1
|
Zhang K, Zhou Z, Liu D, Chen Y, Zhang S, Pan J, Qiao X, Ma D, Su S, Zhu W, Liu Y. Boosting External Quantum Efficiency to 12.0 % of an Ultraviolet OLED by Engineering the Horizontal Dipole Orientation of a Hot Exciton Emitter. Angew Chem Int Ed Engl 2024; 63:e202407502. [PMID: 38721850 DOI: 10.1002/anie.202407502] [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: 04/19/2024] [Indexed: 06/27/2024]
Abstract
Currently, much research effort has been devoted to improving the exciton utilization efficiency and narrowing the emission spectra of ultraviolet (UV) fluorophores for organic light-emitting diode (OLED) applications, while almost no attention has been paid to optimizing their light out-coupling efficiency. Here, we developed a linear donor-acceptor-donor (D-A-D) triad, namely CDFDB, which possesses high-lying reverse intersystem crossing (hRISC) property. Thanks to its integrated narrowband UV photoluminescence (PL) (λPL: 397 nm; FWHM: 48 nm), moderate PL quantum yield (ϕPL: 72 %, Tol), good triplet hot exciton (HE) conversion capability, and large horizontal dipole ratio (Θ//: 92 %), the OLEDs based on CDFDB not only can emit UV electroluminescence with relatively good color purity (λEL: 398 nm; CIEx,y: 0.161, 0.040), but also show a record maximum external quantum efficiency (EQEmax) of 12.0 %. This study highlights the important role of horizontal dipole orientation engineering in the molecular design of HE UV-OLED fluorophores.
Collapse
Affiliation(s)
- Kai Zhang
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, P. R. China
| | - Zhongxin Zhou
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, P. R. China
| | - Denghui Liu
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Yichao Chen
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Shiyue Zhang
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, P. R. China
| | - Jie Pan
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, P. R. China
| | - Xianfeng Qiao
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - ShiJian Su
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Weiguo Zhu
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, P. R. China
| | - Yu Liu
- School of Materials Science and Engineering, Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications, Changzhou University, Changzhou, 213164, P. R. China
| |
Collapse
|
2
|
Zhang Q, Zhang D, Liao Z, Cao YB, Kumar M, Poddar S, Han J, Hu Y, Lv H, Mo X, Srivastava AK, Fan Z. Perovskite Light-Emitting Diodes with Quantum Wires and Nanorods. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024:e2405418. [PMID: 39183527 DOI: 10.1002/adma.202405418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 06/22/2024] [Indexed: 08/27/2024]
Abstract
Perovskite materials, celebrated for their exceptional optoelectronic properties, have seen extensive application in the field of light-emitting diodes (LEDs), where research is as abundant as the proverbial "carloads of books." In this review, the research of perovskite materials is delved into from a dimensional perspective, with a focus on the exemplary performance of low-dimensional perovskite materials in LEDs. This discussion predominantly revolves around perovskite quantum wires and perovskite nanorods. Perovskite quantum wires are versatile in their growth, compatible with both solution-based and vapor-phase growth, and can be deposited over large areas-even on spherical substrates-to achieve commendable electroluminescence (EL). Perovskite nanorods, on the other hand, boast a suite of superior characteristics, such as polarization properties and tunability of the transition dipole moment, endowing them with the great potential to enhance light extraction efficiency. Furthermore, zero-dimensional (0D) perovskite materials like nanocrystals (NCs) are also the subject of widespread research and application. This review reflects on and synthesizes the unique qualities of the aforementioned materials while exploring their vital roles in the development of high-efficiency perovskite LEDs (PeLEDs).
Collapse
Affiliation(s)
- Qianpeng Zhang
- Department of Electronic & Computer Engineering, State Key Laboratory of Advanced Displays and Optoelectronics Technologies, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
- State Key Laboratory of Photovoltaic Science and Technology, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, 200433, China
| | - Daquan Zhang
- Department of Electronic & Computer Engineering, State Key Laboratory of Advanced Displays and Optoelectronics Technologies, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| | - Zebing Liao
- Department of Electronic & Computer Engineering, State Key Laboratory of Advanced Displays and Optoelectronics Technologies, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| | - Yang Bryan Cao
- Department of Electronic & Computer Engineering, State Key Laboratory of Advanced Displays and Optoelectronics Technologies, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| | - Mallem Kumar
- Department of Electronic & Computer Engineering, State Key Laboratory of Advanced Displays and Optoelectronics Technologies, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| | - Swapnadeep Poddar
- Department of Electronic & Computer Engineering, State Key Laboratory of Advanced Displays and Optoelectronics Technologies, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| | - Junchao Han
- State Key Laboratory of Photovoltaic Science and Technology, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, 200433, China
| | - Ying Hu
- State Key Laboratory of Photovoltaic Science and Technology, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, 200433, China
| | - Hualiang Lv
- State Key Laboratory of Photovoltaic Science and Technology, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, 200433, China
| | - Xiaoliang Mo
- State Key Laboratory of Photovoltaic Science and Technology, Shanghai Frontiers Science Research Base of Intelligent Optoelectronics and Perception, Institute of Optoelectronics, Fudan University, Shanghai, 200433, China
| | - Abhishek Kumar Srivastava
- Department of Electronic & Computer Engineering, State Key Laboratory of Advanced Displays and Optoelectronics Technologies, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| | - Zhiyong Fan
- Department of Electronic & Computer Engineering, State Key Laboratory of Advanced Displays and Optoelectronics Technologies, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
- Department of Chemical and Biological Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, 999077, China
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
Feng Y, Xu Y, Qu C, Wang Q, Ye K, Liu Y, Wang Y. Structurally Tunable Donor-Bridge-Fluorophore Architecture Enables Highly Efficient and Concentration-Independent Narrowband Electroluminescence. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2403061. [PMID: 38782371 DOI: 10.1002/adma.202403061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 05/05/2024] [Indexed: 05/25/2024]
Abstract
Luminescent materials with narrowband emission have extraordinary significance for developing ultrahigh-definition display. B-N-containing multiple resonance thermally activated delayed fluorescence (MR-TADF) materials are strong contenders. However, their device performances pervasively encounter detrimental aggregation-caused quenching effect that is highly vulnerable to doping concentration, complicating device fabrication. Therefore, constructing highly efficient and concentration-independent MR-TADF emitters is of pragmatic importance for improving device controllability and reproducibility, simplifying manufacturing procedures, and conserving production costs. Here, by systematic arrangement of donor triphenylamine and fluorophore BNCz on distinct bridges, a spatial confinement strategy has been developed with a donor-bridge-fluorophore architecture. Structurally fine modulation and progressive evolution to construct molecular entities with congested steric hindrance effect that can suppress intermolecular interactions without substantially affecting the luminescence tone of fluorophore BNCz, resulting in highly efficient and concentration-independent narrowband emitters; through isomer engineering, two isomers BN-PCz-TPA and TPA-PCz-BN with different crystal stacking patterns are synthesized by altering the connection mode between triphenylamine and BNCz. As a result, BN-PCz-TPA-based device showcases maximum external quantum efficiency (EQE) of 36.3% with narrow full-width at half-maximum of 27 nm at 10 wt% doping concentration. Even at 20 wt% doping concentration, the maximum EQE remains at 32.5% and the emission spectrum is almost unchanged.
Collapse
Affiliation(s)
- Yu Feng
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yincai Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Cheng Qu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Qingyang Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Kaiqi Ye
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yu Liu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
- Jihua Laboratory, 28 Huandao South Road, Foshan, Guangdong Province, 528200, P. R. China
| |
Collapse
|
5
|
Ding Y, Xiong S, Sun L, Wang Y, Zhou Y, Li Y, Peng J, Fukuda K, Someya T, Liu R, Zhang X. Metal nanowire-based transparent electrode for flexible and stretchable optoelectronic devices. Chem Soc Rev 2024; 53:7784-7827. [PMID: 38953906 DOI: 10.1039/d4cs00080c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
High-quality transparent electrodes are indispensable components of flexible optoelectronic devices as they guarantee sufficient light transparency and electrical conductivity. Compared to commercial indium tin oxide, metal nanowires are considered ideal candidates as flexible transparent electrodes (FTEs) owing to their superior optoelectronic properties, excellent mechanical flexibility, solution treatability, and higher compatibility with semiconductors. However, certain key challenges associated with material preparation and device fabrication remain for the practical application of metal nanowire-based electrodes. In this review, we discuss state-of-the-art solution-processed metal nanowire-based FTEs and their applications in flexible and stretchable optoelectronic devices. Specifically, the important properties of FTEs and a cost-benefit analysis of existing technologies are introduced, followed by a summary of the synthesis strategy, key properties, and fabrication technologies of the nanowires. Subsequently, we explore the applications of metal-nanowire-based FTEs in different optoelectronic devices including solar cells, photodetectors, and light-emitting diodes. Finally, the current status, future challenges, and emerging strategies in this field are presented.
Collapse
Affiliation(s)
- Yu Ding
- Soochow Institute of Energy and Material Innovations, Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Institute of Functional Nano and Soft Materials (FUNSOM) and College of Energy, Soochow University, Suzhou 215006, P. R. China.
| | - Sixing Xiong
- Center for Emergent Matter Science (CEMS), RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
| | - Lulu Sun
- Thin-Film Device Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Yiying Wang
- Soochow Institute of Energy and Material Innovations, Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Institute of Functional Nano and Soft Materials (FUNSOM) and College of Energy, Soochow University, Suzhou 215006, P. R. China.
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215006, P. R. China
| | - Yinhua Zhou
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| | - Yaowen Li
- College of Chemistry, Soochow University, Suzhou 215123, P. R. China
| | - Jun Peng
- Soochow Institute of Energy and Material Innovations, Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Institute of Functional Nano and Soft Materials (FUNSOM) and College of Energy, Soochow University, Suzhou 215006, P. R. China.
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215006, P. R. China
| | - Kenjiro Fukuda
- Center for Emergent Matter Science (CEMS), RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
- Thin-Film Device Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Takao Someya
- Center for Emergent Matter Science (CEMS), RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
- Thin-Film Device Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Ruiyuan Liu
- Soochow Institute of Energy and Material Innovations, Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Institute of Functional Nano and Soft Materials (FUNSOM) and College of Energy, Soochow University, Suzhou 215006, P. R. China.
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215006, P. R. China
| | - Xiaohong Zhang
- Soochow Institute of Energy and Material Innovations, Key Laboratory for Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Institute of Functional Nano and Soft Materials (FUNSOM) and College of Energy, Soochow University, Suzhou 215006, P. R. China.
- Jiangsu Key Laboratory of Advanced Negative Carbon Technologies, Soochow University, Suzhou 215006, P. R. China
| |
Collapse
|
6
|
Madushani B, Mamada M, Goushi K, Katagiri H, Nakanotani H, Hatakeyama T, Adachi C. Hexacarbazolylbenzene: An Excellent Host Molecule Causing Strong Guest Molecular Orientation and the High-Performance OLEDs. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2402275. [PMID: 38865445 DOI: 10.1002/adma.202402275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 05/19/2024] [Indexed: 06/14/2024]
Abstract
Hexacarbazolylbenzene (6CzPh), which is benzene substituted by six carbazole rings, is a simple and attractive compound. Despite the success of a wide variety of carbazole derivatives in organic light-emitting diodes (OLEDs), 6CzPh has not received attention so far. Here, excellent performances of 6CzPh are revealed as a host material in OLEDs regarding conventional host materials. Various strategies are implemented to improve the performance of OLEDs, e.g., triplet utilization by thermally activated delayed fluorescence (TADF) and phosphorescence emitters for maximizing internal quantum efficiency, and molecular orientation control for increasing outcoupling efficiency. The present host material is suited for both criteria. Robustness of the structure and sufficiently high triplet energy enables a high external quantum efficiency with a long device lifetime. Besides, the host material boosts the horizontal molecular orientations of several guest emitters. It is noteworthy that disk-shaped 4CzIPN marks the complete horizontal molecular orientations (Θh = 100%, S = -0.50). These results provide an effective way of improving efficiencies without sacrificing device durability for future OLEDs.
Collapse
Affiliation(s)
- Bhagya Madushani
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Fukuoka, 819-0395, Japan
| | - Masashi Mamada
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Kenichi Goushi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Fukuoka, 819-0395, Japan
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, Nishi, Fukuoka, 819-0395, Japan
| | - Hiroshi Katagiri
- Graduate School of Organic Materials Science, Yamagata University, Yonezawa, Yamagata, 992-8510, Japan
| | - Hajime Nakanotani
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Fukuoka, 819-0395, Japan
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, Nishi, Fukuoka, 819-0395, Japan
| | - Takuji Hatakeyama
- Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Chihaya Adachi
- Center for Organic Photonics and Electronics Research (OPERA), Kyushu University, Fukuoka, 819-0395, Japan
- International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, Nishi, Fukuoka, 819-0395, Japan
| |
Collapse
|
7
|
Cho HH, Gorgon S, Londi G, Giannini S, Cho C, Ghosh P, Tonnelé C, Casanova D, Olivier Y, Baikie TK, Li F, Beljonne D, Greenham NC, Friend RH, Evans EW. Efficient near-infrared organic light-emitting diodes with emission from spin doublet excitons. NATURE PHOTONICS 2024; 18:905-912. [PMID: 39247521 PMCID: PMC11374703 DOI: 10.1038/s41566-024-01458-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 05/07/2024] [Indexed: 09/10/2024]
Abstract
The development of luminescent organic radicals has resulted in materials with excellent optical properties for near-infrared emission. Applications of light generation in this range span from bioimaging to surveillance. Although the unpaired electron arrangements of radicals enable efficient radiative transitions within the doublet-spin manifold in organic light-emitting diodes, their performance is limited by non-radiative pathways introduced in electroluminescence. Here we present a host-guest design for organic light-emitting diodes that exploits energy transfer with up to 9.6% external quantum efficiency for 800 nm emission. The tris(2,4,6-trichlorophenyl)methyl-triphenyl-amine radical guest is energy-matched to the triplet state in a charge-transporting anthracene-derivative host. We show from optical spectroscopy and quantum-chemical modelling that reversible host-guest triplet-doublet energy transfer allows efficient harvesting of host triplet excitons.
Collapse
Affiliation(s)
- Hwan-Hee Cho
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - Giacomo Londi
- Laboratory for Computational Modelling of Functional Materials, Namur Institute of Structured Matter, University of Namur, Namur, Belgium
- Present Address: Department of Chemistry and Industrial Chemistry, University of Pisa, Pisa, Italy
| | - Samuele Giannini
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, Belgium
- Present Address: Institute of Chemistry of OrganoMetallic Compounds, National Research Council (ICCOM-CNR), Pisa, Italy
| | - Changsoon Cho
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
- Institute for Convergence Research and Education in Advanced Technology, Yonsei University, Seoul, Republic of Korea
| | - Pratyush Ghosh
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Claire Tonnelé
- Donostia International Physics Centre, Donostia, Spain
- Ikerbasque Foundation for Science, Bilbao, Spain
| | - David Casanova
- Donostia International Physics Centre, Donostia, Spain
- Ikerbasque Foundation for Science, Bilbao, Spain
| | - Yoann Olivier
- Laboratory for Computational Modelling of Functional Materials, Namur Institute of Structured Matter, University of Namur, Namur, Belgium
| | - Tomi K Baikie
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Feng Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, China
| | - David Beljonne
- Laboratory for Chemistry of Novel Materials, University of Mons, Mons, Belgium
| | - Neil C Greenham
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | | | - Emrys W Evans
- Department of Chemistry, Swansea University, Swansea, UK
- Centre for Integrative Semiconductor Materials, Swansea University, Swansea, UK
| |
Collapse
|
8
|
Sun Y, Xu Z, Wang Y, Niu Z, Xu Z, Li S, Wang W, Liu Y. Enhanced performance of thermally activated delayed fluorescent light emitting diodes by optimized host polarity. OPTICS EXPRESS 2024; 32:17942-17952. [PMID: 38858962 DOI: 10.1364/oe.522090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 04/17/2024] [Indexed: 06/12/2024]
Abstract
The interaction between the intrinsic polarity of the host material and the TADF guest material affects charge injection and transport, exciton formation, charge recombination, and emission mechanisms. Therefore, understanding and controlling the interaction between the intrinsic polarity of the host material and the TADF guest material is very important to realize efficient TADF-OLED devices. This study investigated the molecular interaction between different polar host materials and a thermally activated delayed fluorescence material (DMAc-PPM). It has been found that interaction between the host and guest (π-π stacking interaction, multiple CH/π contacts) greatly influence the molecular transition dipole moment orientation of the guest. And the OLED devices based on the strong polar host (DPEPO) exhibited the highest EQEmax and lowest luminescence intensity, while devices using the weaker polar hosts mCP and CBP achieved higher luminance and lower EQEmax. Then, the strong polar host DPEPO was mixed with the weaker polar hosts CBP and mCP, respectively. The devices prepared based on the mixed-host DPEPO: mCP showed a 2.2 times improvement in EQEmax from 6.3% to 20.1% compared to the single-host mCP. The devices prepared based on the mixed-host DPEPO: CBP showed a 3.1 times improvement in luminance intensity from 1023 cd/m2 to 4236 cd/m2 compared to the single host of DPEPO. This suggests that optimizing the polarity of host materials has the potential to enhance the performance of solution prepared OLED devices.
Collapse
|
9
|
Zeng Y, Liu X, Liu Y, Chen W, Liu F, Li H. 22% Record Efficiency in Nanorod Light-Emitting Diodes Achieved by Gradient Shells. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2310705. [PMID: 38377984 DOI: 10.1002/adma.202310705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 01/08/2024] [Indexed: 02/22/2024]
Abstract
The external quantum efficiency (EQE) in light-emitting diodes (LEDs) based on isotropic quantum dots has approached the theoretical limit of close to 20%. Anisotropic nanorods can break this limit by taking advantage of their directional emission. However, the progress towards higher EQE by using CdSe/CdS nanorods (NRs) faces several challenges, primarily involving the low quantum yield and unbalanced charge injection in devices. Herein, the seeded growth method is modified and anisotropic nanorods are obtained with photoluminescence quantum yield up to 98% by coating a gradient alloyed CdZnSe shell around conventional spherical CdSe seeds. This intermediate alloyed CdZnSe shell combined with a subsequent rod-shaped CdZnS/ZnS shell can effectively suppress the electron delocalization in the typical CdSe/CdS nanorods due to their small conduction bandgap offset. Additionally, this alloyed shell can reduce the hole-injection barrier and create a larger barrier for electron injection, both effects promoting a balanced injection of electrons and holes in LEDs. Hence, LEDs are reached with high brightness (160341 cd m-2) and high efficiency (EQE = 22%, current efficiency = 23.19 cd A-1), which are the highest values to date for nanorod LEDs.
Collapse
Affiliation(s)
- Yicheng Zeng
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Xiaonan Liu
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China
| | - Yuan Liu
- State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning, 116023, China
| | - Weiwei Chen
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Fangze Liu
- Advanced Research Institute of Multidisciplinary Sciences, Beijing Institute of Technology, Beijing, 100081, China
| | - Hongbo Li
- Experimental Center of Advanced Materials, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China
| |
Collapse
|
10
|
Ba G, Yang Y, Huang F, Wang J, Lu Y, Li J, Cheng C, Sui M, Tian J. Gradient Alloy Shell Enabling Colloidal Quantum Wells Light-Emitting Diodes with Efficiency Exceeding 22. NANO LETTERS 2024; 24:4454-4461. [PMID: 38572779 DOI: 10.1021/acs.nanolett.4c00276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2024]
Abstract
Colloidal quantum well (CQW) based light emitting diodes (LEDs) possess extra-high theoretical efficiency, but their performance still lags far behind conventional LEDs due to severe exciton quenching and unbalanced charge injection. Herein, we devised a gradient composition CdxZn1-xS shell to address these issues. The epitaxial shell with gradient composition was achieved through controlling competition between Cd2+ and Zn2+ cations to preferentially bind to the anions S2-. Thus, exciton quenching was suppressed greatly by passivating defects and reducing nonradiative recombination, thereby achieving near-unity photoluminescence quantum yield (PLQY). The gradient energy level of the shell reduced the hole injection barriers and increased the hole injection efficiency to balance the charge injection of LEDs. As a result, the LEDs achieved a high external quantum efficiency (EQE) of 22.83%, luminance of 111,319 cd/m2 and a long operational lifetime (T95@100 cd/m2) over 6,500 h, demonstrating the state-of-the-art performance for the CQW based LEDs.
Collapse
Affiliation(s)
- Guohang Ba
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing,, Beijing 100083, China
| | - Yumin Yang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing,, Beijing 100083, China
| | - Fei Huang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing,, Beijing 100083, China
| | - Junfeng Wang
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing,, Beijing 100083, China
| | - Yue Lu
- Beijing Key Laboratory of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China
| | - Jing Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Chunyan Cheng
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing,, Beijing 100083, China
| | - Manling Sui
- Beijing Key Laboratory of Microstructure and Properties of Solids, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China
| | - Jianjun Tian
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing,, Beijing 100083, China
| |
Collapse
|
11
|
Liu Y, Zhu F, Wang Y, Yan D. High-efficiency crystalline white organic light-emitting diodes. LIGHT, SCIENCE & APPLICATIONS 2024; 13:86. [PMID: 38589356 PMCID: PMC11001915 DOI: 10.1038/s41377-024-01428-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 02/04/2024] [Accepted: 03/17/2024] [Indexed: 04/10/2024]
Abstract
Crystalline white organic light-emitting diodes (C-WOLEDs) are promising candidates for lighting and display applications. It is urgently necessary, however, to develop energy-saving and high-efficiency C-WOLEDs that have stable and powerful emission to meet commercial demands. Here, we report a crystalline host matrix (CHM) with embedded nanoaggregates (NA) structure for developing high-performance C-WOLEDs by employing a thermally activated delayed fluorescence (TADF) material and orange phosphorescent dopants (Phos.-D). The CHM-TADFNA-D WOLED exhibit a remarkable EQE of 12.8%, which is the highest performance WOLEDs based on crystalline materials. The device has a quick formation of excitons and a well-designed energy transfer process, and possesses a fast ramping of luminance and current density. Compared to recently reported high-performance WOLEDs based on amorphous material route, the C-WOLED achieves a low series-resistance Joule-heat loss ratio and an enhanced photon output, demonstrating its significant potential in developing the next-generation WOLEDs.
Collapse
Affiliation(s)
- Yijun Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China
| | - Feng Zhu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China.
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin University, Changchun, 130012, China
| | - Donghang Yan
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China
| |
Collapse
|
12
|
Lee KW, Wan Y, Huang Z, Zhao Q, Li S, Lee CS. Organic Optoelectronic Materials: A Rising Star of Bioimaging and Phototherapy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2306492. [PMID: 37595570 DOI: 10.1002/adma.202306492] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/07/2023] [Indexed: 08/20/2023]
Abstract
Recently, many organic optoelectronic materials (OOMs), especially those used in organic light-emitting diodes (OLEDs), organic solar cells (OSCs), and organic field-effect transistors (OFETs), are explored for biomedical applications including imaging and photoexcited therapies. In this review, recently developed OOMs for fluorescence imaging, photoacoustic imaging, photothermal therapy, and photodynamic therapy, are summarized. Relationships between their molecular structures, nanoaggregation structures, photophysical mechanisms, and properties for various biomedical applications are discussed. Mainly four kinds of OOMs are covered: thermally activated delayed fluorescence materials in OLEDs, conjugated small molecules and polymers in OSCs, and charge-transfer complexes in OFETs. Based on the OOMs unique optical properties, including excitation light wavelength and exciton dynamics, they are respectively exploited for suitable biomedical applications. This review is intended to serve as a bridge between researchers in the area of organic optoelectronic devices and those in the area of biomedical applications. Moreover, it provides guidance for selecting or modifying OOMs for high-performance biomedical uses. Current challenges and future perspectives of OOMs are also discussed with the hope of inspiring further development of OOMs for efficient biomedical applications.
Collapse
Affiliation(s)
- Ka-Wai Lee
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, P. R. China
| | - Yingpeng Wan
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, P. R. China
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P. R. China
| | - Zhongming Huang
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P. R. China
| | - Qi Zhao
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P. R. China
| | - Shengliang Li
- College of Pharmaceutical Sciences, Soochow University, Suzhou, 215123, P. R. China
| | - Chun-Sing Lee
- Center of Super-Diamond and Advanced Films (COSDAF), Department of Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong SAR, P. R. China
| |
Collapse
|
13
|
Yang B, Yan S, Zhang Y, Feng F, Huang W. Stimuli-responsive luminescence from polar cyano/isocyano-derived luminophores via structural tailoring and self-assembly. Dalton Trans 2024; 53:5320-5341. [PMID: 38411983 DOI: 10.1039/d3dt04049f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024]
Abstract
Polar cyano fragments and their isomeric isocyano counterparts have attracted great attention as stimuli-responsive luminescent materials in a wide range of fields including organic light-emitting diode devices, chemical fluorescent sensors, photoelectric semiconductors, anti-counterfeit products, etc., mainly because of their typical electron-deficient activity, noncovalent recognition ability, and variable coordination capacity. The electron-deficient and polar nature of these blocks have significant effects on the properties of the cyano/isocyano-based luminophore materials, especially concerning their condensed state-dependent electronic structures. Among them, donor-acceptor (D-A) derived unimolecular and co-assembled luminophores have attracted more attention because their large delocalized structures and noncovalent interaction recognition sites can rebuild the electronic transfer character in the aggregative state, thus endowing them with outstanding stimuli-responsive luminescent behavior via intermolecular and intramolecular charge transfer in polytropic morphologies. In this perspective paper, we give a brief introduction on stimuli-responsive organic and coordinated luminophores and the documented typical design concepts and applications in recent years. It is expected that this perspective article will not only summarize the recent developments of polar cyano/isocyano-derived luminophores and their coordination compounds via structural tailoring and self-assembly but also throw light on the future of the design of more sophisticated stimuli-responsive architectures and their versatile properties.
Collapse
Affiliation(s)
- Bo Yang
- State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu Province 210093, P. R. China.
| | - Suqiong Yan
- State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu Province 210093, P. R. China.
| | - Yuan Zhang
- State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu Province 210093, P. R. China.
| | - Fanda Feng
- State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu Province 210093, P. R. China.
| | - Wei Huang
- State Key Laboratory of Coordination Chemistry, Nanjing National Laboratory of Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, Jiangsu Province 210093, P. R. China.
- Shenzhen Research Institute of Nanjing University, Shenzhen 518005, P. R. China
| |
Collapse
|
14
|
Bai Z, Wang J, Zou P, Jiang R, Yang D, Ma D, Tang BZ, Zhao Z. Creating Efficient Red Thermally Activated Delayed Fluorescence Materials with Cyano-Substituted 11,12-Diphenyldipyrido[3,2-a:2',3'-c]phenazine Acceptors. Chemistry 2024; 30:e202303990. [PMID: 38060300 DOI: 10.1002/chem.202303990] [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: 12/01/2023] [Revised: 12/07/2023] [Accepted: 12/07/2023] [Indexed: 12/08/2023]
Abstract
Red luminescent materials are essential components for full color display and white lightening based on organic light-emitting diode (OLED) technology, but the extension of emission color towards red or deep red region generally leads to decreased photoluminescence and electroluminescence efficiencies. Herein, we wish to report two new luminescent molecules (2CNDPBPPr-TPA and 4CNDPBPPr-TPA) consisting of cyano-substituted 11,12-diphenyldipyrido[3,2-a:2',3'-c]phenazine acceptors and triphenylamine donors. As the increase of cyano substituents, the emission wavelength is greatly red-shifted and the reverse intersystem crossing process is promoted, resulting in strong red delayed fluorescence. Meanwhile, due to the formation of intramolecular hydrogen bonds, the molecular structures become rigidified and planarized, which brings about large horizontal dipole ratios. As a result, 2CNDPBPPr-TPA and 4CNDPBPPr-TPA can perform as emitters efficiently in OLEDs, furnishing excellent external quantum efficiencies of 28.8 % at 616 nm and 20.2 % at 648 nm, which are significantly improved in comparison with that of the control molecule without cyano substituents. The findings in this work demonstrate that the introduction of cyano substituents to the acceptors of delayed fluorescence molecules could be a facile and effective approach to explore high-efficiency red or deep red delayed fluorescence materials.
Collapse
Affiliation(s)
- Zhentao Bai
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Jianghui Wang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Peng Zou
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Ruming Jiang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Dezhi Yang
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| | - Ben Zhong Tang
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen, Guangdong, 518172, China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology, Guangzhou, 510640, China
| |
Collapse
|
15
|
Lam TL, Li H, Tan K, Chen Z, Tang YK, Yang J, Cheng G, Dai L, Che CM. Sterically Hindered Tetradentate [Pt(O^N^C^N)] Emitters with Radiative Decay Rates up to 5.3 × 10 5 s -1 for Phosphorescent Organic Light-Emitting Diodes with LT 95 Lifetime over 9200 h at 1000 cd m -2. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2307393. [PMID: 37897146 DOI: 10.1002/smll.202307393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/07/2023] [Indexed: 10/29/2023]
Abstract
Described here are sterically hindered tetradentate [Pt(O^N^C^N)] emitters (Pt-1, Pt-2, and Pt-3) developed for stable and high-performance green phosphorescent organic light-emitting diodes (OLEDs). These Pt(II) emitters exhibit strong saturated green phosphorescence (λmax = 517-531 nm) in toluene and mCP thin films with emission quantum yields as high as 0.97, radiative rate constants (kr) as high as 4.4-5.3 × 105 s-1 and reduced excimer emission, and with a preferential horizontally oriented transition dipole ratio of up to 84%. Theoretical calculations show that p-(hetero)arene substituents at the periphery of the ligand scaffolds in Pt-1, Pt-2, and Pt-3 can i) enhance the spin-orbit coupling (SOC) between the lower singlet excited states and the T1 state, and S0→Sn (n = 1 or 2) transition dipole moment, and ii) introducing additional SOC activity and the bright 1ILCT[π(carbazole)→π*(N^C^N)] excited state (Pt-2 and Pt-3), which are the main contributors to the increased kr values. Utilizing these tetradentate Pt(II) emitters, green phosphorescent OLEDs are fabricated with narrow-band electroluminescence (FWHM down to 36 nm), high external quantum efficiency, current efficiency up to 27.6% and 98.7 cd A-1, and an unprecedented device lifetime (LT95) of up to 9270 h at 1000 cd m-2 under laboratory conditions.
Collapse
Affiliation(s)
- Tsz-Lung Lam
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- Hong Kong Quantum AI Lab Limited, Units 909-915, Building 17 W, 17 Science Park West Avenue, Hong Kong Science Park, Pak Shek Kok, Hong Kong
| | - Huiyang Li
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- Guangdong Aglaia Optoelectronic Materials Co., Ltd, Foshan, 528300, China
| | - Kaixin Tan
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Ziyong Chen
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Yu-Kan Tang
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Jun Yang
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- Hong Kong Quantum AI Lab Limited, Units 909-915, Building 17 W, 17 Science Park West Avenue, Hong Kong Science Park, Pak Shek Kok, Hong Kong
| | - Gang Cheng
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- Hong Kong Quantum AI Lab Limited, Units 909-915, Building 17 W, 17 Science Park West Avenue, Hong Kong Science Park, Pak Shek Kok, Hong Kong
- HKU Shenzhen Institute of Research and Innovation, Shenzhen, Guangdong, 518057, P. R. China
| | - Lei Dai
- Guangdong Aglaia Optoelectronic Materials Co., Ltd, Foshan, 528300, China
| | - Chi-Ming Che
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- Hong Kong Quantum AI Lab Limited, Units 909-915, Building 17 W, 17 Science Park West Avenue, Hong Kong Science Park, Pak Shek Kok, Hong Kong
- HKU Shenzhen Institute of Research and Innovation, Shenzhen, Guangdong, 518057, P. R. China
| |
Collapse
|
16
|
Al-Sharji H, Ilmi R, Khan MS. Recent Progress in Phenoxazine-Based Thermally Activated Delayed Fluorescent Compounds and Their Full-Color Organic Light-Emitting Diodes. Top Curr Chem (Cham) 2024; 382:5. [PMID: 38329582 DOI: 10.1007/s41061-024-00450-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 01/04/2024] [Indexed: 02/09/2024]
Abstract
Third-generation organic light-emitting diodes (OLEDs) based on metal-free thermally activated delayed fluorescent (TADF) materials have sparked tremendous interest in the last decade due to their nearly 100% exciton utilization efficiency, which can address the low-efficiency issue of the first-generation fluorescent emitters and the high-cost issue of the second-generation organometallic phosphorescent emitters. Construction of efficient and stable TADF-OLEDs requires utilizing TADF materials with a narrow singlet-triplet energy gap (ΔEST), high photoluminescence quantum yield (PLQY) and short TADF lifetime. A small ΔEST is necessary for an efficient reverse intersystem crossing (RISC) process, which can be achieved through the effective spatial separation of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). TADF emitters have been generally designed as intramolecular charge transfer (ICT) molecules with highly twisted donor-acceptor (D-A) molecular architectures. A wide variety of combinations of electron donors and acceptors have been explored. In this review, we shall focus on recent progress in organic TADF molecules incorporating strong electron-donor phenoxazine moiety and their application as emitting layer (EML) in OLEDs.
Collapse
Affiliation(s)
- Houda Al-Sharji
- Department of Chemistry, Sultan Qaboos University, P. O. Box 36, Al Khod, 123, Oman
| | - Rashid Ilmi
- Department of Chemistry, Sultan Qaboos University, P. O. Box 36, Al Khod, 123, Oman.
| | - Muhammad S Khan
- Department of Chemistry, Sultan Qaboos University, P. O. Box 36, Al Khod, 123, Oman.
| |
Collapse
|
17
|
Chen YS, Lin IH, Huang HY, Liu SW, Hung WY, Wong KT. Exciplex-forming cohost systems with 2,7-dicyanofluorene acceptors for high efficiency red and deep-red OLEDs. Sci Rep 2024; 14:2458. [PMID: 38291066 PMCID: PMC10827723 DOI: 10.1038/s41598-024-52680-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 01/21/2024] [Indexed: 02/01/2024] Open
Abstract
Two 2,7-dicyaonfluorene-based molecules 27-DCN and 27-tDCN are utilized as acceptors (A) to combine with hexaphenylbenzene-centered donors (D) TATT and DDT-HPB for probing the exciplex formation. The photophysical characteristics reveal that the steric hindered 27-tDCN not only can increase the distance of D and A, resulting in a hypsochromic emission, but also dilute the concentration of triplet excitons to suppress non-radiative process. The 27-tDCN-based exciplex-forming blends exhibit better photoluminescence quantum yield (PLQY) as compared to those of 27-DCN-based pairs. In consequence, among these D:A blends, the device employing DDT-HPB:27-tDCN blend as the emissiom layer (EML) exhibits the best EQE of 3.0% with electroluminescence (EL) λmax of 542 nm. To further utilize the exciton electrically generated in exciplex-forming system, two D-A-D-configurated fluorescence emitter DTPNT and DTPNBT are doped into the DDT-HPB:27-tDCN blend. The nice spectral overlap ensures fast and efficient Förster energy transfer (FRET) process between the exciplex-forming host and the fluorescent quests. The red device adopting DDT-HPB:27-tDCN:10 wt% DTPNT as the EML gives EL λmax of 660 nm and maximum external quantum efficiency (EQEmax) of 5.8%, while EL λmax of 685 nm and EQE of 5.0% for the EML of DDT-HPB:27-tDCN:10 wt% DTPNBT. This work manifests a potential strategy to achieve high efficiency red and deep red OLED devices by incorporating the highly fluorescent emitters to extract the excitons generated by the exciplex-forming blend with bulky acceptor for suppressing non-radiative process.
Collapse
Affiliation(s)
- Yi-Sheng Chen
- Organic Electronic Research Center, Ming Chi University of Technology, New Taipei City, 24031, Taiwan
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan
| | - I-Hung Lin
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Hsin-Yuan Huang
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung, 20224, Taiwan
| | - Shun-Wei Liu
- Organic Electronic Research Center, Ming Chi University of Technology, New Taipei City, 24031, Taiwan
| | - Wen-Yi Hung
- Department of Optoelectronics and Materials Technology, National Taiwan Ocean University, Keelung, 20224, Taiwan.
| | - Ken-Tsung Wong
- Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan.
- Institute of Atomic and Molecular Science Academia Sinica, Taipei, 10617, Taiwan.
| |
Collapse
|
18
|
Au-Yeung CC, Leung MY, Lai SL, Cheng SC, Li LK, Tang MC, Kwok WK, Ko CC, Chan MY, Yam VWW. Thermally activated delayed fluorescence tetradentate ligand-containing gold(III) complexes with preferential molecular orientation and their application in organic light-emitting devices. MATERIALS HORIZONS 2024; 11:151-162. [PMID: 37889511 DOI: 10.1039/d3mh00910f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
A new class of thermally activated delayed fluorescence (TADF) pyridine-/pyrazine-containing tetradentate C^C^N^N gold(III) complexes have been designed and synthesized. Displaying photoluminescence quantum yields (PLQYs) of up to 0.77 in solid-state thin films, these complexes showed at-least a six-fold increase in the radiative decay rate constant (kr) in toluene upon increasing temperature from 210 to 360 K. Using variable-temperature (VT) ultrafast transient absorption (TA) spectroscopy, the reverse intersystem crossing (RISC) processes were directly observed and the activation parameters were determined, in line with the results of the Boltzmann two-level model fittings, in which the energy separation values between the lowest-lying singlet excited state (S1) and the lowest-lying triplet excited state (T1), ΔE(S1-T1), of these complexes were estimated to be in the range of 0.16-0.18 eV. Through strategic modification of the position of the electron-donating -tBu substituent in the cyclometalating ligand, the permanent dipole moments (PDMs) of these tetradentate gold(III) emitters could be manipulated to enhance their horizontal alignment in the emitting layer of organic light-emitting devices (OLEDs). Consequently, the resulting vacuum-deposited OLEDs demonstrated a 30% increase in the theoretical out-coupling efficiency (ηout), as well as promising electroluminescence (EL) performance with maximum external quantum efficiencies (EQEs) of up to 15.7%.
Collapse
Affiliation(s)
- Cathay Chai Au-Yeung
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
| | - Ming-Yi Leung
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
- Hong Kong Quantum AI Lab Limited, 17 Science Park West Avenue, Pak Shek Kok, Hong Kong, P. R. China
| | - Shiu-Lun Lai
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
| | - Shun-Cheung Cheng
- Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong, P. R. China
| | - Lok-Kwan Li
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
| | - Man-Chung Tang
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
| | - Wing-Kei Kwok
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
- Hong Kong Quantum AI Lab Limited, 17 Science Park West Avenue, Pak Shek Kok, Hong Kong, P. R. China
| | - Chi-Chiu Ko
- Department of Chemistry, City University of Hong Kong, Kowloon, Hong Kong, P. R. China
| | - Mei-Yee Chan
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
- Hong Kong Quantum AI Lab Limited, 17 Science Park West Avenue, Pak Shek Kok, Hong Kong, P. R. China
| | - Vivian Wing-Wah Yam
- Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China.
- Hong Kong Quantum AI Lab Limited, 17 Science Park West Avenue, Pak Shek Kok, Hong Kong, P. R. China
| |
Collapse
|
19
|
Ma P, Chen Y, Man Y, Qi Q, Guo Y, Wang H, Li Z, Chang P, Qu C, Han C, Xu H. High-Efficiency Ultraviolet Electroluminescence from Multi-Resonance Phosphine Oxide Polycyclic Aromatics. Angew Chem Int Ed Engl 2023:e202316479. [PMID: 38055193 DOI: 10.1002/anie.202316479] [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: 10/31/2023] [Revised: 11/27/2023] [Accepted: 12/05/2023] [Indexed: 12/07/2023]
Abstract
Efficient ultraviolet (UV) electroluminescent materials remain a great challenge, since short peak wavelength <400 nm and narrow full width at half maximum (FWHM) <50 nm are simultaneously required. In this sense, multi-resonance (MR) thermally activated delayed fluorescence (TADF) emitters featuring narrow-band emissions hold the promise for UV applications. Herein, a novel MR-TADF skeleton featuring carbazole-phosphine oxide (P=O) fused aromatics is developed to construct the first two UV MR emitters named CzP2PO and tBCzP2PO. In addition to synergistic resonance effects of P=O and N atom, sp3 -hybrid P atom renders the curved polycyclic planes of CzP2PO and tBCzP2PO, giving rise to their narrowband UV emissions with peak wavelengths <390 nm and FWHM<35 nm. Besides configuration quasi-planarization for radiation enhancement and quenching suppression, P=O moiety further enhances singlet-triplet coupling to facilitate reverse intersystem crossing, resulting in the state-of-the-art photoluminescence quantum yield of 62 % in tBCzP2PO doped films. As consequence, tBCzP2PO endowed its UV organic light-emitting diodes with the peak at 382 nm and FWHM of 32 nm, and especially the record-high external quantum efficiency (EQE) of 15.1 % among all kinds of UV devices. Our results demonstrate great potential of P=O based MR emitters in practical applications including optoelectronics, biology and medicine science.
Collapse
Affiliation(s)
- Peng Ma
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Yingying Chen
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Yi Man
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Quan Qi
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Yuanting Guo
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Huiqin Wang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Zhe Li
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Peng Chang
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Chao Qu
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Chunmiao Han
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| | - Hui Xu
- Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education, School of Chemistry and Materials, Heilongjiang University, Harbin, Heilongjiang, 150080, China
| |
Collapse
|
20
|
Alnasser K, Li S, Sidhik S, Kamau S, Hou J, Hurley N, Alzaid A, Wang S, Yan H, Deng J, Omary MA, Mohite AD, Cui J, Lin Y. Fabrications of twisted moiré photonic crystal and random moiré photonic crystal and their potential applications in light extraction. NANOTECHNOLOGY 2023; 35:025203. [PMID: 37820638 DOI: 10.1088/1361-6528/ad024a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 10/09/2023] [Indexed: 10/13/2023]
Abstract
Twisted moiré photonic crystal is an optical analog of twisted graphene or twisted transition metal dichalcogenide bilayers. In this paper, we report the fabrication of twisted moiré photonic crystals and randomized moiré photonic crystals and their use in enhanced extraction of light in light-emitting diodes (LEDs). Fractional diffraction orders from randomized moiré photonic crystals are more uniform than those from moiré photonic crystals. Extraction efficiencies of 76.5%, 77.8% and 79.5% into glass substrate are predicted in simulations of LED patterned with twisted moiré photonic crystals, defect-containing photonic crystals and random moiré photonic crystals, respectively, at 584 nm. Extraction efficiencies of optically pumped LEDs with 2D perovskite (BA)2(MA)n-1PbnI3n+1ofn= 3 and (5-(2'-pyridyl)-tetrazolato)(3-CF3-5-(2'-pyridyl)pyrazolato) platinum(II) (PtD) have been measured.
Collapse
Affiliation(s)
- Khadijah Alnasser
- Department of Physics, University of North Texas, Denton, TX, United States of America
| | - Shan Li
- Department of Chemistry, University of North Texas, Denton, TX, United States of America
| | - Siraj Sidhik
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, United States of America
| | - Steve Kamau
- Department of Physics, University of North Texas, Denton, TX, United States of America
| | - Jin Hou
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, United States of America
| | - Noah Hurley
- Department of Physics, University of North Texas, Denton, TX, United States of America
| | - Ayman Alzaid
- Department of Computer Science, New Mexico State University, Las Cruces, NM 88003, United States of America
| | - Sicheng Wang
- Department of Chemistry, University of North Texas, Denton, TX, United States of America
| | - Hao Yan
- Department of Chemistry, University of North Texas, Denton, TX, United States of America
| | - Jiangdong Deng
- Center for Nanoscale Systems, Harvard University, Cambridge, MA 02138, United States of America
| | - Mohammad A Omary
- Department of Chemistry, University of North Texas, Denton, TX, United States of America
| | - Aditya D Mohite
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, United States of America
- Applied Physics Program, Smalley-Curl Institute, Rice University, Houston, TX, United States of America
| | - Jingbiao Cui
- Department of Physics, University of North Texas, Denton, TX, United States of America
| | - Yuankun Lin
- Department of Physics, University of North Texas, Denton, TX, United States of America
- Department of Electrical Engineering, University of North Texas, Denton, TX, United States of America
| |
Collapse
|
21
|
Kang SW, Bae EJ, Park YW, Ju BK. Highly Efficient Ultra-Thin EML Blue PHOLEDs with an External Light-Extraction Diffuser. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2357. [PMID: 37630941 PMCID: PMC10458805 DOI: 10.3390/nano13162357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 08/27/2023]
Abstract
In this study, various diffusers are applied to highly efficient ultra-thin emission layer (EML) structure-based blue phosphorescent organic light-emitting diodes (PHOLEDs) to improve the electroluminescence (EL) characteristics and viewing angle. To achieve highly efficient blue PHOLEDs, the EL characteristics of ultra-thin EML PHOLEDs with the various diffusers having different structures of pattern-shape (hemisphere/sphere), size (4~75 μm), distribution (surface/embedded), and packing (close-packed/random) were systematically analyzed. The diffusers showed different enhancements in the overall EL characteristics of efficiencies, viewing angle, and others. The EL characteristics showed apparent dependency on their structure. The external quantum efficiency (EQE) was enhanced mainly by following the orders of pattern, size, and shape. Following the pattern size, the EQE enhancement gradually increased; the largest-sized diffuser with a 75 μm closed-packed hemisphere (diffuser-1) showed a 1.47-fold EQE improvement, which was the highest. Meanwhile, the diffuser with a ~7 μm random embedded sphere with a low density (diffuser 5) showed the lowest 1.02-fold-improved EQE. The reference device with ultra-thin EML structure-based blue PHOLEDs showed a maximum EQE of 16.6%, and the device with diffuser 1 achieved a maximum EQE of 24.3% with a 5.1% wider viewing angle compared to the reference device without a diffuser. For the in-depth analysis, the viewing angle profile of the ultra-thin EML PHOLED device and fluorescent green OLEDs were compared. As a result, the efficiency enhancement characteristics of the diffusers show a difference in the viewing angle profile. Finally, the application of the diffuser successfully demonstrated that the EL efficiency and viewing angle could be selectively improved. Additionally, we found that it was possible to realize a wide viewing angle and achieve considerable EQE enhancement by further investigations using high-density and large-sized embedded structures of light-extraction film.
Collapse
Affiliation(s)
- Shin-Woo Kang
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea; (S.-W.K.)
- Nano and Organic-Electronics Laboratory, Department of Display and Semiconductor Engineering, Sun Moon University, Asan 31460, Republic of Korea
| | - Eun-Jeong Bae
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea; (S.-W.K.)
- Nano and Organic-Electronics Laboratory, Department of Display and Semiconductor Engineering, Sun Moon University, Asan 31460, Republic of Korea
| | - Young-Wook Park
- Nano and Organic-Electronics Laboratory, Department of Display and Semiconductor Engineering, Sun Moon University, Asan 31460, Republic of Korea
| | - Byeong-Kwon Ju
- Display and Nanosensor Laboratory, Department of Electrical Engineering, Korea University, 145, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea; (S.-W.K.)
| |
Collapse
|
22
|
Chen C, Luo X, Kaplan AE, Bawendi MG, Macfarlane RJ, Bathe M. Ultrafast dense DNA functionalization of quantum dots and rods for scalable 2D array fabrication with nanoscale precision. SCIENCE ADVANCES 2023; 9:eadh8508. [PMID: 37566651 PMCID: PMC10421044 DOI: 10.1126/sciadv.adh8508] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 07/14/2023] [Indexed: 08/13/2023]
Abstract
Scalable fabrication of two-dimensional (2D) arrays of quantum dots (QDs) and quantum rods (QRs) with nanoscale precision is required for numerous device applications. However, self-assembly-based fabrication of such arrays using DNA origami typically suffers from low yield due to inefficient QD and QR DNA functionalization. In addition, it is challenging to organize solution-assembled DNA origami arrays on 2D device substrates while maintaining their structural fidelity. Here, we reduced manufacturing time from a few days to a few minutes by preparing high-density DNA-conjugated QDs/QRs from organic solution using a dehydration and rehydration process. We used a surface-assisted large-scale assembly (SALSA) method to construct 2D origami lattices directly on solid substrates to template QD and QR 2D arrays with orientational control, with overall loading yields exceeding 90%. Our fabrication approach enables the scalable, high fidelity manufacturing of 2D addressable QDs and QRs with nanoscale orientational and spacing control for functional 2D photonic devices.
Collapse
Affiliation(s)
- Chi Chen
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Xin Luo
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Alexander E. K. Kaplan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Moungi G. Bawendi
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Robert J. Macfarlane
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Mark Bathe
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
23
|
Ma B, Ding Z, Liu D, Zhou Z, Zhang K, Dang D, Zhang S, Su SJ, Zhu W, Liu Y. A Feasible Strategy for a Highly Efficient Thermally Activated Delayed Fluorescence Emitter Over 900 nm Based on Phenalenone Derivatives. Chemistry 2023; 29:e202301197. [PMID: 37154226 DOI: 10.1002/chem.202301197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/05/2023] [Accepted: 05/08/2023] [Indexed: 05/10/2023]
Abstract
Near-infrared (NIR) organic light-emitting diodes (OLEDs) suffer from the low external electroluminescence (EL) quantum efficiency (EQE), which is a critical obstacle for potential applications. Herein, 1-oxo-1-phenalene-2,3-dicarbonitrile (OPDC) is employed as an electron-withdrawing aromatic ring, and by incorporating with triphenylamine (TPA) and biphenylphenylamine (BBPA) donors, two novel NIR emitters with thermally activated delayed fluorescence (TADF) characteristics, namely OPDC-DTPA and OPDC-DBBPA, are first developed and compared in parallel. Intense NIR emission peaks at 962 and 1003 nm are observed in their pure films, respectively. Contributed by the local excited (LE) characteristics in the triplet (T1 ) state in synergy with the charge transfer (CT) characteristics for the singlet (S1 ) state to activate TADF emission, the solution processable doped NIR OLEDs based on OPDC-DTPA and OPDC-DBBPA yield EL peaks at 834 and 906 nm, accompanied with maximum EQEs of 0.457 and 0.103 %, respectively, representing the state-of-the-art EL performances in the TADF emitter-based NIR-OLEDs in the similar EL emission regions so far. This work manifests a simple and effective strategy for the development of NIR TADF emitters with long wavelength and efficiency synchronously.
Collapse
Affiliation(s)
- Bin Ma
- School of Materials Science and Engineering, Jiangsu Engineering Research Center of Light-Electricity-Heat Energy-Converting Materials and Applications, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Key Laboratories of Environment-Friendly Polymers, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, P. R. China
| | - Zhenming Ding
- School of Materials Science and Engineering, Jiangsu Engineering Research Center of Light-Electricity-Heat Energy-Converting Materials and Applications, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Key Laboratories of Environment-Friendly Polymers, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, P. R. China
| | - Denghui Liu
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Zhongxin Zhou
- School of Materials Science and Engineering, Jiangsu Engineering Research Center of Light-Electricity-Heat Energy-Converting Materials and Applications, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Key Laboratories of Environment-Friendly Polymers, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, P. R. China
| | - Kai Zhang
- School of Materials Science and Engineering, Jiangsu Engineering Research Center of Light-Electricity-Heat Energy-Converting Materials and Applications, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Key Laboratories of Environment-Friendly Polymers, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, P. R. China
| | - Dongfeng Dang
- State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an, 710049, P. R. China
| | - Shiyue Zhang
- School of Materials Science and Engineering, Jiangsu Engineering Research Center of Light-Electricity-Heat Energy-Converting Materials and Applications, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Key Laboratories of Environment-Friendly Polymers, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, P. R. China
| | - Shi-Jian Su
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices, South China University of Technology, Guangzhou, 510640, P. R. China
| | - Weiguo Zhu
- School of Materials Science and Engineering, Jiangsu Engineering Research Center of Light-Electricity-Heat Energy-Converting Materials and Applications, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Key Laboratories of Environment-Friendly Polymers, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, P. R. China
| | - Yu Liu
- School of Materials Science and Engineering, Jiangsu Engineering Research Center of Light-Electricity-Heat Energy-Converting Materials and Applications, Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering, Jiangsu Key Laboratories of Environment-Friendly Polymers, National Experimental Demonstration Center for Materials Science and Engineering, Changzhou University, Changzhou, 213164, P. R. China
| |
Collapse
|
24
|
Gawale Y, Ansari R, Naveen KR, Kwon JH. Forthcoming hyperfluorescence display technology: relevant factors to achieve high-performance stable organic light emitting diodes. Front Chem 2023; 11:1211345. [PMID: 37377883 PMCID: PMC10291061 DOI: 10.3389/fchem.2023.1211345] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 05/26/2023] [Indexed: 06/29/2023] Open
Abstract
Over the decade, there have been developments in purely organic thermally activated delayed fluorescent (TADF) materials for organic light-emitting diodes (OLEDs). However, achieving narrow full width at half maximum (FWHM) and high external quantum efficiency (EQE) is crucial for real display industries. To overcome these hurdles, hyperfluorescence (HF) technology was proposed for next-generation OLEDs. In this technology, the TADF material was considered a sensitizing host, the so-called TADF sensitized host (TSH), for use of triplet excitons via the reverse intersystem crossing (RISC) pathway. Since most of the TADF materials show bipolar characteristics, electrically generated singlet and triplet exciton energies can be transported to the final fluorescent emitter (FE) through Förster resonance energy transfer (FRET) rather than Dexter energy transfer (DET). This mechanism is possible from the S1 state of the TSH to the S1 state of the final fluorescent dopant (FD) as a long-range energy transfer. Considering this, some reports are available based on hyperfluorescence OLEDs, but the detailed analysis for highly efficient and stable devices for commercialization was unclear. So herein, we reviewed the relevant factors based on recent advancements to build a highly efficient and stable hyperfluorescence system. The factors include an energy transfer mechanism based on spectral overlapping, TSH requirements, electroluminescence study based on exciplex and polarity system, shielding effect, DET suppression, and FD orientation. Furthermore, the outlook and future positives with new directions were discussed to build high-performance OLEDs.
Collapse
Affiliation(s)
| | | | | | - Jang Hyuk Kwon
- *Correspondence: Kenkera Rayappa Naveen, ; Jang Hyuk Kwon,
| |
Collapse
|
25
|
Chen D, Tenopala‐Carmona F, Knöller JA, Mischok A, Hall D, Madayanad Suresh S, Matulaitis T, Olivier Y, Nacke P, Gießelmann F, Laschat S, Gather MC, Zysman‐Colman E. Mesogenic Groups Control the Emitter Orientation in Multi-Resonance TADF Emitter Films. Angew Chem Int Ed Engl 2023; 62:e202218911. [PMID: 36760211 PMCID: PMC10947294 DOI: 10.1002/anie.202218911] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023]
Abstract
The use of thermally activated delayed fluorescence (TADF) emitters and emitters that show preferential horizontal orientation of their transition dipole moment (TDM) are two emerging strategies to enhance the efficiency of OLEDs. We present the first example of a liquid crystalline multi-resonance TADF (MR-TADF) emitter, DiKTa-LC. The compound possesses a nematic liquid crystalline phase between 80 °C and 110 °C. Importantly, the TDM of the spin-coated film shows preferential horizontal orientation, with an anisotropy factor, a, of 0.28, which is preserved in doped poly(vinylcarbazole) films. Green-emitting (λEL =492 nm) solution-processed OLEDs based on DiKTa-LC showed an EQEmax of 13.6 %. We thus demonstrate for the first time how self-assembly of a liquid crystalline TADF emitter can lead to the so-far elusive control of the orientation of the transition dipole in solution-processed films, which will be of relevance for high-performance solution-processed OLEDs.
Collapse
Affiliation(s)
- Dongyang Chen
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Francisco Tenopala‐Carmona
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - Julius A. Knöller
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Andreas Mischok
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - David Hall
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
- Laboratory for Chemistry of Novel MaterialsUniversity of MonsMonsBelgium
| | - Subeesh Madayanad Suresh
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Tomas Matulaitis
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| | - Yoann Olivier
- Laboratory for Computational Modeling of Functional MaterialsNamur Institute of Structured MatterUniversité de NamurRue de Bruxelles 615000NamurBelgium
| | - Pierre Nacke
- Institut für Physikalische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Frank Gießelmann
- Institut für Physikalische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Sabine Laschat
- Institut für Organische ChemieUniversität StuttgartPfaffenwaldring 5570569StuttgartGermany
| | - Malte C. Gather
- Humboldt Centre for Nano- and BiophotonicsDepartment of ChemistryUniversity of CologneGreinstr. 4-650939KölnGermany
| | - Eli Zysman‐Colman
- Organic Semiconductor CentreEaStCHEM School of ChemistryUniversity of St AndrewsSt AndrewsFifeKY16 9STUK
| |
Collapse
|
26
|
Kumar V, Kaur P, Singh K. Julolidine based red emitting ESIPT/AIE active material showing luminescence beyond excimer emission: An "on-off" emission response to Cu 2. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 290:122239. [PMID: 36563439 DOI: 10.1016/j.saa.2022.122239] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/06/2022] [Accepted: 12/10/2022] [Indexed: 06/17/2023]
Abstract
A new julolidine-fluorene based excited state intramolecular proton transfer (ESIPT)/aggregate induced emission (AIE) active Schiff-base (JDF) has been synthesized and evaluated for its photophysical properties in solution and aggregated/solid states. The correlation between the emission behavior and the solid state crystal packing structure revealed the interplay of ESIPT coupled excimer reaction occurring in the solid state, which is one of the rare examples reported so far. For a comprehensive comparison, we synthesized a non-ESIPT methyl derivative (JDF-Me) of JDF capable of showing excimer emission only in the solid state. Further, JDF exhibits normal as well as keto emission in solution, upon addition of water, its poor solvent, that promotes aggregation, the fluorescence emission shows the preponderance of the excimer band in the low energy region. It was also interesting to note that in the solid state (thin films), JDF shows emission beyond the excimer emission, which is wavelength dependent. This is attributed to the formation of diverse clusters leading to the extended delocalization beyond excimers, and represents a clustering-triggered emission ascribing bright red color to the solid JDF. Such mélange of emission characteristics of JDF are responsible for the multicolor emission covering a broad range of electromagnetic spectrum, which is demonstrated by the confocal microscopy images of the JDF recorded in different states. Further, in its aggregated state, JDF recognized Cu2+ ions, selectively, manifested in the form of emission quenching via the interaction of Cu2+ ions with the oxygen and nitrogen atoms of JDF inhibiting the excimer formation.
Collapse
Affiliation(s)
- Virendra Kumar
- Department of Chemistry, Centre of Advanced Study, Guru Nanak Dev University, Amritsar 143005, India
| | - Paramjit Kaur
- Department of Chemistry, Centre of Advanced Study, Guru Nanak Dev University, Amritsar 143005, India.
| | - Kamaljit Singh
- Department of Chemistry, Centre of Advanced Study, Guru Nanak Dev University, Amritsar 143005, India.
| |
Collapse
|
27
|
Keruckiene R, Vijaikis E, Chen CH, Lin BY, Huang JX, Chu CC, Dzeng YC, Chen C, Lee JH, Chiu TL, Macionis S, Keruckas J, Butkute R, Grazulevicius JV. Power Efficiency Enhancement of Organic Light-Emitting Diodes Due to the Favorable Horizontal Orientation of a Naphthyridine-Based Thermally Activated Delayed Fluorescence Luminophore. ACS APPLIED ELECTRONIC MATERIALS 2023; 5:1013-1023. [PMID: 36873261 PMCID: PMC9979784 DOI: 10.1021/acsaelm.2c01529] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 01/16/2023] [Indexed: 06/18/2023]
Abstract
Four emitters based on the naphthyridine acceptor moiety and various donor units exhibiting thermally activated delayed fluorescence (TADF) were designed and synthesized. The emitters exhibited excellent TADF properties with a small ΔE ST and a high photoluminescence quantum yield. A green TADF organic light-emitting diode based on 10-(4-(1,8-naphthyridin-2-yl)phenyl)-10H-phenothiazine exhibited a maximum external quantum efficiency of 16.4% with Commission Internationale de L'éclairage coordinates of (0.368, 0.569) as well as a high current and power efficiency of 58.6 cd/A and 57.1 lm/W, respectively. The supreme power efficiency is a record-high value among the reported values of devices with naphthyridine-based emitters. This results from its high photoluminescence quantum yield, efficient TADF, and horizontal molecular orientation. The molecular orientations of the films of the host and the host doped with the naphthyridine emitter were explored by angle-dependent photoluminescence and grazing-incidence small-angle X-ray scattering (GIWAXS). The orientation order parameters (ΘADPL) were found to be 0.37, 0.45, 0.62, and 0.74 for the naphthyridine dopants with dimethylacridan, carbazole, phenoxazine, and phenothiazine donor moieties, respectively. These results were also proven by GIWAXS measurement. The derivative of naphthyridine and phenothiazine was shown to be more flexible to align with the host and to show the favorable horizontal molecular orientation and crystalline domain size, benefiting the outcoupling efficiency and contributing to the device efficiency.
Collapse
Affiliation(s)
- Rasa Keruckiene
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254Kaunas, Lithuania
| | - Eimantas Vijaikis
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254Kaunas, Lithuania
| | - Chia-Hsun Chen
- Materials
Science and Engineering and Physics, Graduate Institute of Photonics
and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei10617, Taiwan
| | - Bo-Yen Lin
- Department
of Opto-Electronics Engineering, National
Dong Hwa University, Shoufeng, Hualien974301, Taiwan
| | - Jing-Xiang Huang
- Materials
Science and Engineering and Physics, Graduate Institute of Photonics
and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei10617, Taiwan
| | - Chun-Chieh Chu
- Materials
Science and Engineering and Physics, Graduate Institute of Photonics
and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei10617, Taiwan
| | - Yi-Chung Dzeng
- Research
Center for Applied Sciences, Academia Sinica, Taipei11529, Taiwan
| | - Chi Chen
- Research
Center for Applied Sciences, Academia Sinica, Taipei11529, Taiwan
| | - Jiun-Haw Lee
- Materials
Science and Engineering and Physics, Graduate Institute of Photonics
and Optoelectronics and Department of Electrical Engineering, National Taiwan University, Taipei10617, Taiwan
| | - Tien-Lung Chiu
- Department
of Electrical Engineering, Yuan Ze University, Chung-Li32003, Taiwan
| | - Simas Macionis
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254Kaunas, Lithuania
| | - Jonas Keruckas
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254Kaunas, Lithuania
| | - Rita Butkute
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254Kaunas, Lithuania
| | - Juozas Vidas Grazulevicius
- Department
of Polymer Chemistry and Technology, Kaunas
University of Technology, K. Barsausko St. 59, LT-50254Kaunas, Lithuania
| |
Collapse
|
28
|
Yu M, Wu X, Liu H, Yang Z, Qiu N, Yang D, Ma D, Tang BZ, Zhao Z. Improving Electroluminescence Efficiency by Linear Polar Host Capable of Promoting Horizontal Dipole Orientation for Dopant. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2206420. [PMID: 36567307 PMCID: PMC9951345 DOI: 10.1002/advs.202206420] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/08/2022] [Indexed: 06/17/2023]
Abstract
In doped organic light-emitting diodes (OLEDs), the host materials play an important role in emitting layers. Most studies about host materials mainly focus on their energy levels and carrier transport behaviors, while less attention is paid to their influence on the dipole orientation of dopants, which closely associate with the light out-coupling efficiency (ηout ) of the device. Herein, a linear polar host material (l-CzTRZ) consisting of carbazole donor, triazine acceptor, and the conjugated para-terphenyl skeleton is developed and its crystal and electronic structures, thermal and electrochemical stabilities, optical property, and carrier transport ability are investigated. l-CzTRZ prefers ordered horizontal orientation and favors electron transport in neat film. More importantly, it can promote horizontal dipole orientation for the dopants via dipole-dipole interaction, furnishing an excellent horizontal dipole ratio of 91.5% and thus a high ηout of 43% for the phosphorescent dopant (PO-01-TB). Consequently, the OLED with l-CzTRZ host and PO-01-TB dopant attains state-of-the-art electroluminescence efficiencies of 135.5 cd A-1 , 135.7 lm W-1 and 41.3%, with a small roll-off of 9.7% at 5000 cd m-2 luminance. The presented significant impact of the host on the dipole orientation of the dopant shall enlighten the design of host materials to improve OLED performance.
Collapse
Affiliation(s)
- Maoxing Yu
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Xing Wu
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Hao Liu
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Zuguo Yang
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Nuoling Qiu
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Dezhi Yang
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Ben Zhong Tang
- School of Science and EngineeringShenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhenGuangdong518172China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| |
Collapse
|
29
|
Lee H, Braveenth R, Muruganantham S, Jeon CY, Lee HS, Kwon JH. Efficient pure blue hyperfluorescence devices utilizing quadrupolar donor-acceptor-donor type of thermally activated delayed fluorescence sensitizers. Nat Commun 2023; 14:419. [PMID: 36697409 PMCID: PMC9876909 DOI: 10.1038/s41467-023-35926-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
The hyperfluorescence (HF) system has drawn great attention in display technology. However, the energy loss mechanism by low reverse intersystem crossing rate (kRISC) and the Dexter energy transfer (DET) channel is still challenging. Here, we demonstrate that this can be mitigated by the quadrupolar donor-acceptor-donor (D-A-D) type of thermally activated delayed fluorescence (TADF) sensitizer materials, DBA-DmICz and DBA-DTMCz. Further, the HF device with DBA-DTMCz and ν-DABNA exhibited 43.9% of high maximum external quantum efficiency (EQEmax) with the Commission Internationale de l'Éclairage coordinates of (0.12, 0.16). The efficiency values recorded for the device are among the highest reported for HF devices. Such high efficiency is assisted by hindered DET process through i) high kRISC, and ii) shielded lowest unoccupied molecular orbital with the presence of two donors in D-A-D type of skeleton. Our current study provides an effective way of designing TADF sensitizer for future HF technology.
Collapse
Affiliation(s)
- Hyuna Lee
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Ramanaskanda Braveenth
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Subramanian Muruganantham
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Chae Yeon Jeon
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Hyun Seung Lee
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea
| | - Jang Hyuk Kwon
- Organic Optoelectronic Device Lab (OODL), Department of Information Display, Kyung Hee University, 26, Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Republic of Korea.
| |
Collapse
|
30
|
Nagamura N, Sasabe H, Sato H, Ito N, Abe S, Sukegawa Y, Yokoyama D, Kaji H, Kido J. Robust Spirobifluorene Core Based Hole Transporters with High Mobility for Long-Life Green Phosphorescent Organic Light-Emitting Devices. Chemistry 2023; 29:e202202636. [PMID: 36173978 DOI: 10.1002/chem.202202636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Indexed: 01/04/2023]
Abstract
Using a tailored high triplet energy hole transport layer (HTL) is a suitable way to improve the efficiency and extend the lifetime of organic light-emitting devices (OLEDs), which can use all molecular excitons of singlets and triplets. In this study, dibenzofuran (DBF)-end-capped and spirobifluorene (SBF) core-based HTLs referred as TDBFSBF1 and TDBFSBF2 were effectively developed. TDBFSBF1 exhibited a high glass transition temperature of 178 °C and triplet energy of 2.5 eV. Moreover, a high external quantum efficiency of 22.0 %, long operational lifetime at 50 % of the initial luminance of 89,000 h, and low driving voltage at 1000 cd m-2 of 2.95 V were achieved in green phosphorescent OLEDs using TDBFSBF1. Further, a high-hole mobility μh value of 1.9×10-3 cm2 V-1 s-1 was recorded in TDBFSBF2. A multiscale simulation successfully reproduced the experimental μh values and indicated that the reorganization energy was the primary factor in determining the mobility differences among these SBF core based HTLs.
Collapse
Affiliation(s)
- Natsuo Nagamura
- 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 of Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan.,Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Hiroki Sato
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Nozomi Ito
- Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Shoki Abe
- Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Yoshihito Sukegawa
- Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Daisuke Yokoyama
- Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan.,Research Center of Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| | - Hironori Kaji
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
| | - Junji Kido
- Department of Organic Materials Science, Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan.,Research Center of Organic Electronics (ROEL), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan.,Frontier Center for Organic Materials (FROM), Yamagata University, 4-3-16 Jonan, Yonezawa, Yamagata, 992-8510, Japan
| |
Collapse
|
31
|
Wang Q, Xu Y, Yang T, Xue J, Wang Y. Precise Functionalization of a Multiple-Resonance Framework: Constructing Narrowband Organic Electroluminescent Materials with External Quantum Efficiency over 40. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2205166. [PMID: 36325646 DOI: 10.1002/adma.202205166] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 10/10/2022] [Indexed: 06/16/2023]
Abstract
It is of important strategic significance to develop high-efficiency narrowband organic electroluminescent materials that can be employed to fabricate ultrahigh-definition displays with wide color gamut. This topic implies a great challenge to molecular design and synthesis, especially for the development of universality, diversity, scalability, and robustness of molecular architectonics. In this work, a synthetic methodology is demonstrated for functionalizing brominated BN-containing multiple-resonance (MR) frameworks with multifarious functional groups, such as donors, acceptors, and moieties without obvious push-pull electron properties. The m-DPAcP-BNCz-based organic light-emitting diode (OLED) exhibits green emission with a full-width at half-maximum (FWHM) of 28 nm and a maximum external quantum efficiency (EQE) of 40.6%. The outstanding performance of m-DPAcP-BNCz is attributed to the perfect integration of the inherent advantages of the MR framework and the donor-acceptor configuration, which can not only achieve bathochromic shift and narrowband emission, but also obtain high photoluminescence (PL) quantum yield (ΦPL ) and horizontal emitting dipole orientation ratio (Θ// ). This straightforward and efficient approach provides insightful guidance for the construction and enrichment of more high-efficiency narrowband emitters.
Collapse
Affiliation(s)
- Qingyang Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yincai Xu
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Tong Yang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Jianan Xue
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, P. R. China
- Jihua Laboratory, 28 Huandao South Road, Foshan, Guangdong Province, 528200, P. R. China
| |
Collapse
|
32
|
Jang HJ, Lee JY. Key Factor Managing the Horizontal Emitting Dipole Orientation of a Thermally Activated Delayed Fluorescence Emitter in a Mixed Host. ACS APPLIED MATERIALS & INTERFACES 2022; 14:54907-54913. [PMID: 36453592 DOI: 10.1021/acsami.2c20210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Horizontal emitting dipole orientation (EDO) of thermally activated delayed fluorescence (TADF) molecules in a mixed host was studied by altering the host materials and host composition of the mixed host to gain insight into the important parameter of the host governing the EDO of TADF emitters. Five different host materials were combined with 1,3-bis(carbazol-9-yl)benzene (mCP), demonstrating that the host-dopant interaction is crucial to the absolute value of the horizontal EDO of the TADF emitters, whereas the glass transition temperature (Tg) is the important parameter determining the EDO dependence upon host composition. The mixed host of mCP with a high Tg host maintained high horizontal EDO in the mCP poor host composition, while that of mCP with a low Tg host showed average horizontal EDO of two hosts. Therefore, the combination of a high Tg n-type host enabling a strong host-dopant interaction with the p-type host with the usage of the n-type-host-rich composition is effective to achieve high horizontal EDO in the mixed-host-based TADF emitting layer.
Collapse
Affiliation(s)
- Ho Jin Jang
- School of Chemical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi 16419, Korea
| | - Jun Yeob Lee
- School of Chemical Engineering, Sungkyunkwan University, 2066 Seobu-ro, Jangan-gu, Suwon, Gyeonggi 16419, Korea
| |
Collapse
|
33
|
Yang J, Hu D, Zhu F, Ma Y, Yan D. High-efficiency blue-emission crystalline organic light-emitting diodes sensitized by "hot exciton" fluorescent nanoaggregates. SCIENCE ADVANCES 2022; 8:eadd1757. [PMID: 36516245 PMCID: PMC9750145 DOI: 10.1126/sciadv.add1757] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 11/18/2022] [Indexed: 05/31/2023]
Abstract
Sensitizing fluorescent materials is an effective way to maximally use excitons and obtain high-efficiency blue organic light-emitting diodes (OLEDs). However, it is a persistent challenge for present amorphous thin-film OLEDs to improve photon emission under low driving voltage, severely impeding the development of OLED technology. Here, we propose a novel OLED architecture consisting of a crystalline host matrix (CHM) and embedded "hot exciton" nanoaggregates (HENAs), which effectively sensitize blue dopant (D) emission. Owing to the advantages of the crystalline thin-film route, the device exhibits largely enhanced blue photon output [Commission International de L'Eclairage coordinates of (0.15, 0.17)], with a low turn-on/operation voltage of 2.5 V (at 1 cd/m2)/3.3 V (at 1000 cd/m2), an extremely low Joule heat loss ratio (7.8% at 1000 cd/m2), and a maximum external quantum efficiency (EQE) up to 9.14%. These areal photon output features have outperformed the present amorphous thin-film blue OLEDs with high EQE, demonstrating that the CHM-HENA-D OLED is promising for future OLEDs.
Collapse
Affiliation(s)
- Jingjie Yang
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Dehua Hu
- State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Feng Zhu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| | - Yuguang Ma
- State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Donghang Yan
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, China
| |
Collapse
|
34
|
Zhou D, Tong GSM, Cheng G, Tang YK, Liu W, Ma D, Du L, Chen JR, Che CM. Stable Tetradentate Gold(III)-TADF Emitters with Close to Unity Quantum Yield and Radiative Decay Rate Constant of up to 2 × 10 6 s -1 : High-Efficiency Green OLEDs with Operational Lifetime (LT 90 ) Longer than 1800 h at 1000 cd m -2. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2206598. [PMID: 36208071 DOI: 10.1002/adma.202206598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 09/23/2022] [Indexed: 06/16/2023]
Abstract
High maximum external quantum efficiency (EQEmax ), small efficiency roll-offs, and long operational lifetime at practical luminances are three crucial parameters for commercialization of organic light-emitting diodes (OLEDs). To simultaneously achieve these goals, it is desirable to have the radiative decay rate constant (kr ) as large as possible, which, for a thermally activated delayed fluorescent (TADF) emitter, requires both a large S1 →S0 radiative decay rate constant (kr S ) and a small singlet-triplet energy gap (ΔEST ). Here, the design of a class of tetradentate gold(III) TADF complexes for narrowing the ΔEST while keeping the kr S large is reported. The as-synthesized complexes display green emission with close to unity emission quantum yields, and kr approaching 2 × 106 s-1 in thin films. The vacuum-deposited green OLEDs based on 1 and 4 demonstrate maximum EQEs of up to 24 and 27% with efficiency roll-offs of 5.5 and 2.2% at 1000 cd m-2 , respectively; the EQEs maintain high at 10 000 cd m-2 (19% (1) and 24% (4)). A long LT90 device lifetime of 1820 h at 1000 cd m-2 for complex 1 is achieved, which is one of the longest device lifetimes of TADF-OLEDs reported in the literature.
Collapse
Affiliation(s)
- Dongling Zhou
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Glenna So Ming Tong
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Gang Cheng
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, Guangdong, 515041, China
| | - Yu-Kan Tang
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Wei Liu
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology Guangzhou, Guangzhou, 510640, China
| | - Dongge Ma
- State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, South China University of Technology Guangzhou, Guangzhou, 510640, China
| | - Lili Du
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- School of Life Science, Jiangsu University, Zhenjiang, 212013, China
| | - Jian-Rui Chen
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, Guangdong, 515041, China
| | - Chi-Ming Che
- State Key Laboratory of Synthetic Chemistry, HKU-CAS Joint Laboratory on New Materials, Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
- Chemistry and Chemical Engineering Guangdong Laboratory, Shantou, Guangdong, 515041, China
| |
Collapse
|
35
|
Marcato T, Krumeich F, Shih CJ. Confinement-Tunable Transition Dipole Moment Orientation in Perovskite Nanoplatelet Solids and Binary Blends. ACS NANO 2022; 16:18459-18471. [PMID: 36350363 DOI: 10.1021/acsnano.2c06600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Tuning the transition dipole moment (TDM) orientation in low-dimensional semiconductors is of fundamental and practical interest, as it enables high-efficiency nanophotonics and light-emitting diodes. However, despite recent progress in nanomaterials physics and chemistry, material systems that allow continuous tuning of the TDM orientation remain rare. Here, combining k-space photoluminescence spectroscopy and multiscale modeling, we demonstrate that the TDM orientation in lead halide perovskite (LHP) nanoplatelet (NPL) solids is largely confinement-tunable through the NPL geometry that regulates the anisotropy of Bloch states, dielectric confinement, and exciton fine structure. We further quantified the role of uniaxial ordering during NPL assembly in modifying the macroscopic emission directionality of thin films, which is especially important in actual optoelectronic devices. Our theoretical framework successfully corroborates the previous prediction of exciton bright level order reversal with experimental evidence of a counterintuitive reduction of in-plane dipole ratio in ultrathin (one- and two-monolayer-thick) NPLs, even at room temperature. More interestingly, the NPLs retain their TDM orientation in binary blends irrespective of interparticle energy transfer, owing to the phase segregation and NPL-NPL decoupling, enabling the design of films whose fluorescence exhibits an intrinsic angle-dependent color gradient.
Collapse
Affiliation(s)
- Tommaso Marcato
- Institute for Chemical and Bioengineering, ETH Zürich, 8093Zürich, Switzerland
| | - Frank Krumeich
- Laboratory of Inorganic Chemistry, ETH Zürich, 8093Zürich, Switzerland
| | - Chih-Jen Shih
- Institute for Chemical and Bioengineering, ETH Zürich, 8093Zürich, Switzerland
| |
Collapse
|
36
|
Jiang W, Zhao G, Tian W, Sun Y. Aggregation-Induced Intermolecular Charge Transfer Emission for Solution-Processable Bipolar Host Material via Adjusting the Length of Alkyl Chain. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27228099. [PMID: 36432201 PMCID: PMC9698787 DOI: 10.3390/molecules27228099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 11/14/2022] [Accepted: 11/15/2022] [Indexed: 11/23/2022]
Abstract
Molecules with donor-spacer-acceptor configuration have been developed rapidly given their peculiar properties. How to utilize intermolecular interactions and charge transfers for solution-processed organic light-emitting diodes (OLEDs) greatly relies on molecular design strategy. Herein, soluble luminophores with D-spacer-A motif were constructed via shortening the alkyl chain from nonane to propane, where the alkyl chain was utilized as a spatial linker between the donor and acceptor. The alkyl chain blocks the molecular conjugation and induces the existence of aggregation-induced intermolecular CT emission, as well as the improved solubility and morphology in a solid-state film. In addition, the length of the alkyl chain affects the glass transition temperature, carrier transport and balance properties. The mCP-3C-TRZ with nonane as the spacer shows better thermal stability and bipolar carrier transport ability, so the corresponding solution-processable phosphorescent organic light-emitting diodes exhibit superior external quantum efficiency of 9.8% when using mCP-3C-TRZ as a host material. This work offers a promising strategy to establish a bipolar host via utilizing intermolecular charge transfer process in an aggregated state.
Collapse
|
37
|
Huang Z, Lei B, Yang D, Ma D, Bin Z, You J. Modified Intramolecular‐Lock Strategy Enables Efficient Thermally Activated Delayed Fluorescence Emitters for Non‐Doped OLEDs. Angew Chem Int Ed Engl 2022; 61:e202213157. [DOI: 10.1002/anie.202213157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Indexed: 11/17/2022]
Affiliation(s)
- Zhenmei Huang
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
| | - Bowen Lei
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. 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 P. R. 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 P. R. China
| | - Zhengyang Bin
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
| | - Jingsong You
- Key Laboratory of Green Chemistry and Technology of Ministry of Education College of Chemistry Sichuan University Chengdu 610064 P. R. of China
| |
Collapse
|
38
|
Wu TL, Lei J, Hsieh CM, Chen YK, Huang PY, Lai PT, Chou TY, Lin WC, Chen W, Yu CH, Hsu LY, Lin HW, Cheng CH. Substituent engineering of the diboron molecular architecture for a nondoped and ultrathin emitting layer. Chem Sci 2022; 13:12996-13005. [PMID: 36425506 PMCID: PMC9667920 DOI: 10.1039/d2sc04725j] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 10/18/2022] [Indexed: 02/02/2024] Open
Abstract
Owing to the high technology maturity of thermally activated delayed fluorescence (TADF) emitter design with a specific molecular shape, extremely high-performance organic light-emitting diodes (OLEDs) have recently been achieved via various doping techniques. Recently, undoped OLEDs have drawn immense attention because of their manufacturing cost reduction and procedure simplification. However, capable materials as host emitters are rare and precious because general fluorophores in high-concentration states suffer from serious aggregation-caused quenching (ACQ) and undergo exciton quenching. In this work, a series of diboron materials, CzDBA, iCzDBA, and tBuCzDBA, is introduced to realize the effect of steric hindrance and the molecular aspect ratio via experimental and theoretical studies. We computed transition electric dipole moment (TEDM) and molecular dynamics (MD) simulations as a proof-of-concept model to investigate the molecular stacking in neat films. It is worth noting that the pure tBuCzDBA film with a high horizontal ratio of 92% is employed to achieve a nondoped OLED with an excellent external quantum efficiency of 26.9%. In addition, we demonstrated the first ultrathin emitting layer (1 nm) TADF device, which exhibited outstanding power efficiency. This molecular design and high-performance devices show the potential of power-saving and economical fabrication for advanced OLEDs.
Collapse
Affiliation(s)
- Tien-Lin Wu
- Department of Chemistry, National Tsing Hua University Hsinchu 300044 Taiwan
| | - Jian Lei
- Department of Chemistry, National Tsing Hua University Hsinchu 300044 Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica Taipei 10617 Taiwan
| | - Chia-Min Hsieh
- Department of Chemistry, National Tsing Hua University Hsinchu 300044 Taiwan
| | - Yi-Kuan Chen
- Department of Chemistry, National Tsing Hua University Hsinchu 300044 Taiwan
| | - Pei-Yun Huang
- Department of Chemistry, National Tsing Hua University Hsinchu 300044 Taiwan
| | - Po-Ting Lai
- Department of Materials Science and Engineering, National Tsing Hua University Hsinchu 300044 Taiwan
| | - Tsu-Yu Chou
- Department of Materials Science and Engineering, National Tsing Hua University Hsinchu 300044 Taiwan
| | - Wei-Chen Lin
- Department of Engineering Science, National Cheng Kung University Tainan 701 Taiwan
| | - Wei Chen
- Department of Engineering Science, National Cheng Kung University Tainan 701 Taiwan
| | - Chi-Hua Yu
- Department of Engineering Science, National Cheng Kung University Tainan 701 Taiwan
| | - Liang-Yan Hsu
- Institute of Atomic and Molecular Sciences, Academia Sinica Taipei 10617 Taiwan
| | - Hao-Wu Lin
- Department of Materials Science and Engineering, National Tsing Hua University Hsinchu 300044 Taiwan
| | - Chien-Hong Cheng
- Department of Chemistry, National Tsing Hua University Hsinchu 300044 Taiwan
- Department of Chemistry, National Sun Yat-sen University Kaohsiung 80424 Taiwan
| |
Collapse
|
39
|
Kim J, Hwang KY, Kim S, Lim J, Kang B, Lee KH, Choi B, Kwak S, Lee JY. Enhancing Horizontal Ratio of Transition Dipole Moment in Homoleptic Ir Complexes for High Outcoupling Efficiency of Organic Light-Emitting Diodes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203903. [PMID: 36055795 PMCID: PMC9631091 DOI: 10.1002/advs.202203903] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 08/12/2022] [Indexed: 06/15/2023]
Abstract
The light-emitting dipole orientation (EDO) of a phosphorescent emitter is a key to improving the external quantum efficiency (EQE) of organic light-emitting diodes (OLEDs) without structural modification of the device. Here, four homoleptic Ir complexes as a phosphorescent emitter are systematically designed based on the molecular structure of tris(2-phenylpyridine)iridium(III) (Ir(ppy)3 ) to control the EDO. Trimethylsilane, methyl, 2-methylpropyl, and cyclopentylmethyl group substituted to pyridine ring of the ligand contribute to the improvement of the EDO from 76.5% for Ir(ppy)3 to 87.5%. A linear relationship between the EDO and the aspect ratio (geometric anisotropy factor) is founded, implying the importance of the effective area for the nonbonding force between host and dopant molecules. Also, it is investigated that the EDO enhancement mainly originates from the vertical alignment of the C3 axis of molecule in the substrate axis rather than the change in the direction of the transition dipole alignment in the molecular axis. The optical simulation reveals that the outcoupling efficiency of phosphorescent OLEDs adopting new dopants reaches 38.4%. The green OLEDs exhibiting 28.3% of EQE, 103.2 cd A-1 of current efficiency, and 98.2 lm W-1 of power efficiency are demonstrated, which is understood to have little electrical loss.
Collapse
Affiliation(s)
- Jae‐Min Kim
- School of Chemical EngineeringSungkyunkwan University2066, Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
| | - Kyu Young Hwang
- Samsung Advanced Institute of TechnologySamsung Electronics Co. Ltd.SuwonGyeonggi‐do16678Republic of Korea
| | - Sungmin Kim
- Samsung Advanced Institute of TechnologySamsung Electronics Co. Ltd.SuwonGyeonggi‐do16678Republic of Korea
| | - Junseop Lim
- School of Chemical EngineeringSungkyunkwan University2066, Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
| | - Byungjoon Kang
- Samsung Advanced Institute of TechnologySamsung Electronics Co. Ltd.SuwonGyeonggi‐do16678Republic of Korea
| | - Kum Hee Lee
- Samsung Advanced Institute of TechnologySamsung Electronics Co. Ltd.SuwonGyeonggi‐do16678Republic of Korea
| | - Byoungki Choi
- Samsung Advanced Institute of TechnologySamsung Electronics Co. Ltd.SuwonGyeonggi‐do16678Republic of Korea
| | - Seung‐Yeon Kwak
- Samsung Advanced Institute of TechnologySamsung Electronics Co. Ltd.SuwonGyeonggi‐do16678Republic of Korea
| | - Jun Yeob Lee
- School of Chemical EngineeringSungkyunkwan University2066, Seobu‐ro, Jangan‐guSuwonGyeonggi‐do16419Republic of Korea
| |
Collapse
|
40
|
Kim JM, Lim J, Lee JY. Understanding the charge dynamics in organic light-emitting diodes using convolutional neural network. MATERIALS HORIZONS 2022; 9:2551-2563. [PMID: 35861172 DOI: 10.1039/d2mh00373b] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Knowledge about the charge dynamics in organic light-emitting diodes (OLEDs) is a critical clue to optimize device architecture for enhancing the power efficiency and driving voltage characteristics in addition to the external quantum efficiency. In this work, we demonstrated that the charge behavior according to the operation voltage of OLEDs could be understood by introducing the convolutional neural network (CNN) of the machine learning framework without additional analysis of the unipolar charge devices. The CNN model trained using a two-dimensional (2D) modulus fingerprint simultaneously predicted the mobilities of the charge transport and emitting layers, realizing a deep understanding of the complicated data that humans cannot interpret. The machine learning model successfully describes the electrical properties of the organic layers in the actual devices configurated by different electron-transporting materials and the composition of cohosts in the emitting layer. For the first time, it was revealed that 2D fingerprints extracted using frequency- and voltage-dependent modulus spectra were effective data to represent comprehensive charge dynamics of OLEDs. The interpretation and perspective of the machine learning approach in this work were also discussed.
Collapse
Affiliation(s)
- Jae-Min Kim
- School of Chemical Engineering, Sungkyunkwan University, Suwon Campus, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 16419, Republic of Korea.
| | - Junseop Lim
- School of Chemical Engineering, Sungkyunkwan University, Suwon Campus, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 16419, Republic of Korea.
| | - Jun Yeob Lee
- School of Chemical Engineering, Sungkyunkwan University, Suwon Campus, 2066, Seobu-ro, Jangan-gu, Suwon-si, Gyeonggi-do, 16419, Republic of Korea.
| |
Collapse
|
41
|
Zhang HY, Yang HY, Zhang M, Lin H, Tao SL, Zheng CJ, Zhang XH. A novel orange-red thermally activated delayed fluorescence emitter with high molecular rigidity and planarity realizing 32.5% external quantum efficiency in organic light-emitting diodes. MATERIALS HORIZONS 2022; 9:2425-2432. [PMID: 35839078 DOI: 10.1039/d2mh00639a] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Simultaneous optimization of photoluminescence quantum yield (ΦPL) and horizontally oriented dipoles (Θ‖) is considerably challenging for orange and red thermally activated delayed fluorescence (TADF) emitters, due to the conflicts between enhancing molecular rigidity and improving molecular planarity. Herein, a novel orange-red TADF emitter 10-(dipyrido[3,2-a:2',3'-c]phenazin-11-yl)-10H-spiro[acridine-9,9'-fluorene] (SAF-2NP) was constructed with a donor-acceptor structure. The highly rigid donor and acceptor segments ensure the overall rigidity of the emitter. More importantly, the quasi-coplanar structure between the acceptor and the fluorene moiety in the donor unit enlarges the molecular plane without weakening rigidity. Consequently, SAF-2NP exhibited extremely high ΦPL and Θ‖ of 99% and 85%, respectively. The optimal organic light-emitting diode using SAF-2NP as the emitter and 4,4'-di(9H-carbazol-9-yl)-1,1'-biphenyl (CBP) as the host demonstrated an unparalleled external quantum efficiency of 32.5% and a power efficiency of 85.2 lm W-1 without any extra light extraction structure. This work provides a feasible strategy to establish efficient orange and red TADF emitters with both high rigidity and planarity.
Collapse
Affiliation(s)
- Heng-Yuan Zhang
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China.
| | - Hao-Yu Yang
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China.
| | - Ming Zhang
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China.
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, 215123, P. R. China
| | - Hui Lin
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China.
| | - Si-Lu Tao
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China.
| | - Cai-Jun Zheng
- School of Optoelectronic Science and Engineering, University of Electronic Science and Technology of China (UESTC), Chengdu, 610054, P. R. China.
| | - Xiao-Hong Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Suzhou, 215123, P. R. China
| |
Collapse
|
42
|
Chen YL, Chin WC, Tsai CW, Chiu CC, Tien CH, Ye ZT, Han P. Wide-Angle Mini-Light-Emitting Diodes without Optical Lens for an Ultrathin Flexible Light Source. MICROMACHINES 2022; 13:1326. [PMID: 36014247 PMCID: PMC9415139 DOI: 10.3390/mi13081326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/14/2022] [Accepted: 08/14/2022] [Indexed: 06/15/2023]
Abstract
This report outlines a proposed method of packaging wide-angle (WA) mini-light-emitting diode (mini-LED) devices without optical lenses to create a highly efficient, ultrathin, flexible planar backlight for portable quantum dot light-emitting diode (QLED) displays. Since the luminous intensity curve for mini-LEDs generally recommends a beam angle of 120°, numerous LEDs are necessary to achieve a uniform surface light source for a QLED backlight. The light-guide layer and diffusion layer were packaged together on a chip surface to create WA mini-LEDs with a viewing angle of 180°. These chips were then combined with a quantum dot (QD) film and an optical film to create a high-efficiency, ultrathin, flexible planar light source with excellent color purity that can be used as a QLED display backlight. A 6 in (14.4 cm) light source was used as an experimental sample. When 1.44 W was supplied to the sample, the 3200-piece WA mini-LED with a flexible planar QLED display had a beam angle of 180° on the luminous intensity curve, a planar backlight thickness of 0.98 mm, a luminance of 10,322 nits, and a luminance uniformity of 92%.
Collapse
Affiliation(s)
- Yen-Lung Chen
- Graduate Institute of Precision Engineering, National Chung Hsing University, Taichung 402, Taiwan
| | - Wen-Chung Chin
- Department of R&D Center, TOP RAYS Co., Ltd., Taichung 402, Taiwan
| | - Chun-Wei Tsai
- Department of R&D Center, i-Wavefront Technology Ltd., New Taipei City 231625, Taiwan
| | - Chang-Che Chiu
- Department of Mechanical Engineering, Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, Taichung 402, Taiwan
| | - Ching-Ho Tien
- Department of Electronic Engineering, Lunghwa University of Science and Technology, Taoyuan 333326, Taiwan
| | - Zhi-Ting Ye
- Department of Mechanical Engineering, Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, Taichung 402, Taiwan
| | - Pin Han
- Graduate Institute of Precision Engineering, National Chung Hsing University, Taichung 402, Taiwan
| |
Collapse
|
43
|
Xu Y, Wang Q, Wei J, Peng X, Xue J, Wang Z, Su S, Wang Y. Constructing Organic Electroluminescent Material with Very High Color Purity and Efficiency Based on Polycyclization of the Multiple Resonance Parent Core. Angew Chem Int Ed Engl 2022; 61:e202204652. [DOI: 10.1002/anie.202204652] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Yincai Xu
- State Key Lab of Supramolecular Structure and Materials College of Chemistry Jilin University Changchun 130012 P. R. China
| | - Qingyang Wang
- State Key Lab of Supramolecular Structure and Materials College of Chemistry Jilin University Changchun 130012 P. R. China
| | - Jinbei Wei
- State Key Lab of Supramolecular Structure and Materials College of Chemistry Jilin University Changchun 130012 P. R. China
| | - Xiaomei Peng
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices South China University of Technology Guangzhou 510640 P. R. China
| | - Jianan Xue
- State Key Lab of Supramolecular Structure and Materials College of Chemistry Jilin University Changchun 130012 P. R. China
| | - Zhiheng Wang
- Jihua Laboratory 28 Huandao South Road Foshan 528200, Guangdong Province P. R. China
| | - Shi‐Jian Su
- State Key Laboratory of Luminescent Materials and Devices and Institute of Polymer Optoelectronic Materials and Devices South China University of Technology Guangzhou 510640 P. R. China
| | - Yue Wang
- State Key Lab of Supramolecular Structure and Materials College of Chemistry Jilin University Changchun 130012 P. R. China
- Jihua Laboratory 28 Huandao South Road Foshan 528200, Guangdong Province P. R. China
| |
Collapse
|
44
|
Wei J, Yang Y, Liu X, Li R, Li S. 2,3‐Disubstituted Fluorene Scaffold for Efficient Green Phosphorescent Organic Light‐Emitting Diodes. Chemistry 2022; 28:e202200756. [DOI: 10.1002/chem.202200756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Indexed: 11/09/2022]
Affiliation(s)
- Jia‐Jia Wei
- School of Environment and Chemical Engineering Jiangsu Ocean University 59 Cangwu Road, Haizhou District Lianyungang 222005 P. R. China
| | - Yong‐Jian Yang
- School of Environment and Chemical Engineering Jiangsu Ocean University 59 Cangwu Road, Haizhou District Lianyungang 222005 P. R. China
| | - Xiang‐Yang Liu
- WISPO Advanced Materials (Suzhou) Co., Ltd. 200 Xingpu Road, Shengpu Street, Suzhou Industrial Park (SIP) Suzhou 215126 P. R. China
| | - Runlai Li
- College of Polymer Science & Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065 P. R. China
| | - Shu‐an Li
- School of Environment and Chemical Engineering Jiangsu Ocean University 59 Cangwu Road, Haizhou District Lianyungang 222005 P. R. China
| |
Collapse
|
45
|
Zou Y, Hu J, Yu M, Miao J, Xie Z, Qiu Y, Cao X, Yang C. High-Performance Narrowband Pure-Red OLEDs with External Quantum Efficiencies up to 36.1% and Ultralow Efficiency Roll-Off. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2201442. [PMID: 35588162 DOI: 10.1002/adma.202201442] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 04/28/2022] [Indexed: 06/15/2023]
Abstract
High-color-purity blue and green organic light-emitting diodes (OLEDs) have been resolved thanks to the development of B/N-based polycyclic multiple resonance (MR) emitters. However, due to the derivatization limit of B/N polycyclic structures, the design of red MR emitters remains challenging. Herein, a series of novel red MR emitters is reported by para-positioning N-π-N, O-π-O, B-π-B pairs onto a benzene ring to construct an MR central core. These emitters can be facilely and modularly synthesized, allowing for easy fine-tuning of emission spectra by peripheral groups. Moreover, these red MR emitters display excellent photophysical properties such as near-unity photoluminescence quantum yield (PLQY), fast radiative decay rate (kr ) up to 7.4 × 107 s-1 , and most importantly, narrowband emission with full-width at half-maximum (FWHM) of 32 nm. Incorporating these MR emitters, pure red OLEDs sensitized by phosphor realize state-of-the-art device performances with external quantum efficiency (EQE) exceeding 36%, ultralow efficiency roll-off (EQE remains as high as 25.1% at the brightness of 50 000 cd m-2 ), ultrahigh brightness over 130 000 cd m-2 , together with good device lifetime.
Collapse
Affiliation(s)
- Yang Zou
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Jiahao Hu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Mingxin Yu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Jingsheng Miao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Ziyang Xie
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Yuntao Qiu
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Xiaosong Cao
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Chuluo Yang
- Shenzhen Key Laboratory of New Information Display and Storage Materials, College of Materials Science and Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| |
Collapse
|
46
|
3-(N,N-Diphenylamino)carbazole Donor Containing Bipolar Derivatives with Very High Glass Transition Temperatures as Potential TADF Emitters for OLEDs. COATINGS 2022. [DOI: 10.3390/coatings12070932] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Well-defined electroactive bipolar derivatives of new structure have been synthesized from 3-(N,N-diphenylamino)-9H-carbazole and bis(4-fluorophenyl)sulfone, 4-fluorophenylsulfone or 4,4′-difluorobenzophenone, respectively. The full characterization of their structure is described. The amorphous materials with very high glass transition temperatures of 111–173 °C also possess high thermal stability, with onset decomposition temperatures of 351–398 °C. Some of the compounds having the best solubility were tested as the emitters dispersed in 4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP) host for preparation of organic light emitting diodes (OLEDs). A device containing 15 wt% of the guest bis[4-{3-(N,N-diphenylamino)carbazol-9-yl}phenyl] sulfone demonstrated the best overall characteristics with maximum brightness exceeding 2630 cd/m2, current efficiency of 3.2 cd/A, power efficiency of 2.2 lm/W, and external quantum efficiency exceeding 1.7% at 100 cd/m2.
Collapse
|
47
|
Zhang C, Zhang D, Bin Z, Liu Z, Zhang Y, Lee H, Kwon JH, Duan L. Color-Tunable All-Fluorescent White Organic Light-Emitting Diodes with a High External Quantum Efficiency Over 30% and Extended Device Lifetime. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2103102. [PMID: 34293225 DOI: 10.1002/adma.202103102] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 05/20/2021] [Indexed: 06/13/2023]
Abstract
White organic light-emitting diodes (WOLEDs) with high efficiencies and tunable colors attracts considerable interest from the industry and academia. Thermally activated delayed-fluorescence (TADF) emitters can revolutionize such WOLED devices; however, they still suffer from poor performances. In this study, an advanced double-emissive-layer device architecture capable of hole-trapping TADF-sensitized emissions is proposed to not only achieve a recombination zone shift for the tunable colors but also accelerate exciton emission dynamics for high efficiency and alleviated roll-off. The proof-of-concept WOLEDs exhibit significant shifts in their Commission Internationale de l'Eclairage (CIE) coordinates and correlated color temperatures from (0.40, 0.47) and 4088 K at 100 cd m-2 to (0.27, 0.33) and 9269 K at 5000 cd m-2 . Additionally, the maximum external quantum efficiency (EQE) reaches 30.7% and remains >25% over a wide luminance range of 500-5000 cd m-2 , along with an extended LT80 of over 20 000 h at an initial luminance of 100 cd m-2 . This is the first time that all-fluorescent WOLEDs have been used to realize an EQE exceeding 30%, thereby establishing a new benchmark in this field.
Collapse
Affiliation(s)
- Chen Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Dongdong Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Zhengyang Bin
- College of Chemistry, Sichuan University, Chengdu, 610064, P. R. China
| | - Ziyang Liu
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Yuewei Zhang
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
| | - Hyuna Lee
- Department of Information Display, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Jang Hyuk Kwon
- Department of Information Display, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Lian Duan
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
- Center for Flexible Electronics Technology Tsinghua University, Beijing, 100084, P. R. China
| |
Collapse
|
48
|
Xu Y, Wang Q, Wei J, Peng X, Xue J, Wang Z, Su SJ, Wang Y. Constructing Organic Electroluminescent Material with Very High Color Purity and Efficiency Based on Polycyclization of Multiple Resonance Parent Core. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202204652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Yincai Xu
- Jilin University State Key Lab of Supramolecular Structure and Materials 130012 Changchun CHINA
| | - Qingyang Wang
- Jilin University State Key Lab of Supramolecular Structure and Materials 130012 Changchun CHINA
| | - Jinbei Wei
- Jilin University State Key Lab of Supramolecular Structure and Materials 130012 Changchun CHINA
| | - Xiaomei Peng
- South China University of Technology State Key Laboratory of Luminescent Materials and Devices 510640 Guangzhou CHINA
| | - Jianan Xue
- Jilin University State Key Lab of Supramolecular Structure and Materials 130012 Changchun CHINA
| | | | - Shi-Jian Su
- South China University of Technology State Key Laboratory of Luminescent Materials and Devices 510640 Guangzhou CHINA
| | - Yue Wang
- State Key Laboratory of Supramolecular Structure and Materials, Jilin UniversityChangchun 130012, P. R. China CHINA
| |
Collapse
|
49
|
Shen P, Liu H, Zhuang Z, Zeng J, Zhao Z, Tang BZ. Through-Space Conjugated Electron Transport Materials for Improving Efficiency and Lifetime of Organic Light-Emitting Diodes. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2200374. [PMID: 35322599 PMCID: PMC9130898 DOI: 10.1002/advs.202200374] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/03/2022] [Indexed: 05/05/2023]
Abstract
Thermally stable electron transport (ET) materials with high electron mobility and high triplet state energy level are highly desired for the fabrication of efficient and stable organic light-emitting diodes (OLEDs). Herein, a new design strategy of constructing through-space conjugated folded configuration is proposed to explore robust ET materials, opposite to the widely used planar configuration. By bonding two quinolines to the 9,10-positions of phenanthrene, two novel folded molecules with high thermal and morphological stabilities and high triplet state energy levels (>2.7 eV) are created. These folded molecules possess excellent ET ability with electron mobilities of three orders of magnitude higher than those of linear and planar counterparts. Theoretical calculation and crystallography analysis demonstrate the through-space conjugated folded configuration has not only reduced reorganization energy but also enlarged charge transfer integral at various dimensions, bringing about efficient multi-dimensional ET, independent of molecular orientation. By adopting the folded molecule as ET layers, OLEDs with no matter delayed fluorescence or phosphorescence emitters can achieve high external quantum efficiencies and long operational lifetimes simultaneously. This work paves a new avenue towards robust ET materials to improve efficiency and stability of OLEDs.
Collapse
Affiliation(s)
- Pingchuan Shen
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Hao Liu
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Zeyan Zhuang
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Jiajie Zeng
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Zujin Zhao
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
| | - Ben Zhong Tang
- State Key Laboratory of Luminescent Materials and DevicesGuangdong Provincial Key Laboratory of Luminescence from Molecular AggregatesSouth China University of TechnologyGuangzhou510640China
- Shenzhen Institute of Aggregate Science and TechnologySchool of Science and EngineeringThe Chinese University of Hong KongShenzhenGuangdong518172China
- AIE InstituteGuangzhou Development DistrictHuangpuGuangzhou510530China
| |
Collapse
|
50
|
Kang N, Cho S, Leonhardt EE, Liu C, Verkhoturov SV, Woodward WHH, Eller MJ, Yuan T, Fitzgibbons TC, Borguet YP, Jahnke AA, Sokolov AN, McIntire T, Reinhardt C, Fang L, Schweikert EA, Spencer LP, Sun G, Xie G, Trefonas P, Wooley KL. Topological Design of Highly Anisotropic Aligned Hole Transporting Molecular Bottlebrushes for Solution-Processed OLEDs. J Am Chem Soc 2022; 144:8084-8095. [PMID: 35471843 DOI: 10.1021/jacs.2c00420] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Polyvinyl polymers bearing pendant hole transport functionalities have been extensively explored for solution-processed hole transport layer (HTL) technologies, yet there are only rare examples of high anisotropic packing of the HT moieties of these polymers into substrate-parallel orientations within HTL films. For small molecules, substrate-parallel alignment of HT moieties is a well-established approach to improve overall device performance. To address the longstanding challenge of extension from vapor-deposited small molecules to solution-processable polymer systems, a fundamental chemistry tactic is reported here, involving the positioning of HT side chains within macromolecular frameworks by the construction of HT polymers having bottlebrush topologies. Applying state-of-the-art polymer synthetic techniques, various functional subunits, including triphenylamine (TPA) for hole transport and adhesion to the substrate, and perfluoro alkyl-substituted benzyloxy styrene for migration to the air interface, were organized with exquisite control over the composition and placement throughout the bottlebrush topology. Upon assembling the HT bottlebrush (HTB) polymers into monolayered HTL films on various substrates through spin-casting and thermal annealing, the backbones of HTBs were vertically aligned while the grafts with pendant TPAs were extended parallel to the substrate. The overall design realized high TPA π-stacking along the out-of-plane direction of the substrate in the HTLs, which doubled the efficiency of organic light-emitting diodes compared with linear poly(vinyl triphenylamine)s.
Collapse
Affiliation(s)
| | | | | | - Chun Liu
- The Dow Chemical Company, Midland, Michigan 48667, United States
| | | | | | | | | | | | | | | | | | - Travis McIntire
- The Dow Chemical Company, Midland, Michigan 48667, United States
| | - Carl Reinhardt
- The Dow Chemical Company, Midland, Michigan 48667, United States
| | | | | | | | | | - Guohua Xie
- Sauvage Center for Molecular Sciences and Hubei Key Lab on Organic and Polymeric Optoelectronic Materials, Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Peter Trefonas
- DuPont, Electronics and Imaging Division, Marlborough, Massachusetts 01752, United States
| | | |
Collapse
|