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Woo JY, Park MH, Jeong SH, Kim YH, Kim B, Lee TW, Han TH. Advances in Solution-Processed OLEDs and their Prospects for Use in Displays. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2207454. [PMID: 36300804 DOI: 10.1002/adma.202207454] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 10/05/2022] [Indexed: 06/16/2023]
Abstract
This review outlines problems and progress in development of solution-processed organic light-emitting diodes (SOLEDs) in industry and academia. Solution processing has several advantages such as low consumption of materials, low-cost processing, and large-area manufacturing. However, use of a solution process entails complications, such as the need for solvent resistivity and solution-processable materials, and yields SOLEDs that have limited luminous efficiency, severe roll-off characteristics, and short lifetime compared to OLEDs fabricated using thermal evaporation. These demerits impede production of practical SOLED displays. This review outlines the industrial demands for commercial SOLEDs and the current status of SOLED development in industries and academia, and presents research guidelines for the development of SOLEDs that have high efficiency, long lifetime, and good processability to achieve commercialization.
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Affiliation(s)
- Joo Yoon Woo
- Division of Materials Science and Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea
| | - Min-Ho Park
- Department of Organic Materials and Fiber Engineering, Soongsil University, 369 Sangdo-Ro, Dongjak-Gu, Seoul, 06978, Republic of Korea
| | - Su-Hun Jeong
- Future Technology Research Center, LG Chem, Ltd., 30, Magokjunang 10-ro, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Young-Hoon Kim
- Department of Energy Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea
| | - Byungjae Kim
- Future Technology Research Center, LG Chem, Ltd., 30, Magokjunang 10-ro, Gangseo-gu, Seoul, 07794, Republic of Korea
| | - Tae-Woo Lee
- Department of Materials Science and Engineering, School of Chemical and Biological Engineering, Institute of Engineering Research, Research Institute of Advanced Materials, Soft Foundry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Tae-Hee Han
- Division of Materials Science and Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea
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Je H, Cho MJ, Kwon NY, Park SH, Kang MJ, Baek HI, Youn J, Han CW, Choi DH. Universal Polymeric Hole Transporting Material for Solution-Processable Green and Blue Thermally Activated Delayed Fluorescence OLEDs. ACS APPLIED MATERIALS & INTERFACES 2023; 15:9792-9799. [PMID: 36780202 DOI: 10.1021/acsami.2c23092] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
To obtain high-efficiency solution-processed organic light-emitting diodes (OLEDs), a hole transport material (HTM) capable of solution processing with excellent charge transport properties is required. In this study, a new vinyl polymer (PmCP) containing hole-transporting 1,3-di(9H-carbazol-9-yl)benzene (mCP) in the side chain was successfully synthesized via radical polymerization. PmCP showed good film-forming ability and thermal stability. Moreover, PmCP has a higher triplet energy value and hole mobility than poly(N-vinylcarbazole) (PVK) used as a reference HTM, which can be applied as a hole transport layer (HTL) in thermally activated delayed fluorescence (TADF) OLEDs, providing green and blue emissions. PmCP-based solution-processable TADF-OLEDs containing green- and blue-emitting layers were easily fabricated without damaging the lower HTL while using ethyl acetate as an orthogonal solvent. The corresponding OLEDs possess high external quantum efficiencies of 29.60% and 11.00% for the green- and blue-emitting devices, respectively. They show superior performances compared to PVK-based devices used as a reference. It was confirmed that PmCP as a solution-processable HTM can replace PVK and is universally applicable to both green- and blue-emitting devices.
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Affiliation(s)
- Hyeondoo Je
- 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
| | - 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
| | - 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, Korea
| | - Junho Youn
- LG Display, E2 Block LG Science Park 30, Magokjungang 10-ro, Gangseo-gu, Seoul 07796, Korea
| | - Chang Wook Han
- 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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Je H, Cho S, Kwon NY, Lee DW, Cho MJ, Choi DH. Customized Orthogonal Solvent System with Various Hole-Transporting Polymers for Highly Reproducible Solution-Processable Organic Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2022; 14:35969-35977. [PMID: 35894557 DOI: 10.1021/acsami.2c07659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Recently, various hosts and emitters for solution-processable thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs) have been developed. However, a few studies have been conducted on hole transport materials (HTMs) with differentiated solubility characteristics for manufacturing multilayer OLEDs using a solution process. Here, three new hole transport (HT) styrene polymers, PICz, PPBCz, and PTPCz, were synthesized by radical polymerization. Each of the polymers exhibited increases in their highest occupied molecular orbital (HOMO) levels and better hole-transporting abilities than poly(9-vinylcarbazole) (PVK) as a reference HT polymer. Furthermore, the three HT polymers exhibited different solubilities in toluene. Therefore, it was not possible to use a toluene solution to prepare the emitting layer (EML). To overcome this problem, ethyl acetate (EA), in which the three HT polymers are insoluble, was used as an orthogonal solvent to prepare an EML solution. In EA-solution-processed green-emitting TADF-OLEDs, the three HT-polymer-based devices displayed somewhat low turn-on voltages of 2.8 V and high external quantum efficiencies (EQEs) of >23%. These values are superior to those of a device with a PVK-HT layer. In addition, the devices manufactured with the EA solution showed high-performance reproducibility owing to the stable formation of each layer. In this study, we removed the HTM solubility constraint by dramatically changing the solvent for preparing the EML solution and provided an efficient strategy for the fabrication of OLED devices via solution processes in the future.
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Affiliation(s)
- Hyeondoo Je
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Seunguk Cho
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Na Yeon Kwon
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Dong Won Lee
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Korea
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Li C, Harrison AK, Liu Y, Zhao Z, Zeng C, Dias FB, Ren Z, Yan S, Bryce MR. Asymmetrical-Dendronized TADF Emitters for Efficient Non-doped Solution-Processed OLEDs by Eliminating Degenerate Excited States and Creating Solely Thermal Equilibrium Routes. Angew Chem Int Ed Engl 2022; 61:e202115140. [PMID: 34870886 PMCID: PMC9306820 DOI: 10.1002/anie.202115140] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Indexed: 12/03/2022]
Abstract
The mechanism of thermally activated delayed fluorescence (TADF) in dendrimers is not clear. We report that fully-conjugated or fully-nonconjugated structures cause unwanted degenerate excited states due to multiple identical dendrons, which limit their TADF efficiency. We have synthesized asymmetrical "half-dendronized" and "half-dendronized-half-encapsulated" emitters. By eliminating degenerate excited states, the triplet locally excited state is ≥0.3 eV above the lowest triplet charge-transfer state, assuring a solely thermal equilibrium route for an effective spin-flip process. The isolated encapsulating tricarbazole unit can protect the TADF unit, reducing nonradiative decay and enhancing TADF performance. Non-doped solution-processed devices reach a high external quantum efficiency (EQEmax ) of 24.0 % (65.9 cd A-1 , 59.2 lm W-1 ) with CIE coordinates of (0.24, 0.45) with a low efficiency roll-off and EQEs of 23.6 % and 21.3 % at 100 and 500 cd m-2 .
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Affiliation(s)
- Chensen Li
- State Key Laboratory of Chemical Resource EngineeringCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029China
- Chemistry DepartmentDurham UniversitySouth RoadDurhamDH1 3LEUK
| | | | - Yuchao Liu
- Key Laboratory of Rubber-PlasticsMinistry of EducationQingdao University of Science & TechnologyQingdao266042P.R. China
| | - Zhennan Zhao
- State Key Laboratory of Chemical Resource EngineeringCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029China
| | - Cheng Zeng
- Key Laboratory of Rubber-PlasticsMinistry of EducationQingdao University of Science & TechnologyQingdao266042P.R. China
| | | | - Zhongjie Ren
- State Key Laboratory of Chemical Resource EngineeringCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029China
| | - Shouke Yan
- State Key Laboratory of Chemical Resource EngineeringCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing100029China
- Key Laboratory of Rubber-PlasticsMinistry of EducationQingdao University of Science & TechnologyQingdao266042P.R. China
| | - Martin R. Bryce
- Chemistry DepartmentDurham UniversitySouth RoadDurhamDH1 3LEUK
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Li C, Harrison AK, Liu Y, Zhao Z, Zeng C, Dias FB, Ren Z, Yan S, Bryce MR. Asymmetrical‐Dendronized TADF Emitters for Efficient Non‐doped Solution‐Processed OLEDs by Eliminating Degenerate Excited States and Creating Solely Thermal Equilibrium Routes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202115140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Chensen Li
- State Key Laboratory of Chemical Resource Engineering College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
- Chemistry Department Durham University South Road Durham DH1 3LE UK
| | | | - Yuchao Liu
- Key Laboratory of Rubber-Plastics Ministry of Education Qingdao University of Science & Technology Qingdao 266042 P.R. China
| | - Zhennan Zhao
- State Key Laboratory of Chemical Resource Engineering College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Cheng Zeng
- Key Laboratory of Rubber-Plastics Ministry of Education Qingdao University of Science & Technology Qingdao 266042 P.R. China
| | - Fernando B. Dias
- Physics Department Durham University South Road Durham DH1 3LE UK
| | - Zhongjie Ren
- State Key Laboratory of Chemical Resource Engineering College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
| | - Shouke Yan
- State Key Laboratory of Chemical Resource Engineering College of Materials Science and Engineering Beijing University of Chemical Technology Beijing 100029 China
- Key Laboratory of Rubber-Plastics Ministry of Education Qingdao University of Science & Technology Qingdao 266042 P.R. China
| | - Martin R. Bryce
- Chemistry Department Durham University South Road Durham DH1 3LE UK
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Kwon G, Kim SH, Kim D, Lee K, Jeon Y, Park CS, You J. Vapor phase polymerization for electronically conductive nanopaper based on bacterial cellulose/poly(3,4-ethylenedioxythiophene). Carbohydr Polym 2021; 257:117658. [PMID: 33541667 DOI: 10.1016/j.carbpol.2021.117658] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/28/2020] [Accepted: 01/12/2021] [Indexed: 10/22/2022]
Abstract
Eco-friendly conductive polymer nanocomposites have garnered attention as an effective alternative for conventional conductive nanocomposites. Here, we report the fabrication and optimization of flexible, self-standing, and conductive bacterial cellulose/poly(3,4-ethylene dioxythiophene) (BC/PEDOT) nanocomposites using the vapor phase polymerization (VPP) method. Eco-friendly bacterial cellulose (BC) is used as a flexible matrix, and the highly conductive PEDOT polymer is introduced into the BC matrix to achieve electronic conductivity. We demonstrate that vapor phase polymerized BC/PEDOT composites exhibit more than 10 times lower sheet resistance (18 Ω/square) compared to solution polymerized BC/PEDOT (188 Ω/square). The resultant BC/PEDOT fabricated could be bent up to 100 times and completely rolled up without a notable decrease in electronic performance. Moreover, bent BC/PEDOT films enable operation of a green light-emitting diode (LED) light, indicating the flexibility and stability of conductive BC/PEDOT films. Overall, this study suggests a strategy for the development of eco-friendly, flexible, and conductive nanocomposite films.
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Affiliation(s)
- Goomin Kwon
- Department of Plant & Environmental New Resources and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, South Korea
| | - Se-Hyun Kim
- Department of Food Science and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin 17104, Republic of Korea
| | - Dabum Kim
- Department of Plant & Environmental New Resources and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, South Korea
| | - Kangyun Lee
- Department of Plant & Environmental New Resources and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, South Korea
| | - Youngho Jeon
- Department of Plant & Environmental New Resources and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, South Korea
| | - Cheon-Seok Park
- Department of Food Science and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, Yongin 17104, Republic of Korea.
| | - Jungmok You
- Department of Plant & Environmental New Resources and Biotechnology and Institute of Life Science and Resources, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 446-701, South Korea.
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7
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Liu D, Wei JY, Tian WW, Jiang W, Sun YM, Zhao Z, Tang BZ. Endowing TADF luminophors with AIE properties through adjusting flexible dendrons for highly efficient solution-processed nondoped OLEDs. Chem Sci 2020; 11:7194-7203. [PMID: 33033608 PMCID: PMC7499814 DOI: 10.1039/d0sc02194f] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 06/15/2020] [Indexed: 12/20/2022] Open
Abstract
The amalgamation of thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) properties, termed AIE-TADF, is a promising strategy to design novel robust luminescent materials. Herein, we transform 2,3,4,5,6-penta(9H-carbazol-9-yl)benzonitrile (5CzBN) from an ACQ molecule into an AIEgen by simply decorating the 5CzBN core with alkyl chain-linked spirobifluorene dendrons. By increasing the number of flexible dendrons, these materials can not only show obvious AIE-TADF characteristics and uniform film morphology, but can also exhibit better resistance to isopropyl alcohol, which are beneficial to fully solution-processed OLEDs. Notably, 5CzBN-PSP shows great device efficiency with an external quantum efficiency (EQE), current efficiency and power efficiency of 20.1%, 58.7 cd A-1 and 46.2 lm W-1, respectively and achieved record-breaking efficiency in solution-processed nondoped OLEDs based on AIE emitters. This work demonstrates a general approach to explore new efficient emitters by the marriage of AIE and TADF which could potentially improve their performance in various areas.
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Affiliation(s)
- Dan Liu
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research , Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device , School of Chemistry and Chemical Engineering , Southeast University , Nanjing , 211189 , China .
| | - Jing Yi Wei
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research , Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device , School of Chemistry and Chemical Engineering , Southeast University , Nanjing , 211189 , China .
| | - Wen Wen Tian
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research , Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device , School of Chemistry and Chemical Engineering , Southeast University , Nanjing , 211189 , China .
| | - Wei Jiang
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research , Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device , School of Chemistry and Chemical Engineering , Southeast University , Nanjing , 211189 , China .
| | - Yue Ming Sun
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research , Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device , School of Chemistry and Chemical Engineering , Southeast University , Nanjing , 211189 , China .
| | - Zheng Zhao
- 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 999077 , China .
| | - Ben Zhong Tang
- 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 999077 , China .
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Tang Y, Xie G, Yin X, Gao Y, Ding J, Yang C. Unravelling Electroplex Emission from Long-Range Charge Transfer Based on a Phosphorescent Dendrimer as the Electron Donor. J Phys Chem Lett 2020; 11:5255-5262. [PMID: 32519541 DOI: 10.1021/acs.jpclett.0c01482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We report the exceptionally long-range charge-transfer-induced electroplex between a neat dendrimer emitter and the adjacent electron-transporting layer (ETL). Interestingly, the electroplex exists even in the dilute emitter with a sufficiently low concentration (0.5 wt %) in an inert host. The iridium dendrimer with the carbazole-based dendritic ligands exhibits bright emission, peaking at 536 nm, with a full width at half-maximum (fwhm) of 77 nm in the devices without any ETLs. Unexpectedly, once the ETLs are inserted, a significantly broadened emission (fwhm = 115 nm) is detectable under electroluminescence. Taking advantage of the broad interfacial electroplex emission, a hybrid warm-white device was demonstrated by combining a sky-blue thermally activated delayed fluorescence emitter, exhibiting a maximum external quantum efficiency of 13.7%, which is an order of magnitude higher than that of any other reported works based on the electroplex white organic light-emitting diodes.
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Affiliation(s)
- Yang Tang
- Sauvage Center for Molecular Sciences, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan 430072, People's Republic of China
- College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - Guohua Xie
- Sauvage Center for Molecular Sciences, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan 430072, People's Republic of China
| | - Xiaojun Yin
- College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, People's Republic of China
| | - Yuhan Gao
- Sauvage Center for Molecular Sciences, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan 430072, People's Republic of China
| | - Junqiao Ding
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
| | - Chuluo Yang
- Sauvage Center for Molecular Sciences, Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan 430072, People's Republic of China
- College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, People's Republic of China
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9
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Recent progress in phosphorescent Ir(III) complexes for nondoped organic light-emitting diodes. Coord Chem Rev 2020. [DOI: 10.1016/j.ccr.2020.213283] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Jeong CH, Godumala M, Yoon J, Choi S, Kim YW, Choi DH, Cho MJ, Choi DH. Hole-Transporting Side-Chain Polymer Bearing a Thermally Crosslinkable Bicyclo[4.2.0]octa-1,3,5-trien-3-yl Group for High-Performing Thermally Activated Delayed Fluorescence OLED. ACS APPLIED MATERIALS & INTERFACES 2019; 11:17602-17609. [PMID: 31012568 DOI: 10.1021/acsami.9b03446] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A new side-chain polymer (X-TPACz) bearing hole-transporting pendant groups accompanying a thermally crosslinkable entity was synthesized using N-([1,1'-biphenyl]-4-yl)- N-(4-(9-(4-vinylbenzyl)-9 H-carbazol-3-yl)phenyl)bicyclo[4.2.0]octa-1(6),2,4-trien-3-amine (6) via addition polymerization. The X-TPACz could be spontaneously crosslinked without using any further reagents and showed a good film-forming property upon low-temperature thermal treatment. The thermal curing temperature for the X-TPACz film was optimized to be 180 °C based on a differential scanning calorimetry thermogram. Moreover, the thermal degradation temperature of X-TPACz measured to be over 467 °C using thermogravimetric analysis demonstrated that it shows excellent thermal stability. In particular, X-TPACz exhibits the highest occupied molecular orbital (HOMO) energy level to be -5.26 eV, which is beneficial for facile hole injection and transportation. Consequently, the thermally activated delayed fluorescence organic light-emitting diodes fabricated using X-TPACz as the hole-transporting material showed state-of-the-art performances with a low turn-on voltage ( Von) of only 2.7 V and a high external quantum efficiency (EQE) of 19.18% with a high current efficiency (CE) of 66.88 cd/A and a high power efficiency (PE) of 60.03 lm/W, which are highly superior to those of the familiar poly(9-vinylcarbazole) (PVK)-based devices ( Von = 3.9 V, EQE of 17.42%, with CE of 58.33 cd/A and PE of 33.32 lm/W). The extremely low turn-on voltage and high EQE were found to be due to the higher-lying highest occupied molecular orbital energy level ( EHOMO = -5.23 eV) and better hole-transporting property of X-TPACz than those of PVK.
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Affiliation(s)
- Cheol Hun Jeong
- Department of Chemistry, Research Institute for Natural Sciences , Korea University , 145 Anam-ro , Sungbuk-gu, Seoul 02841 , Korea
| | - Mallesham Godumala
- Department of Chemistry, Research Institute for Natural Sciences , Korea University , 145 Anam-ro , Sungbuk-gu, Seoul 02841 , Korea
| | - Jiwon Yoon
- Department of Chemistry, Research Institute for Natural Sciences , Korea University , 145 Anam-ro , Sungbuk-gu, Seoul 02841 , Korea
| | - Suna Choi
- Department of Chemistry, Research Institute for Natural Sciences , Korea University , 145 Anam-ro , Sungbuk-gu, Seoul 02841 , Korea
| | - Yong Woo Kim
- LT Materials , 113-19, Dangha-Ro , Namsa-Myeon, Cheoin-Gu, Yongin-Si , Gyeonggi-Do 17118 , Korea
| | - Dae Hyuk Choi
- LT Materials , 113-19, Dangha-Ro , Namsa-Myeon, Cheoin-Gu, Yongin-Si , Gyeonggi-Do 17118 , Korea
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Sciences , Korea University , 145 Anam-ro , Sungbuk-gu, Seoul 02841 , Korea
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Sciences , Korea University , 145 Anam-ro , Sungbuk-gu, Seoul 02841 , Korea
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Liu D, Tian W, Feng Y, Zhang X, Ban X, Jiang W, Sun Y. Achieving 20% External Quantum Efficiency for Fully Solution-Processed Organic Light-Emitting Diodes Based on Thermally Activated Delayed Fluorescence Dendrimers with Flexible Chains. ACS APPLIED MATERIALS & INTERFACES 2019; 11:16737-16748. [PMID: 30986027 DOI: 10.1021/acsami.8b22662] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Actualizing high-efficiency thermally activated delayed fluorescent (TADF) organic light-emitting diodes (OLEDs) with fully wet processes is of great significance to the development of purely organic electroluminescence and the application of large-area OLED displays. Herein, new strategies are proposed to develop the TADF dendrimers with tunable colors by adjusting the way of linking branches to the core and the numbers of peripheral branches. Due to an energy gradient and efficient exciton utilization in the core-dendron system, the solution-processed OLEDs with the four dendrimers 5CzBN-O-Cz, 5CzBN-O-2Cz, 5CzBN-Cz, and 5CzBN-2Cz all give rise to low turn-on voltages and great device efficiency. Notably, 5CzBN-2Cz affords record-high fully solution-processed TADF OLEDs with external quantum efficiency of above 20%, which is significantly comparable to the efficiency of TADF OLEDs based on vacuum deposition. The work offers a guideline for designing solution-processable materials, paving the way toward practical applications of large-area fully solution-processed OLEDs.
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Affiliation(s)
- Dan Liu
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering , Southeast University , Nanjing 211189 , China
| | - Wenwen Tian
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering , Southeast University , Nanjing 211189 , China
| | - Yingli Feng
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering , Southeast University , Nanjing 211189 , China
| | - Xusheng Zhang
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering , Southeast University , Nanjing 211189 , China
| | - Xinxin Ban
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering , Southeast University , Nanjing 211189 , China
- Jiangsu Key Laboratory of Function Control Technology for Advanced Materials, School of Chemical Engineering , Huaihai Institute of Technology , Lianyungang , Jiangsu 222005 , China
| | - Wei Jiang
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering , Southeast University , Nanjing 211189 , China
| | - Yueming Sun
- Jiangsu Province Hi-Tech Key Laboratory for Bio-Medical Research, Jiangsu Engineering Laboratory of Smart Carbon-Rich Materials and Device, School of Chemistry and Chemical Engineering , Southeast University , Nanjing 211189 , China
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12
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Zhang B, Cheng Y. Recent Advances in Conjugated TADF Polymer Featuring in Backbone‐Donor/Pendant‐Acceptor Structure: Material and Device Perspectives. CHEM REC 2018; 19:1624-1643. [PMID: 30511821 DOI: 10.1002/tcr.201800152] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/07/2018] [Indexed: 01/11/2023]
Affiliation(s)
- Baohua Zhang
- Center for Advanced Analytical Science, c/o School of Chemistry and Chemical EngineeringGuangzhou University, Guangzhou 510006 P. R. China
| | - Yanxiang Cheng
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022 P. R. China
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13
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Wang Y, Wang S, Ding J, Wang L. Multinuclear Iridium Complex Encapsulated by Oligocarbazole Dendrons for Enhanced Nondoped Device Efficiency. ACS OMEGA 2018; 3:15308-15314. [PMID: 31458192 PMCID: PMC6643811 DOI: 10.1021/acsomega.8b02579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Accepted: 10/30/2018] [Indexed: 06/10/2023]
Abstract
A dendritic multinuclear Ir complex, namely Cz-3IrB-IrG, has been designed and synthesized by introducing the second-generation oligocarbazole dendrons into its periphery. Because of the characteristic encapsulation, the intermolecular interactions could be effectively alleviated to prevent the unwanted triplet-triplet annihilation stemmed from the outer blue Ir complexes. Compared with 3IrB-IrG in the absence of dendrons, the film photoluminescence quantum yield of Cz-3IrB-IrG is greatly increased from 0.46 to 0.82 together with a small blue-shifted emission from 524 to 520 nm. On the basis of Cz-3IrB-IrG as the emitting layer alone, the nondoped device realizes a promising luminous efficiency of 40.9 cd/A (12.0%), much higher than that of 3IrB-IrG (32.6 cd/A, 9.7%). The obtained improvement clearly indicates that further dendronization toward multinuclear Ir complex will provide an alternative strategy to construct highly efficient phosphors used for nondoped phosphorescent organic light-emitting diodes.
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Affiliation(s)
- Yang Wang
- State
Key Laboratory of Polymer Physics and Chemistry, Changchun Institute
of Applied Chemistry, Chinese Academy of
Sciences, Changchun 130022, P. R. China
- Department
of Materials Science and Engineering and The Shenzhen Key Laboratory
for Printed Organic Electronics, Southern
University of Science and Technology of China (SUSTech), Shenzhen 518055, 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
| | - Junqiao Ding
- State
Key Laboratory of Polymer Physics and Chemistry, Changchun Institute
of Applied Chemistry, Chinese Academy of
Sciences, Changchun 130022, P. R. China
- University
of Science and Technology of China, Hefei 230026, 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
- University
of Science and Technology of China, Hefei 230026, P. R. China
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14
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Matsuoka K, Albrecht K, Nakayama A, Yamamoto K, Fujita K. Highly Efficient Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes with Fully Solution-Processed Organic Multilayered Architecture: Impact of Terminal Substitution on Carbazole-Benzophenone Dendrimer and Interfacial Engineering. ACS APPLIED MATERIALS & INTERFACES 2018; 10:33343-33352. [PMID: 30187748 DOI: 10.1021/acsami.8b09451] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A series of second-generation carbazole-benzophenone dendrimer substituted by several functional groups at terminal positions (subG2B) was investigated toward a thermally activated delayed fluorescence (TADF) emitter for nondoped emissive layer (EML) application in a solution-processed organic light-emitting diode (OLED). Substitution was found to dramatically alter the photophysical properties of the dendritic TADF emitters. The introduction of tert-butyl and phenyl group endows the subG2Bs with aggregation-induced emission enhancement character by suppression of internal conversion in singlet excited states. In the meantime, the introduction of a methoxy group resulted in aggregation-caused quenching character. The device performance of the OLED, where subG2B neat films were incorporated as nondoped EMLs, was found to be highly enhanced by adopting fully solution-processed organic multilayer architecture in comparison to the devices with a vacuum-deposited electron transporting layer (ETL), achieving a maximum external quantum efficiency of 17.0%. Such improvement was attributable to the improved carrier balance via intermixing at solution-processed EML/ETL interfaces. It was also found that the post-thermal annealing of the OLED at appropriate temperatures could be beneficial to enhance OLED performance by promoting the intermixing EML/ETL interface to some extent. Our findings emphasize the potential utility of dendritic TADF emitters in the solution-processed TADF-OLED and increase the importance to manipulate dendrimer/small molecule interfaces.
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Affiliation(s)
- Kenichi Matsuoka
- Institute for Materials Chemistry and Engineering , Kyushu University , 6-1 Kasuga koen , Kasuga, Fukuoka 816-8580 , Japan
| | | | - Akira Nakayama
- Institute for Catalysis , Hokkaido University , Sapporo 001-0021 , Japan
| | | | - Katsuhiko Fujita
- Institute for Materials Chemistry and Engineering , Kyushu University , 6-1 Kasuga koen , Kasuga, Fukuoka 816-8580 , Japan
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15
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McEwan JA, Clulow AJ, Nelson A, Jansen-van Vuuren RD, Burn PL, Gentle IR. Morphology of OLED Film Stacks Containing Solution-Processed Phosphorescent Dendrimers. ACS APPLIED MATERIALS & INTERFACES 2018; 10:3848-3855. [PMID: 29356504 DOI: 10.1021/acsami.7b15542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Organic light-emitting devices containing solution-processed emissive dendrimers can be highly efficient. The most efficient devices contain a blend of the light-emitting dendrimer in a host and one or more charge-transporting layers. Using neutron reflectometry measurements with in situ photoluminescence, we have investigated the structure of the as-formed film as well as the changes in film structure and dendrimer emission under thermal stress. It was found that the as-formed film stacks comprising poly(3,4-ethylenedioxythiophene):polystyrene sulfonate/host:dendrimer/1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (where the host was deuterated 4,4'-N,N'-di(carbazolyl)biphenyl or tris(4-carbazol-9-ylphenyl)amine, the host:dendrimer layer was solution-processed, and the 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene evaporated) had well-defined interfaces, indicating good wetting of each of the layers by the subsequently deposited layer. Upon thermal annealing, there was no change in the poly(3,4-ethylenedioxythiophene):polystyrene sulfonate/host:dendrimer interface, but once the temperature reached above the Tg of the host:dendrimer layer, it became a supercooled liquid into which 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene dissolved. When the film stacks were held at a temperature just above the onset of the diffusion process, they underwent an initial relatively fast diffusion process before reaching a quasi-stable state at that temperature.
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Affiliation(s)
- Jake A McEwan
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Andrew J Clulow
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Andrew Nelson
- Australian Nuclear Science and Technology Organisation , Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Ross D Jansen-van Vuuren
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Paul L Burn
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland , Brisbane, QLD 4072, Australia
| | - Ian R Gentle
- Centre for Organic Photonics & Electronics, School of Chemistry and Molecular Biosciences, The University of Queensland , Brisbane, QLD 4072, Australia
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16
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Zhou N, Wang S, Xiao Y, Li X. A Novel trans
-1-(9-Anthryl)-2-phenylethene Derivative Containing a Phenanthroimidazole Unit for Application in Organic Light-Emitting Diodes. Chem Asian J 2017; 13:81-88. [DOI: 10.1002/asia.201701371] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Revised: 10/17/2017] [Indexed: 11/11/2022]
Affiliation(s)
- Nonglin Zhou
- School of Chemical Engineering and Technology; Tianjin University; Tianjin 300354 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin); Tianjin 300072 China
| | - Shirong Wang
- School of Chemical Engineering and Technology; Tianjin University; Tianjin 300354 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin); Tianjin 300072 China
| | - Yin Xiao
- School of Chemical Engineering and Technology; Tianjin University; Tianjin 300354 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin); Tianjin 300072 China
| | - Xianggao Li
- School of Chemical Engineering and Technology; Tianjin University; Tianjin 300354 China
- Collaborative Innovation Center of Chemical Science and Engineering (Tianjin); Tianjin 300072 China
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