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Tong KN, Wu C, Wu Y, Li S, Jin Z, Shi K, Jung S, Wang X, Guan Y, Yang C, Wei G. Cascading Energy Transfer for Highly Efficient Deep-Red OLED Emission with Cyclometalated [3+2+1] Iridium Complexes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2307500. [PMID: 37940631 DOI: 10.1002/smll.202307500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/17/2023] [Indexed: 11/10/2023]
Abstract
The promising cyclometalated iridium (III) complexes have been proved to possess great potential in vacuum-deposited organic light-emitting diodes (OLEDs) applications for full-color displays and white solid-state lighting sources. Herein, based on the unique bidentate ligand of dibenzo[a,c]phenazine (dbpz) group with strong conjugated effect of aromatic rings for red emission, four novel [3+2+1] coordinated iridium (III) emissive materials have been rationally designed and synthesized. The monodentate ligands of -CN and -OCN have been effectively employed to tune the deep-red emission of 628-675 nm with high photoluminescence quantum yields up to 98%. Moreover, all devices displayed deep-red color coordinates ranging from (0.675, 0.325) to (0.716, 0.284), which is close to the standard-red color coordinates of (0.708, 0.292), as recommended by International Telecommunication Union Radiocommunication (ITU-R) BT.2020. The device based on nBuIr(dbpz)CN with an exciplex cohost has exhibited maximum external quantum efficiencies of 20.7% and good stability. With nBuIr(dbpz)CN as an effective sensitizer, the nBuIr(dbpz)OCN based phosphorescent OLED devices have successfully demonstrated cascading energy transfer processes, contributing to pure red emission with maximum luminance as high as 6471 cd m-2. Therefore, this work has been successfully demonstrated rational molecular design strategy of [3+2+1] iridium complexes to obtain highly efficient deep-red electrophosphorescent emission.
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Affiliation(s)
- Kai-Ning Tong
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Chengcheng Wu
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
| | - Yuan Wu
- PURI Materials, Shenzhen, 518133, China
| | - Siqi Li
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Zhaoyun Jin
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Kefei Shi
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
| | - Sinyeong Jung
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
| | - Xin Wang
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | | | - Chen Yang
- PURI Materials, Shenzhen, 518133, China
| | - Guodan Wei
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
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2
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Liu S, Wang M, Hou T, Shen X. Unprecedented hetero-coordinated Ir(C^N) 2tmd complexes containing both five- and six-membered Ir-(C^N) rings based on phenanthrylpyridine ligands: syntheses, crystal structures and photophysical properties. Dalton Trans 2023; 52:11120-11129. [PMID: 37494113 DOI: 10.1039/d3dt01809a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
By using 2-(9-phenanthryl)pyridine (phpyr) and its derivatives as cyclometalated ligands, we synthesized a set of isomeric red-emitting complexes Ir(phpyr-R)2tmd (R = -H, -CF3, -F and -CH3, tmd = 2,2,6,6-tetramethylheptane-3,5-dione) with different coordinated modes, including bis-five-membered and five- + six-membered Ir-(C^N) ring chelating modes. The latter are the first examples of hetero-coordinated Ir(C^N)2(L^X)-type complexes containing both five- and six-membered Ir-(C^N) metallocycles. Their coordination geometries were distinctly determined using X-ray crystallographic analysis. Compared to typical bis-five-membered ring-chelated complexes, these novel hetero-coordinated isomers show bathochromic emission and lower quantum yields. On careful analysis of their electrochemical behavior and DFT calculations, it has been found that the regulatory effects of the solitary six-membered metallocycles in Ir(phpyr-R)2tmd could not only stabilize the LUMO but also destabilize the HOMO, leading to a narrower energy gap. More importantly, DFT calculations of the relative energies of these isomeric complexes demonstrated that bis-five-membered and five- + six-membered chelating modes are more stable compared to bis-six-membered rings, consistent with experiments. This work provides guidance for the structural design of Ir(C^N)2(L^X)-type complexes.
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Affiliation(s)
- Sen Liu
- State Key Laboratory of Materials-oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
- Zhangjiagang Institute of Nanjing Tech University, Suzhou 215600, P. R. China
| | - Mengyun Wang
- State Key Laboratory of Materials-oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
| | - Tianjiao Hou
- State Key Laboratory of Materials-oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
- Jiangsu Academy of Chemical Inherent Safety, Nanjing210009, P. R. China
| | - Xuan Shen
- State Key Laboratory of Materials-oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, P. R. China.
- Zhangjiagang Institute of Nanjing Tech University, Suzhou 215600, P. R. China
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Wang L, Miao J, Zhang Y, Wu C, Huang H, Wang X, Yang C. Discrete Mononuclear Platinum(II) Complexes Realize High-Performance Red Phosphorescent OLEDs with EQEs of up to 31.8% and Superb Device Stability. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2303066. [PMID: 37327208 DOI: 10.1002/adma.202303066] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/14/2023] [Indexed: 06/18/2023]
Abstract
Designing mononuclear platinum(II) complexes that do not rely on intermolecular aggregation for high-performance red organic light-emitting diodes remains a formidable challenge. In this work, three robust red-emitting Pt(II) complexes are created by utilizing a rigid 4-coordination configuration, where the ligands are formed by linking electron-donor of triphenylamine (TPA) moieties with electron-acceptor of pyridine, isoquinoline, and/or δ-carboline units. The thermal stability, electrochemical, and photophysical properties of the complexes are thoroughly examined. The complexes display efficient red phosphorescence, with high photoluminescence quantum yields and short excited lifetimes. The OLEDs dope with these complexes exhibit high maximum external quantum efficiencies (EQEs) of up to 31.8% with minimal efficiency roll-off even at high brightness. Significantly, the devices demonstrate exceptional long operational lifetime, with a T90 lifetime of over 14000 h at initial luminance of 1000 cd m-2 , indicating the potential for these complexes to be practically utilizes.
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Affiliation(s)
- Lian Wang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P. R. China
| | - Jingsheng Miao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P. R. China
| | - Youming Zhang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P. R. China
- Shenzhen Institute of Information Technology, Shenzhen, 518172, P. R. China
| | - Chengjun Wu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P. R. China
| | - Hong Huang
- Shenzhen Institute of Information Technology, Shenzhen, 518172, P. R. China
| | - Xinzhong Wang
- Shenzhen Institute of Information Technology, Shenzhen, 518172, P. R. China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518055, P. R. China
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Jiang C, Yoon S, Nguyen YH, Teets TS. Modular Imine Chelates with Variable Anionic Donors Promote Red Phosphorescence in Cyclometalated Iridium Complexes. Inorg Chem 2023. [PMID: 37410956 DOI: 10.1021/acs.inorgchem.3c01770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
The lack of red and deep-red emitting molecular phosphors with high photoluminescence quantum yields remains a significant fundamental challenge and has implications in optoelectronic technologies for color displays and other consumer products. In this work, we introduce a series of seven new red or deep-red emitting heteroleptic bis-cyclometalated iridium(III) complexes, supported by five different ancillary ligands (L^X) from the salicylaldimine and 2-picolinamide families. Previous work had shown that electron-rich anionic chelating "L^X" ligands can be effective in supporting efficient red phosphorescence, and the complementary approach described here, in addition to being synthetically simpler, offers two key advantages over the previous designs. First, the "L" and "X" functionalities can be independently tuned, providing excellent control over the electronic energy levels and excited-state dynamics. Second, these classes of L^X ligands can have beneficial impacts on the excited-state dynamics but do not significantly perturb the emission color profile. Cyclic voltammetry experiments show that the substituents on the L^X ligand impact the HOMO energy but have a minimal effect on the LUMO energy. Photoluminescence measurements reveal that all the compounds luminesce in the red or deep-red region as a function of the cyclometalating ligand and exhibit exceptionally high photoluminescence quantum yields (ΦPL), comparable or superior to the best-performing red-emitting iridium complexes.
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Affiliation(s)
- Chenggang Jiang
- University of Houston, Department of Chemistry, 3585 Cullen Blvd., Room 112, Houston, Texas 77204-5003, United States
| | - Sungwon Yoon
- University of Houston, Department of Chemistry, 3585 Cullen Blvd., Room 112, Houston, Texas 77204-5003, United States
| | - Yennie H Nguyen
- University of Houston, Department of Chemistry, 3585 Cullen Blvd., Room 112, Houston, Texas 77204-5003, United States
| | - Thomas S Teets
- University of Houston, Department of Chemistry, 3585 Cullen Blvd., Room 112, Houston, Texas 77204-5003, United States
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Zhu ZL, Gnanasekaran P, Yan J, Zheng Z, Lee CS, Chi Y, Zhou X. Efficient Blue Electrophosphorescence and Hyperphosphorescence Generated by Bis-tridentate Iridium(III) Complexes. Inorg Chem 2022; 61:8898-8908. [PMID: 35635511 DOI: 10.1021/acs.inorgchem.2c01026] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Four blue-emissive iridium(III) complexes bearing a 3,3'-(1,3-phenylene)bis[1-isopropyl-6-(trifluoromethyl)-3H-imidazo[4,5-b]pyridin-2-ylidene]-based pincer chelate, which are derived from PXn·H3(PF6)2, where n = 1-4, and a cyclometalating chelate given from 9-[6-[5-(trifluoromethyl)-2λ2-pyrazol-3-yl]pyridin-2-yl]-9H-carbazole [(PzpyCz)H2], were successfully synthesized and employed as both an emissive dopant and a sensitizer in the fabrication of organic light-emitting diode (OLED) devices. These functional chelates around a IrIII atom occupied two mutually orthogonal coordination arrangements and adopted the so-called bis-tridentate architectures. Theoretical studies confirmed the dominance of the electronic transition by the pincer chelates, while the dianionic PzpyCz chelate was only acting as a spectator group. Phosphorescent OLED devices with [Ir(PX3)(PzpyCz)] (B3) as the dopant gave a maximum external quantum efficiency (EQE) of 21.93% and CIExy of (0.144, 0.157) and was subjected to only ∼10% of roll-off in efficiency at a high current density of 1000 cd m-2. Blue-emissive narrow-band hyperphosphorescence was also obtained using B3 as an assistant sensitizer and ν-DABNA as a terminal emitter, giving both an improved EQE of 26.17% and CIExy of (0.116, 0.144), confirming efficient Förster resonance energy transfer in this hyperdevice.
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Affiliation(s)
- Ze-Lin Zhu
- Department of Materials Science and Engineering, Department of Chemistry, and Center of Super-Diamond Advanced Films, City University of Hong Kong, Kowloon Tong 999077, Hong Kong SAR, China
| | - Premkumar Gnanasekaran
- Frontier Research Center on Fundamental and Applied Sciences of Matters and Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Jie Yan
- Department of Materials Science and Engineering, Department of Chemistry, and Center of Super-Diamond Advanced Films, City University of Hong Kong, Kowloon Tong 999077, Hong Kong SAR, China
| | - Zhong Zheng
- Department of Materials Science and Engineering, Department of Chemistry, and Center of Super-Diamond Advanced Films, City University of Hong Kong, Kowloon Tong 999077, Hong Kong SAR, China
| | - Chun-Sing Lee
- Department of Materials Science and Engineering, Department of Chemistry, and Center of Super-Diamond Advanced Films, City University of Hong Kong, Kowloon Tong 999077, Hong Kong SAR, China
| | - Yun Chi
- Department of Materials Science and Engineering, Department of Chemistry, and Center of Super-Diamond Advanced Films, City University of Hong Kong, Kowloon Tong 999077, Hong Kong SAR, China.,Frontier Research Center on Fundamental and Applied Sciences of Matters and Department of Chemistry, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Xiuwen Zhou
- School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072, Australia
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Tai WS, Gnanasekaran P, Chen YY, Hung WY, Zhou X, Chou TC, Lee GH, Chou PT, You C, Chi Y. Rational Tuning of Bis-Tridentate Ir(III) Phosphors to Deep-Blue with High Efficiency and Sub-microsecond Lifetime. ACS APPLIED MATERIALS & INTERFACES 2021; 13:15437-15447. [PMID: 33759493 DOI: 10.1021/acsami.1c00238] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
A new class of bis-tridentate Ir(III) complexes (Dap-1-4) was synthesized using carbene pincer pro-chelates PC1·H3(PF6)2 or PC2·H3(PF6)2 with either imidazolylidene or imidazo[4,5-b]pyridin-2-ylidene appendages, together with a second cyclometalating 2,6-diaryoxypyridine chelate, L1H2 and L2H2, differed by a NMe2 donor at the central pyridinyl fragment. The respective emission tuning between the ultraviolet and blue region was rationalized using time-dependent density functional theory (TD-DFT) approaches. Next, a highly efficient blue emitter (Dap-5) was synthesized by concomitant addition of two methyl groups and a single CF3 substituent at the central phenyl and peripheral imidazo[4,5-b]pyridin-2-ylidene entities of the carbene pincer chelate, respectively. The organic light-emitting diode (OLED) device with 15 wt % Dap-5 in DPEPO shows electroluminescence at 468 nm and with CIE (0.14, 0.15) and a max external quantum efficiency (max EQE) of 16.8% with low efficiency roll-off (EQE of 14.4% at 1000 cd m-2); the latter is attributed to the relatively shortened triplet excited-state radiative lifetime. These results highlight the adequateness of bis-tridentate Ir(III) phosphors in fabrication of practical blue-emitting OLEDs.
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Affiliation(s)
- Wun-Shan Tai
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Premkumar Gnanasekaran
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
| | - Yi-Yang Chen
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Wen-Yi Hung
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Xiuwen Zhou
- School of Mathematics and Physics, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Tai-Che Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Gene-Hsiang Lee
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Pi-Tai Chou
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Caifa You
- Department of Chemistry, Department of Materials Sciences and Engineering, and Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon 999077, Hong Kong SAR, China
| | - Yun Chi
- Department of Chemistry and Frontier Research Center on Fundamental and Applied Sciences of Matters, National Tsing Hua University, Hsinchu 30013, Taiwan
- Department of Chemistry, Department of Materials Sciences and Engineering, and Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Kowloon 999077, Hong Kong SAR, China
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7
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Li D, Li J, Liu D, Li W, Ko CL, Hung WY, Duan C. Highly Efficient Simple-Structure Sky-Blue Organic Light-Emitting Diode Using a Bicarbazole/Cyanopyridine Bipolar Host. ACS APPLIED MATERIALS & INTERFACES 2021; 13:13459-13469. [PMID: 33703891 DOI: 10.1021/acsami.0c20128] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Up to now, the most efficient blue phosphorescent organic light-emitting diode (PhOLED) was achieved with a maximum external quantum efficiency (ηext) of 34.1% by using an exciplex cohost. It still remains a challenge to obtain such high efficiencies using a single-host matrix. In this work, a highly efficient sky-blue PhOLED is successfully fabricated using a newly developed bipolar host material, namely 5-(2-(9H-[3,9'-bicarbazol]-9-yl)phenyl)nicotinonitrile (o-PyCNBCz), which realizes a ηext of 29.4% at a practical luminance of 100 cd m-2 and a maximum ηext of 34.6% (at 23 cd m-2). The present device is characterized by simple configuration with a single host and single emitting layer. o-PyCNBCz also reveals high efficiency of 28.2% (94.8 cd A-1) when used as the host for green PhOLED. Under identical conditions, o-PyCNBCz always outperforms than its isomer 3-PyCNBCz (5-(9-phenyl-9H-[3,9'-bicarbazol]-6-yl)nicotinonitrile) in terms of more balanced charge transportation, higher photoluminescent quantum yields of over 90%, and higher horizontal orientation ratio of the emitting dipole for the host-dopant films, which finally lead to its superior performance in PhOLEDs. It is observed that all these merits of o-PyCNBCz benefit from its ortho-linking style of carbazole (p-type unit) and cyanopyridine (n-type unit) on the phenylene bridge and the resultant molecular conformation.
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Affiliation(s)
- Deli Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Jiuyan Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Di Liu
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Wei Li
- State Key Laboratory of Fine Chemicals, College of Chemical Engineering, Dalian University of Technology, 2 Linggong Road, Dalian 116024, China
| | - Chang-Lun Ko
- Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 202, Taiwan
| | - Wen-Yi Hung
- Institute of Optoelectronic Sciences, National Taiwan Ocean University, Keelung 202, Taiwan
| | - Chunhui Duan
- Institute of Polymer Optoelectronic Materials and Devices, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
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8
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Tian H, Liu D, Li J, Ma M, Lan Y, Wei W, Niu R, Song K. Pure red phosphorescent iridium( iii) complexes containing phenylquinazoline ligands for highly efficient organic light-emitting diodes. NEW J CHEM 2021. [DOI: 10.1039/d1nj01795k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
By incorporating a methoxy group at the 6- and 7-sites of the quinazoline ring of phenylquinazoline cyclometalating ligands, the iridium complexes realize pure red phosphorescence. The PHOLED based on Ir2 achieves CIE of (0.65, 0.34) and a higher external quantum efficiency of 26.22%.
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Affiliation(s)
- Houru Tian
- State Key Laboratory of Fine Chemicals
- College of Chemical Engineering
- Dalian University of Technology
- Dalian
- China
| | - Di Liu
- State Key Laboratory of Fine Chemicals
- College of Chemical Engineering
- Dalian University of Technology
- Dalian
- China
| | - Jiuyan Li
- State Key Laboratory of Fine Chemicals
- College of Chemical Engineering
- Dalian University of Technology
- Dalian
- China
| | - Mengyao Ma
- State Key Laboratory of Fine Chemicals
- College of Chemical Engineering
- Dalian University of Technology
- Dalian
- China
| | - Ying Lan
- State Key Laboratory of Fine Chemicals
- College of Chemical Engineering
- Dalian University of Technology
- Dalian
- China
| | - Wenkui Wei
- State Key Laboratory of Fine Chemicals
- College of Chemical Engineering
- Dalian University of Technology
- Dalian
- China
| | - Rui Niu
- State Key Laboratory of Fine Chemicals
- College of Chemical Engineering
- Dalian University of Technology
- Dalian
- China
| | - Kai Song
- State Key Laboratory of Fine Chemicals
- College of Chemical Engineering
- Dalian University of Technology
- Dalian
- China
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9
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Ding L, Zang CX, Wen L, Shan GG, Gao Y, Sun HZ, Xie WF, Su ZM. High-Performance and Stable Warm White OLEDs Based on Orange Iridium(III) Phosphors Modified with Simple Alkyl Groups. Organometallics 2020. [DOI: 10.1021/acs.organomet.0c00472] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lei Ding
- 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
| | - 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
| | - 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
| | - Ying Gao
- Jilin Engineering Normal University Changchun 130052, 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
| | - 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
- School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun, Jilin 130012, People’s Republic of China
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10
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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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11
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Li Y, Yao C, Zhong D, Li H, Liu B, Feng Z, Sun Y, Zhou G, Yang Z. Phosphorescent cyanide sensor based on a 2-phenylpyridine(ppy)-type cyclometalated Ir(III) complex bearing dimesitylboron group with concentration distinguishing ability. J Organomet Chem 2020. [DOI: 10.1016/j.jorganchem.2020.121274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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12
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Liang B, Yu Z, Zhuang X, Wang J, Wei J, Ye K, Zhang Z, Liu Y, Wang Y. Achieving High-Performance Pure-Red Electrophosphorescent Iridium(III) Complexes Based on Optimizing Ancillary Ligands. Chemistry 2020; 26:4410-4418. [PMID: 32017269 DOI: 10.1002/chem.201905690] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 02/02/2020] [Indexed: 11/07/2022]
Abstract
Two new iridium(III) complexes were synthesized by introducing two trifluoromethyl groups into an ancillary ligand to develop pure-red emitters for organic light-emitting diodes (OLEDs). The electron-donating ability of the ancillary ligands is suppressed, owing to the electron-withdrawing nature of trifluoromethyl groups, which can reduce the HOMO energy levels compared with those of compounds without trifluoromethyl groups. However, the introduction of trifluoromethyl groups into the ancillary ligand has little impact on the LUMO energy levels. Therefore, a well-tuned, pure-red, excited-state energy was achieved by regulating the relative energy level between the HOMO and LUMO. OLEDs with these complexes as emitters showed high external quantum efficiencies (EQEs) of 26 % and realized high EQEs of about 25 % and fairly low driving voltages of 3.3-3.6 V for practical luminance of 1000 cd m-2 , as well as excellent Commission Internationale de L'Eclairage (CIE) coordinates of (0.66, 0.33) and (0.67, 0.33); thus, this demonstrates the successful molecular design strategy by modifying the electron-donating ability of ancillary ligand.
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Affiliation(s)
- Baoyan Liang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
| | - Zhanshuang Yu
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
| | - Xuming Zhuang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
| | - Jiaxuan Wang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
| | - Jinbei Wei
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
| | - Kaiqi Ye
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
| | - Zuolun Zhang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
| | - Yu Liu
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, P.R. China
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Chen Z, Zhang H, Wen D, Wu W, Zeng Q, Chen S, Wong WY. A simple and efficient approach toward deep-red to near-infrared-emitting iridium(iii) complexes for organic light-emitting diodes with external quantum efficiencies of over 10. Chem Sci 2020; 11:2342-2349. [PMID: 34084394 PMCID: PMC8157343 DOI: 10.1039/c9sc05492h] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
While the external quantum efficiency (EQE) of iridium(iii) (Ir(iii)) phosphor based near-infrared organic light-emitting diodes (NIR OLEDs) has been limited to 5.7% to date, there is no significant EQE improvement for these types of OLEDs due to the lack of efficient Ir(iii) emitters. Here, a convenient approach within three synthetic steps is developed to afford two novel and efficient deep-red to near-infrared (DR-NIR) emitting phosphors (CNIr and TCNIr), in which a cyano group is added into a commercial red emitter named Ir(piq)2(acac) to significantly stabilize the lowest unoccupied molecular orbitals of the newly designed Ir(iii) complexes. They emit strong DR-NIR phosphorescence emissions at a wavelength of around 700 nm, with relatively high absolute quantum efficiencies of around 45% for their doped films. DR-NIR OLEDs made using CNIr and TCNIr exhibit high-efficiencies, affording peak EQEs of 10.62% and 9.59% with emission peak wavelengths of 690 and 706 nm, respectively. All these devices represent the most efficient Ir(iii)-based DR-NIR OLEDs with a similar color gamut. The simplified synthesis procedure of the DR-NIR-emitting phosphors in conjunction with their excellent performance in OLEDs confirms our efficient strategy to achieve the DR-NIR-emitting Ir(iii) phosphors.
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Affiliation(s)
- Zhao Chen
- School of Applied Physics and Materials, Wuyi University Jiangmen 529020 P. R. China
| | - Hongyang Zhang
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University (PolyU) Hung Hom Hong Kong P. R. China .,PolyU Shenzhen Research Institute Shenzhen 518057 P. R. China
| | - Dawei Wen
- School of Applied Physics and Materials, Wuyi University Jiangmen 529020 P. R. China
| | - Wenhai Wu
- School of Applied Physics and Materials, Wuyi University Jiangmen 529020 P. R. China
| | - Qingguang Zeng
- School of Applied Physics and Materials, Wuyi University Jiangmen 529020 P. R. China
| | - Shuming Chen
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology Shenzhen 518055 P. R. China
| | - Wai-Yeung Wong
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University (PolyU) Hung Hom Hong Kong P. R. China .,PolyU Shenzhen Research Institute Shenzhen 518057 P. R. China
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Lu JJ, Liang X, Luo XF, Wu ZG, Zheng YX. Efficient blue, green and red iridium( iii) complexes with noncovalently-linked pyrazole/pyrazolide rings for organic light-emitting diodes. NEW J CHEM 2020. [DOI: 10.1039/c9nj05218f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Blue, green and red iridium(iii) complexes using a new pyrazole/pyrazolide ancillary ligand system, and their application in OLEDs with EQEs of up to 21.0% and low efficiency roll-off.
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Affiliation(s)
- Jun-Jian Lu
- State Key Laboratory of Coordination Chemistry
- Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Xiao Liang
- State Key Laboratory of Coordination Chemistry
- Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Xu-Feng Luo
- State Key Laboratory of Coordination Chemistry
- Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Zheng-Guang Wu
- State Key Laboratory of Coordination Chemistry
- Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - You-Xuan Zheng
- State Key Laboratory of Coordination Chemistry
- Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
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Wei F, Lai SL, Zhao S, Ng M, Chan MY, Yam VWW, Wong KMC. Ligand Mediated Luminescence Enhancement in Cyclometalated Rhodium(III) Complexes and Their Applications in Efficient Organic Light-Emitting Devices. J Am Chem Soc 2019; 141:12863-12871. [PMID: 31310721 DOI: 10.1021/jacs.9b06308] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A series of luminescent cyclometalated rhodium(III) complexes have been designed and prepared. The improved luminescence property is realized by the judicious choice of a strong σ-donor cyclometalating ligand with a lower-lying intraligand (IL) state that would raise the d-d excited state and introduction of a lower-lying emissive IL excited state. These complexes exhibit high thermal stability and considerable luminescence quantum yields as high as up to 0.65 in thin film, offering themselves as promising light-emitting materials in OLEDs. Respectable external quantum efficiencies of up to 12.2% and operational half-lifetimes of over 3000 h at 100 cd m-2 have been achieved. This work demonstrates a breakthrough as the first example of an efficient rhodium(III) emitter for OLED application and opens up a new avenue for diversifying the development of OLED materials with rhodium metal being utilized as phosphors.
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Affiliation(s)
- Fangfang Wei
- Department of Chemistry , Southern University of Science and Technology , 1088 Xueyuan Blvd. , Shenzhen 518055 , PR China
| | - Shiu-Lun Lai
- Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee, Hong Kong) and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Shunan Zhao
- Department of Chemistry , Southern University of Science and Technology , 1088 Xueyuan Blvd. , Shenzhen 518055 , PR China
| | - Maggie Ng
- Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee, Hong Kong) and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Mei-Yee Chan
- Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee, Hong Kong) and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Vivian Wing-Wah Yam
- Institute of Molecular Functional Materials (Areas of Excellence Scheme, University Grants Committee, Hong Kong) and Department of Chemistry , The University of Hong Kong , Pokfulam Road , Hong Kong , PR China
| | - Keith Man-Chung Wong
- Department of Chemistry , Southern University of Science and Technology , 1088 Xueyuan Blvd. , Shenzhen 518055 , PR China
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