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Izawa S, Morimoto M, Fujimoto K, Banno K, Majima Y, Takahashi M, Naka S, Hiramoto M. Blue organic light-emitting diode with a turn-on voltage of 1.47 V. Nat Commun 2023; 14:5494. [PMID: 37730676 PMCID: PMC10511415 DOI: 10.1038/s41467-023-41208-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 08/25/2023] [Indexed: 09/22/2023] Open
Abstract
Among the three primary colors, blue emission in organic light-emitting diodes (OLEDs) are highly important but very difficult to develop. OLEDs have already been commercialized; however, blue OLEDs have the problem of requiring a high applied voltage due to the high-energy of blue emission. Herein, an ultralow voltage turn-on at 1.47 V for blue emission with a peak wavelength at 462 nm (2.68 eV) is demonstrated in an OLED device with a typical blue-fluorescent emitter that is widely utilized in a commercial display. This OLED reaches 100 cd/m2, which is equivalent to the luminance of a typical commercial display, at 1.97 V. Blue emission from the OLED is achieved by the selective excitation of the low-energy triplet states at a low applied voltage by using the charge transfer (CT) state as a precursor and triplet-triplet annihilation, which forms one emissive singlet from two triplet excitons.
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Affiliation(s)
- Seiichiro Izawa
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan.
- Joining and Welding Research Institute, Osaka University, 11-1, Mihogaoka, Ibaraki, Osaka, 567-0047, Japan.
- Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
| | - Masahiro Morimoto
- Academic Assembly Faculty of Engineering, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan.
| | - Keisuke Fujimoto
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka, 432-8561, Japan.
| | - Koki Banno
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka, 432-8561, Japan
| | - Yutaka Majima
- Laboratory for Materials and Structures, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa, 226-8503, Japan
| | - Masaki Takahashi
- Department of Applied Chemistry, Faculty of Engineering, Shizuoka University, 3-5-1 Johoku, Naka-ku, Hamamatsu, Shizuoka, 432-8561, Japan
| | - Shigeki Naka
- Academic Assembly Faculty of Engineering, University of Toyama, 3190 Gofuku, Toyama, 930-8555, Japan
| | - Masahiro Hiramoto
- Institute for Molecular Science, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan
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Song J, Guan Y, Wang C, Li W, Bao X, Niu L. Effect of Conductive Polymers PEDOT:PSS on Exciton Recombination and Conversion in Doped-Type BioLEDs. Polymers (Basel) 2023; 15:3275. [PMID: 37571169 PMCID: PMC10421517 DOI: 10.3390/polym15153275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 07/28/2023] [Accepted: 07/29/2023] [Indexed: 08/13/2023] Open
Abstract
Although the effect of the conductive polymers PEDOT:PSS on the electroluminescence performance of doped-type organic light-emitting diodes (OLEDs) has been studied, the process of PEDOT:PSS regulation of exciton recombination region and concentration within the deoxyribonucleic acid (DNA)-based doped-type BioLEDs is still obscure. In this study, we fabricated Bio-devices with and without PEDOT:PSS using varying spin-coating speeds of PEDOT:PSS. The Alq3:Rubrene-based BioLEDs achieve higher luminance (44,010 cd/m2) and higher luminance efficiency (8.1 cd/A), which are increased by 186% and 478%, respectively, compared to the reference BioLEDs without PEDOT:PSS. Similarly, the maximum luminance and efficiency of blue TCTA:TPBi exciplex-type BioLEDs are increased by 224% and 464%. In particular, our findings reveal that with an increasing thickness of PEDOT:PSS, the region of exciton recombination shifts towards the interface between the emitting layer (EML) and the hole transport layer (HTL). Meanwhile, the concentration of singlet exciton (S1,Rub) and triplet exciton (T1,Rub) increases, and the triplet-triplet annihilation (TTA) process is enhanced, resulting in the enhanced luminescence and efficiency of the devices. Accordingly, we provide a possible idea for achieving high performance doped-type BioLEDs by adding conductive polymers PEDOT:PSS, and revealing the effect of exciton recombination and conversion in BioLEDs given different PEDOT:PSS thicknesses.
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Affiliation(s)
| | - Yunxia Guan
- College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, China; (J.S.); (C.W.); (W.L.); (X.B.)
| | | | | | | | - Lianbin Niu
- College of Physics and Electronic Engineering, Chongqing Normal University, Chongqing 401331, China; (J.S.); (C.W.); (W.L.); (X.B.)
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3
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Yu Y, Zhao C, Ma L, Yan L, Jiao B, Li J, Xi J, Si J, Li Y, Xu Y, Dong H, Dai J, Yuan F, Zhu P, Jen AKY, Wu Z. Harvesting the Triplet Excitons of Quasi-Two-Dimensional Perovskite toward Highly Efficient White Light-Emitting Diodes. J Phys Chem Lett 2022; 13:3674-3681. [PMID: 35438498 DOI: 10.1021/acs.jpclett.2c00996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Utilization of triplet excitons, which generally emit poorly, is always fundamental to realize highly efficient organic light-emitting diodes (LEDs). While triplet harvest and energy transfer via electron exchange between triplet donor and acceptor are fully understood in doped organic phosphorescence and delayed fluorescence systems, the utilization and energy transfer of triplet excitons in quasi-two-dimensional (quasi-2D) perovskite are still ambiguous. Here, we use an orange-phosphorescence-emitting ultrathin organic layer to probe triplet behavior in the sky-blue-emitting quasi-2D perovskite. The delicate white LED architecture enables a carefully tailored Dexter-like energy-transfer mode that largely harvests the triplet excitons in quasi-2D perovskite. Our white organic-inorganic LEDs achieve maximum forward-viewing external quantum efficiency of 8.6% and luminance over 15 000 cd m-2, exhibiting a significant efficiency enhancement versus the corresponding sky-blue perovskite LED (4.6%). The efficient management of energy transfer between excitons in quasi-2D perovskite and Frenkel excitons in the organic layer opens the door to fully utilizing excitons for white organic-inorganic LEDs.
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Affiliation(s)
- Yue Yu
- School of Physics and Optoelectronic Engineering, Xidian University, Xi'an 710071, China
| | - Chenjing Zhao
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Lin Ma
- School of Physics and Optoelectronic Engineering, Xidian University, Xi'an 710071, China
| | - Lihe Yan
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Bo Jiao
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jingrui Li
- Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jun Xi
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jinhai Si
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yuren Li
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Yanmin Xu
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Hua Dong
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Jinfei Dai
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Fang Yuan
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Peichao Zhu
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
| | - Alex K-Y Jen
- Department of Physics & Materials Science, City University of Hong Kong, Kowloon, Hong Kong
| | - Zhaoxin Wu
- Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, School of Electronic Science and Engineering, Xi'an Jiaotong University, Xi'an 710049, China
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Kang SW, Baek DH, Ju BK, Park YW. Green phosphorescent organic light-emitting diode exhibiting highest external quantum efficiency with ultra-thin undoped emission layer. Sci Rep 2021; 11:8436. [PMID: 33875674 PMCID: PMC8055988 DOI: 10.1038/s41598-021-86333-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 03/12/2021] [Indexed: 11/09/2022] Open
Abstract
In this study, we report highly efficient green phosphorescent organic light-emitting diodes (OLEDs) with ultra-thin emission layers (EMLs). We use tris[2-phenylpyridinato-C2,N]iridium(III) (Ir(ppy)3), a green phosphorescent dopant, for creating the OLEDs. Under systematic analysis, the peak external quantum efficiency (EQE) of an optimized device based on the ultra-thin EML structure is found to be approximately 24%. This result is highest EQE among ultra-thin EML OLEDs and comparable to the highest efficiency achieved by OLEDs using Ir(ppy)3 that are fabricated via conventional doping methods. Moreover, this result shows that OLEDs with ultra-thin EML structures can achieve ultra-high efficiency.
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Affiliation(s)
- Shin Woo Kang
- Display and Nanosystem Laboratory, School of Electrical Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.,Nano and Organic-Electronics Laboratory, Department of Display and Semiconductor Engineering, Sun Moon University, Asan, Chungcheongnam-do, 31460, Republic of Korea
| | - Dong-Hyun Baek
- Center for Next Generation Semiconductor Technology, Department of Display and Semiconductor Engineering, Sun Moon University, Asan, Chungcheongnam-do, 31460, Republic of Korea
| | - Byeong-Kwon Ju
- Display and Nanosystem Laboratory, School of Electrical Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
| | - Young Wook Park
- Nano and Organic-Electronics Laboratory, Department of Display and Semiconductor Engineering, Sun Moon University, Asan, Chungcheongnam-do, 31460, Republic of Korea.
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5
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Andrikopoulos K, Anastasopoulos C, Kallitsis JK, Andreopoulou AK. Bis-Tridendate Ir(III) Polymer-Metallocomplexes: Hybrid, Main-Chain Polymer Phosphors for Orange-Red Light Emission. Polymers (Basel) 2020; 12:E2976. [PMID: 33322188 PMCID: PMC7764732 DOI: 10.3390/polym12122976] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/10/2020] [Accepted: 12/10/2020] [Indexed: 12/23/2022] Open
Abstract
In this work, hybrid polymeric bis-tridentate iridium(III) complexes bearing derivatives of terpyridine (tpy) and 2,6-di(phenyl) pyridine as ligands were successfully synthesized and evaluated as red-light emitters. At first, the synthesis of small molecular bis-tridendate Ir(III) complexes bearing alkoxy-, methyl-, or hydroxy-functionalized terpyridines and a dihydroxyphenyl-pyridine moiety was accomplished. Molecular complexes bearing two polymerizable end-hydroxyl groups and methyl- or alkoxy-decorated terpyridines were copolymerized with difluorodiphenyl-sulphone under high temperature polyetherification conditions. Alternatively, the post-polymerization complexation of the terpyridine-iridium(III) monocomplexes onto the biphenyl-pyridine main chain homopolymer was explored. Both cases afforded solution-processable metallocomplex-polymers possessing the advantages of phosphorescent emitters in addition to high molecular weights and excellent film-forming ability via solution casting. The structural, optical, and electrochemical properties of the monomeric and polymeric heteroleptic iridium complexes were thoroughly investigated. The polymeric metallocomplexes were found to emit in the orange-red region (550-600 nm) with appropriate HOMO and LUMO levels to be used in conjunction with blue-emitting hosts. By varying the metal loading on the polymeric backbone, the emitter's specific emission maxima could be successfully tuned.
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Affiliation(s)
- Konstantinos Andrikopoulos
- Department of Chemistry, University of Patras, University Campus Rio-Patras, GR26504 Patras, Greece; (K.A.); (C.A.); (J.K.K.)
| | - Charalampos Anastasopoulos
- Department of Chemistry, University of Patras, University Campus Rio-Patras, GR26504 Patras, Greece; (K.A.); (C.A.); (J.K.K.)
| | - Joannis K. Kallitsis
- Department of Chemistry, University of Patras, University Campus Rio-Patras, GR26504 Patras, Greece; (K.A.); (C.A.); (J.K.K.)
- Foundation for Research and Technology, Hellas/Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Platani Str., GR26504 Patras, Greece
| | - Aikaterini K. Andreopoulou
- Department of Chemistry, University of Patras, University Campus Rio-Patras, GR26504 Patras, Greece; (K.A.); (C.A.); (J.K.K.)
- Foundation for Research and Technology, Hellas/Institute of Chemical Engineering Sciences (FORTH/ICE-HT), Platani Str., GR26504 Patras, Greece
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6
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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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7
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Liu J, Chen K, Khan SA, Shabbir B, Zhang Y, Khan Q, Bao Q. Synthesis and optical applications of low dimensional metal-halide perovskites. NANOTECHNOLOGY 2020; 31:152002. [PMID: 31751979 DOI: 10.1088/1361-6528/ab5a19] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Metal halide perovskites have received substantial attention in research communities due to their outstanding efficiency achievements in the field of photovoltaics, optoelectronics and electronics, exhibiting extraordinary optical, electrical and mechanical properties. The exceptional structural tunability enables perovskite material to possess low-dimensional form at the atomic level and extends their applications into optoelectronic and photonic fields. This review discusses the recent progress of synthetic routes and fundamental optoelectronic properties of low-dimensional metal halide perovskites. In addition, the focus is to highlight the potential applications of perovskites in various devices including solar cells, light-emitting diodes, lasers, waveguides and memory devices. Finally, outlooks and the challenges that face the development of the perovskite materials in the near future are also presented.
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Affiliation(s)
- Jingying Liu
- Department of Materials Science and Engineering, ARC Centre of Excellence in Future Low-Energy Electronics Technologies (FLEET), Monash University, Clayton, Victoria 3800, Australia
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Faraco TA, de O X Silva H, da S Barud H, Maciel IO, da Silva RR, Quirino WG, Fragneaud B, Ribeiro CA, Dos S Dias D, G Pandoli O, Cremona M, Legnani C. Ecological Biosubstrates Obtained from Onion Pulp ( Allium cepa L.) for Flexible Organic Light-Emitting Diodes. ACS APPLIED MATERIALS & INTERFACES 2019; 11:42420-42428. [PMID: 31635456 DOI: 10.1021/acsami.9b14029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A new biopolymer obtained from onion pulp (Allium cepa L.) was employed to produce a sustainable substrate for flexible organic light-emitting diodes (FOLEDs). Indium tin oxide (ITO) and SiO2 thin films were deposited by rf-magnetron sputtering onto these biosubstrates to obtain flexible, transparent, and conductive anodes, on top of which FOLEDs were produced. This new biomaterial exhibits an optical transparency of 63% at 550 nm. ITO films were optimized by varying rf power during deposition onto the biopolymers, and their electrical properties are comparable to the those of ITO grown on top of rigid substrates: a carrier concentration of -3.63 × 1021 cm-3 and carrier mobility of 7.72 cm2 V-1 s-1 for the optimized film. Consequently, the sheet resistance and resistivity of this ITO film were 8.92 Ω sq-1 and 2.23 × 10-4 Ω cm, respectively, hence allowing the production of FOLEDs. The A. cepa L. based FOLED was fabricated using CuPc, β-NPB, and Alq3 as organic layers, and it exhibited a maximum luminance of about 2062 cd m-2 at 16.6 V. The current efficiency reached a maximum value of 2.1 cd A-1 at 85.3 mA cm-2. The obtained results suggest the possibility to use these substrates for innovative biocompatible applications in optoelectronics, such as photodynamic therapy.
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Affiliation(s)
- Thales A Faraco
- Grupo de Nanociência e Nanotecnologia (NANO), Departamento de Física , Universidade Federal de Juiz de Fora (UFJF) , Juiz de Fora , MG 36036-330 , Brazil
| | - Hálice de O X Silva
- Grupo de Nanociência e Nanotecnologia (NANO), Departamento de Física , Universidade Federal de Juiz de Fora (UFJF) , Juiz de Fora , MG 36036-330 , Brazil
| | - Hernane da S Barud
- Laboratório de Biopolímeros e Biomateriais (BIOPOLMAT), Departamento de Química , Universidade de Araraquara (UNIARA) , Araraquara , SP 14801-340 , Brazil
| | - Indhira O Maciel
- Grupo de Nanociência e Nanotecnologia (NANO), Departamento de Física , Universidade Federal de Juiz de Fora (UFJF) , Juiz de Fora , MG 36036-330 , Brazil
| | - Robson R da Silva
- Instituto de Física de São Carlos , Universidade de São Paulo (USP) , São Carlos , SP 13566-590 , Brazil
| | - Welber G Quirino
- Grupo de Nanociência e Nanotecnologia (NANO), Departamento de Física , Universidade Federal de Juiz de Fora (UFJF) , Juiz de Fora , MG 36036-330 , Brazil
| | - Benjamin Fragneaud
- Grupo de Nanociência e Nanotecnologia (NANO), Departamento de Física , Universidade Federal de Juiz de Fora (UFJF) , Juiz de Fora , MG 36036-330 , Brazil
| | - Clóvis A Ribeiro
- Instituto de Química , Universidade Estatual Paulista Júlio de Mesquita Filho, (UNESP) , Araraquara , SP 14801-970 , Brazil
| | | | - Omar G Pandoli
- Departamento de Química , Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) , Rio de Janeiro , RJ 22453-970 , Brazil
| | - Marco Cremona
- Laboratório de Optoeletrônica Molecular (LOEM), Departamento de Física , Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) , Rio de Janeiro , RJ 22453-970 , Brazil
| | - Cristiano Legnani
- Grupo de Nanociência e Nanotecnologia (NANO), Departamento de Física , Universidade Federal de Juiz de Fora (UFJF) , Juiz de Fora , MG 36036-330 , Brazil
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Manna B, Nandi A, Ghosh R. Energy transfer-mediated white light emission from Nile red-doped 9,10-diphenylanthracene nanoaggregates upon excitation with near UV light. Photochem Photobiol Sci 2019; 18:2748-2758. [PMID: 31593198 DOI: 10.1039/c9pp00272c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The low cost, ease of preparation, colour tunability and wide application range garnered huge research interest on organic light emitting diode materials (OLED). The development of white light-emitting organic diode materials is mostly targeted for this. Anthracene derivatives have recently emerged as low-cost and efficient blue light-emitting diodes. However, developing efficient organic diode materials that cover the entire visible spectrum is very challenging. Herein, we demonstrated that Nile red (NR)-doped 9,10-diphenylanthracene (DPA) nanoaggregates provided strong white light emission upon excitation with near UV light. The dual emissions of the DPA nanoaggregates covering the blue and green regions were exploited and combined with the controlled red emission of the properly doped NR dye to cover the full visible spectrum, rendering white light emission with a quantum yield of >0.4. The fluorescence spectra of the DPA nanoaggregates doped with NR at various concentrations were monitored and their CIE coordinates were followed to evaluate the proper doping ratio for equal-energy white-light emission. Concurrent time-resolved emission studies provided mechanistic insights into the energy transfer from the exciton and excimer states of DPA to NR. It was revealed that the energy transfer from the singlet excitonic state of DPA followed the diffusion-assisted resonance energy transfer (RET) model. On the other hand, the excimer state showed negligible diffusion and energy transfer from this state found to follow the single-step Förster resonance energy transfer mechanism. The observation of efficient white light emission in the doped DPA nanoaggregates was proposed to have prospective applications in OLED devices, given the fact that triplet excitons may be exploited for emission through the efficient triplet-triplet annihilation contribution to fluorescence enhancement.
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Affiliation(s)
- Biswajit Manna
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
| | - Amitabha Nandi
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India. and Homi Bhabha National Institute, Anushakti Nagar, Mumbai-400 094, India
| | - Rajib Ghosh
- Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
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Yang Z, Mao Z, Xu C, Chen X, Zhao J, Yang Z, Zhang Y, Wu W, Jiao S, Liu Y, Aldred MP, Chi Z. A sterically hindered asymmetric D-A-D' thermally activated delayed fluorescence emitter for highly efficient non-doped organic light-emitting diodes. Chem Sci 2019; 10:8129-8134. [PMID: 31857879 PMCID: PMC6836986 DOI: 10.1039/c9sc01686d] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 07/03/2019] [Indexed: 01/09/2023] Open
Abstract
An ortho-substituent design strategy promoting steric hindrance has afforded excellent AIE-TADF emitters, and high-efficiency TADF-OLEDs have been subsequently demonstrated.
Thermally activated delayed fluorescence (TADF) materials have opened a new chapter for high-efficiency and low-cost organic light-emitting diodes (OLEDs). Herein, we describe a novel and effective design strategy for TADF emitters which includes introducing a carbazole donor unit at the ortho-position, at which the donor and acceptor groups are spatially in close proximity to guarantee the existence of intramolecular electrostatic attraction and through-space charge transfer, leading to reduced structural vibrations, suppressed non-radiative decay and rapid radiative decay to avoid excited state energy loss. As a result, a green TADF emitter (2Cz-DPS) showing high solid-state photoluminescence quantum efficiency (91.9%) and excellent OLED performance was produced. Theoretical simulations reveal that the non-adiabatic coupling accelerates the reverse intersystem crossing of 2Cz-DPS, resulting in a state-of-the-art non-doped OLED with an extremely high external quantum efficiency of 28.7%.
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Affiliation(s)
- Zhan Yang
- PCFM Lab , GDHPPC Lab , Guangdong Engineering Technology , Research Center for High-performance Organic and Polymer Photo-electric, Functional Films , State Key Laboratory of OEMT , School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , China . ; ;
| | - Zhu Mao
- PCFM Lab , GDHPPC Lab , Guangdong Engineering Technology , Research Center for High-performance Organic and Polymer Photo-electric, Functional Films , State Key Laboratory of OEMT , School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , China . ; ;
| | - Chao Xu
- Key Laboratory of Theoretical Chemistry of Environment , Ministry of Education , School of Chemistry & Environment , South China Normal University , Guangzhou 510006 , PR China
| | - Xiaojie Chen
- PCFM Lab , GDHPPC Lab , Guangdong Engineering Technology , Research Center for High-performance Organic and Polymer Photo-electric, Functional Films , State Key Laboratory of OEMT , School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , China . ; ;
| | - Juan Zhao
- PCFM Lab , GDHPPC Lab , Guangdong Engineering Technology , Research Center for High-performance Organic and Polymer Photo-electric, Functional Films , State Key Laboratory of OEMT , School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , China . ; ;
| | - Zhiyong Yang
- PCFM Lab , GDHPPC Lab , Guangdong Engineering Technology , Research Center for High-performance Organic and Polymer Photo-electric, Functional Films , State Key Laboratory of OEMT , School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , China . ; ;
| | - Yi Zhang
- PCFM Lab , GDHPPC Lab , Guangdong Engineering Technology , Research Center for High-performance Organic and Polymer Photo-electric, Functional Films , State Key Laboratory of OEMT , School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , China . ; ;
| | - William Wu
- R&D Center , Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd. , Shenzhen 518132 , China
| | - Shibo Jiao
- R&D Center , Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd. , Shenzhen 518132 , China
| | - Yang Liu
- R&D Center , Shenzhen China Star Optoelectronics Semiconductor Display Technology Co., Ltd. , Shenzhen 518132 , China
| | - Matthew P Aldred
- PCFM Lab , GDHPPC Lab , Guangdong Engineering Technology , Research Center for High-performance Organic and Polymer Photo-electric, Functional Films , State Key Laboratory of OEMT , School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , China . ; ;
| | - Zhenguo Chi
- PCFM Lab , GDHPPC Lab , Guangdong Engineering Technology , Research Center for High-performance Organic and Polymer Photo-electric, Functional Films , State Key Laboratory of OEMT , School of Chemistry , Sun Yat-Sen University , Guangzhou 510275 , China . ; ;
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11
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Watanabe Y, Sasabe H, Kido J. Review of Molecular Engineering for Horizontal Molecular Orientation in Organic Light-Emitting Devices. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2019. [DOI: 10.1246/bcsj.20180336] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yuichiro Watanabe
- Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Hisahiro Sasabe
- Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan
| | - Junji Kido
- Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan
- Research Center for Organic Electronics (ROEL), Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata 992-8510, Japan
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12
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Siddiqui QT, Awasthi AA, Bhui P, Parab P, Muneer M, Bose S, Agarwal N. TADF and exciplex emission in a xanthone–carbazole derivative and tuning of its electroluminescence with applied voltage. RSC Adv 2019; 9:40248-40254. [PMID: 35542672 PMCID: PMC9076223 DOI: 10.1039/c9ra08227a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 11/26/2019] [Indexed: 11/21/2022] Open
Abstract
Materials showing white light emission have found applications in a variety of solid state devices especially in display technology. For white light emission, doping of red (R), green (G) and blue (B) emitters in a host matrix is commonly practised. However, finding RGB emitters of similar stability with homogenous doping is challenging. Furthermore, such devices suffer from color purity in the long run. Small organic light emitters, capable of colour tuning and having a broad emission spectrum are in high demand as they provide colour stability, reproducibility, a simple device geometry and high efficiency. Recently, it has been shown that the efficiency of OLEDs can be enhanced by employing thermally activated delayed fluorescence (TADF) materials. Here, we designed and synthesised a xanthone–carbazole based D-A-D material (Xan-Cbz) for TADF properties. Blue TADF emission, in neat thin films, at 470 nm was observed and further investigated by studying delayed fluorescence and lifetime measurements. In addition, a blend of Xan-Cbz with NPD shows exciplex emission at 525 nm in thin film. OLEDs based on Xan-Cbz were fabricated using several device configurations. OLEDs having the device configuration ITO/PEDOT:PSS/NPD/Xan-Cbz/Bphen/LiF-Al showed a luminance of 1.96 × 104 Cd m−2 (at a current density of 50 mA cm−2) and VON at ∼6 V. Electroluminescence showed the features of both neat emission (470 nm) of Xan-Cbz and its exciplex (525 nm) with NPD. Further, colour tuning was observed as a function of applied voltage and the ratio of light intensity (I525/I470) of neat and exciplex emission was found to decrease with increasing voltage. Greenish-blue emission (CIE coordinates: 0.202, 0.382) from Xan-Cbz OLEDs was obtained. Xan-Cbz showed its neat emission (at 470 nm) in ITO/PEDOT:PSS/CBP/Xan-Cbz/Bphen/LiF-Al and pure exciplex emission (at 525 nm) in ITO/PEDOT:PSS/NPD:Xan-Cbz/Bphen/LiF-Al device configurations. Thus in this article we showed blue TADF emission, exciplex emission and voltage dependent color tuning in OLEDs based on a small organic emitter. Xanthone–carbazole (Xan–Cbz) derivative is synthesized and its photophysical properties are explored. OLEDs of Xan–Cbz shows tunability of electro-luminescence with applied voltage.![]()
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Affiliation(s)
- Qamar T. Siddiqui
- School of Chemical Sciences
- UM-DAE, Centre for Excellence in Basic Sciences
- University of Mumbai
- Mumbai
- India
| | - Ankur A. Awasthi
- School of Chemical Sciences
- UM-DAE, Centre for Excellence in Basic Sciences
- University of Mumbai
- Mumbai
- India
| | - Prabhjyot Bhui
- School of Physical Sciences
- UM-DAE, Centre for Excellence in Basic Sciences
- University of Mumbai
- Mumbai
- India
| | - Pradnya Parab
- School of Physical Sciences
- UM-DAE, Centre for Excellence in Basic Sciences
- University of Mumbai
- Mumbai
- India
| | - Mohammad Muneer
- Department of Chemistry
- Aligarh Muslim University
- Aligarh
- India
| | - Sangita Bose
- School of Physical Sciences
- UM-DAE, Centre for Excellence in Basic Sciences
- University of Mumbai
- Mumbai
- India
| | - Neeraj Agarwal
- School of Chemical Sciences
- UM-DAE, Centre for Excellence in Basic Sciences
- University of Mumbai
- Mumbai
- India
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13
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Chen Y, Ying S, Sun Q, Dai Y, Qiao X, Yang D, Chen J, Ma D. High efficiency hybrid white organic light-emitting diodes based on a simple and efficient exciton regulation emissive layer structure. RSC Adv 2018; 8:40883-40893. [PMID: 35557900 PMCID: PMC9091617 DOI: 10.1039/c8ra08753a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 11/30/2018] [Indexed: 11/25/2022] Open
Abstract
It is well-known that hybrid white organic light-emitting diodes (WOLEDs) are constructed by blue fluorophors and red-green or orange phosphors, therefore, theoretically exhibiting the advantages of long lifetime and high efficiency. However, the efficiency is far from reaching the expected values. Here, we designed a simple and efficient exciton regulation emissive layer (EML) structure to fabricate high efficiency hybrid WOLEDs. The EML sequentially comprises a yellow EML of phosphor doped hole-transporting material, a blue EML of a blend of hole- and electron-transporting materials and an exciton regulation layer of ultra-thin green phosphor inserted in electron-transporting material. It can be seen that the emissive excitons are well regulated by such a strategic EML structure. The resulting WOLEDs exhibit a maximum forward viewing external quantum efficiency and power efficiency of 18.2% and 72.9 lm W−1, respectively, and they are as high as 16.7% and 61.7 lm W−1 at 100 cd m−2, and 12.5% and 37.7 lm W−1 at 1000 cd m−2, showing the positive properties of high efficiency and low efficiency roll-off. Such outstanding performance will greatly promote the development of high performance hybrid WOLEDs. High performance hybrid WOLEDs based on a blue fluorescent EML and inserted an exciton regulation layer of ultrathin green phosphor.![]()
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Affiliation(s)
- Yuwen Chen
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 People's Republic of China
| | - Shian Ying
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 People's Republic of China
| | - Qian Sun
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 People's Republic of China
| | - Yanfeng Dai
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 People's Republic of China
| | - Xianfeng Qiao
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 People's Republic of China
| | - Dezhi Yang
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 People's Republic of China
| | - Jiangshan Chen
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 People's Republic of China
| | - Dongge Ma
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 People's Republic of China
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14
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Li H. Gate Tunable Organic Light Emitting Diodes: Principles and Prospects. CHEM REC 2018; 19:1471-1482. [PMID: 30094924 DOI: 10.1002/tcr.201800086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 07/25/2018] [Indexed: 11/08/2022]
Abstract
This record summarizes our recent developments on gate-tunable organic light-emitting diodes (OLEDs). The key point is to modulate the charge carrier injection barrier by the applied gate potential. One way is to electrochemically dope charge carrier injection layer through porous electrodes. The electrochemically doped charge carrier layer thus form gate-tunable contact with porous electrodes. Another way is to modulate the work-function of electrodes that can have varied charge carrier injection barriers following the applied gate potential. Gate-tunable OLEDs based on these two working principles have been fabricated, characterized and demonstrated for displaying simple digitals and letters. New materials including dielectric, porous electrodes, work function tunable electrodes, and charge carrier injection materials have been further explored for performance improvement.
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Affiliation(s)
- Huaping Li
- Atom Optoelectronics, 440 Hindry Avenue, Unit E, Los Angeles, California, 90301
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15
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Wang S, Zhao L, Zhang B, Ding J, Xie Z, Wang L, Wong WY. High-Energy-Level Blue Phosphor for Solution-Processed White Organic Light-Emitting Diodes with Efficiency Comparable to Fluorescent Tubes. iScience 2018; 6:128-137. [PMID: 30240606 PMCID: PMC6137322 DOI: 10.1016/j.isci.2018.07.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 06/19/2018] [Accepted: 07/19/2018] [Indexed: 10/28/2022] Open
Abstract
A high-energy-level blue phosphor FIr-p-OC8 has been developed for solution-processed white organic light-emitting diodes (WOLEDs) with comparable fluorescent tube efficiency. Benefiting from the electron-donating nature of the introduced alkoxy, FIr-p-OC8 shows not only efficient blue light but also elevated highest occupied molecular orbital/lowest unoccupied molecular orbital levels to well match the dendritic host H2. Consequently, the hole scattering between FIr-p-OC8 and H2 can be prevented to favor the direct exciton formation on the blue phosphor, leading to reduced driving voltage and thus improved power efficiency. By exploiting this approach, a maximum power efficiency of 68.5 lm W-1 is achieved for FIr-p-OC8-based white devices, slightly declining to 47.0 lm W-1 at a practical luminance of 1,000 cd m-2. This efficiency can be further raised to 96.3 lm W-1 @ 1,000 cd m-2 when a half-sphere is applied to increase light out-coupling. We believe that our results can compete with commercial fluorescent tubes, representing an important progress in solution-processed WOLEDs.
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Affiliation(s)
- Shumeng Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PRC
| | - Lei Zhao
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PRC
| | - Baohua Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PRC.
| | - Junqiao Ding
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PRC; University of Science and Technology of China, Hefei 230026, PRC.
| | - Zhiyuan Xie
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PRC; University of Science and Technology of China, Hefei 230026, PRC
| | - Lixiang Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, PRC; University of Science and Technology of China, Hefei 230026, PRC
| | - Wai-Yeung Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, PRC; Institute of Molecular Functional Materials and Department of Chemistry, Hong Kong Baptist University, Waterloo Road, Hong Kong, PRC.
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16
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Wen LL, Zang CX, Gao Y, Shan GG, Sun HZ, Wang T, Xie WF, Su ZM. Molecular Engineering of Phenylbenzimidazole-Based Orange Ir(III) Phosphors toward High-Performance White OLEDs. Inorg Chem 2018; 57:6029-6037. [PMID: 29741881 DOI: 10.1021/acs.inorgchem.8b00527] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
To develop B-O complementary-color white organic light-emitting diodes (WOLEDs) exhibiting high efficiency and low roll-off as well as color stability simultaneously, we have designed two orange iridium(III) complexes by simply controlling the position of the methoxyl group on the cyclometalated ligand. The obtained emitters mOMe-Ir-BQ and pOMe-Ir-BQ show good photophysical and electrochemical stabilities with a broadened full width at half-maximum close to 100 nm. The corresponding devices realize highly efficient electrophosphorescence with a maximum current efficiency (CE) and power efficiency (PE) of 24.4 cd A-1 and 15.3 lm W-1 at a high doping concentration of 15 wt %. Furthermore, the complementary-color all-phosphor WOLEDs based on these phosphors exhibit good performance with a maximum CE of 31.8 cd A-1, PE of 25.0 lm W-1, and external quantum efficiency of 15.5%. Particularly, the efficiency of this device is still as high as 29.3 cd A-1 and 14.2% at the practical brightness level of 1000 cd m-2, giving a small roll-off. Meanwhile, extremely high color stability is achieved by these devices with insignificant chromaticity variation.
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Affiliation(s)
- Li-Li Wen
- Institute of Functional Material Chemistry and National & Local United Engineering Lab for Power Battery, Faculty of Chemistry , Northeast Normal University , Changchun 130024 , People's Republic of China
| | - Chun-Xiu Zang
- State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering , Jilin University , Changchun , Jilin 130012 , People's Republic of China
| | - Ying Gao
- Institute of Functional Material Chemistry and National & Local United Engineering Lab for Power Battery, Faculty of Chemistry , Northeast Normal University , Changchun 130024 , People's Republic of China
| | - Guo-Gang Shan
- Institute of Functional Material Chemistry and National & Local United Engineering Lab for Power Battery, Faculty of Chemistry , Northeast Normal University , Changchun 130024 , People's Republic of China
| | - Hai-Zhu Sun
- Institute of Functional Material Chemistry and National & Local United Engineering Lab for Power Battery, Faculty of Chemistry , Northeast Normal University , Changchun 130024 , People's Republic of China
| | - Tong Wang
- Army Armor Academy NCO Institute , Changchun 130017 , People's Republic of China
| | - Wen-Fa Xie
- State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering , Jilin University , Changchun , Jilin 130012 , People's Republic of China
| | - Zhong-Min Su
- Institute of Functional Material Chemistry and National & Local United Engineering Lab for Power Battery, Faculty of Chemistry , Northeast Normal University , Changchun 130024 , People's Republic of China
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17
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Zhang T, Shi C, Zhao C, Wu Z, Chen J, Xie Z, Ma D. Extremely Low Roll-Off and High Efficiency Achieved by Strategic Exciton Management in Organic Light-Emitting Diodes with Simple Ultrathin Emitting Layer Structure. ACS APPLIED MATERIALS & INTERFACES 2018; 10:8148-8154. [PMID: 29436812 DOI: 10.1021/acsami.8b00513] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Phosphorescent organic light-emitting diodes (OLEDs) possess the property of high efficiency but have serious efficiency roll-off at high luminance. Herein, we manufactured high-efficiency phosphorescent OLEDs with extremely low roll-off by effectively locating the ultrathin emitting layer (UEML) away from the high-concentration exciton formation region. The strategic exciton management in this simple UEML architecture greatly suppressed the exciton annihilation due to the expansion of the exciton diffusion region; thus, this efficiency roll-off at high luminance was significantly improved. The resulting green phosphorescent OLEDs exhibited the maximum external quantum efficiency of 25.5%, current efficiency of 98.0 cd A-1, and power efficiency of 85.4 lm W-1 and still had 25.1%, 94.9 cd A-1, and 55.5 lm W-1 at 5000 cd m-2 luminance, and retained 24.3%, 92.7 cd A-1, and 49.3 lm W-1 at 10 000 cd m-2 luminance, respectively. Compared with the usual structures, the improvement demonstrated in this work displays potential value in applications.
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Affiliation(s)
- Tianmu Zhang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , University of Chinese Academy of Sciences , Changchun 130022 , P. R. China
| | - Changsheng Shi
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , University of Chinese Academy of Sciences , Changchun 130022 , P. R. China
| | - Chenyang Zhao
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , University of Chinese Academy of Sciences , Changchun 130022 , P. R. China
| | - Zhongbin Wu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , University of Chinese Academy of Sciences , Changchun 130022 , P. R. China
| | - Jiangshan Chen
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
| | - Zhiyuan Xie
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , University of Chinese Academy of Sciences , Changchun 130022 , P. R. China
| | - Dongge Ma
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry , University of Chinese Academy of Sciences , Changchun 130022 , P. R. China
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices , South China University of Technology , Guangzhou 510640 , P. R. China
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18
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Jhulki S, Seth S, Rafiq S, Ghosh A, Chow TJ, Moorthy JN. Nitrogen-Free Bifunctional Bianthryl Leads to Stable White-Light Emission in Bilayer and Multilayer OLED Devices. ACS OMEGA 2018; 3:1416-1424. [PMID: 31458471 PMCID: PMC6641470 DOI: 10.1021/acsomega.7b01712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 01/19/2018] [Indexed: 06/10/2023]
Abstract
White organic light-emitting diodes (WOLEDs) are at the center stage of OLED research today because of their advantages in replacing the high energy-consuming lighting technologies in vogue for a long time. New materials that emit white light in simple devices are much sought after. We have developed two novel electroluminescent materials, referred to as BABZF and BATOMe, based on a twisted bianthryl core, which are brilliantly fluorescent, thermally highly stable with high T d and T g, and exhibit reversible redox property. Although inherently blue emissive, BABZF leads to white-light emission (CIE ≈ 0.28, 0.33) with a moderate power efficiency of 2.24 lm/W and a very high luminance of 15 600 cd/m2 in the fabricated multilayer nondoped OLED device. This device exhibited excellent color stability over a range of applied potential. Remarkably, similar white-light emission was captured even from a double-layer device, attesting to the innate hole-transporting ability of BABZF despite it being non-nitrogenous, that is, lacking any traditional hole-transporting di-/triarylamino group(s). Similar studies with BATOMe led to inferior device performance results, thereby underscoring the importance of dibenzofuryl groups in BABZF. Experimental as well as theoretical studies suggest the possibility of emission from multiple species involving BABZF and its exciplex and electroplex in the devices. The serendipitously observed white-light emission from a double-layer device fabricated with an unconventional hole-transporting material (HTM) opens up new avenues to create new non-nitrogenous HTMs that may lead to more efficient white-light emission in simple double-layer devices.
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Affiliation(s)
- Samik Jhulki
- Department
of Chemistry, Indian Institute of Technology
Kanpur, Kanpur 208016, India
| | - Saona Seth
- Department
of Chemistry, Indian Institute of Technology
Kanpur, Kanpur 208016, India
| | - Shahnawaz Rafiq
- Frick
Chemistry Laboratory, Princeton University, Princeton, New Jersey 08544, United States
| | - Avijit Ghosh
- Institute
of Chemistry Academia Sinica, Taipei, Taiwan 115
- Department
of Chemistry, Tunghai University, Taichung, Taiwan 407
| | - Tahsin J. Chow
- Institute
of Chemistry Academia Sinica, Taipei, Taiwan 115
- Department
of Chemistry, Tunghai University, Taichung, Taiwan 407
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19
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Page Z, Narupai B, Pester CW, Bou Zerdan R, Sokolov A, Laitar DS, Mukhopadhyay S, Sprague S, McGrath AJ, Kramer JW, Trefonas P, Hawker CJ. Novel Strategy for Photopatterning Emissive Polymer Brushes for Organic Light Emitting Diode Applications. ACS CENTRAL SCIENCE 2017; 3:654-661. [PMID: 28691078 PMCID: PMC5492409 DOI: 10.1021/acscentsci.7b00165] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Indexed: 05/25/2023]
Abstract
A light-mediated methodology to grow patterned, emissive polymer brushes with micron feature resolution is reported and applied to organic light emitting diode (OLED) displays. Light is used for both initiator functionalization of indium tin oxide and subsequent atom transfer radical polymerization of methacrylate-based fluorescent and phosphorescent iridium monomers. The iridium centers play key roles in photocatalyzing and mediating polymer growth while also emitting light in the final OLED structure. The scope of the presented procedure enables the synthesis of a library of polymers with emissive colors spanning the visible spectrum where the dopant incorporation, position of brush growth, and brush thickness are readily controlled. The chain-ends of the polymer brushes remain intact, affording subsequent chain extension and formation of well-defined diblock architectures. This high level of structure and function control allows for the facile preparation of random ternary copolymers and red-green-blue arrays to yield white emission.
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Affiliation(s)
- Zachariah
A. Page
- Materials Research Laboratory and Department of Chemistry and Biochemistry, University of California Santa Barbara, California 93106, United States
| | - Benjaporn Narupai
- Materials Research Laboratory and Department of Chemistry and Biochemistry, University of California Santa Barbara, California 93106, United States
| | - Christian W. Pester
- Materials Research Laboratory and Department of Chemistry and Biochemistry, University of California Santa Barbara, California 93106, United States
| | - Raghida Bou Zerdan
- Materials Research Laboratory and Department of Chemistry and Biochemistry, University of California Santa Barbara, California 93106, United States
| | - Anatoliy Sokolov
- The
Dow Chemical Company, Midland, Michigan 48674, United States
| | - David S. Laitar
- The
Dow Chemical Company, Midland, Michigan 48674, United States
| | | | - Scott Sprague
- The
Dow Chemical Company, Midland, Michigan 48674, United States
| | - Alaina J. McGrath
- Materials Research Laboratory and Department of Chemistry and Biochemistry, University of California Santa Barbara, California 93106, United States
| | - John W. Kramer
- The
Dow Chemical Company, Midland, Michigan 48674, United States
| | - Peter Trefonas
- The
Dow Electronic Materials Company, 455 Forest Street, Marlborough, Massachusetts 01752, United States
| | - Craig J. Hawker
- Materials Research Laboratory and Department of Chemistry and Biochemistry, University of California Santa Barbara, California 93106, United States
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20
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Yu Z, Wu Y, Xiao L, Chen J, Liao Q, Yao J, Fu H. Organic Phosphorescence Nanowire Lasers. J Am Chem Soc 2017; 139:6376-6381. [PMID: 28414231 DOI: 10.1021/jacs.7b01574] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Organic solid-state lasers (OSSLs) based on singlet fluorescence have merited intensive study as an important class of light sources. Although the use of triplet phosphors has led to 100% internal quantum efficiency in organic light-emitting diodes (OLEDs), stumbling blocks in triplet lasing include generally forbidden intersystem crossing (ISC) and a low quantum yield of phosphorescence (ΦP). Here, we reported the first triplet-phosphorescence OSSL from a nanowire microcavity of a sulfide-substituted difluoroboron compound. As compared with the unsubstituted parent compound, the lone pair of electrons of sulfur substitution plus the intramolecular charge transfer interaction introduced by the nitro moiety lead to an highly efficient T1 (π,π*) ← S1 (n,π*) ISC (ΦISC = 100%) and a moderate ΦP (10%). This, plus the optical feedback provided by nanowire Fabry-Perot microcavity, enables triplet-phosphorescence OSSL emission at 650 nm under pulsed excitation. Our results open the door for a whole new class of laser materials based on previously untapped triplet phosphors.
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Affiliation(s)
- Zhenyi Yu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300072, People's Republic of China.,Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.,Graduate University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Yishi Wu
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China
| | - Lu Xiao
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.,Graduate University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Jianwei Chen
- Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.,Graduate University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Qing Liao
- Department of Chemistry, Capital Normal University , Beijing 100048, People's Republic of China
| | - Jiannian Yao
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300072, People's Republic of China.,Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.,Graduate University of Chinese Academy of Sciences , Beijing 100049, People's Republic of China
| | - Hongbing Fu
- Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, Tianjin University, and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin) , Tianjin 300072, People's Republic of China.,Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.,Department of Chemistry, Capital Normal University , Beijing 100048, People's Republic of China
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21
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Xu T, Zhou JG, Huang CC, Zhang L, Fung MK, Murtaza I, Meng H, Liao LS. Highly Simplified Tandem Organic Light-Emitting Devices Incorporating a Green Phosphorescence Ultrathin Emitter within a Novel Interface Exciplex for High Efficiency. ACS APPLIED MATERIALS & INTERFACES 2017; 9:10955-10962. [PMID: 28271707 DOI: 10.1021/acsami.6b16094] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Herein we report a novel design philosophy of tandem OLEDs incorporating a doping-free green phosphorescent bis[2-(2-pyridinyl-N)phenyl-C](acetylacetonato)iridium(III) (Ir(ppy)2(acac)) as an ultrathin emissive layer (UEML) into a novel interface-exciplex-forming structure of 1,1-bis[(di-4-tolylamino)phenyl]cyclohexane (TAPC) and 1,3,5-tri(p-pyrid-3-yl-phenyl)benzene (TmPyPB). Particularly, relatively low working voltage and remarkable efficiency are achieved and the designed tandem OLEDs exhibit a peak current efficiency of 135.74 cd/A (EQE = 36.85%) which is two times higher than 66.2 cd/A (EQE = 17.97%) of the device with a single emitter unit. This might be one of the highest efficiencies of OLEDs applying ultrathin emitters without light extraction. Moreover, with the proposed structure, the color gamut of the displays can be effectively increased from 76% to 82% NTSC if the same red and blue emissions as those in the NTSC are applied. A novel form of harmonious fusion among interface exciplex, UEML, and tandem structure is successfully realized, which sheds light on further development of ideal OLED structure with high efficiency, simplified fabrication, low power consumption, low cost, and improved color gamut, simultaneously.
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Affiliation(s)
- Ting Xu
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
- School of Advanced Materials, Shenzhen Graduate School, Peking University , Shenzhen 518055, China
| | - Jun-Gui Zhou
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Chen-Chao Huang
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Lei Zhang
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Man-Keung Fung
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
| | - Imran Murtaza
- Key Laboratory of Flexible Electronics and Institute of Advanced Materials, Jiangsu National Synergistic Innovation Centre for Advanced Materials, Nanjing Tech University , Nanjing 211816, China
- Department of Physics, International Islamic University , Islamabad 44000, Pakistan
| | - Hong Meng
- School of Advanced Materials, Shenzhen Graduate School, Peking University , Shenzhen 518055, China
- Key Laboratory of Flexible Electronics and Institute of Advanced Materials, Jiangsu National Synergistic Innovation Centre for Advanced Materials, Nanjing Tech University , Nanjing 211816, China
| | - Liang-Sheng Liao
- Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University , Suzhou, Jiangsu 215123, China
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22
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Meng L, Wang H, Wei X, Liu J, Chen Y, Kong X, Lv X, Wang P, Wang Y. Highly Efficient Nondoped Organic Light Emitting Diodes Based on Thermally Activated Delayed Fluorescence Emitter with Quantum-Well Structure. ACS APPLIED MATERIALS & INTERFACES 2016; 8:20955-61. [PMID: 27452075 DOI: 10.1021/acsami.6b07563] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Highly efficiency nondoped thermally activated delayed fluorescence (TADF) organic light emitting diodes (OLEDs) with multiquantum wells structure were demonstrated. By using an emitting layer with seven quantum wells, the nondoped TADF OLEDs exhibit high efficiency with EQE of 22.6%, a current efficiency of 69 cd/A, and a power efficiency of 50 lm/W, which are higher than those of the conventional doped OLED and among the best of the TADF OLEDs. The high performance of the devices can be ascribed to effective confinement of the charges and excitons in the emission layer by the quantum well structure. The emission layer with multiquantum well structure is demonstrated to be cost effective for highly efficient nondoped TADF OLEDs and holds great potential for organic electronics.
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Affiliation(s)
- Lingqiang Meng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Hui Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Xiaofang Wei
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Jianjun Liu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Yongzhen Chen
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Xiangbin Kong
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China
- University of Chinese Academy of Sciences , Beijing 100049, China
| | - Xiaopeng Lv
- Soochow University , Suzhou, Jiangsu Province, China
| | - Pengfei Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China
| | - Ying Wang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190, China
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