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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: 31] [Impact Index Per Article: 15.5] [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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Cheng WC, Tsai MR, Chen SA. Creation of Dual Thermally Activated Delayed-Fluorescence Exciplexes in a Bulk Emitting Layer and Its Interface with an Electron Transport Layer for Promoting the Performance of Thermally Activated Delayed-Fluorescence Organic Light-Emitting Diodes Fabricated by a Solution Process. ACS APPLIED MATERIALS & INTERFACES 2023. [PMID: 37339450 DOI: 10.1021/acsami.3c06128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2023]
Abstract
An exciplex, which is composed of electron donor and acceptor molecules and formed by intermolecular charge transfer, is an excited-state species that is able to emit light or transfer its energy to a lower-energy emitter. In reported exciplex-based organic light-emitting diodes (OLEDs), their working mechanism is to generate exciplexes either in the bulk emitting layer (bulk exciplex) or at its interface with an electron transport layer (interface exciplex); both types give promising device performance. Here, we propose a novel strategy of creating both types of exciplexes simultaneously (dual exciplexes) for the generation of more exciplexes for better device performance as indicated in the improved photoluminescence quantum yield (PLQY). Impressively, the dual exciplex-based device with blue thermally activated delayed fluorescence (TADF) emitter 9,9-dimethyl-9,10-dihydroacridine-2,4,6-triphenyl-1,3,5-triazine (DMAC-TRZ) exhibits a record-high maximum external quantum efficiency (EQEmax) of 26.7% among the solution-processed TADF blue OLEDs. By further doping with the red-emitting phosphor emitter into the EML, the white device also gives a record-high EQEmax of 24.1% among the solution-processed TADF-phosphor hybrid white OLEDs (T-P WOLEDs) with the Commission Internationale de L'Eclairage (CIE) coordinates of (0.34, 0.42), color rendering index of 70, and correlated color temperature of 5198 K. Furthermore, both blue and white devices show an ultralow efficiency roll-off with external quantum efficiencies at a practical brightness value of 1000 cd m-2 (EQE1000) of 25.1 and 23.9%, respectively. This is the first report of employing a dual exciplex-based OLED with excellent device performance.
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Affiliation(s)
- Wei-Chih Cheng
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Meng Rong Tsai
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Show-An Chen
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
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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: 5] [Impact Index Per Article: 2.5] [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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Hybrid white organic light‐emitting diodes based on platinum complex. J CHIN CHEM SOC-TAIP 2022. [DOI: 10.1002/jccs.202200113] [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]
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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: 0.3] [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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Phenanthroimidazole substituted imidazo[1,2-a]pyridine derivatives for deep-blue electroluminescence with CIEy ∼ 0.08. J Photochem Photobiol A Chem 2022. [DOI: 10.1016/j.jphotochem.2021.113600] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Nie K, Ma X, Lin P, Kumar N, Wang L, Mei L. Synthesis and luminescence properties of apatite-type red-emitting Ba2La8(GeO4)6O2:Eu3+ phosphors. J RARE EARTH 2021. [DOI: 10.1016/j.jre.2020.10.019] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Zhang Y, Li J, Quan Y, Ye S, Cheng Y. Solution-Processed White Circularly Polarized Organic Light-Emitting Diodes Based on Chiral Binaphthyl Emitters. Chemistry 2020; 27:589-593. [PMID: 32881099 DOI: 10.1002/chem.202003721] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/01/2020] [Indexed: 11/08/2022]
Abstract
By combining the blue and orange CPL or functionalized bis-benzoxanethones emitters (S-/R-BN-tCz and S-/R-BN-PXZ), warm white CP-OLEDs were fabricated using solution-processed single emitting layer strategy. The successful realization of white CP-EL benefited from the same stable binaphthyl chirality and similar rigid structure of the two emissive CPL emitters. The devices exhibited the low turn-on voltage of ≈4.3 V, maximum luminance of ≈10200 cd m-2 and maximum current efficiency of ≈2.0 cd A-1 . Most significantly, the devices with CIE coordinates of (0.32, 0.45) displayed intense CP-EL signals in the spectral range of 450 to 650 nm, and showed stable gEL values of ≈10-3 as the luminance increased from 100 to 6000 cd m-2 . To the best of our knowledge, this work provides for the first time a simple and feasible strategy to fabricate solution-processed white CP-OLEDs based on the co-doping of the CPL emitters.
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Affiliation(s)
- Yu Zhang
- Key Laboratory of High Performance Polymer Materials and Technology, of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.,Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory, of Advanced Organic Materials, School of Chemistry and Chemical, Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Jie Li
- Key Laboratory of High Performance Polymer Materials and Technology, of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.,Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory, of Advanced Organic Materials, School of Chemistry and Chemical, Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Yiwu Quan
- Key Laboratory of High Performance Polymer Materials and Technology, of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.,Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory, of Advanced Organic Materials, School of Chemistry and Chemical, Engineering, Nanjing University, Nanjing, 210023, P. R. China
| | - Shanghui Ye
- Key Laboratory of High Performance Polymer Materials and Technology, of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.,Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory, of Advanced Organic Materials, School of Chemistry and Chemical, Engineering, Nanjing University, Nanjing, 210023, P. R. China.,Key Laboratory for Organic Electronics & Information Displays, (KLOEID), Institute of Advanced Materials, National Synergistic Innovation, Center, for Advanced Materials (SICAM), Nanjing University of Posts and Telecommunications, Nanjing, 210023, P. R. China
| | - Yixiang Cheng
- Key Laboratory of High Performance Polymer Materials and Technology, of Ministry of Education, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210023, P. R. China.,Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory, of Advanced Organic Materials, School of Chemistry and Chemical, Engineering, Nanjing University, Nanjing, 210023, P. R. China
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