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Shi K, Wu C, Zhang H, Tong KN, He W, Li W, Jin Z, Jung S, Li S, Wang X, Gong S, Zhang Y, Zhang D, Kang F, Chi Y, Yang C, Wei G. Enhanced Emitting Dipole Orientation Based on Asymmetric Iridium(III) Complexes for Efficient Saturated-Blue Phosphorescent OLEDs. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024:e2402349. [PMID: 39137939 DOI: 10.1002/advs.202402349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 06/02/2024] [Indexed: 08/15/2024]
Abstract
Three novel asymmetric Ir(III) complexes have been rationally designed to optimize their emitting dipole orientations (EDO) and enhance light outcoupling in blue phosphorescent organic light-emitting diodes (OLEDs), thereby boosting their external quantum efficiency (EQE). Bulky electron-donating groups (EDGs), namely: carbazole (Cz), di-tert-butyl carbazole (tBuCz), and phenoxazine (Pxz) are incorporated into the tridentate dicarbene pincer chelate to induce high degree of packing anisotropy, simultaneously enhancing their photophysical properties. Angle-dependent photoluminescence (ADPL) measurements indicate increased horizontal transition dipole ratios of 0.89 and 0.90 for the Ir(III) complexes Cz-dfppy-CN and tBuCz-dfppy-CN, respectively. Analysis of the single crystal structure and density functional theory (DFT) calculation results revealed an inherent correlation between molecular aspect ratio and EDO. Utilizing the newly obtained emitters, the blue OLED devices demonstrated exceptional performance, achieving a maximum EQE of 30.7% at a Commission International de l'Eclairage (CIE) coordinate of (0.140, 0.148). Optical transfer matrix-based simulations confirmed a maximum outcoupling efficiency of 35% due to improved EDO. Finally, the tandem OLED and hyper-OLED devices exhibited a maximum EQE of 44.2% and 31.6%, respectively, together with good device stability. This rational molecular design provides straightforward guidelines to reach highly efficient and stable saturated blue emission.
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Affiliation(s)
- Kefei Shi
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Chengcheng Wu
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - He Zhang
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, China
| | - Kai-Ning Tong
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Wei He
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Wansi Li
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
| | - Zhaoyun Jin
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Sinyeong Jung
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Siqi Li
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Xin Wang
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Shaolong Gong
- Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan, 430072, China
| | - Yuewei Zhang
- Laboratory of Flexible Electronics Technology, Tsinghua University, Beijing, China
| | - Dongdong Zhang
- Key Laboratory of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, China
| | - Feiyu Kang
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
| | - Yun Chi
- Department of Materials Science and Engineering, Department of Chemistry and Center of Super-Diamond and Advanced Films (COSDAF), City University of Hong Kong, Hong Kong SAR, 999077, China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, China
| | - Guodan Wei
- Tsinghua-Berkeley Shenzhen Institute (TBSI), Tsinghua University, Shenzhen, 518055, China
- Institute of Materials Research, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China
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Parshina EK, Deriabin KV, Kolesnikov IE, Novikov AS, Kocheva AN, Golovenko EA, Islamova RM. Iridium(III)-Incorporating Self-Healing Polysiloxanes as Materials for Light-Emitting Oxygen Sensors. Macromol Rapid Commun 2024:e2400450. [PMID: 39072911 DOI: 10.1002/marc.202400450] [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: 06/13/2024] [Revised: 07/05/2024] [Indexed: 07/30/2024]
Abstract
Polymer-metal complexes (PMCs) based on poly(2,2'-bipyridine-4,4'-dicarboxamide-co-polydimethylsiloxanes) with cyclometalated di(2-phenylpyridinato-C2,N')iridium(III) fragments and cross-linked by Zn2+ (Zn[Ir]-BipyPDMSs) or Ir3+ (Ir[Ir]-BipyPDMSs) represent flexible, stretchable, phosphorescent, and self-healing molecular oxygen sensors. PMCs provide strong phosphorescence at λem = 595-605 nm. Zn[Ir]-BipyPDMS with PDMS chain length of Mn = 5000 has the highest quantum yield of 9.3% and is a molecular oxygen sensor at different O2 concentrations (0-100 vol%) compared to Ir[Ir]-BipyPDMSs. A Stern-Volmer constant is determined for Zn[Ir]-BipyPDMS as KSV = 0.014%-1, which is similar to the reported oxygen-sensitive iridium(III) complexes. All synthesized PMCs exhibit high elongation at break (up to 1100%) and self-healing efficiency (up to 99%).
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Affiliation(s)
- Elizaveta K Parshina
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - Konstantin V Deriabin
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - Ilya E Kolesnikov
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - Alexander S Novikov
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - Anastasia N Kocheva
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - Ekaterina A Golovenko
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - Regina M Islamova
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
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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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Jang EB, Choi GS, Bae EJ, Ju BK, Park YW. Doping-Free Phosphorescent and Thermally Activated Delayed Fluorescent Organic Light-Emitting Diodes with an Ultra-Thin Emission Layer. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2366. [PMID: 37630950 PMCID: PMC10458739 DOI: 10.3390/nano13162366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 08/11/2023] [Accepted: 08/16/2023] [Indexed: 08/27/2023]
Abstract
We report the electroluminescence (EL) characteristics of blue ultra-thin emissive layer (U-EML) phosphorescent (PH) organic light-emitting diodes (OLED) and thermally activated delayed fluorescence (TADF) OLED. A variety of transport layer (TL) materials were used in the fabricated OLEDs. The well-known FIrpic and DMAC-DPS were used with a thickness of 0.3 nm, which is relatively thicker than the optimal thickness (0.15 nm) of the blue phosphorescent ultra-thin emissive layer to ensure sufficient energy transfer. While FIrpic showed overall high efficiency in various TLs, DMAC-DPS exhibited three times lower efficiency in limited TLs. To clarify/identify low efficiency and to improve the EL, the thickness of DMAC-DPS was varied. A significantly higher and comparable efficiency was observed with a thickness of 4.5 nm, which is 15 times thicker. This thickness was oriented from the TADF itself, which reduces quenching in a triplet-triplet annihilation compared to the PH process. The thinner optimal thickness compared with ~30 nm of fluorescent OLEDs suggests that there still is quenching taking place. We expect that the efficiency of TADF U-EML OLEDs can be enhanced through further research on controlling the exciton quenching using multiple U-EMLs with spacers and a novel material with a high energy transfer rate (ΔES-T).
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Affiliation(s)
- Eun-Bi Jang
- Nano and Organic-Electronics Laboratory, SunMoon University, Asan 31460, Republic of Korea; (E.-B.J.); (G.-S.C.)
| | - Geun-Su Choi
- Nano and Organic-Electronics Laboratory, SunMoon University, Asan 31460, Republic of Korea; (E.-B.J.); (G.-S.C.)
- Display and Nanosystem Laboratory, Department of Electrical Engineering, Korea University, 145, Anam-ro, Seoul 02841, Republic of Korea
| | - Eun-Jeong Bae
- Nano and Organic-Electronics Laboratory, SunMoon University, Asan 31460, Republic of Korea; (E.-B.J.); (G.-S.C.)
- Display and Nanosystem Laboratory, Department of Electrical Engineering, Korea University, 145, Anam-ro, Seoul 02841, Republic of Korea
| | - Byeong-Kwon Ju
- Display and Nanosystem Laboratory, Department of Electrical Engineering, Korea University, 145, Anam-ro, Seoul 02841, Republic of Korea
| | - Young-Wook Park
- Nano and Organic-Electronics Laboratory, SunMoon University, Asan 31460, Republic of Korea; (E.-B.J.); (G.-S.C.)
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Rashamuse TJ, Mohlala RL, Coyanis EM, Magwa NP. A Review: Blue Fluorescent Zinc (II) Complexes for OLEDs-A Last Five-Year Recap. Molecules 2023; 28:5272. [PMID: 37446930 DOI: 10.3390/molecules28135272] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/03/2023] [Accepted: 07/05/2023] [Indexed: 07/15/2023] Open
Abstract
Blue emissions in organic light-emitting diodes (OLEDs) are essential for their application in solid-state lighting and full-colour flat panel displays. On the other hand, high-power blue emitters are still uncommon, especially those that can achieve the Commission Internationale de l'Eclairage (CIE, X, Y) coordinates of (0.14, 0.08) in the National Television System Committee (NTSC) blue standard and have high external quantum efficiencies (EQE) of more than 5% because their molecular design presents an enormous challenge. Therefore, creating effective, stable, pure, and deep blue fluorescent materials is vital. Here, it is addressed how useful blue fluorescent Zn (II) complexes are for making organic light-emitting diodes (OLEDs). Utilizing Zn (II) complexes is appealing because of their favourable luminous characteristics, acceptance and mobility, and affordability. This mini-review article aims to provide an overview of Zn (II) complexes that emit blue fluorescent light and have been reported since 2018, while highlighting the unique qualities that make them appropriate OLED materials.
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Affiliation(s)
- Thompho Jason Rashamuse
- Nanotechnology Innovation Centre, Health Platform, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa
| | - Reagan Lehlogonolo Mohlala
- Nanotechnology Innovation Centre, Health Platform, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa
| | - Elena Mabel Coyanis
- Nanotechnology Innovation Centre, Health Platform, Advanced Materials Division, Mintek, Private Bag X3015, Randburg 2125, South Africa
| | - Nomampondo Penelope Magwa
- Department of Chemistry, University of South Africa, Private Bag X6, Florida, Roodepoort 1710, South Africa
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Huang YC, Yuan JB, Qin ZQ, Li HY, Xue W, Li TY. Selective and sensitive detection of Zn(II) in solution and nanofibers using phosphorescent iridium(III) complexes. Sep Purif Technol 2022. [DOI: 10.1016/j.seppur.2022.123040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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Park HJ, Jang JH, Lee JH, Hwang DH. Highly Efficient Deep-Blue Phosphorescent OLEDs Based on a Trimethylsilyl-Substituted Tetradentate Pt(II) Complex. ACS APPLIED MATERIALS & INTERFACES 2022; 14:34901-34908. [PMID: 35867806 DOI: 10.1021/acsami.2c06891] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Compared to Ir(III) complexes with octahedral geometries, Pt(II) complexes with square planar geometries show superior optical properties because their flat shapes lead to an orientation that enhances the outcoupling of organic light-emitting diodes (OLEDs). However, the flat shapes of Pt(II) complexes typically induce a bathochromic shift, limiting their application in high-performance deep-blue phosphorescent OLEDs with high color purity. In this study, bulky trimethylsilyl (TMS)-substituted blue phosphorescent Pt(II) complex (PtON7-TMS) is successfully synthesized to improve color purity. The TMS substituent containing Si atom effectively suppresses intermolecular interaction and aggregation even when the complex concentration in the film state is higher than 30 wt %. As a result, the PtON7-TMS-based OLEDs exhibit a maximum external quantum efficiency of 21.4%, along with a pure-blue color of CIE (0.14, 0.09) at 20 wt % doping concentration and a full-width at half maximum of 30 nm. The pure blue color is maintained at a higher doping concentration (>30 wt %).
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Affiliation(s)
- Hea Jung Park
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Republic of Korea
| | - Jee-Hun Jang
- Department of Materials Science and Engineering, 3D Convergence Center, Inha University, Incheon 22212, Republic of Korea
| | - Jeong-Hwan Lee
- Department of Materials Science and Engineering, 3D Convergence Center, Inha University, Incheon 22212, Republic of Korea
| | - Do-Hoon Hwang
- Department of Chemistry and Chemistry Institute for Functional Materials, Pusan National University, Busan 46241, Republic of Korea
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Liu S, Han J, Wang W, Chang Y, Wang R, Wang Z, Li G, Zhu D, Bryce MR. AIE-active Ir( iii) complexes functionalised with a cationic Schiff base ligand: synthesis, photophysical properties and applications in photodynamic therapy. Dalton Trans 2022; 51:16119-16125. [DOI: 10.1039/d2dt02960j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two AIE-active Ir(iii) cationic complexes containing Schiff base ligands were synthesised. Ir-2-N+ NPs are shown to be good PSs in vitro for PDT.
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Affiliation(s)
- Shengnan Liu
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, Jilin Province 130024, P. R. China
| | - Jiahong Han
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, Jilin Province 130024, P. R. China
| | - Weijin Wang
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, Jilin Province 130024, P. R. China
| | - Yulei Chang
- State Key Laboratory of Luminescence and Applications, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, Jilin Province 130033, China
| | - Runlin Wang
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, Jilin Province 130024, P. R. China
| | - Ziwei Wang
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, Jilin Province 130024, P. R. China
| | - Guangzhe Li
- Jilin Provincial Science and Technology Innovation Center of Health Food of Chinese Medicine, Changchun University of Chinese Medicine, Changchun, Jilin Province 130117, P. R. China
| | - Dongxia Zhu
- Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun, Jilin Province 130024, P. R. China
| | - Martin R. Bryce
- Department of Chemistry, Durham University, Durham, DH1 3LE, UK
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