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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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Lee H, Nam H, Yeo HJ, Yang H, Kim T. High Efficiency over 15% by Breaking the Theoretical Efficiency Limit of Fluorescent Organic Light-Emitting Diodes with Localized Surface Plasmon Resonance Effects. ACS APPLIED MATERIALS & INTERFACES 2023; 15:35290-35301. [PMID: 37458705 DOI: 10.1021/acsami.3c07064] [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
The theoretical efficiency limit of fluorescence organic light-emitting diodes (OLEDs) was successfully surpassed by utilizing the localized surface plasmon resonance (LSPR) effect with conventional emissive materials. The interaction between polaritons and plexcitons generated during the LSPR process was also analyzed experimentally. As a result, the external quantum efficiency (EQE) increased dramatically from 6.01 to 15.43%, significantly exceeding the theoretical efficiency limit of fluorescent OLEDs. Additionally, we introduced a new concept of the LSPR effect, called "LSPR sensitizer", which allowed for simultaneous improvement in color conversion and efficiency through cascade transfer of the LSPR effect. To the best of our knowledge, the EQE and the current efficiency of our LSPR-OLED are the highest among LSPR-based fluorescent OLEDs to date.
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Affiliation(s)
- Hakjun Lee
- Department of Information Display, Hongik University, Seoul 04066, Korea
| | - Hyewon Nam
- Department of Information Display, Hongik University, Seoul 04066, Korea
| | - Hyo-Jin Yeo
- Department of Materials Science and Engineering, Hongik University, Seoul 04066, Korea
| | - Heesun Yang
- Department of Materials Science and Engineering, Hongik University, Seoul 04066, Korea
| | - Taekyung Kim
- Department of Information Display, Hongik University, Seoul 04066, Korea
- Department of Materials Science and Engineering, Hongik University, Sejong 30016, Korea
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3
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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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Yiu TC, Gnanasekaran P, Chen WL, Lin WH, Lin MJ, Wang DY, Lu CW, Chang CH, Chang YJ. Multifaceted Sulfone-Carbazole-Based D-A-D Materials: A Blue Fluorescent Emitter as a Host for Phosphorescent OLEDs and Triplet-Triplet Annihilation Up-Conversion Electroluminescence. ACS APPLIED MATERIALS & INTERFACES 2023; 15:1748-1761. [PMID: 36576167 DOI: 10.1021/acsami.2c21294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Electroluminescence (EL) from the singlet-excited (S1) state is the ideal choice for stable, high-performing deep-blue organic light-emitting diodes (OLEDs) owing to the advantages of an adequately short radiative lifetime, improved device durability, and low cost, which are the most important criteria for their commercialization. Herein, we present the design and synthesis of three donor-acceptor-donor (D-A-D)-configured deep-blue fluorescent materials (denoted as TC-1, TC-2, and TC-3) composed of a thioxanthone or diphenyl sulfonyl acceptor and phenyl carbazolyl donor. These systems exhibit strong deep-blue photoluminescence (422-432 nm) in solutions and redshifted emission (472-486 nm) in thin films. The solid-state photoluminescence quantum yield (PLQY) was estimated to be 78 and 94% for TC-2 and TC-3, respectively. TC-2 and TC-3 possess good molecular packing and large molecular cross-sectional areas, which not only improves the PLQY but enhances the triplet-triplet annihilation up-conversion (TTAUC) efficiency of fluorescent emitters. Furthermore, both compounds were applied as an acceptor for confirming their TTAUC property using bis(2-methyldibenzo[f,h]quinoxaline)(acetylacetonate)iridium(III) (Ir(MDQ)2acac) as the sensitizer. Non-doped OLEDs based on TC-2 and TC-3 exhibit blue EL in the 461-476 nm range. In particular, TC-3 exhibits a maximum external quantum efficiency (EQEmax) of 5.1%, and its EL maximum is 476 nm. In addition, the three emitters were employed as hosts in red OLEDs using bis(1-phenylisoquinoline)(acetylacetonate)iridium(III) (Ir(piq)2acac) as the phosphorescent dopant. The red phosphorescent OLEDs based on TC-1, TC-2, and TC-3 achieve excellent EQEmax values of 21.6, 22.9, and 21.9%, respectively, and peak luminance efficiencies of 12.0, 14.0, and 12.3 cd A-1. These results highlight these fluorophores' versatility and promising prospects in practical OLED applications.
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Affiliation(s)
- Tsz Chung Yiu
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan
| | | | - Wei-Ling Chen
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Wei-Han Lin
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Ming-Jun Lin
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Di-Yan Wang
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan
| | - Chin-Wei Lu
- Department of Applied Chemistry, Providence University, Taichung 43301, Taiwan
| | - Chih-Hao Chang
- Department of Electrical Engineering, Yuan Ze University, Taoyuan 32003, Taiwan
| | - Yuan Jay Chang
- Department of Chemistry, Tunghai University, Taichung 40704, Taiwan
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Hung MK, Chung ST, Sharma S, Tsai KW, Wu JY, Chen SA. Poly(acridan-grafted biphenyl germanium) with High Triplet Energy as a Universal Host for High-Efficiency Thermally Activated Delayed Fluorescence Full-Color Devices and Their Hybrid with Phosphor for White Light Electroluminescence. ACS APPLIED MATERIALS & INTERFACES 2022; 14:55873-55885. [PMID: 36475581 DOI: 10.1021/acsami.2c17703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Developing an effective host for highly efficient full-color electroluminescence devices through a solution-process is still a challenge at present. Here, we use the σ-π conjugated polymer, poly(acridan grafted biphenyl germanium) P(DMAC-Ge), having the highest triplet energy (ET) 2.86 eV among conjugated polymers as the host in sky-blue phosphorescence, TADFs (blue (B), green (G), and red (R)), and hybrid white (W) PLEDs. Upon doping with a sky-blue phosphor-emitter (Firpic), the resulting device gives the high EQEmax 19.7% with Bmax 24,918 cd/m2. The Ge-containing polymer backbone can provide as a channel for electron transport and charge trap into the guest as manifested by the electroluminescence dynamics. Further introducing the bipolar material DCzPPy as cohost, the devices with a sky-blue phosphor (Firpic) and each of the TADF-guests─B (DMAC-TRZ), G (DACT-II), and R (TPA-DCPP) in the EML─achieve the high maximum EQEs as 19.7%, 19.4%, 21.5% and 3.82% with the emission peaks at 470, 485, 508, and 630 nm, respectively. As the three guests (DMAC-TRZ, Ir-O, Ir-R) are doped together into the emitting layer, we obtain a TADF-phosphor (T-P) hybrid white PLED giving a record-high EQE 22.5% among the solution processed hybrid OLED with CIE (0.34, 0.40) and Bmax 28,945 cd/m2. These results manifest that P(DMAC-Ge) is a potential polymer host for full-color TADF and hybrid white light PLEDs with high performance.
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Affiliation(s)
- Miao-Ken Hung
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Shang-Ting Chung
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Sunil Sharma
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Kuen-Wei Tsai
- Department of Chemical Engineering, National Tsing-Hua University, Hsinchu 30013, Taiwan
| | - Jun-Yi Wu
- 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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Lee DW, Hwang J, Kim HJ, Lee H, Ha JM, Woo HY, Park S, Cho MJ, Choi DH. Novel V-Shaped Bipolar Host Materials for Solution-Processed Thermally Activated Delayed Fluorescence OLEDs. ACS APPLIED MATERIALS & INTERFACES 2021; 13:49076-49084. [PMID: 34628848 DOI: 10.1021/acsami.1c14098] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Three V-shaped host molecules with a cyclohexane linker were successfully synthesized for thermally activated delayed fluorescence organic light-emitting diodes (TADF-OLEDs). The unipolar host molecules, BBCzC and BTDC, contained two 9-phenyl-9H-3,9'-bicarbazole (PBCz) moieties and two 2,12-di-tert-butyl-7-phenyl-5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene (PDBNA) moieties, respectively. BCzTC, a bipolar host molecule, consisted of a donor unit, PBCz, and an acceptor unit, PDBNA, connected by a cyclohexane linker. Three host molecules showed good solubility in various organic solvents, making them suitable for solution processing. Among the solution-processed green TADF-OLEDs using three host molecules and a green TADF emitter, the one with BCzTC showed the highest external quantum efficiency of up to 30% with a high power efficiency of 71 lm W-1 and a current efficiency of 102 cd A-1. Compared with BBCzC and BTDC, BCzTC exhibited a relatively high photoluminescence quantum yield (PLQY), an excellent balance in hole and electron transport properties in the emitting layer, and more efficient energy transfer to the emitter, giving such an excellent device performance.
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Affiliation(s)
- Dong Won Lee
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jinhyo Hwang
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Hyung Jong Kim
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Hyoseong Lee
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jung Min Ha
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Han Young Woo
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Sungnam Park
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Science, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
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Hu J, Wang Y, Li Q, Shao S, Wang L, Jing X, Wang F. Hyperfluorescent polymers enabled by through-space charge transfer polystyrene sensitizers for high-efficiency and full-color electroluminescence. Chem Sci 2021; 12:13083-13091. [PMID: 34745539 PMCID: PMC8513886 DOI: 10.1039/d1sc04389g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 09/01/2021] [Indexed: 01/05/2023] Open
Abstract
Fluorescent polymers are suffering from low electroluminescence efficiency because triplet excitons formed by electrical excitation are wasted through nonradiative pathways. Here we demonstrate the design of hyperfluorescent polymers by employing through-space charge transfer (TSCT) polystyrenes as sensitizers for triplet exciton utilization and classic fluorescent chromophores as emitters for light emission. The TSCT polystyrene sensitizers not only have high reverse intersystem crossing rates for rapid conversion of triplet excitons into singlet ones, but also possess tunable emission bands to overlap the absorption spectra of fluorescent emitters with different bandgaps, allowing efficient energy transfer from the sensitizers to emitters. The resultant hyperfluorescent polymers exhibit full-color electroluminescence with peaks expanding from 466 to 640 nm, and maximum external quantum efficiencies of 10.3–19.2%, much higher than those of control fluorescent polymers (2.0–3.6%). These findings shed light on the potential of hyperfluorescent polymers in developing high-efficiency solution-processed organic light-emitting diodes and provide new insights to overcome the electroluminescence efficiency limitation for fluorescent polymers. Hyperfluorescent polymers with high efficiency and full-color electroluminescence are developed by using through-space charge transfer polystyrenes as sensitizers for exciton utilization and fluorescent chromophores as emitters for light emission.![]()
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Affiliation(s)
- Jun Hu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences Changchun Jilin 130022 China .,School of Applied Chemistry and Engineering, University of Science and Technology of China Hefei Anhui 230026 China
| | - Yinuo Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences Changchun Jilin 130022 China .,School of Applied Chemistry and Engineering, University of Science and Technology of China Hefei Anhui 230026 China
| | - Qiang Li
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences Changchun Jilin 130022 China .,School of Applied Chemistry and Engineering, University of Science and Technology of China Hefei Anhui 230026 China
| | - Shiyang Shao
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences Changchun Jilin 130022 China
| | - Lixiang Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences Changchun Jilin 130022 China .,School of Applied Chemistry and Engineering, University of Science and Technology of China Hefei Anhui 230026 China
| | - Xiabin Jing
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences Changchun Jilin 130022 China
| | - Fosong Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences Changchun Jilin 130022 China
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Xu H, Lin J, Jiang X, Jin Y, Lin Z, Zhang X, Li X, Yang H, Wu Z. Study on the difference in exciton generation processes for a single host and exciplex-type co-host. OPTICS LETTERS 2021; 46:4840-4843. [PMID: 34598213 DOI: 10.1364/ol.439516] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 09/01/2021] [Indexed: 06/13/2023]
Abstract
We distinctly reveal the difference in the exciton generation processes in phosphorescent organic light-emitting devices with an exciplex-type co-host and a single host. Excitons in the co-host consisting of 4,4,4-tris(N-carbazolyl)-triphenylamine and 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene are created via efficient energy transfer from the exciplex to the phosphorescent dopant. In contrast, excitons in the single host of 4,4,4-tris(N-carbazolyl)-triphenylamine are formed by the combination of holes and electrons trapped by the phosphorescent dopants. The optimized device utilizing the co-host system exhibits highly superior performance relative to the single-host device. The maximum external quantum efficiency and maximum luminance are 14.88% and 90,700cd/m2 for the co-host device, being 1.6 times and 3.6 times the maximum external efficiency and maximum luminance for the single-host device, respectively. Significantly, the critical current density, evaluating the device efficiency roll-off characteristic, is as high as 327.8mA/cm2, which is highly superior to 120.8mA/cm2 for the single-host device, indicating the notable alleviation in efficiency roll-off for the co-host device. The significant improvement in device performance is attributed to eliminating the exciton quenching resulting from the captured holes and the efficient energy transfer from the exciplex-type co-host to the phosphorescent emitter incurred by the reverse intersystem crossing process.
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Nam S, Kim JW, Bae HJ, Maruyama YM, Jeong D, Kim J, Kim JS, Son W, Jeong H, Lee J, Ihn S, Choi H. Improved Efficiency and Lifetime of Deep-Blue Hyperfluorescent Organic Light-Emitting Diode using Pt(II) Complex as Phosphorescent Sensitizer. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2100586. [PMID: 34137208 PMCID: PMC8373157 DOI: 10.1002/advs.202100586] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 04/20/2021] [Indexed: 05/19/2023]
Abstract
Although the organic light-emitting diode (OLED) has been successfully commercialized, the development of deep-blue OLEDs with high efficiency and long lifetime remains a challenge. Here, a novel hyperfluorescent OLED that incorporates the Pt(II) complex (PtON7-dtb) as a phosphorescent sensitizer and a hydrocarbon-based and multiple resonance-based fluorophore as an emitter (TBPDP and ν-DABNA) in the device emissive layer (EML), is proposed. Such an EML system can promote efficient energy transfer from the triplet excited states of the sensitizer to the singlet excited states of the fluorophore, thus significantly improving the efficiency and lifetime of the device. As a result, a deep-blue hyperfluorescent OLED using a multiple resonance-based fluorophore (ν-DABNA) with Commission Internationale de L'Eclairage chromaticity coordinate y below 0.1 is demonstrated, which attains a narrow full width at half maximum of ≈17 nm, fourfold increased maximum current efficiency of 48.9 cd A-1 , and 19-fold improved half-lifetime of 253.8 h at 1000 cd m-2 compared to a conventional phosphorescent OLED. The findings can lead to better understanding of the hyperfluorescent OLEDs with high performance.
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Affiliation(s)
- Sungho Nam
- Samsung Advanced Institute of TechnologySamsung Electronics Co., Ltd.130 Samsung‐roSuwon‐siGyeonggi‐do16678Republic of Korea
| | - Ji Whan Kim
- Samsung Advanced Institute of TechnologySamsung Electronics Co., Ltd.130 Samsung‐roSuwon‐siGyeonggi‐do16678Republic of Korea
| | - Hye Jin Bae
- Samsung Advanced Institute of TechnologySamsung Electronics Co., Ltd.130 Samsung‐roSuwon‐siGyeonggi‐do16678Republic of Korea
| | - Yusuke Makida Maruyama
- Samsung Advanced Institute of TechnologySamsung Electronics Co., Ltd.130 Samsung‐roSuwon‐siGyeonggi‐do16678Republic of Korea
| | - Daun Jeong
- Data and Information Technology CenterSamsung Electronics Co., Ltd.1 Samsungjeonja‐roHwaseong‐siGyeonggi‐do18448Republic of Korea
| | - Joonghyuk Kim
- Samsung Advanced Institute of TechnologySamsung Electronics Co., Ltd.130 Samsung‐roSuwon‐siGyeonggi‐do16678Republic of Korea
| | - Jong Soo Kim
- Samsung Advanced Institute of TechnologySamsung Electronics Co., Ltd.130 Samsung‐roSuwon‐siGyeonggi‐do16678Republic of Korea
| | - Won‐Joon Son
- Data and Information Technology CenterSamsung Electronics Co., Ltd.1 Samsungjeonja‐roHwaseong‐siGyeonggi‐do18448Republic of Korea
| | - Hyein Jeong
- Display Research CenterSamsung Display Co.1 Samsung‐roYongin‐siGyeonggi‐do17113Republic of Korea
| | - Jaesang Lee
- Department of Electrical and Computer EngineeringInter‐University Semiconductor Research CenterSeoul National UniversitySeoul08826Republic of Korea
| | - Soo‐Ghang Ihn
- Samsung Advanced Institute of TechnologySamsung Electronics Co., Ltd.130 Samsung‐roSuwon‐siGyeonggi‐do16678Republic of Korea
| | - Hyeonho Choi
- Samsung Advanced Institute of TechnologySamsung Electronics Co., Ltd.130 Samsung‐roSuwon‐siGyeonggi‐do16678Republic of Korea
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10
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Ran Y, Yang G, Liu Y, Han W, Gao G, Su R, Bin Z, You J. A methyl-shield strategy enables efficient blue thermally activated delayed fluorescence hosts for high-performance fluorescent OLEDs. MATERIALS HORIZONS 2021; 8:2025-2031. [PMID: 34846479 DOI: 10.1039/d1mh00530h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Here, we report a novel methyl-shield strategy to design ideal TADF hosts for the improvement of the performance of TSF-OLEDs. The methyl group on the xanthone acceptor acts like a shield to protect the luminance center from close intermolecular hydrogen bonding with adjacent molecules, thus alleviating exciton quenching, and meanwhile the small size of the methyl group almost does not disturb the π-π stacking between acceptors, thus maintaining fast electron-transport pathways. dMeACRXTO having two methyl shields is exploited as the host to achieve a record-high EQE of 32.3%, which represents the first report of an EQE above 30% in TSF-OLEDs.
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Affiliation(s)
- You Ran
- Key Laboratory of Green Chemistry and Technology of Ministry of Education, College of Chemistry, Sichuan University, 29 Wangjiang Road, Chengdu 610064, People's Republic of China.
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Hong G, Gan X, Leonhardt C, Zhang Z, Seibert J, Busch JM, Bräse S. A Brief History of OLEDs-Emitter Development and Industry Milestones. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2021; 33:e2005630. [PMID: 33458866 DOI: 10.1002/adma.202005630] [Citation(s) in RCA: 251] [Impact Index Per Article: 83.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/12/2020] [Indexed: 06/12/2023]
Abstract
Organic light-emitting diodes (OLEDs) have come a long way ever since their first introduction in 1987 at Eastman Kodak. Today, OLEDs are especially valued in the display and lighting industry for their promising features. As one of the research fields that equally inspires and drives development in academia and industry, OLED device technology has continuously evolved over more than 30 years. OLED devices have come forward based on three generations of emitter materials relying on fluorescence (first generation), phosphorescence (second generation), and thermally activated delayed fluorescence (third generation). Furthermore, research in academia and industry toward the fourth generation of OLEDs is in progress. Excerpts from the history of green, orange-red, and blue OLED emitter development on the side of academia and milestones achieved by key players in the industry are included in this report.
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Affiliation(s)
- Gloria Hong
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry (IOC), Fritz-Haber-Weg 6, Karlsruhe, 76131, Germany
| | - Xuemin Gan
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry (IOC), Fritz-Haber-Weg 6, Karlsruhe, 76131, Germany
| | - Céline Leonhardt
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry (IOC), Fritz-Haber-Weg 6, Karlsruhe, 76131, Germany
| | - Zhen Zhang
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry (IOC), Fritz-Haber-Weg 6, Karlsruhe, 76131, Germany
| | - Jasmin Seibert
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry (IOC), Fritz-Haber-Weg 6, Karlsruhe, 76131, Germany
| | - Jasmin M Busch
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry (IOC), Fritz-Haber-Weg 6, Karlsruhe, 76131, Germany
| | - Stefan Bräse
- Karlsruhe Institute of Technology (KIT), Institute of Organic Chemistry (IOC), Fritz-Haber-Weg 6, Karlsruhe, 76131, Germany
- Karlsruhe Institute of Technology (KIT), Institute of Biological and Chemical Systems-Functional Molecular Systems (IBCS-FMS), Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen, 76344, Germany
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12
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He Y, Qiao Z, Cai X, Li M, Li W, Xie W, Qiu W, Wang L, Su SJ. Pyridine-Based Bipolar Hosts for Solution-Processed Bluish-Green Thermally Activated Delayed Fluorescence Devices: A Subtle Regulation of Chemical Stability and Carrier Transportation. ACS APPLIED MATERIALS & INTERFACES 2020; 12:49905-49914. [PMID: 33079524 DOI: 10.1021/acsami.0c14123] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Versatile host materials with good chemical stability and carrier-transporting ability are quite responsible for achieving stable solution-processed thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs). Herein, we reported three bipolar dendritic hosts with or without the electron-withdrawing pyridine moiety via 6-site-linkages, namely, 3,3'-bis(3,3″,6,6″-tetra-tert-butyl-9'H-[9,3':6',9″-tercarbazol]-9'-yl)-1,1'-biphenyl (mCDtCBP), 3,3″,6,6″-tetra-tert-butyl-9'-(6-(3-(3,3″,6,6″-tetra-tert-butyl-9'H-[9,3':6',9″-tercarbazol]-9'-yl)phenyl)pyridine-2-yl)-9'H-9,3':6',9″-tercarbazole (mCDtCBPy), and 6,6'-bis(3,3″,6,6″-tetra-tert-butyl-9'H-[9,3':6',9″-tercarbazol]-9'-yl)-2,2'-bipyridine (mCDtCBDPy), exhibiting outstanding solubility, thermal stability as well as electrochemical stability. According to the calculation of bond dissociation energy (BDE), photodegradation results, and carrier dynamics evaluation, a significant relationship between device stability and the pyridine-based dendritic hosts was uncovered. Using mCDtCDPy with the highest electron mobility as the host, the solution-processed bluish-green TADF-OLED showed the shortest operational lifetime due to the unbalanced charge fluxes despite its highest anionic BDE for good chemical stability. However, the device based on mCDtCBPy exhibited twice longer lifetime than that based on mCDtCBP in spite of their similar balanced charge transportation, highlighting the importance of higher anionic BDE of the C-N bond in the device degradation process. Our findings unveiled a potential approach to achieve a subtle regulation of chemical stability and carrier transportation for realizing stable solution-processed TADF-OLEDs.
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Affiliation(s)
- Yanmei He
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
| | - Zhenyang Qiao
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
| | - Xinyi Cai
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
| | - Mengke Li
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
| | - Wei Li
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
| | - Wentao Xie
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
| | - Weidong Qiu
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
| | - Liangying Wang
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
| | - Shi-Jian Su
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Wushan Road 381, Guangzhou 510640, Guangdong Province, P. R. China
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13
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Polgar AM, Tonge CM, Christopherson CJ, Paisley NR, Reyes AC, Hudson ZM. Thermally Assisted Fluorescent Polymers: Polycyclic Aromatic Materials for High Color Purity and White-Light Emission. ACS APPLIED MATERIALS & INTERFACES 2020; 12:38602-38613. [PMID: 32846499 DOI: 10.1021/acsami.0c07892] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Thermally activated delayed fluorescence (TADF) sensitization of fluorescence is a promising strategy to improve the color purity and operational lifetime of conventional TADF organic light-emitting diodes (OLEDs). Here, we propose a new design strategy for TADF-sensitized fluorescence based on acrylic polymers with a pendant energy-harvesting host, a TADF sensitizer, and fluorescent emitter monomers. Fluorescent emitters were rationally designed from a series of homologous polycyclic aromatic amines, resulting in efficient and color-pure polymeric fluorophores capable of harvesting both singlet and triplet excitons. Macromolecular analogues of blue, green, and yellow fourth-generation OLED emissive layers were prepared in a facile manner by Cu(0) reversible deactivation radical polymerization, with emission quantum yields up to 0.83 in air and narrow emission bands with full width at half-maximum as low as 57 nm. White-light emission can easily be achieved by enforcing incomplete energy transfer between a deep blue TADF sensitizer and yellow fluorophore to yield a single white-emissive polymer with CIE coordinates (0.33, 0.39) and quantum yield 0.77. Energy transfer to the fluorescent emitters occurs at rates of 1-4 × 108 s-1, significantly faster than deactivation caused by internal conversion or intersystem crossing. Rapid energy transfer facilitates high triplet exciton utilization and efficient sensitized emission, even when TADF emitters with a low quantum yield are used as photosensitizers. Our results indicate that a broad library of untapped polymers exhibiting efficient TADF-sensitized fluorescence should be readily accessible from known TADF materials, including many monomers previously thought unsuitable for use in OLEDs.
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Affiliation(s)
- Alexander M Polgar
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Christopher M Tonge
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Cheyenne J Christopherson
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Nathan R Paisley
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Annelie C Reyes
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
| | - Zachary M Hudson
- Department of Chemistry, The University of British Columbia, 2036 Main Mall, Vancouver, British Columbia V6T 1Z1, Canada
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14
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Godumala M, Hwang J, Kang H, Jeong JE, Harit AK, Cho MJ, Woo HY, Park S, Choi DH. High-Performance, Solution-Processable Thermally Activated Delayed Fluorescent Organic Light-Emitting Diodes Realized via the Adjustment of the Composition of the Organoboron Acceptor Monomer in Copolymer Host Materials. ACS APPLIED MATERIALS & INTERFACES 2020; 12:35300-35310. [PMID: 32654477 DOI: 10.1021/acsami.0c10293] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Organic polymers that exhibit features pertinent to functioning as host materials for thermally activated delayed fluorescence (TADF) emitters have considerable potential in solution-processable organic light-emitting diodes (OLEDs), allowing simple, low-cost, and large-area applications. In particular, polymer hosts have superior characteristics, including facile functionality to introduce various electron donor and acceptor entities, the ability to uniformly disperse and contain small molecular dopants, and the ability to produce more smooth and homogeneous films, compared to those of their small-molecule counterparts. This manuscript describes the design and development of three new styrene-based copolymers (ABP91, ABP73, and ABP55) bearing diphenylacridine as the electron donor and 2,12-di-tert-butyl-7-phenyl-5,9-dioxa-13b-boranaphtho[3,2,1-de]anthracene as the electron acceptor. In particular, ABP91, ABP73, and ABP55 were synthesized via variations in the ratio of donor to acceptor monomers to substantiate their influence in OLED applications. With the ability of the styrene backbone of interrupting the direct electronic coupling between the adjacent electron donor and acceptor entities through non-conjugated linkages, high triplet energy can be inherited by the resulting polymers (>2.70 eV). Furthermore, these materials manifest thermal robustness through high decomposition temperatures (between 348 and 366 °C) and high glass transition temperatures (between 234 and 277 °C). Consequently, solution-processable OLEDs fabricated using the newly synthesized copolymers as host materials and the familiar t4CzIPN as a green-emissive TADF dopant deliver state-of-the-art performance with maximum external quantum efficiencies of 21.8, 22.2, and 19.7% for ABP91, ABP73, and ABP55, respectively. To our knowledge, this is, to date, the best performance reported when organic polymers are used as host materials in solution-processable TADF OLEDs. The pragmatic outcomes obtained in this study can provide useful insights into the structure-property relationship to the OLED community for the further development of efficient polymer hosts for use in solution-processable TADF OLEDs.
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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
| | - Jinhyo Hwang
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Hyunchul Kang
- 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
| | - Amit Kumar Harit
- 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
| | - Han Young Woo
- 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
| | - 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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15
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Godumala M, Yoon J, Park SY, Lee C, Kim Y, Jeong JE, Park S, Woo HY, Cho MJ, Choi DH. 5H-Benzo[d]Benzo[4,5]Imidazo[2,1-b][1,3]Thiazine as a Novel Electron-Acceptor Cored High Triplet Energy Bipolar Host Material for Efficient Solution-Processable Thermally Activated Delayed Fluorescence Organic Light-Emitting Diodes. Front Chem 2020; 8:61. [PMID: 32117885 PMCID: PMC7020745 DOI: 10.3389/fchem.2020.00061] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 01/20/2020] [Indexed: 11/13/2022] Open
Abstract
Organic entities that can transport electrons are seldom available to develop adequate bipolar host materials applicable for solution-processable thermally activated delayed fluorescence (TADF)-organic light-emitting diodes (OLEDs). Therefore, the introduction of new electron-affine entities that plausibly demonstrate high triplet energy (E T) is of urgent need. In this contribution, we introduced benzimidazo[1,2-a][3,1]benzothiazine (BBIT) as a novel electron-affine entity and developed two new bipolar host materials, CzBBIT and 2CzBBIT. Both host materials exhibit high E T of 3.0 eV, superior thermal robustness with the thermal decomposition temperature of up to 392°C, a glass transition temperature of up to 161°C, and high solubility in common organic solvents. Consequently, the solution-processable OLEDs fabricated using a recognized IAcTr-out as the green TADF emitter doped into CzBBIT as the host, realized a maximum external quantum efficiency (EQE) of 23.3%, while the 2CzBBIT:IAcTr-out blend film-based device displayed an EQE of 18.7%. These outcomes corroborated that this work could shed light on the scientific community on the design of new electron-affine entities to establish the effective use of bipolar host materials toward proficient solution-processable TADF-OLEDs.
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Affiliation(s)
- Mallesham Godumala
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Jiwon Yoon
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Seo Yeon Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Chiho Lee
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Youngseo Kim
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Ji-Eun Jeong
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Sungnam Park
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Han Young Woo
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Min Ju Cho
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
| | - Dong Hoon Choi
- Department of Chemistry, Research Institute for Natural Sciences, Korea University, Seoul, South Korea
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16
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Sudheendran Swayamprabha S, Dubey DK, Shahnawaz, Yadav RAK, Nagar MR, Sharma A, Tung F, Jou J. Approaches for Long Lifetime Organic Light Emitting Diodes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 8:2002254. [PMID: 33437576 PMCID: PMC7788592 DOI: 10.1002/advs.202002254] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/26/2020] [Indexed: 06/14/2023]
Abstract
Organic light emitting diodes (OLEDs) have been well known for their potential usage in the lighting and display industry. The device efficiency and lifetime have improved considerably in the last three decades. However, for commercial applications, operational lifetime still lies as one of the looming challenges. In this review paper, an in-depth description of the various factors which affect OLED lifetime, and the related solutions is attempted to be consolidated. Notably, all the known intrinsic and extrinsic degradation phenomena and failure mechanisms, which include the presence of dark spot, high heat during device operation, substrate fracture, downgrading luminance, moisture attack, oxidation, corrosion, electron induced migrations, photochemical degradation, electrochemical degradation, electric breakdown, thermomechanical failures, thermal breakdown/degradation, and presence of impurities within the materials and evaporator chamber are reviewed. Light is also shed on the materials and device structures which are developed in order to obtain along with developed materials and device structures to obtain stable devices. It is believed that the theme of this report, summarizing the knowledge of mechanisms allied with OLED degradation, would be contributory in developing better-quality OLED materials and, accordingly, longer lifespan devices.
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Affiliation(s)
| | - Deepak Kumar Dubey
- Department of Materials Science and EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan, Republic of China
| | - Shahnawaz
- Department of Materials Science and EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan, Republic of China
| | - Rohit Ashok Kumar Yadav
- Department of Materials Science and EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan, Republic of China
| | - Mangey Ram Nagar
- Department of Materials Science and EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan, Republic of China
| | - Aayushi Sharma
- Birla Institute of Technology & Science‐PilaniShamirpet‐Keesara Road, Jawahar Nagar, ShameerpetHyderabadTelangana500078India
| | - Fu‐Ching Tung
- Department of Solid State Lighting TechnologyMechanical and Mechatronics Systems Research Labs.Industrial Technology and Research InstituteHsinchu31057Taiwan, Republic of China
| | - Jwo‐Huei Jou
- Department of Materials Science and EngineeringNational Tsing Hua UniversityHsinchu30013Taiwan, Republic of China
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17
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Ngo PS, Hung MK, Tsai KW, Sharma S, Chen SA. Highly Efficient Solution-Processed Thermally Activated Delayed Fluorescence Bluish-Green and Hybrid White Organic Light-Emitting Diodes Using Novel Bipolar Host Materials. ACS APPLIED MATERIALS & INTERFACES 2019; 11:45939-45948. [PMID: 31724847 DOI: 10.1021/acsami.9b14168] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Two pyridine-containing bipolar host materials with high triplet energy, 9,10-dihydro-9,9-dimethyl-10-(3-(6-(3-(9,9-dimethylacridin-10(9H)-yl)phenyl)pyridin-2-yl)phenyl acridin (DDMACPy) and N-(3-(6-(3-(diphenyl amino)phenyl)pyridin-2-yl)phenyl)-N-phenylbenzenamine (DTPAPy), are synthesized from the modification of the commonly adapted host material 2,6-bis(3-(9H-carbazol-9-yl)phenyl)pyridine (DCzPPy). The highest occupied molecular orbital levels of DDMACPy (5.50 eV) and DTPAPy (5.60 eV) are found to be shallower than that of DCzPPy (5.90 eV) that leads to the improvement in hole injection from the hole transport layer PEDOT:PSS (WF = 5.10 eV). These host materials are used in the emitting layer of bluish-green organic light-emitting diode (OLED) with the thermally activated delayed fluorescence (TADF) emitter, 9,9-dimethyl-9,10-dihydroacridine-2,4,6-triphenyl-1,3,5-triazine, as the guest. The DDMACPy-based device shows the highest performance among them, with the maximum external quantum efficiency (EQEmax), current efficiency (CEmax), and power efficiency (PEmax) of 21.0%, 53.1 cd A-1, and 44.0 lm W-1 at CIE (0.17, 0.42), respectively. By further doping with the red-emitting phosphor iridium(III) bis(2-phenylquinoline)(2,2,6,6-tetramethylheptane-3,5-ionate) [Ir(dpm)PQ2] and yellow-emitting phosphor iridium(III) bis(4-(4-t-butylphenyl)thieno[3,2-c]pyridinato-N,C20)acetylacetonate (PO-01-TB) emitters into the bluish-green emitting layer, a TADF-phosphor hybrid white OLED (T-P WOLED) is obtained with excellent EQEmax, CEmax, and PEmax of 17.4%, 48.7 cd A-1, and 44.5 lm W-1 at CIE (0.35, 0.44), respectively. Moreover, both the bluish-green and WOLED show a low efficiency roll-off with external quantum efficiencies at the brightness of 1000 cd m-2 (EQE1000) of 18.7 and 16.2%, respectively, which are the highest performance records among the solution-processed TADF bluish-green and T-P WOLEDs.
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Affiliation(s)
- Phu Si Ngo
- Department of Chemical Engineering , National Tsing-Hua University , Hsinchu 30013 , Taiwan
| | - Miao-Ken Hung
- Department of Chemical Engineering , National Tsing-Hua University , Hsinchu 30013 , Taiwan
| | - Kuen-Wei Tsai
- Department of Chemical Engineering , National Tsing-Hua University , Hsinchu 30013 , Taiwan
| | - Sunil Sharma
- 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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18
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Cheng G, Kwak Y, To WP, Lam TL, Tong GSM, Sit MK, Gong S, Choi B, Choi WI, Yang C, Che CM. High-Efficiency Solution-Processed Organic Light-Emitting Diodes with Tetradentate Platinum(II) Emitters. ACS APPLIED MATERIALS & INTERFACES 2019; 11:45161-45170. [PMID: 31718137 DOI: 10.1021/acsami.9b11715] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The realization of high-efficiency solution-processed organic light-emitting diodes (OLEDs) using phosphorescent tetradentate Pt(II) emitters and bipolar organic hosts is demonstrated in this work. To investigate the effect of organic host on the platinum dopant, the performances of solution-processed Pt-OLEDs with various combinations between four tetradentate Pt(II) emitters, including two newly developed tetra-Pt-S2 and tetra-Pt-S3 and three bipolar organic hosts m-TPAPy, o-TPAPy, and o-CzPy, have been analyzed and compared. Among the tetradentate Pt(II) complexes studied in this work, tetra-Pt-S3 exhibited the best electroluminescent performance attributable to its bulky molecular scaffold structure, high emission quantum yield, and good solubility in common organic solvents. High external quantum efficiencies (EQEs) of up to 22.4% were achieved in the solution-processed OLED with tetra-Pt-S3 emitter and m-TPAPy host at the dopant concentration of 4 wt %. At a high luminance of 1000 cd m-2, the EQE of this device decreased slightly to 21.0%.
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Affiliation(s)
- Gang Cheng
- HKU Shenzhen Institute of Research and Innovation , Shenzhen 518053 , P. R. China
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong SAR , P. R. China
| | - Yoonhyun Kwak
- Samsung Electronics, Organic Material Lab, SAIT , 130 Samsung-ro , Yeongtong-gu, Suwon-si , Gyeonggi-do 16678 , Korea
| | - Wai-Pong To
- HKU Shenzhen Institute of Research and Innovation , Shenzhen 518053 , P. R. China
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong SAR , P. R. China
| | - Tsz-Lung Lam
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong SAR , P. R. China
| | - Glenna So Ming Tong
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong SAR , P. R. China
| | - Man-Ki Sit
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong SAR , P. R. China
| | - Shaolong Gong
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry , Wuhan University , Wuhan 430072 , P. R. China
| | - Byoungki Choi
- Samsung Electronics, Organic Material Lab, SAIT , 130 Samsung-ro , Yeongtong-gu, Suwon-si , Gyeonggi-do 16678 , Korea
| | - Wha Il Choi
- Samsung Electronics, Samsung Research Funding & Incubation Center for Future Technology Seoul R&D Campus , Umyeon dong 33, Seongchon-gil , Seocho-gu, Seoul 06765 , Korea
| | - Chuluo Yang
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry , Wuhan University , Wuhan 430072 , P. R. China
| | - Chi-Ming Che
- HKU Shenzhen Institute of Research and Innovation , Shenzhen 518053 , P. R. China
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong SAR , P. R. China
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19
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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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20
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Highly efficient solution-processed blue organic light-emitting diodes based on thermally activated delayed fluorescence emitters with spiroacridine donor. J IND ENG CHEM 2019. [DOI: 10.1016/j.jiec.2019.06.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Ledwon P, Wiosna-Salyga G, Chapran M, Motyka R. The Effect of Acceptor Structure on Emission Color Tuning in Organic Semiconductors with D-π-A-π-D Structures. NANOMATERIALS 2019; 9:nano9081179. [PMID: 31426483 PMCID: PMC6724117 DOI: 10.3390/nano9081179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 08/07/2019] [Accepted: 08/13/2019] [Indexed: 12/16/2022]
Abstract
A series of novel donor-acceptor D-π-A-π-D compounds were synthesized and characterized in order to determine the influence of different acceptor units on their properties. The introduction of acceptor moieties had a direct impact on the HOMO and LUMO energy levels. Fluorescence spectra of compounds can be changed by the choice of an appropriate acceptor and were shifted from the green to the near-infrared part of spectra. Due to observed concentration induced emission quenching, the green exciplex type host was used to evaluate the potential of synthesized molecules as emitters in organic light emitting diodes (OLEDs).
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Affiliation(s)
- Przemyslaw Ledwon
- Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice, Poland.
| | - Gabriela Wiosna-Salyga
- Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland.
| | - Marian Chapran
- Department of Molecular Physics, Lodz University of Technology, Zeromskiego 116, 90-924 Lodz, Poland
| | - Radoslaw Motyka
- Faculty of Chemistry, Silesian University of Technology, Strzody 9, 44-100 Gliwice, Poland
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22
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Byeon SY, Lee DR, Yook KS, Lee JY. Recent Progress of Singlet-Exciton-Harvesting Fluorescent Organic Light-Emitting Diodes by Energy Transfer Processes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1803714. [PMID: 30761642 DOI: 10.1002/adma.201803714] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 07/30/2018] [Indexed: 05/21/2023]
Abstract
The external quantum efficiency (EQE) of organic light-emitting diodes (OLEDs) has been dramatically improved by developing highly efficient organic emitters such as phosphorescent emitters and thermally activated delayed fluorescent (TADF) emitters. However, high-EQE OLED technologies suffer from relatively poor device lifetimes in spite of their high EQEs. In particular, the short lifetimes of blue phosphorescent and TADF OLEDs remain a big hurdle to overcome. Therefore, the high-EQE approach harvesting singlet excitons of fluorescent emitters by energy transfer processes from the host or sensitizer has been explored as an alternative for high-EQE OLED strategies. Recently, there has been a big jump in the EQE and device lifetime of singlet-exciton-harvesting fluorescent OLEDs. Recent progress on the materials and device structure is discussed herein.
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Affiliation(s)
- Sung Yong Byeon
- School of Chemical and Engineering, Sunkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 446-740, South Korea
| | - Dong Ryun Lee
- School of Chemical and Engineering, Sunkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 446-740, South Korea
| | - Kyoung Soo Yook
- School of Chemical and Engineering, Sunkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 446-740, South Korea
| | - Jun Yeob Lee
- School of Chemical and Engineering, Sunkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 446-740, South Korea
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23
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Shi H, Zou L, Huang K, Wang H, Sun C, Wang S, Ma H, He Y, Wang J, Yu H, Yao W, An Z, Zhao Q, Huang W. A Highly Efficient Red Metal-free Organic Phosphor for Time-Resolved Luminescence Imaging and Photodynamic Therapy. ACS APPLIED MATERIALS & INTERFACES 2019; 11:18103-18110. [PMID: 31037937 DOI: 10.1021/acsami.9b01615] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Developing highly efficient red metal-free organic phosphors for biological applications is a formidable challenge. Here, we report a novel molecular design principle to obtain red metal-free organic phosphors with long emission lifetime (504.6 μs) and high phosphorescence efficiency (14.6%) from the isolated molecules in the crystal. Furthermore, the well-dispersed phosphorescent nanodots (PNDs) with the particle size around 5 nm are prepared through polymer-encapsulation in an aqueous solution, which show good biocompatibility and low cytotoxicity. The metal-free PNDs are successfully applied to time-resolved luminescence imaging to eliminate background fluorescence interference both in vitro and vivo as well as effective photodynamic anticancer therapy for the first time. This work will not only pave a pathway to develop highly efficient metal-free RTP materials but also expand the scope of their applications to biomedical fields.
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Affiliation(s)
- Huifang Shi
- Institute of Flexible Electronics (IFE) , Northwestern Polytechnical University (NPU) , 127 West Youyi Road , Xi'an 710072 , China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Liang Zou
- Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM) , Nanjing University of Posts and Telecommunications , Wenyuan Road 9 , Nanjing 210023 , China
| | - Kaiwei Huang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - He Wang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Chen Sun
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Shan Wang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Huili Ma
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Yarong He
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Jianpu Wang
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Haidong Yu
- Institute of Flexible Electronics (IFE) , Northwestern Polytechnical University (NPU) , 127 West Youyi Road , Xi'an 710072 , China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Wei Yao
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Zhongfu An
- Institute of Flexible Electronics (IFE) , Northwestern Polytechnical University (NPU) , 127 West Youyi Road , Xi'an 710072 , China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
| | - Qiang Zhao
- Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM) , Nanjing University of Posts and Telecommunications , Wenyuan Road 9 , Nanjing 210023 , China
| | - Wei Huang
- Institute of Flexible Electronics (IFE) , Northwestern Polytechnical University (NPU) , 127 West Youyi Road , Xi'an 710072 , China
- Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) , Nanjing Tech University (NanjingTech) , 30 South Puzhu Road , Nanjing 211816 , China
- Key Laboratory for Organic Electronics and Information Displays & Jiangsu Key Laboratory for Biosensors, Institute of Advanced Materials (IAM) , Nanjing University of Posts and Telecommunications , Wenyuan Road 9 , Nanjing 210023 , China
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24
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Kim HG, Shin H, Ha YH, Kim R, Kwon SK, Kim YH, Kim JJ. Triplet Harvesting by a Fluorescent Emitter Using a Phosphorescent Sensitizer for Blue Organic-Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2019; 11:26-30. [PMID: 30543096 DOI: 10.1021/acsami.8b17957] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The development of highly efficient blue organic light-emitting diodes (OLEDs) with good stability is currently the most important issue in OLED displays and lighting. This paper reports an efficient blue fluorescent OLED based on a deep-blue-emitting phosphorescent sensitizer [(dfpysipy)2Ir(mpic)] and a conventional fluorescent emitter (TBPe). Efficient triplet harvesting by the fluorescent emitter occurs in the OLED because of sensitization even though the difference in the emission energy between the phosphorescent and fluorescent emissions was only 0.05 eV. These results clearly demonstrate the potential for realizing highly efficient blue fluorescent OLEDs using phosphorescent sensitizers without requiring ultraviolet-emitting phosphorescent dye.
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25
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Cai M, Zhang D, Duan L. High Performance Thermally Activated Delayed Fluorescence Sensitized Organic Light‐Emitting Diodes. CHEM REC 2018; 19:1611-1623. [DOI: 10.1002/tcr.201800148] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 11/23/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Minghan Cai
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua University Beijing 100084 China
| | - Dongdong Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua University Beijing 100084 China
| | - Lian Duan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of EducationDepartment of ChemistryTsinghua University Beijing 100084 China
- Center for Flexible Electronics TechnologyTsinghua University Beijing 100084 China
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