zhou D, Zhang B, Yu Z, Liao Q, Fu H. tert-Butyl-substituted bicarbazole as a bipolar host material for efficient green and yellow PhOLEDs. NEW J CHEM 2020. [DOI: 10.1039/d0nj01210f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We designed a novel bipolar host material with a high ET and thermal stability for multi-colour PhOLEDs.
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Affiliation(s)
- Dandan Zhou
- School of Science
- Tianjin University
- Tianjin 300072
- P. R. China
| | - Bingqian Zhang
- Beijing Key Laboratory for Optical Materials and Photonic Devices
- Department of Chemistry
- Capital Normal University
- Beijing 100048
- P. R. China
| | - Zhenyi Yu
- School of Science
- Tianjin University
- Tianjin 300072
- P. R. China
| | - Qing Liao
- Beijing Key Laboratory for Optical Materials and Photonic Devices
- Department of Chemistry
- Capital Normal University
- Beijing 100048
- P. R. China
| | - Hongbing Fu
- School of Science
- Tianjin University
- Tianjin 300072
- P. R. China
- Beijing Key Laboratory for Optical Materials and Photonic Devices
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29
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Liu Y, Zhu J, Chen Y, Liang W, Zhou H, Huang J, Xia Z, Su J. Bicarbazole/nitrogen heterocycle based bipolar host materials for efficient green phosphorescent organic light-emitting diodes. Tetrahedron 2020. [DOI: 10.1016/j.tet.2019.06.047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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30
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Godumala M, Yoon J, Lee C, Jeong JE, Park S, Woo HY, Cho MJ, Choi DH. Chromenopyrazole-based bipolar host materials for solution-processable thermally activated delayed fluorescence OLEDs exhibiting high efficiency and low roll-off. Chem Commun (Camb) 2019; 55:12952-12955. [PMID: 31602441 DOI: 10.1039/c9cc05983k] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This study reports the design, synthesis, and characterization of two new bipolar host materials, DCzCP and TCzCP. Both materials were implemented as hosts by doping a known green thermally activated delayed fluorescent (TADF) emitter (t4CzIPN) in solution-processable OLEDs. DCzCP-based devices afford the best performance with the maximum external quantum efficiency (EQE) of 21.2%. Notably, the EQE was maintained at 20.7% and 19.7% at a practical luminance of 500 cd m-2 and 1000 cd m-2, respectively, demonstrating very small roll-off.
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Affiliation(s)
- Mallesham Godumala
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Jiwon Yoon
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Chiho Lee
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Ji-Eun Jeong
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Sungnam Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Han Young Woo
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
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31
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Kim JU, Wong MY, Kumar S, Hayes OG, Duncan F, Chan CY, Wong BYW, Ye H, Cui LS, Nakanotani H, Zysman-Colman E, Adachi C. High-triplet-energy Bipolar Host Materials Based on Phosphine Oxide Derivatives for Efficient Sky-blue Thermally Activated Delayed Fluorescence Organic Light-emitting Diodes with Reduced Roll-off. CHEM LETT 2019. [DOI: 10.1246/cl.190412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Jong Uk Kim
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- JST, ERATO, Adachi Molecular Exciton Engineering Project, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Michael Y. Wong
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, UK, KY16 9ST
| | - Shiv Kumar
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, UK, KY16 9ST
| | - Oliver G. Hayes
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, UK, KY16 9ST
| | - Finlay Duncan
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, UK, KY16 9ST
| | - Chin-Yiu Chan
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Ben Yiu-Wing Wong
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hao Ye
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Lin-Song Cui
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Hajime Nakanotani
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- JST, ERATO, Adachi Molecular Exciton Engineering Project, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
| | - Eli Zysman-Colman
- Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, St Andrews, Fife, UK, KY16 9ST
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA) and Department of Applied Chemistry, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- JST, ERATO, Adachi Molecular Exciton Engineering Project, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan
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32
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Zeng W, Zhou T, Ning W, Zhong C, He J, Gong S, Xie G, Yang C. Realizing 22.5% External Quantum Efficiency for Solution-Processed Thermally Activated Delayed-Fluorescence OLEDs with Red Emission at 622 nm via a Synergistic Strategy of Molecular Engineering and Host Selection. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1901404. [PMID: 31222835 DOI: 10.1002/adma.201901404] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 05/29/2019] [Indexed: 06/09/2023]
Abstract
Developing high-efficiency solution-processable thermally activated delayed-fluorescence (TADF) emitters, especially in longer wavelength regions, is a formidable challenge. Three red TADF emitters, namely NAI_R1, NAI_R2, and NAI_R3, are developed by phenyl encapsulation and tert-butyl substitution on a prototypical 1,8-naphthalimide-acridine hybrid. This design strategy not only grants these molecules high solubility, excellent thermal stability, and good film-forming ability, but also pulls down their charge-transfer (CT) energy levels excited states. Furthermore, dispersing these emitters into two different host materials of mCP and mCPCN finely tailors their CT-state energy levels. More importantly, a synergistic combination of molecular engineering and host selection can effectively manipulate the competition between the radiative and nonradiative decay rates of the CT singlet states of these emitters and the reverse intersystem crossing from their triplet to singlet states. Consequently, the optimal combination of NAI_R3 emitter and mCP host successfully results in a state-of-the-art external quantum efficiency (EQE) of 22.5% for solution-processed red TADF organic light-emitting diodes (OLEDs) with an emission peak above 620 nm. This finding demonstrates that a synergistic strategy of molecular engineering and host selection with TADF emitters could provide a new pathway for developing efficient solution-processable TADF systems.
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Affiliation(s)
- Weixuan Zeng
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, P. R. China
- Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Tao Zhou
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, P. R. China
| | - Weimin Ning
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, P. R. China
| | - Cheng Zhong
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, P. R. China
| | - Jiawei He
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, P. R. China
| | - Shaolong Gong
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, P. R. China
| | - Guohua Xie
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, P. R. China
| | - Chuluo Yang
- Department of Chemistry, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Wuhan University, Wuhan, 430072, P. R. China
- Shenzhen Key Laboratory of Polymer Science and Technology, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
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Hu S, Zeng J, Zhu X, Guo J, Chen S, Zhao Z, Tang BZ. Universal Bipolar Host Materials for Blue, Green, and Red Phosphorescent OLEDs with Excellent Efficiencies and Small-Efficiency Roll-Off. ACS APPLIED MATERIALS & INTERFACES 2019; 11:27134-27144. [PMID: 31271279 DOI: 10.1021/acsami.9b06995] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Host materials are indispensable for the fabrication of organic light-emitting diodes (OLEDs) with phosphorescent emitters, but high-quality host materials that can efficiently and simultaneously function in blue, green, and red phosphorescent OLEDs (PHOLEDs) are much rare. In this work, four bipolar materials are developed using carbazole and 9,9-dimethyl-9,10-dihydroacridine as hole-transporting groups, pyridine as electron-transporting groups, and biphenyl and m-methylbiphenyl as π-spacers. The crystal and electronic structures indicate that these materials have highly twisted conformations, which endow them with aggregation-induced emission features, intramolecular charge transfer processes, wide energy band gaps, and high triplet energies. The carrier transport ability and energy transfer property analyses show that these materials are able to achieve balanced hole and electron transports and can serve as bipolar host materials for PHOLEDs. A series of monochromatic PHOLEDs with different phosphorescent dopants, including blue-emissive FIrpic, green-emissive Ir(ppy)2(acac), and red-emissive Ir(piq)2(acac), are fabricated by employing these four host materials. The green PHOLEDs can provide an impressive luminance of up to 230 200 cd m-2. Based on an identical host material, excellent external quantum efficiencies as high as 25.12, 24.73, and 19.71%, as well as minor efficiency roll-off, are attained for blue, green, and red PHOLEDs, respectively, clearly demonstrating the promising applications as universal bipolar host materials in PHOLEDs with monochromatic light and white light.
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Affiliation(s)
- Shimin Hu
- State Key Laboratory of Luminescent Materials and Devices, Center for Aggregation-Induced Emission , South China University of Technology , Guangzhou 510640 , China
| | - Jiajie Zeng
- State Key Laboratory of Luminescent Materials and Devices, Center for Aggregation-Induced Emission , South China University of Technology , Guangzhou 510640 , China
| | - Xiangyu Zhu
- State Key Laboratory of Luminescent Materials and Devices, Center for Aggregation-Induced Emission , South China University of Technology , Guangzhou 510640 , China
| | - Jingjing Guo
- State Key Laboratory of Luminescent Materials and Devices, Center for Aggregation-Induced Emission , South China University of Technology , Guangzhou 510640 , China
| | - Shuming Chen
- Department of Electrical and Electronic Engineering , South University of Science and Technology of China , Shenzhen , Guangdong 518055 , China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices, Center for Aggregation-Induced Emission , South China University of Technology , Guangzhou 510640 , China
| | - Ben Zhong Tang
- State Key Laboratory of Luminescent Materials and Devices, Center for Aggregation-Induced Emission , South China University of Technology , Guangzhou 510640 , China
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction , The Hong Kong University of Science and Technology , Clear Water Bay , Kowloon , Hong Kong , China
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34
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Sarma M, Wong KT. Development of Materials for Blue Organic Light Emitting Devices. CHEM REC 2019; 19:1667-1692. [PMID: 30835939 DOI: 10.1002/tcr.201800156] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 01/29/2019] [Indexed: 01/20/2023]
Abstract
The success of organic light emitting diodes (OLED) has been witnessed by the commercialization of this technology for manufacturing the vivid and colorful displays used in our daily life now. The prospective growth of OLED technology on display industry will be optimistic. Over the last three decades, many different approaches on material and device designs have been implemented for improving the efficiency and stability of OLED devices. These efforts install main cornerstones to support the great achievement of OLED technology. However, until now, the performance and stability of blue OLEDs still have some concerns. This troublesome issue should be totally conquered before the large-scale manufactures dominated over other display technologies, particularly liquid crystal-based displays, takes place. Though significant progress has already been made to achieve high performance and long lifetime blue OLEDs, this topic still remains as one of the hot researches in OLEDs. We have been working on this area for about two decades and made some notable contributions. Consequently, in this personal account we have outlined our efforts to obtain better performing blue OLEDs by utilizing a range of emitters based on fluorescence, phosphorescence, delayed fluorescence and exciplex systems. We have also developed some novel host materials for blue OLEDs, which are worth mentioning in this account.
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Affiliation(s)
- Monima Sarma
- Department of Chemistry National Taiwan University, Taipei, 10617, Taiwan.,Department of Chemistry, KL University (KLEF), Vaddeswaram, Andhra Pradesh, 522502, India
| | - Ken-Tsung Wong
- Department of Chemistry National Taiwan University, Taipei, 10617, Taiwan.,Institute of Atomic and Molecular Science Academia Sinica, Taipei, 10617, Taiwan
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35
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Liu Y, Liu J, Yan S, Ren Z. Synthesis and Charge-Transporting Properties of Dibenzothiphene Dioxide-Based Polysiloxanes. Chem Asian J 2018; 13:3254-3260. [PMID: 30203621 DOI: 10.1002/asia.201801099] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 09/08/2018] [Indexed: 11/09/2022]
Abstract
We designed and synthesized a dibenzothiphene dioxide-based homopolysiloxane, PDBTSi, and a carbazole-dibenzothiophene dioxide alternating copolysiloxane, PCzSi-alt-PDBTSi, respectively. Both PDBTSi and PCzSi-alt-PDBTSi possess an improved solubility, good film-forming ability and extremely high thermal stability due to introduction of polysiloxane main chains. Meanwhile, PDBTSi and PCzSi-alt-PDBTSi exhibit high triplet energy levels of 2.95 eV and 3.05 eV, respectively. Furthermore, PDBTSi possesses good electron-transporting property with an electron mobility of 1.02×10-4 cm2 V-1 s-1 and a relatively balanced hole mobility of 8.76×10-5 cm2 V-1 s-1 . In contrast, PCzSi-alt-PDBTSi exhibits an electron mobility of 4.65×10-5 cm2 V-1 s-1 and a hole mobility of 1.17×10-4 cm2 V-1 s-1 . Therefore, our results here provide a feasible strategy to obtain solution-processed polysiloxane materials with high and balanced electron- and hole-transporting properties.
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Affiliation(s)
- Yuchao Liu
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Junteng Liu
- Beijing Key Laboratory of Membrane Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Shouke Yan
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zhongjie Ren
- State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
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36
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Joseph V, Justin Thomas KR, Yang WY, Kumar Yadav RA, Kumar Dubey D, Jou JH. Tetra-substituted Dipolar Carbazoles: Tuning Optical and Electroluminescence Properties by Linkage Variation. ASIAN J ORG CHEM 2018. [DOI: 10.1002/ajoc.201800248] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Vellaichamy Joseph
- Organic Materials Laboratory; Department of Chemistry; Indian Institute of Technology Roorkee; Roorkee 247 667 India
| | - K. R. Justin Thomas
- Organic Materials Laboratory; Department of Chemistry; Indian Institute of Technology Roorkee; Roorkee 247 667 India
| | - Wan Yun Yang
- Department of Materials science and engineering; National Tsing Hua University; Hsinchu 30013 Taiwan
| | - Rohit Ashok Kumar Yadav
- Department of Materials science and engineering; National Tsing Hua University; Hsinchu 30013 Taiwan
| | - Deepak Kumar Dubey
- Department of Materials science and engineering; National Tsing Hua University; Hsinchu 30013 Taiwan
| | - Jwo-Huei Jou
- Department of Materials science and engineering; National Tsing Hua University; Hsinchu 30013 Taiwan
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37
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Zeng W, Lai HY, Lee WK, Jiao M, Shiu YJ, Zhong C, Gong S, Zhou T, Xie G, Sarma M, Wong KT, Wu CC, Yang C. Achieving Nearly 30% External Quantum Efficiency for Orange-Red Organic Light Emitting Diodes by Employing Thermally Activated Delayed Fluorescence Emitters Composed of 1,8-Naphthalimide-Acridine Hybrids. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:1704961. [PMID: 29218854 DOI: 10.1002/adma.201704961] [Citation(s) in RCA: 226] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/14/2017] [Indexed: 05/18/2023]
Abstract
The combination of rigid acridine donor and 1,8-naphthalimide acceptor has afforded two orange-red emitters of NAI-DMAC and NAI-DPAC with high rigidity in molecular structure and strongly pretwisted charge transfer state. Endowed with high photoluminescence quantum yields (ΦPL ), distinct thermally activated delayed fluorescence (TADF) characteristics, and preferentially horizontal emitting dipole orientations, these emitters afford record-high orange-red TADF organic light-emitting diodes (OLEDs) with external quantum efficiencies of up to 21-29.2%, significantly surpassing all previously reported orange-to-red TADF OLEDs. Notably, the influence of microcavity effect is verified to support the record-high efficiency. This finding relaxes the usually stringent material requirements for effective TADF emitters by comprising smaller radiative transition rates and less than ideal ΦPL s.
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Affiliation(s)
- Weixuan Zeng
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Hsin-Yu Lai
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Wei-Kai Lee
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Min Jiao
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Yi-Jiun Shiu
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Cheng Zhong
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Shaolong Gong
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Tao Zhou
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Guohua Xie
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
| | - Monima Sarma
- Department of Chemistry, Institute of Atomic and Molecular Science Academia Sinica, National Taiwan University, Taipei, 10617, Taiwan
| | - Ken-Tsung Wong
- Department of Chemistry, Institute of Atomic and Molecular Science Academia Sinica, National Taiwan University, Taipei, 10617, Taiwan
| | - Chung-Chih Wu
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Chuluo Yang
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, P. R. China
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38
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Zhang L, Li XL, Luo D, Xiao P, Xiao W, Song Y, Ang Q, Liu B. Strategies to Achieve High-Performance White Organic Light-Emitting Diodes. MATERIALS (BASEL, SWITZERLAND) 2017; 10:E1378. [PMID: 29194426 PMCID: PMC5744313 DOI: 10.3390/ma10121378] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 11/25/2017] [Accepted: 11/27/2017] [Indexed: 01/09/2023]
Abstract
As one of the most promising technologies for next-generation lighting and displays, white organic light-emitting diodes (WOLEDs) have received enormous worldwide interest due to their outstanding properties, including high efficiency, bright luminance, wide viewing angle, fast switching, lower power consumption, ultralight and ultrathin characteristics, and flexibility. In this invited review, the main parameters which are used to characterize the performance of WOLEDs are introduced. Subsequently, the state-of-the-art strategies to achieve high-performance WOLEDs in recent years are summarized. Specifically, the manipulation of charges and excitons distribution in the four types of WOLEDs (fluorescent WOLEDs, phosphorescent WOLEDs, thermally activated delayed fluorescent WOLEDs, and fluorescent/phosphorescent hybrid WOLEDs) are comprehensively highlighted. Moreover, doping-free WOLEDs are described. Finally, issues and ways to further enhance the performance of WOLEDs are briefly clarified.
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Affiliation(s)
| | - Xiang-Long Li
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.
| | - Dongxiang Luo
- School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, China.
| | - Peng Xiao
- School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China.
| | | | | | - Qinshu Ang
- Shunde Polytechnic, Foshan 528300, China.
| | - Baiquan Liu
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China.
- LUMINOUS! Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering, Nanyang Technological University, Nanyang Avenue, Singapore 639798, Singapore.
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39
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Joseph V, Thomas KRJ, Singh M, Sahoo S, Jou JH. Manipulation of Donor-Acceptor Interactions in Carbazole-Based Emitters by Chromophore Choice To Achieve Near-UV Emission. European J Org Chem 2017. [DOI: 10.1002/ejoc.201701285] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Vellaichamy Joseph
- Organic Materials Laboratory; Department of Chemistry; Indian Institute of Technology Roorkee; 247 667 Roorkee India
| | - K. R. Justin Thomas
- Organic Materials Laboratory; Department of Chemistry; Indian Institute of Technology Roorkee; 247 667 Roorkee India
| | - Meenu Singh
- Department of Materials science and engineering; National Tsing Hua University; 30013 Hsinchu Taiwan
| | - Snehasis Sahoo
- Department of Materials science and engineering; National Tsing Hua University; 30013 Hsinchu Taiwan
| | - Jwo-Huei Jou
- Department of Materials science and engineering; National Tsing Hua University; 30013 Hsinchu Taiwan
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40
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Wang F, Liu D, Li J, Ma M. Modulation of n-Type Units in Bipolar Host Materials toward High-Performance Phosphorescent OLEDs. ACS APPLIED MATERIALS & INTERFACES 2017; 9:37888-37897. [PMID: 29017329 DOI: 10.1021/acsami.7b11667] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
9'-Pyridinyl-9'H-9,3':6',9″-tercarbazole (PyCz) is a bipolar host material in phosphorescent organic light-emitting diodes (PhOLEDs). A second n-type unit, either pyridine or diphenylphosphine dioxide (DPPO), is introduced onto the pyridine ring of PyCz at para- or metasite to design and prepare four novel "dual n-type unit bipolar host" materials m-BPyCz, p-BPyCz, m-POPyCz, and p-POPyCz. The incorporation of the second n-type unit pulls down the lowest unoccupied molecular orbitals and facilitates electron injection and transportation, resulting in better charge-balancing ability. As a result, these dual n-type unit bipolar hosts exhibit higher efficiencies and slower efficiency roll-off in their blue and green PhOLEDs. In particular, m-POPyCz containing a bulky DPPO as the second n-type unit with a metalinking possesses the best charge-balancing state and generates a maximum external quantum efficiency (ηext) of 27.0% (corresponding to a current efficiency of 51.9 cd A-1 and a power efficiency of 46.5 lm W-1) in its sky-blue device and still remained at a high ηext of 23.6% even at the practical brightness of 1000 cd m-2. These results clearly demonstrate that the "dual n-type unit bipolar hosts" with an optimized substitution position and steric effect is a new and effective type of host materials for high-performance OLEDs.
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Affiliation(s)
- Fang Wang
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| | - Di Liu
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| | - Jiuyan Li
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
| | - Mengyao Ma
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology , Dalian 116024, China
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41
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Kuo HH, Chen YT, Devereux LR, Wu CC, Fox MA, Kuei CY, Chi Y, Lee GH. Bis-Tridentate Ir(III) Metal Phosphors for Efficient Deep-Blue Organic Light-Emitting Diodes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1702464. [PMID: 28635052 DOI: 10.1002/adma.201702464] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 05/22/2017] [Indexed: 05/27/2023]
Abstract
Emissive Ir(III) metal complexes possessing two tridentate chelates (bis-tridentate) are known to be more robust compared to those with three bidentate chelates (tris-bidentate). Here, the deep-blue-emitting, bis-tridentate Ir(III) metal phosphors bearing both the dicarbene pincer ancillary such as 2,6-diimidazolylidene benzene and the 6-pyrazolyl-2-phenoxylpyridine chromophoric chelate are synthesized. A deep-blue organic light-emitting diode from one phosphor exhibits Commission Internationale de l'Eclairage (CIE(x,y) ) coordinates of (0.15, 0.17) with maximum external quantum efficiency (max. EQE) of 20.7% and EQE = 14.6% at the practical brightness of 100 cd m-2 .
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Affiliation(s)
- Hsin-Hung Kuo
- Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Yi-Ting Chen
- Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Leon R Devereux
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK
| | - Chung-Chih Wu
- Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Mark A Fox
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK
| | - Chu-Yun Kuei
- Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Yun Chi
- Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Gene-Hsiang Lee
- Instrumentation Center, National Taiwan University, Taipei, 10617, Taiwan
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42
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Sarma M, Tsai WL, Lee WK, Chi Y, Wu CC, Liu SH, Chou PT, Wong KT. Anomalously Long-Lasting Blue PhOLED Featuring Phenyl-Pyrimidine Cyclometalated Iridium Emitter. Chem 2017. [DOI: 10.1016/j.chempr.2017.08.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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43
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Ihn S, Lee N, Jeon SO, Sim M, Kang H, Jung Y, Huh DH, Son YM, Lee SY, Numata M, Miyazaki H, Gómez‐Bombarelli R, Aguilera‐Iparraguirre J, Hirzel T, Aspuru‐Guzik A, Kim S, Lee S. An Alternative Host Material for Long-Lifespan Blue Organic Light-Emitting Diodes Using Thermally Activated Delayed Fluorescence. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2017; 4:1600502. [PMID: 28852613 PMCID: PMC5566347 DOI: 10.1002/advs.201600502] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 01/05/2017] [Indexed: 05/23/2023]
Abstract
It has been challenging to find stable blue organic light emitting diodes (OLEDs) that rely on thermally activated delayed fluorescence (TADF). Lack of stable host materials well-fitted to the TADF emitters is one of the critical reasons. The most popular host for blue TADF, bis[2-(diphenylphosphino)phenyl] ether oxide (DPEPO), leads to unrealistically high maximum external quantum efficiency. DPEPO is however an unstable material and has a poor charge transporting ability, which in turn induces an intrinsic short OLED operating lifespan. Here, an alternative host material is introduced which educes the potential efficiency and device lifespan of given TADF emitters with the appropriateness of replacing the most popular host material, DPEPO, in developing blue TADF emitters. It simultaneously provides much longer device lifespan and higher external quantum efficiency at a practical brightness due to its high material stability and electron-transport-type character well-fitted for hole-transport-type TADF emitters.
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Affiliation(s)
- Soo‐Ghang Ihn
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Namheon Lee
- Samsung SDI130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Soon Ok Jeon
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Myungsun Sim
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Hosuk Kang
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Yongsik Jung
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Dal Ho Huh
- Samsung SDI130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Young Mok Son
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Sae Youn Lee
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Masaki Numata
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Hiroshi Miyazaki
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Rafael Gómez‐Bombarelli
- Department of Chemistry and Chemical BiologyHarvard University12 Oxford StCambridgeMA02138USA
| | | | - Timothy Hirzel
- Department of Chemistry and Chemical BiologyHarvard University12 Oxford StCambridgeMA02138USA
| | - Alán Aspuru‐Guzik
- Department of Chemistry and Chemical BiologyHarvard University12 Oxford StCambridgeMA02138USA
| | - Sunghan Kim
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
| | - Sangyoon Lee
- Samsung Advanced Institute of TechnologySamsung Electronics Co., LTD130 Samsung‐ro, Yeongtong‐guSuwon‐siGyeonggi‐do16678South Korea
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Park IS, Seo H, Tachibana H, Kim JU, Zhang J, Son SM, Yasuda T. Cyclohexane-Coupled Bipolar Host Materials with High Triplet Energies for Organic Light-Emitting Diodes Based on Thermally Activated Delayed Fluorescence. ACS APPLIED MATERIALS & INTERFACES 2017; 9:2693-2700. [PMID: 27997105 DOI: 10.1021/acsami.6b13002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Thermally activated delayed fluorescence-based organic light-emitting diodes (TADF-OLEDs) have recently attracted tremendous research interest as next-generation optoelectronic devices. However, there are a limited number of host materials with an appropriately high lowest-excited triplet energy (ET) and bipolar charge transport properties for high-efficiency TADF-OLEDs. Moreover, these host materials should have high thermal and morphological stabilities. In this study, we develop novel bipolar host materials consisting of an electron-donating 9-phenylcarbazole unit and an electron-accepting triphenylphosphine oxide, triphenylphosphine sulfide, or 2,4,6-triphenyl-1,3,5-triazine unit linked by a nonconjugated cyclohexane core. These bipolar host materials possess high glass-transition temperatures of over 100 °C and high ET values of approximately 3.0 eV. TADF-OLEDs employing these bipolar host materials could achieve high external electroluminescence quantum efficiencies of up to 21.7% together with reduced efficiency roll-off characteristics, because of expansion of the charge-recombination zone within the emission layer arising from the bipolar charge transport ability of these host materials.
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Affiliation(s)
| | - Hongwook Seo
- Department of Graphic Arts and Information Engineering, Pukyong National University , #100, Yong Dang-dong, Nam-gu, Busan 608-020, Korea
| | | | - Joung Uk Kim
- Department of Graphic Arts and Information Engineering, Pukyong National University , #100, Yong Dang-dong, Nam-gu, Busan 608-020, Korea
| | - Jinbo Zhang
- Department of Graphic Arts and Information Engineering, Pukyong National University , #100, Yong Dang-dong, Nam-gu, Busan 608-020, Korea
| | - Se Mo Son
- Department of Graphic Arts and Information Engineering, Pukyong National University , #100, Yong Dang-dong, Nam-gu, Busan 608-020, Korea
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45
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Hsu CW, Ly KT, Lee WK, Wu CC, Wu LC, Lee JJ, Lin TC, Liu SH, Chou PT, Lee GH, Chi Y. Triboluminescence and Metal Phosphor for Organic Light-Emitting Diodes: Functional Pt(II) Complexes with Both 2-Pyridylimidazol-2-ylidene and Bipyrazolate Chelates. ACS APPLIED MATERIALS & INTERFACES 2016; 8:33888-33898. [PMID: 27960361 DOI: 10.1021/acsami.6b12707] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We report the utilization of both pyrid-2-yl-imidazolylidene and dianionic bipz chelates as constituents in syntheses of a new series of charge-neutral Pt(II) complexes 1-4, among which complex 4 revealed remarkable triboluminescence, i.e., generation of photoemission upon grinding or cracking of the solid sample. The triboluminescence is found to be sensitive to the subtle changes of the associated substituents of pyrid-2-yl-imidazolylidene chelate, as verified by the disappearance of the triboluminescence for complexes 1-3. Alternatively, the well-ordered solid packing of 3, as indicated by the grazing incidence X-ray scattering experiment, serves as an ideal emitter for the fabrication of highly efficient OLEDs, rendering high external quantum efficienciy (25.9%) and luminesce efficiency (90 cd A-1) at the practical brightness of 100 cd m-2. The rather low roll-off in efficiency (24.4%, 85 cd A-1 at high brightness of 1000 cd m-2) is attributed to the short excited-state lifetime of 3 (∼800 ns) in the solid state, which in turn is associated with the MMLCT transition character.
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Affiliation(s)
- Che-Wei Hsu
- Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan
| | - Kiet Tuong Ly
- Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan
| | | | | | - Lai-Chin Wu
- Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan
| | - Jey-Jau Lee
- Synchrotron Radiation Research Center , Hsinchu 30076, Taiwan
| | | | | | | | | | - Yun Chi
- Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan
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46
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Li W, Li J, Liu D, Li D, Zhang D. Dual n-type units including pyridine and diphenylphosphine oxide: effective design strategy of host materials for high-performance organic light-emitting diodes. Chem Sci 2016; 7:6706-6714. [PMID: 28451114 PMCID: PMC5355805 DOI: 10.1039/c6sc01797e] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Accepted: 07/08/2016] [Indexed: 12/02/2022] Open
Abstract
By using pyridine and diphenylphosphine oxide (DPPO) as dual n-type units, two novel bipolar hosts, namely (5-(3,5-di(9H-carbazol-9-yl)phenyl)pyridin-3-yl)diphenylphosphine oxide (m-PyPOmCP), and (6-(3,5-di(9H-carbazol-9-yl)phenyl)pyridin-3-yl)diphenylphosphine oxide (p-PyPOmCP) are developed for blue and green phosphorescent organic light-emitting diodes (PhOLEDs). Direct linking of the dual n-type units not only pulls the LUMOs down, but also keeps the HOMO levels shallow, and leads to high triplet energies (2.78-2.86 eV) and small singlet-triplet energy differences (0.23-0.35 eV). Blue and green PhOLEDs are fabricated using FIrpic and Ir(ppy)3 as dopants in the hosts. A low turn-on voltage of 2.6 V is achieved for the green PhOLEDs. The m-PyPOmCP hosted blue PhOLED achieves a high current efficiency of 55.6 cd A-1 (corresponding to a maximum external quantum efficiency of 25.3% and a power efficiency of 43.6 lm W-1). The p-PyPOmCP hosted green PhOLED exhibits an efficiency of 98.2 cd A-1 (28.2% and 102.8 lm W-1). These data are among the best values for blue and green PhOLEDs reported so far. These "dual n-type units" hosts show much better performance than their DPPO-free analogue, clearly proving that the direct linking of DPPO and pyridine as dual n-type units is an effective molecular design strategy for host materials for use in high-performance PhOLEDs.
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Affiliation(s)
- Wei Li
- State Key Laboratory of Fine Chemicals , College of Chemical Engineering , Dalian University of Technology , 2 Linggong Road , Dalian 116024 , P. R. China .
| | - Jiuyan Li
- State Key Laboratory of Fine Chemicals , College of Chemical Engineering , Dalian University of Technology , 2 Linggong Road , Dalian 116024 , P. R. China .
| | - Di Liu
- College of Chemistry , Dalian University of Technology , P. R. China
| | - Deli Li
- College of Chemistry , Dalian University of Technology , P. R. China
| | - Dan Zhang
- College of Chemistry , Dalian University of Technology , P. R. China
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47
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Li W, Li J, Liu D, Li D, Wang F. Cyanopyridine Based Bipolar Host Materials for Green Electrophosphorescence with Extremely Low Turn-On Voltages and High Power Efficiencies. ACS APPLIED MATERIALS & INTERFACES 2016; 8:21497-21504. [PMID: 27479511 DOI: 10.1021/acsami.6b04395] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Low driving voltage and high power efficiency are basic requirements when practical applications of organic light emitting diodes (OLEDs) in displays and lighting are considered. Two novel host materials m-PyCNmCP and 3-PyCNmCP incorporating cyanopyridine moiety as electron-transporting unit are developed for use in fac-tris(2-phenylpyridine)iridium(III) (Ir(ppy)3) based green phosphorescent OLEDs (PhOLEDs). Extremely low turn-on voltages of 2.01 and 2.27 V are realized, which are even lower than the theoretical limit of the emitted photon energy (hv)/electron charge (e) (2.37 V) of Ir(ppy)3. High power efficiency of 101.4 lm/W (corresponding to a maximum external quantum efficiency of 18.4%) and 119.3 lm/W (24.7%) are achieved for m-PyCNmCP and 3-PyCNmCP based green PhOLEDs. The excellent EL performance benefits from the ideal parameters of host materials by combining cyano and pyridine to enhance the n-type feature. The energetic favorable alignment of HOMO/LUMO levels of hosts with adjacent layers and the dopant for easy charge injections and direct charge trapping by dopant, their bipolar feature to balance charge transportations, sufficiently high triplet energy and small singlet/triplet energy difference (0.38 and 0.43 eV) combine to be responsible for the extremely low driving voltages and high power efficiencies of the green PhOLEDs.
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Affiliation(s)
- Wei Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology , 2 Linggong Road, Dalian 116024, China
| | - Jiuyan Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology , 2 Linggong Road, Dalian 116024, China
| | - Di Liu
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology , 2 Linggong Road, Dalian 116024, China
| | - Deli Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology , 2 Linggong Road, Dalian 116024, China
| | - Fang Wang
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology , 2 Linggong Road, Dalian 116024, China
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48
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Lin TA, Chatterjee T, Tsai WL, Lee WK, Wu MJ, Jiao M, Pan KC, Yi CL, Chung CL, Wong KT, Wu CC. Sky-Blue Organic Light Emitting Diode with 37% External Quantum Efficiency Using Thermally Activated Delayed Fluorescence from Spiroacridine-Triazine Hybrid. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:6976-83. [PMID: 27271917 DOI: 10.1002/adma.201601675] [Citation(s) in RCA: 390] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/01/2016] [Indexed: 05/21/2023]
Abstract
Extremely efficient sky-blue organic electroluminescence with external quantum efficiency of ≈37% is achieved in a conventional planar device structure, using a highly efficient thermally activated delayed fluorescence emitter based on the spiroacridine-triazine hybrid and simultaneously possessing nearly unitary (100%) photoluminescence quantum yield, excellent thermal stability, and strongly horizontally oriented emitting dipoles (with a horizontal dipole ratio of 83%).
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Affiliation(s)
- Ting-An Lin
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Tanmay Chatterjee
- Department of Chemistry, National Taiwan University, and Institute of Atomic and Molecular Science, Academia Sinica, Taipei, 10617, Taiwan
| | - Wei-Lung Tsai
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Wei-Kai Lee
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Meng-Jung Wu
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Min Jiao
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Kuan-Chung Pan
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
| | - Chih-Lung Yi
- Department of Chemistry, National Taiwan University, and Institute of Atomic and Molecular Science, Academia Sinica, Taipei, 10617, Taiwan
| | - Chin-Lung Chung
- Department of Chemistry, National Taiwan University, and Institute of Atomic and Molecular Science, Academia Sinica, Taipei, 10617, Taiwan
| | - Ken-Tsung Wong
- Department of Chemistry, National Taiwan University, and Institute of Atomic and Molecular Science, Academia Sinica, Taipei, 10617, Taiwan
| | - Chung-Chih Wu
- Department of Electrical Engineering, Graduate Institute of Electronics Engineering and Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, 10617, Taiwan
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49
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Ren Z, Nobuyasu RS, Dias FB, Monkman AP, Yan S, Bryce MR. Pendant Homopolymer and Copolymers as Solution-Processable Thermally Activated Delayed Fluorescence Materials for Organic Light-Emitting Diodes. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b01216] [Citation(s) in RCA: 123] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Zhongjie Ren
- State
Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
| | | | | | | | - Shouke Yan
- State
Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, China
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50
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Kuei CY, Tsai WL, Tong B, Jiao M, Lee WK, Chi Y, Wu CC, Liu SH, Lee GH, Chou PT. Bis-Tridentate Ir(III) Complexes with Nearly Unitary RGB Phosphorescence and Organic Light-Emitting Diodes with External Quantum Efficiency Exceeding 31%. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2016; 28:2795-800. [PMID: 26894982 DOI: 10.1002/adma.201505790] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/11/2015] [Indexed: 05/16/2023]
Abstract
A new class of neutral bis-tridentate Ir(III) metal complexes that show nearly unitary red, green, and blue emissions in solution is prepared and employed for the fabrication of both monochrome and white-emitting organic light-emitting diodes, among which a green device gives external quantum efficiency exceeding 31%.
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Affiliation(s)
- Chu-Yun Kuei
- Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Wei-Lung Tsai
- Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Bihai Tong
- Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan
- College of Metallurgy and Resources, Institute of Molecular Engineering and Applied Chemistry, Anhui University of Technology, Ma'anshan, Anhui, 243002, China
| | - Min Jiao
- Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Wei-Kai Lee
- Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Yun Chi
- Department of Chemistry, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Chung-Chih Wu
- Graduate Institute of Electronics Engineering and Department of Electrical Engineering, National Taiwan University, Taipei, 10617, Taiwan
| | - Shih-Hung Liu
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Gene-Hsiang Lee
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
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