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Zhang W, Li Y, Zhang G, Yang X, Chang X, Xing G, Dong H, Wang J, Wang D, Mai Z, Jiang X. Advances in Host-Free White Organic Light-Emitting Diodes Utilizing Thermally Activated Delayed Fluorescence: A Comprehensive Review. MICROMACHINES 2024; 15:703. [PMID: 38930673 PMCID: PMC11205739 DOI: 10.3390/mi15060703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2024] [Revised: 05/18/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024]
Abstract
The ever-growing prominence and widespread acceptance of organic light-emitting diodes (OLEDs), particularly those employing thermally activated delayed fluorescence (TADF), have firmly established them as formidable contenders in the field of lighting technology. TADF enables achieving a 100% utilization rate and efficient luminescence through reverse intersystem crossing (RISC). However, the effectiveness of TADF-OLEDs is influenced by their high current density and limited device lifetime, which result in a significant reduction in efficiency. This comprehensive review introduces the TADF mechanism and provides a detailed overview of recent advancements in the development of host-free white OLEDs (WOLEDs) utilizing TADF. This review specifically scrutinizes advancements from three distinct perspectives: TADF fluorescence, TADF phosphorescence and all-TADF materials in host-free WOLEDs. By presenting the latest research findings, this review contributes to the understanding of the current state of host-free WOLEDs, employing TADF and underscoring promising avenues for future investigations. It aims to serve as a valuable resource for newcomers seeking an entry point into the field as well as for established members of the WOLEDs community, offering them insightful perspectives on imminent advancements.
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Affiliation(s)
- Wenxin Zhang
- College of Information Technology, Jilin Engineering Research Center of Optoelectronic Materials and Devices, Jilin Normal University, Siping 136000, China; (W.Z.); (Y.L.); (X.C.); (H.D.)
- Key Laboratory of Functional Materials Physics and Chemistry of Ministry of Education, Jilin Normal University, Siping 136000, China
| | - Yaxin Li
- College of Information Technology, Jilin Engineering Research Center of Optoelectronic Materials and Devices, Jilin Normal University, Siping 136000, China; (W.Z.); (Y.L.); (X.C.); (H.D.)
- Key Laboratory of Functional Materials Physics and Chemistry of Ministry of Education, Jilin Normal University, Siping 136000, China
| | - Gang Zhang
- College of Information Technology, Jilin Engineering Research Center of Optoelectronic Materials and Devices, Jilin Normal University, Siping 136000, China; (W.Z.); (Y.L.); (X.C.); (H.D.)
- Key Laboratory of Functional Materials Physics and Chemistry of Ministry of Education, Jilin Normal University, Siping 136000, China
| | - Xiaotian Yang
- Key Laboratory of Preparation and Applications of Environmental Friendly Material of the Ministry of Education, College of Chemistry, Jilin Normal University, Changchun 130103, China;
| | - Xi Chang
- College of Information Technology, Jilin Engineering Research Center of Optoelectronic Materials and Devices, Jilin Normal University, Siping 136000, China; (W.Z.); (Y.L.); (X.C.); (H.D.)
- Key Laboratory of Functional Materials Physics and Chemistry of Ministry of Education, Jilin Normal University, Siping 136000, China
| | - Guoliang Xing
- Jilin Special Equipment Inspection Center, Jilin Special Equipment Accident Investigation Service Center, No. 866 Huadan Street, Longtan District, Jilin 132013, China;
| | - He Dong
- College of Information Technology, Jilin Engineering Research Center of Optoelectronic Materials and Devices, Jilin Normal University, Siping 136000, China; (W.Z.); (Y.L.); (X.C.); (H.D.)
- Key Laboratory of Functional Materials Physics and Chemistry of Ministry of Education, Jilin Normal University, Siping 136000, China
| | - Jin Wang
- College of Information Technology, Jilin Engineering Research Center of Optoelectronic Materials and Devices, Jilin Normal University, Siping 136000, China; (W.Z.); (Y.L.); (X.C.); (H.D.)
- Key Laboratory of Functional Materials Physics and Chemistry of Ministry of Education, Jilin Normal University, Siping 136000, China
| | - Dandan Wang
- Hubei Jiufengshan Laboratory, Wuhan 430206, China; (D.W.); (Z.M.)
| | - Zhihong Mai
- Hubei Jiufengshan Laboratory, Wuhan 430206, China; (D.W.); (Z.M.)
| | - Xin Jiang
- State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Changchun 130012, China;
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Zhao W, Hu X, Kong F, Tang J, Yan D, Wang J, Liu Y, Sun Y, Sheng R, Chen P. Progress in Research on White Organic Light-Emitting Diodes Based on Ultrathin Emitting Layers. MICROMACHINES 2024; 15:626. [PMID: 38793199 PMCID: PMC11123088 DOI: 10.3390/mi15050626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Revised: 04/26/2024] [Accepted: 04/29/2024] [Indexed: 05/26/2024]
Abstract
White organic light-emitting diodes (WOLEDs) hold vast prospects in the fields of next-generation displays and solid-state lighting. Ultrathin emitting layers (UEMLs) have become a research hotspot because of their unique advantage. On the basis of simplifying the device structure and preparation process, they can achieve electroluminescent performance comparable to that of doped devices. In this review, we first discuss the working principles and advantages of WOLEDs based on UEML architecture, which can achieve low cost and more flexibility by simplifying the device structure and preparation process. Subsequently, the successful applications of doping and non-doping technologies in fluorescent, phosphorescent, and hybrid WOLEDs combined with UEMLs are discussed, and the operation mechanisms of these WOLEDs are emphasized briefly. We firmly believe that this article will bring new hope for the development of UEML-based WOLEDs in the future.
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Affiliation(s)
- Wencheng Zhao
- Institute of Physics and Electronic Information, Yantai University, Yantai 264005, China; (W.Z.); (X.H.); (F.K.); (J.T.); (D.Y.); (Y.S.)
| | - Xiaolin Hu
- Institute of Physics and Electronic Information, Yantai University, Yantai 264005, China; (W.Z.); (X.H.); (F.K.); (J.T.); (D.Y.); (Y.S.)
| | - Fankang Kong
- Institute of Physics and Electronic Information, Yantai University, Yantai 264005, China; (W.Z.); (X.H.); (F.K.); (J.T.); (D.Y.); (Y.S.)
| | - Jihua Tang
- Institute of Physics and Electronic Information, Yantai University, Yantai 264005, China; (W.Z.); (X.H.); (F.K.); (J.T.); (D.Y.); (Y.S.)
| | - Duxv Yan
- Institute of Physics and Electronic Information, Yantai University, Yantai 264005, China; (W.Z.); (X.H.); (F.K.); (J.T.); (D.Y.); (Y.S.)
| | - Jintao Wang
- Institute of Information Engineering, Yantai Institute of Technology, Yantai 264005, China;
| | - Yuru Liu
- Institute of Engineering Training Center, Yantai University, Yantai 264005, China;
| | - Yuanping Sun
- Institute of Physics and Electronic Information, Yantai University, Yantai 264005, China; (W.Z.); (X.H.); (F.K.); (J.T.); (D.Y.); (Y.S.)
| | - Ren Sheng
- Institute of Physics and Electronic Information, Yantai University, Yantai 264005, China; (W.Z.); (X.H.); (F.K.); (J.T.); (D.Y.); (Y.S.)
| | - Ping Chen
- Institute of Physics and Electronic Information, Yantai University, Yantai 264005, China; (W.Z.); (X.H.); (F.K.); (J.T.); (D.Y.); (Y.S.)
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Yang M, Zhao TX, Ji SC, Tao XD, Chen XL, Meng L, Liang D, Lu CZ. Voltage-Dependent Emission Varying from Blue to Orange–Red from a Nondoped Organic Light-Emitting Diode with a Single Emitter. NANOMATERIALS 2022; 12:nano12142333. [PMID: 35889558 PMCID: PMC9320025 DOI: 10.3390/nano12142333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 07/01/2022] [Accepted: 07/04/2022] [Indexed: 11/29/2022]
Abstract
Organic light-emitting diodes (OLEDs) with tunable emission colors, especially white OLEDs, have rarely been observed with a single emitter in a single emissive layer. In this paper, we report a new compound featuring a D–A–D structure, 9,9′-(pyrimidine-2,5-diylbis(2,1-phenylene))bis(3,6-di-tert-butyl-9H-carbazole) (PDPC). A nondoped OLED using this compound as a single emitter exhibits unique voltage-dependent dual emission. The emission colors range from blue to orange–red with an increase in voltage, during which white electroluminescence with a Commission Internationale De L’Eclairage (CIE) coordinate of (0.35, 0.29) and a color render index (CRI) value of 93 was observed. A comparative study revealed that the dual emission simultaneously originates from the monomers and excimers of the emitter. This study provides insight into understanding the multimer-excited mechanism and developing novel color-tunable OLEDs.
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Affiliation(s)
- Mingxue Yang
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Tian-Xiang Zhao
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Si-Chao Ji
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xiao-Dong Tao
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xu-Lin Chen
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Lingyi Meng
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
| | - Dong Liang
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
| | - Can-Zhong Lu
- CAS Key Laboratory of Design and Assembly of Functional Nanostructures, and Fujian Provincial Key Laboratory of Nanomaterials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China; (M.Y.); (T.-X.Z.); (S.-C.J.); (X.-D.T.); (X.-L.C.); (L.M.); (D.L.)
- Xiamen Institute of Rare Earth Materials, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Xiamen 361021, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Correspondence:
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Miao Y, Yin M. Recent progress on organic light-emitting diodes with phosphorescent ultrathin (<1nm) light-emitting layers. iScience 2022; 25:103804. [PMID: 35198870 PMCID: PMC8844833 DOI: 10.1016/j.isci.2022.103804] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In recent years, phosphorescent dyes forming ultrathin light-emitting layers (<1 nm, UEMLs) have been widely applied to fabricate monochromatic and white organic light-emitting diodes (OLEDs) owing to its merits of simplified device structure and preparation process, more flexible design, lower material consumption, and complete exciton utilization. In addition, it was demonstrated that the OLEDs with UEMLs achieved high electroluminescence performance comparable to the conventional doping-based devices. Structurally, OLEDs were structured with phosphorescent UEMLs inserted into nonluminous materials, heterojunction interface as well as into luminescent materials including phosphorescent, conventional fluorescent, thermally activated delayed fluorescence, and exciplex emitters. We carefully reviewed the successful applications of UEMLs in OLEDs and underlying working mechanism of corresponding devices, and also emphasized the representative achievements about OLEDs with UEMLs, aimed at forming a comprehensive summary of the present research for UEMLs-based OLEDs. In the end, we also gave an outlook for the future development of UEMLs-based OLEDs
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Zhang C, Lu Y, Liu Z, Zhang Y, Wang X, Zhang D, Duan L. A π-D and π-A Exciplex-Forming Host for High-Efficiency and Long-Lifetime Single-Emissive-Layer Fluorescent White Organic Light-Emitting Diodes. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2004040. [PMID: 32893390 DOI: 10.1002/adma.202004040] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Exciplex-forming hosts with thermally activated delayed fluorescence (TADF) provide a viable opportunity to unlock the full potential of the yet-to-be improved power efficiencies (PEs) and stabilities of all-fluorescent white organic light-emitting diodes (WOLEDs), but this, however, is hindered by the lack of stable blue exciplexes. Here, an advanced exciplex system is proposed by incorporating bipolar charge-transport π-spacers into both the electron-donor (D) and the electron-accepter (A) to increase their distance for hypsochromic-shifted emission while maintaining the superior transporting ability. By using spirofluorene as the π-spacer, 3,3'-bicarbazole as the D-unit, and 2,4,6-triphenyl-1,3,5-triazine as the A-unit, a π-D and π-A exciplex with sky-blue emission and fast reverse intersystem crossing process is thereof constructed. Combining this exciplex-forming host, a blue TADF-sensitizer, and a yellow conventional fluorescent dopant in a single-emissive-layer, the fabricated warm-white-emissive device simultaneously exhibits a low driving voltage of 3.08 V, an external quantum efficiency of 21.4%, and a remarkable T80 (time to 80% of the initial luminance) of >8200 h at 1000 cd m-2 , accompanied by a new benchmark PE of 69.6 lm W-1 among all-fluorescent WOLEDs.
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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
| | - Yang Lu
- Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education, Department of Chemistry, Tsinghua University, Beijing, 100084, 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
| | - Xuewen Wang
- Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory, Xianhu Hydrogen Valley, Foshan, 528200, 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
| | - 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
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Ke X, Gu H, Chen L, Zhao X, Tian J, Shi Y, Chen X, Zhang C, Jiang H, Liu S. Multi-objective collaborative optimization strategy for efficiency and chromaticity of stratified OLEDs based on an optical simulation method and sensitivity analysis. OPTICS EXPRESS 2020; 28:27532-27546. [PMID: 32988045 DOI: 10.1364/oe.398998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
The low efficiency and dissatisfactory chromaticity remain as important challenges on the road to the OLED commercialization. In this paper, we propose a multi-objective collaborative optimization strategy to simultaneously improve the efficiency and ameliorate the chromaticity of the stratified OLED devices. Based on the formulations derived for the current efficiency and the chromaticity Commission International de L'Eclairage (CIE) of OLEDs, an optical sensitivity model is presented to quantitatively analyze the influence of the layer thickness on the current efficiency and the CIE. Subsequently, an evaluation function is defined to effectively balance the current efficiency as well as the CIE, and a collaborative optimization strategy is further proposed to simultaneously improve both of them. Simulations are comprehensively performed on a typical top-emitting blue OLED to demonstrate the necessity and the effectivity of the proposed strategy. The influences of the layer thickness incorporated in the blue OLED are ranked based on the sensitivity analysis method, and by optimizing the relative sensitive layer thicknesses in the optical views, a 16% improvement can be achieved for the current efficiency of the OLED with desired CIE meantime. Hence, the proposed multi-objective collaborative optimization strategy can be well applied to design high-performance OLED devices by improving the efficiency without chromaticity quality degradation.
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