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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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2
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Lin KH, Corminboeuf C. FB-ECDA: Fragment-based Electronic Coupling Decomposition Analysis for Organic Amorphous Semiconductors. J Phys Chem A 2020; 124:10624-10634. [DOI: 10.1021/acs.jpca.0c09743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kun-Han Lin
- Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
| | - Clémence Corminboeuf
- Laboratory for Computational Molecular Design, Institute of Chemical Sciences and Engineering and National Centre for Computational Design and Discovery of Novel Materials (MARVEL), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland
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3
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Yu R, Wang P, Meng X, He L. Sky-blue-emitting cationic iridium complexes with carbazole-type counter-anions and their use for efficient solution-processed organic light-emitting diodes. Dalton Trans 2020; 49:8967-8975. [PMID: 32558861 DOI: 10.1039/d0dt01872d] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The control of counter-anion is a facile approach to tune the overall properties of cationic iridium complexes for optoelectronic applications. Here, we report for the first time the use of electron-rich carbazole-type counter-anions in cationic iridium complexes and the use of such complexes as dopants in solution-processed organic light-emitting diodes (OLEDs). PF6-, 4-(9H-carbazol-9-yl)benzenesulfonate (CAZ-SO3-), and 4-(9'H-[9,3':6',9''-tercarbazol]-9'-yl)benzenesulfonate (TCAZ-SO3-) have been employed as the counter-anions of sky-blue-emitting complexes R, 1 and 2, respectively. The carbazole-type counter-anions do not largely disturb the phosphorescence of the cations and the complexes show similar emission properties in solution and films. The close proximity of the carbazole-type anions to the phosphorescent cations allows efficient energy-transfer from the former to the latter in films. When used as dopants in solution-processed OLEDs, complexes 1 and 2 show higher performances than complex R because the hole-trapping effects of the carbazole-type counter-anions largely improve the carrier-recombination balance in the emissive layers. In particular, the double-layer sky-blue device based on complex 2 with strong hole-trapping by TCAZ-SO3- affords a high peak current efficiency of 27.1 cd A-1. The work reveals that electron-rich carbazole-type anions are promising counter-anions for cationic iridium complexes toward optoelectronic applications.
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Affiliation(s)
- Renyou Yu
- College of Chemistry, Key Laboratory of Pesticide and Chemical Biology of Ministry of Education, Hubei International Scientific and Technological Cooperation Base of Pesticide and Green Synthesis, Central China Normal University, Wuhan 430079, People's Republic of China.
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Yang Y, Yang L, Li X, Zhao L, Wang S, Ding J, Wang L. Trap-Controlled White Electroluminescence From a Single Red-Emitting Thermally Activated Delayed Fluorescence Polymer. Front Chem 2020; 8:287. [PMID: 32373586 PMCID: PMC7186499 DOI: 10.3389/fchem.2020.00287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 03/23/2020] [Indexed: 11/13/2022] Open
Abstract
Single white-emitting polymers have been reported by incorporating the second-generation carbazole dendron into the side chain of a red-emitting thermally activated delayed fluorescence (TADF) polymer. Due to the prevented hole trap effect, in this case, excitons can be generated simultaneously on the polymeric host and the red TADF dopant to give a dual emission. Consequently, a bright white electroluminescence is achieved even at a dopant loading as high as 5 mol.%, revealing a maximum luminous efficiency of 16.1 cd/A (12.0 lm/W, 8.2%) and Commission Internationale de l'Eclairage (CIE) coordinates of (0.42, 0.32). The results clearly indicate that the delicate tuning of charge trap is a promising strategy to develop efficient single white-emitting polymers, whose low-band-gap chromophore content can be up to a centesimal level.
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Affiliation(s)
- Yun Yang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.,School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, China
| | - Liuqing Yang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.,School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, China
| | - Xuefei Li
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.,School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, China
| | - Lei Zhao
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China
| | - Shumeng Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China
| | - Junqiao Ding
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.,School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, China
| | - Lixiang Wang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, China.,School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, China
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Jeon S, Sun C, Yu SH, Kwon SK, Chung DS, Jeong YJ, Kim YH. Synthesis of Cyclopentadithiophene-Diketopyrrolopyrrole Donor-Acceptor Copolymers for High-Performance Nonvolatile Floating-Gate Memory Transistors with Long Retention Time. ACS APPLIED MATERIALS & INTERFACES 2020; 12:2743-2752. [PMID: 31868340 DOI: 10.1021/acsami.9b20307] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Organic flash memories that employ solution-processed polymer semiconductors preferentially require internal stability of their active channel layers. In this paper, a series of new donor-acceptor copolymers based on cyclopentadithiophene (CDT) and diketopyrrolopyrrole (DPP) are synthesized to obtain high performance and operational stability of nonvolatile floating-gate memory transistors with various additional donor units including thiophene, thiophene-vinylene-thiophene (CDT-DPP-TVT), selenophene, and selenophene-vinylene-selenophene. Detailed analyses on the photophysical, two-dimensional grazing incident X-ray diffraction, and bias stress stability are discussed, which reveal that the CDT-DPP-TVT exhibits excellent bias stress stability over 105 s. To utilize the robust nature of CDT-DPP-TVT, floating-gate transistors are fabricated by embedding Au nanoparticles between Cytop layers as a charge storage site. The resulting memory devices reveal bistable current states with high on/off current ratio larger than 104 and each state can be distinguished for more than 1 year, indicating a long retention time. Moreover, repetitive writing-reading-erasing-reading test clearly supports the reproducible memory operation with reversible and reliable electrical responses. All these results suggest that the internal stability of CDT-DPP-TVT makes this copolymer a promising material for application in reliable organic flash memory.
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Affiliation(s)
- Soyeon Jeon
- Department of Energy Science and Engineering , Daegu Gyeongbuk Institute of Science and Technology (DGIST) , Daegu 42988 , Republic of Korea
| | - Cheng Sun
- Department of Chemistry and RIGET , Gyeongsang National University , Jinju 52828 , Republic of Korea
| | - Seong Hoon Yu
- Department of Energy Science and Engineering , Daegu Gyeongbuk Institute of Science and Technology (DGIST) , Daegu 42988 , Republic of Korea
| | - Soon-Ki Kwon
- Department of Materials Engineering and Convergence Technology and ERI , Gyeongsang National University , Jinju 660-701 , Republic of Korea
| | - Dae Sung Chung
- Department of Energy Science and Engineering , Daegu Gyeongbuk Institute of Science and Technology (DGIST) , Daegu 42988 , Republic of Korea
| | - Yong Jin Jeong
- Department of Materials Science & Engineering , Korea National University of Transportation , Chungju 27469 , Republic of Korea
| | - Yun-Hi Kim
- Department of Chemistry and RIGET , Gyeongsang National University , Jinju 52828 , Republic of Korea
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6
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Teaching an Old Poly(arylene ether) New Tricks: Efficient Blue Thermally Activated Delayed Fluorescence. iScience 2019; 15:147-155. [PMID: 31055216 PMCID: PMC6502736 DOI: 10.1016/j.isci.2019.04.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/10/2019] [Accepted: 04/16/2019] [Indexed: 11/25/2022] Open
Abstract
Polymer light-emitting diodes are attractive for optoelectronic applications owing to their brightness and ease of processing. However, often metals have to be inserted to increase the luminescence efficiency, and producing blue emitters is a challenge. Here we present a strategy to make blue thermally activated delayed fluorescence (TADF) polymers by directly embedding a small molecular blue TADF emitter into a poly(aryl ether) (PAE) backbone. Thanks to the oxygen-induced negligible electronic communication between neighboring TADF fragments, its corresponding blue delayed fluorescence can be inherited by the developed polymers. These polymers are free from metal catalyst contamination and show improved thermal stability. Through device optimization, a current efficiency of 29.7 cd/A (21.2 lm/W, 13.2%) is realized together with Commission Internationale de L'Eclairage coordinates of (0.18, 0.32). The value is competitive with blue phosphorescent polymers, highlighting the importance of the PAE backbone in achieving high-performance blue delayed fluorescence at a macromolecular level. Directly embedding a small molecular blue TADF emitter in a poly(aryl ether) backbone Oxygen-induced negligible electron communication leads to blue delayed fluorescence The achieved device efficiency is competitive with blue phosphorescent polymers
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Zhang D, Duan L. Polycyclic Aromatic Hydrocarbon Derivatives toward Ideal Electron-Transporting Materials for Organic Light-Emitting Diodes. J Phys Chem Lett 2019; 10:2528-2537. [PMID: 31038961 DOI: 10.1021/acs.jpclett.9b00526] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
One seemingly fundamental issue for electron-transporting materials (ETMs) in organic light-emitting diodes (OLEDs) is the mutual exclusion of a high electron-transporting mobility ( μe) and a large molecular triplet energy for good exciton confinement. Very recently, a trade-off was realized by adopting polycyclic aromatic hydrocarbon (PAH) derivatives as bipolar ETMs. Though the intrinsic low triplet energy of PAH moieties, good exciton confinement abilities are realized by manipulating the peripheral groups, integrating large μe values and long-term stabilities simultaneously. The resulting state-of-the-art OLED performances manifest the bright future of such ETMs. This Perspective summarizes the theoretical and experimental work relating to the relationship between the molecular structure of PAH-type ETMs and their electronic properties, focusing on charge transfer and exciton confinement abilities; the Perspective concludes by providing a vision of future developments in this field.
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Affiliation(s)
- Dongdong Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry , Tsinghua University , Beijing 100084 , China
- Center for Flexible Electronics Technology , Tsinghua University , Beijing 100084 , P.R. China
| | - Lian Duan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry , Tsinghua University , Beijing 100084 , China
- Center for Flexible Electronics Technology , Tsinghua University , Beijing 100084 , P.R. China
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Cai M, Zhang D, Xu J, Hong X, Zhao C, Song X, Qiu Y, Kaji H, Duan L. Unveiling the Role of Langevin and Trap-Assisted Recombination in Long Lifespan OLEDs Employing Thermally Activated Delayed Fluorophores. ACS APPLIED MATERIALS & INTERFACES 2019; 11:1096-1108. [PMID: 30525372 DOI: 10.1021/acsami.8b16784] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Recent research studies on noble-metal-free thermally activated delayed fluorescent (TADF) materials have boosted the efficiencies of organic light-emitting diodes (OLEDs) to unity. However, the short lifespan still hinders their further practical application. Carrier recombination pathways have been reported to have a significant influence on the efficiencies of TADF devices, though their effects on device lifetimes remain rarely studied. Here, we have designed and synthesized five pyrimidine or pyrazine/carbazole isomers as hosts for TADF OLEDs to explore the inherent role of Langevin recombination (LR) and trap-assisted recombination (TAR) in device lifetimes. It is revealed that for LR dominant devices, lifetimes would increase by reducing the host triplet energy levels, whereas for TAR dominant devices, lifetimes are insensitive to the host triplet excitons as recombination mainly takes place on dopants. Still, LR dominant devices are favored as they offer more room for optimization. We further apply this concept in designing a stable LR dominant blue TADF device, achieving a long LT50 (lifespan up to 50% of the initial luminance) of 269 h and high external quantum efficiency of 17.9% at 1000 cd m-2 simultaneously.
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Affiliation(s)
| | | | | | | | | | | | | | - Hironori Kaji
- Institute for Chemical Research , Kyoto University , Uji , Kyoto 6611-0011 , Japan
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9
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Tyutnev AP, Novikov SV, Saenko VS, Pozhidaev ED. Comparative Monte-Carlo simulations of charge carrier transport in amorphous molecular solids as given by three most common models of disorder: The dipolar glass, the Gaussian disorder, and their mix. J Chem Phys 2017; 147:114901. [PMID: 28938818 DOI: 10.1063/1.5002527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We have performed Monte-Carlo simulations of the charge carrier transport in a model molecularly doped polymer using three most popular hopping theories (the dipolar glass model, the Gaussian disorder model, and an intermediate between them) in a wide range of applied electric fields and temperatures. Time of flight transients have been computed and analyzed in logarithmic coordinates to study the Poole-Frenkel field dependence, the non-Arrhenius mobility temperature dependence, and the nondispersive versus dispersive current shapes. We also have made an attempt to estimate the total disorder energy directly from simulation data at the lowest electric field thus checking the consistency of the model fitting. Computational results have been compared with the analytical and experimental information available in the literature.
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Affiliation(s)
- A P Tyutnev
- National Research University Higher School of Economics, 20 Miasnitskaya Ulitsa, Moscow 101000, Russia
| | - S V Novikov
- National Research University Higher School of Economics, 20 Miasnitskaya Ulitsa, Moscow 101000, Russia
| | - V S Saenko
- National Research University Higher School of Economics, 20 Miasnitskaya Ulitsa, Moscow 101000, Russia
| | - E D Pozhidaev
- National Research University Higher School of Economics, 20 Miasnitskaya Ulitsa, Moscow 101000, Russia
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10
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Li H, Brédas JL. Kinetic Monte Carlo Modeling of Charge Carriers in Organic Electronic Devices: Suppression of the Self-Interaction Error. J Phys Chem Lett 2017; 8:2507-2512. [PMID: 28520427 DOI: 10.1021/acs.jpclett.7b01161] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Kinetic Monte Carlo (KMC) simulations have emerged as an important tool to help improve the efficiency of organic electronic devices by providing a better understanding of their device physics. In the KMC simulation of an organic device, the reliability of the results depends critically on the accuracy of the chosen charge-transfer rates, which are themselves strongly influenced by the site-energy differences. These site-energy differences include components coming from the electrostatic forces present in the system, which are often evaluated through electric potentials described by the Poisson equation. Here we show that the charge-carrier self-interaction errors that appear when evaluating the site-energy differences can lead to unreliable simulation results. To eliminate these errors, we propose two approaches that are also found to reduce the impact of finite-size effects. As a consequence, reliable results can be obtained at reduced computational costs. The proposed methodologies can be extended to other device simulation techniques as well.
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Affiliation(s)
- Haoyuan Li
- Laboratory for Computational and Theoretical Chemistry of Advanced Materials, Physical Science and Engineering Division, King Abdullah University of Science and Technology , Thuwal 23955-6900, Kingdom of Saudi Arabia
| | - Jean-Luc Brédas
- Laboratory for Computational and Theoretical Chemistry of Advanced Materials, Physical Science and Engineering Division, King Abdullah University of Science and Technology , Thuwal 23955-6900, Kingdom of Saudi Arabia
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