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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.
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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
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Zhao F, Kong J, Zhang W, Kuang Z, Zhou M. Triplet Excited-State Dynamics in Benzothiadiazole-Based Thermally Activated Delayed Fluorescence Compound. J Phys Chem Lett 2024:2885-2892. [PMID: 38447087 DOI: 10.1021/acs.jpclett.4c00145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
The "hot exciton" thermally activated delayed fluorescence (TADF) materials have attracted considerable research interest for their utilization of high-lying triplet excitons. In this work, we reported the mechanism of photoluminescence by revealing the spectral evolution from singlet to triplet states in "hot exciton" TADF molecules by transient absorption (TA) spectra and triplet sensitization experiments. The internal conversion and intersystem crossing are much faster than reverse intersystem crossing (RISC), so that high-lying triplet states (Tn) are difficult to accumulate to be observed in the transient absorption spectra. In contrast, the emergence of delayed fluorescence in time-resolved emission spectra demonstrates the existence of a high-lying RISC process (hRISC) from Tn to S1. Triplet sensitization experiments successfully identified the spectral features of the T1 state in the TA spectra. This work sheds light on critical factors for the systematic design of these materials to achieve a high emission quantum yield.
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Affiliation(s)
- Fangming Zhao
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026, China
| | - Jie Kong
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026, China
| | - Wei Zhang
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026, China
| | - Zhuoran Kuang
- School of Science, Beijing University of Posts and Telecommunications (BUPT), Beijing 100876, P. R. China
| | - Meng Zhou
- Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026, China
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Liu D, Zhu F, Yan D. Crystalline organic thin films for crystalline OLEDs (II): weak epitaxy growth of phenanthroimidazole derivatives. RSC Adv 2023; 13:15586-15593. [PMID: 37228674 PMCID: PMC10203860 DOI: 10.1039/d3ra03095d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/15/2023] [Indexed: 05/27/2023] Open
Abstract
The ordered molecular arrangement of crystalline organic semiconductors facilitates high carrier mobility and light emission in organic light-emitting diode (OLED) devices. It has been demonstrated that the weak epitaxy growth (WEG) process is a valuable crystallization route for fabricating crystalline thin-film OLEDs (C-OLEDs). Recently, C-OLEDs based on crystalline thin films of phenanthroimidazole derivatives have exhibited excellent luminescent properties such as high photon output at low driving voltage and high power efficiency. Achieving effective control of organic crystalline thin film growth is crucial for the development of new C-OLEDs. Herein, we report the studies on morphology structure and growth behavior of the phenanthroimidazole derivative WEG thin films. The oriented growth of WEG crystalline thin films is determined by channeling and lattice matching between the inducing layer and active layer. Large-size and continuous WEG crystalline thin films can be obtained by controlling the growth conditions.
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Affiliation(s)
- Dan 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
| | - 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
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Chen P, Wang D, Luo L, Meng J, Zhou Z, Dai X, Zou Y, Tan L, Shao X, Di CA, Jia C, Zhang HL, Liu Z. Self-Doping Naphthalene Diimide Conjugated Polymers for Flexible Unipolar n-Type OTFTs. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2300240. [PMID: 36812459 DOI: 10.1002/adma.202300240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/15/2023] [Indexed: 05/19/2023]
Abstract
The development of high-performance organic thin-film transistor (OTFT) materials is vital for flexible electronics. Numerous OTFTs are so far reported but obtaining high-performance and reliable OTFTs simultaneously for flexible electronics is still challenging. Herein, it is reported that self-doping in conjugated polymer enables high unipolar n-type charge mobility in flexible OTFTs, as well as good operational/ambient stability and bending resistance. New naphthalene diimide (NDI)-conjugated polymers PNDI2T-NM17 and PNDI2T-NM50 with different contents of self-doping groups on their side chains are designed and synthesized. The effects of self-doping on the electronic properties of resulting flexible OTFTs are investigated. The results reveal that the flexible OTFTs based on self-doped PNDI2T-NM17 exhibit unipolar n-type charge-carrier properties and good operational/ambient stability thanks to the appropriate doping level and intermolecular interactions. The charge mobility and on/off ratio are fourfold and four orders of magnitude higher than those of undoped model polymer, respectively. Overall, the proposed self-doping strategy is useful for rationally designing OTFT materials with high semiconducting performance and reliability.
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Affiliation(s)
- Pinyu Chen
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China
| | - Dongyang Wang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Liang Luo
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China
| | - Jinqiu Meng
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China
| | - Zhaoqiong Zhou
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China
| | - Xiaojuan Dai
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Ye Zou
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Luxi Tan
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, China
| | - Xiangfeng Shao
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China
| | - Chong-An Di
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Chunyang Jia
- State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Integrated Circuit Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Hao-Li Zhang
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China
| | - Zitong Liu
- State Key Laboratory of Applied Organic Chemistry (SKLAOC), Key Laboratory of Special Function Materials and Structure Design, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000, China
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