Article
Materials Science, Multidisciplinary
Xuan Zeng, Yu-Hsin Huang, Shaolong Gong, Xuguang Yin, Wei-Kai Lee, Xiao Xiao, Yu Zhang, Weixuan Zeng, Chen-Han Lu, Chang-Cheng Lee, Xiu-Qin Dong, Cheng Zhong, Chung-Chih Wu, Chuluo Yang
Summary: This study successfully achieved active control of the dipole orientation of organic emitters by designing a linear TADF molecule, PhNAI-PMSBA, with an emitting dipole orientation ratio of 95%, substantially higher than traditional emitters. This unique feature is attributed to the inherently horizontal molecular orientation of the molecule and the good agreement between its transition dipole moment direction and molecular long axis.
SCIENCE CHINA-MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Xuan Zeng, Yu-Hsin Huang, Shaolong Gong, Pan Li, Wei-Kai Lee, Xiao Xiao, Yu Zhang, Cheng Zhong, Chung-Chih Wu, Chuluo Yang
Summary: A novel A-D-A' type TADF emitter TRZ-SBA-NAI was developed, displaying dual emission in solution with a dominant orange-red emission and an anti-Kasha's rule sky-blue emission shoulder. The doped TRZ-SBA-NAI showed only orange-red emission with a high photoluminescence quantum yield of 87%, and achieved a record-high external quantum efficiency of 31.7% with an electroluminescence peak at 593 nm.
MATERIALS HORIZONS
(2021)
Article
Chemistry, Multidisciplinary
Umamahesh Balijapalli, Yi-Ting Lee, Buddhika S. B. Karunathilaka, Ganbaatar Tumen-Ulzii, Morgan Auffray, Youichi Tsuchiya, Hajime Nakanotani, Chihaya Adachi
Summary: Three TADF molecules PQ1, PQ2, and PQ3, featuring planar acceptor manipulation and high steric hindrance, exhibit high molecular rigidity that suppresses nonradiative decay of excitons, leading to improved photoluminescence quantum yields. PQ3, with well-aligned excited states, enhances reverse intersystem crossing rate constant and displays a high external EL quantum efficiency in the orange-red OLED.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Xiaomei Peng, Weidong Qiu, Wenqi Li, Mengke Li, Wentao Xie, Wei Li, Jianying Lin, Jiaji Yang, Xin Li, Shi-jian Su
Summary: The study utilized a TADF material with high horizontal dipole ratio to fabricate highly efficient white OLEDs. By adjusting the orientation of the emitters and carrier recombination, high quantum efficiency and spectral stability were achieved.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Zheyi Cai, Xing Wu, Hao Liu, Jingjing Guo, Dezhi Yang, Dongge Ma, Zujin Zhao, Ben Zhong Tang
Summary: Tailor-made red TADF molecules with intramolecular hydrogen bonding show NIR emissions in neat films and red delayed fluorescence in doped films, with high photoluminescence quantum yields. They exhibit high optical out-coupling factors due to their horizontal orientation in films. The non-doped OLEDs emit NIR lights with maximum external quantum efficiencies, while doped OLEDs achieve record-breaking efficiency levels with red lights emission. These new red TADF materials have great potentials in display and lighting devices.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Engineering, Environmental
Xu Gong, Chen-Han Lu, Wei-Kai Lee, Pan Li, Yu-Hsin Huang, Zhanxiang Chen, Lisi Zhan, Chung-Chih Wu, Shaolong Gong, Chuluo Yang
Summary: By designing rigid and strong electron-rich donor moieties, researchers synthesized two red emitters with high rigidity and linear D-A molecular skeleton, showing distinct TADF nature and high efficiencies. The resulting OLEDs achieved high external quantum efficiency and excellent emission characteristics in the red color gamut.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Sen Wu, Abhishek Kumar Gupta, Kou Yoshida, Junyi Gong, David Hall, David B. Cordes, Alexandra M. Z. Slawin, Ifor D. W. Samuel, Eli Zysman-Colman
Summary: In this study, we demonstrate the method of improving OLED performance by carefully selecting the donor. By decorating the DiKTa core with TPA and DPA, we achieved bright and narrowband green and red emission, respectively. The OLEDs based on these emitters showed outstanding performance with the highest external quantum efficiencies.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Nanoscience & Nanotechnology
Ho Jin Jang, Jun Yeob Lee
Summary: The orientation of thermally activated delayed fluorescence (TADF) molecules in a mixed host was studied by changing the host materials, revealing that the host-dopant interaction is crucial to the absolute value of the horizontal dipole orientation of the TADF emitters. Additionally, the glass transition temperature plays an important role in the dependence of the dipole orientation on host composition.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Changjiang Zhou, Chen Cao, Dezhi Yang, Xiaosong Cao, He Liu, Dongge Ma, Chun-Sing Lee, Chuluo Yang
Summary: This study designed and synthesized two red TADF emitters with horizontal orientation, among which PXZ-AQPhPy achieved a high external quantum efficiency of 19.6%, providing a simple and effective design strategy for selectively promoting the horizontal orientation of red TADF emitters.
MATERIALS CHEMISTRY FRONTIERS
(2021)
Article
Materials Science, Multidisciplinary
Jingxian Fang, Zhangshan Liu, Jinshi Li, Ning Zhuang, Dezhi Yang, Dongge Ma, Ben Zhong Tang, Zujin Zhao
Summary: In this work, a series of efficient blue thermally activated delayed fluorescence materials were designed and synthesized. These materials exhibited excellent thermal stability, high photoluminescence quantum yields, and large horizontal dipole ratios. Non-doped and doped OLEDs fabricated using these materials as emitters showed outstanding maximum external quantum efficiencies and good operational device lifetime, providing deep-blue to sky-blue lights.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Physical
Kai Zhang, Xiao Zhang, Jianzhong Fan, Yuzhi Song, Jian Fan, Chuan-Kui Wang, Lili Lin
Summary: The theoretical predictions of luminescence properties and photophysical mechanisms of a spiro-acridine based molecule DBPz-2spAc in different states were conducted in this study, showing that the solid state can improve luminescence efficiency. OLEDs based on DBPz-2spAc exhibit high luminescence efficiency.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Hiroshi Tasaki, So Shikita, In Seob Park, Takuma Yasuda
Summary: This study introduces a family of TADF materials functionalized with carboxylate esters, which demonstrate high external electroluminescence quantum efficiencies of 6.3-18.7% in non-doped organic light-emitting diodes due to their suppressed concentration-quenching effect in neat films.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Chemistry, Physical
Wei Liu, Cheng Zhang, Riccardo Alessandri, Benjamin T. Diroll, Yang Li, Heyi Liang, Xiaochun Fan, Kai Wang, Himchan Cho, Youdi Liu, Yahao Dai, Qi Su, Nan Li, Songsong Li, Shinya Wai, Qiang Li, Shiyang Shao, Lixiang Wang, Jie Xu, Xiaohong Zhang, Dmitri V. Talapin, Juan J. de Pablo, Sihong Wang
Summary: We have synthesized stretchable electroluminescent polymers that can achieve near-unity theoretical quantum yield through thermally activated delayed fluorescence. Our polymers display 125% stretchability and 10% external quantum efficiency, and demonstrate a fully stretchable organic light-emitting diode. Stretchable light-emitting materials are crucial for the development of skin-like displays and optical biostimulation applications.
Article
Engineering, Environmental
Tao Hua, Yu-Chun Liu, Chih-Wei Huang, Nengquan Li, Changjiang Zhou, Zhongyan Huang, Xiaosong Cao, Chung-Chih Wu, Chuluo Yang
Summary: In this study, two novel highly efficient blue thermally activated delayed fluorescence (TADF) materials were synthesized, overcoming the concentration quenching effects and efficiency roll-offs. The synthesized compounds exhibited high horizontal dipole orientation and photoluminescence quantum yields, demonstrating excellent TADF properties and stable emission characteristics. OLEDs based on these compounds achieved high efficiency and brightness.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Chen-Zong Yang, Ze-Hui Pan, Kai Zhang, Jing-Wen Tai, Chuan-Kui Wang, Lei Ding, Man-Keung Fung, Jian Fan
Summary: Thermally activated delayed fluorescence (TADF) materials with emission in the deep red and near infrared (DR/NIR) region are underresearched due to the limited choice of strong donor/acceptor units. The current mainstream strategy for the design of DR/NIR TADFs is to increase the acceptor strength via the introduction of multiple sub-acceptor units, thereby narrowing the bandgap. In this work, the intramolecular charge transfer (ICT) effect was applied for the development of acceptor units to achieve efficient DR/NIR TADFs.
MATERIALS HORIZONS
(2023)
Article
Chemistry, Multidisciplinary
Yincai Xu, Qingyang Wang, Xinliang Cai, Chenglong Li, Yue Wang
Summary: In this study, highly efficient organic light-emitting diodes that exhibit pure green emission and circularly polarized electroluminescence signal were developed by integrating circularly polarized luminescence and thermally activated delayed fluorescence emission induced by multiple resonance effect. This represents a significant advancement in the field of organic electronics.
ADVANCED MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Yuanyuan Cui, Jing Liu, Zhiqiang Li, Mingyang Ji, Meng Zhao, Meihua Shen, Xue Han, Tao Jia, Chenglong Li, Yue Wang
Summary: Organic-small-molecule photothermal materials with excellent photothermal properties have been proposed as promising solar absorbent materials. By fusing two strong electron-withdrawing units, a rigid planar acceptor with stronger electron-withdrawing ability was obtained to construct donor-acceptor-type organic-small-molecule solar-energy-absorbing material. The synthesized compound exhibited a strong intramolecular charge transfer character, broad optical absorption, favorable photothermal properties, and high photothermal conversion ability.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Xinliang Cai, Jianan Xue, Chenglong Li, Baoyan Liang, Ao Ying, Yao Tan, Shaolong Gong, Yue Wang
Summary: In this study, a ternary boron-oxygen-nitrogen embedded polycyclic aromatic hydrocarbon with multiple resonance thermally activated delayed fluorescence (MR-TADF) properties, named DBNO, was developed. The designed molecule exhibits a vivid green emission with high photoluminescence quantum yield and an extremely narrow full width at half maximum. The organic light-emitting diode (OLED) based on DBNO shows significantly improved device performance with a narrowband green emission and high external quantum efficiency achieved through the TADF-sensitization mechanism.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Physical
Yixuan Gao, Yaxin Wang, Zilong Guo, Yan Wan, Chenglong Li, Bing Yang, Wensheng Yang, Xiaonan Ma
Summary: This study investigates the photophysics of two MR-TADF emitters using quantum chemical calculation and ultrafast transient absorption spectroscopy. It reveals that TBN-TPA undergoes two-step relaxation in S-1 state, which is favored for narrowband emission.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)
Article
Materials Science, Multidisciplinary
Xianju Yan, Zong Cheng, Tong Yang, Chenglong Li, Yue Wang
Summary: By synthesizing and studying two different compounds with different molecular structures, the potential of being host materials was explored. It was found that one of the compounds (DCzBNPh-2) was the best host for constructing phosphorescent organic light-emitting diodes.
ORGANIC ELECTRONICS
(2022)
Article
Materials Science, Multidisciplinary
Ning Xie, Jiaxuan Wang, Tingting Huang, Liupeng Zhao, Peng Sun, Geyu Lu, Yue Wang, Chenglong Li
Summary: Pure organic crystal DMAB exhibits efficient room-temperature phosphorescence and shows long-lasting phosphorescence under light irradiation. This phosphorescent property can be further enhanced by UV irradiation and can be switched off by oxygen consumption in a cyclic process. The crystal structure is beneficial to phosphorescence and can be utilized for oxygen sensing and anticounterfeiting.
ADVANCED OPTICAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Yuanyuan Cui, Yexuan Pu, Zhiqiang Li, Baoyan Liang, Chenglong Li, Yue Wang
Summary: Two series of isomers based on biphenyl and two typical donor groups diphenylamine and 9,9-dimethyl-9,10-dihydroacridine are developed to investigate the effect of isomerization on structures and photophysical properties. Computational simulations and photophysical analyses demonstrate that the substitution positions not only influence molecular conformations, but also frontier molecular orbital distributions, which further impact the photoluminescence properties. The study reveals that twisted structures facilitate the separation of frontier molecular orbitals, while more planar structures contribute to higher luminescent intensity. Additionally, room temperature phosphorescence (RTP) is observed when these isomers are doped in 4,4'-dibromo-1,1'-biphenyl, with the p-DDPA/DBBP complex exhibiting the highest intensity of phosphorescence and the longest lifetime.
Article
Chemistry, Multidisciplinary
Xinliang Cai, Yincai Xu, Yue Pan, Linjie Li, Yexuan Pu, Xuming Zhuang, Chenglong Li, Yue Wang
Summary: A solution-processable red OLED with high purity and efficiency was developed by introducing auxiliary donor and acceptor moieties into the HOMO and LUMO positions of the MR-TADF system. The molecule BN-R exhibited a narrowband pure-red emission at 624 nm, with a high luminous efficiency of 94% and a narrow bandwidth of 46 nm. The solution-processable pure-red OLED based on BN-R showed a state-of-the-art external quantum efficiency over 20% and a long operational lifetime of 1088 hours at an initial luminance of 1000 cd m(-2), with Commission Internationale de I'eclairage coordinates of (0.663, 0.337).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Yincai Xu, Qingyang Wang, Xiaoxian Song, Yue Wang, Chenglong Li
Summary: This article summarizes a new strategy called CP-MR-TADF for generating organic emitters with circularly polarized luminescence (CPL) activity, thermally activated delayed fluorescence (TADF), and narrowband emission. High-performance red, green, and blue CP-MR-TADF emitters have been developed using this strategy. The present status, progress, future opportunities, and present challenges in the field of CP-MR-TADF materials in organic light-emitting diodes (OLEDs) are discussed.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Nanoscience & Nanotechnology
Jing Liu, Luoqing Wang, Tao Jia, Zuoyu Wang, Tao Xu, Nan An, Meng Zhao, Ruoyu Zhang, Xiuhua Zhao, Chenglong Li
Summary: Solar-driven interfacial evaporation for seawater desalination is limited by low evaporation rate, salt crystallization, and energy collection issues. Inspired by the unique aggregate structure of black soil, a salt-collecting device is designed to achieve continuous evaporation and mineral salt collection. Furthermore, the design strategy of BS-like aggregate photothermal materials, using halloysite and nigrosin doping, enables multistage sunlight utilization and efficient water transport. This work demonstrates a practical solution for low-cost seawater desalination and resource recovery.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
Xianju Yan, Zhiqiang Li, Qingyang Wang, Yupei Qu, Yincai Xu, Yue Wang
Summary: By regulating the molecular structure and optimizing the device configuration, the efficiency roll-off of OLEDs based on MR-TADF emitters in a high brightness circumstance has been successfully reduced. The tDPA-DtCzB-based OLED exhibits narrowband sky-blue emission and high EQE at practical high luminance, making it an attractive candidate for wide color gamut displays.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Chemistry, Physical
Xue Han, Zuoyu Wang, Meihua Shen, Jing Liu, Yuxi Lei, Zhiqiang Li, Tao Jia, Yue Wang
Summary: By synthesizing the organic small molecule 4OCSPC, a material with efficient utilization of solar energy for water-electricity cogeneration has been successfully designed. This material exhibits excellent photothermal properties and thermal/photo-stability, achieving high efficiency water evaporation and power generation.
JOURNAL OF MATERIALS CHEMISTRY A
(2021)
Article
Chemistry, Multidisciplinary
Hanbo Yu, Xiaoxian Song, Ning Xie, Jiaxuan Wang, Chenglong Li, Yue Wang
Summary: The study introduces a novel multifunctional molecule TPA-DQP, which exhibits polymorphism, efficient TADF emission, and MCL property, with reversible crystal-to-crystal phase transitions in response to external stimuli. The TPA-DQP-based OLED device achieves high external quantum efficiency and represents the best performance for deep-red OLEDs based on MCL-active TADF emitters, providing insight into the relationship between molecular packing modes and photoluminescent behavior.
ADVANCED FUNCTIONAL MATERIALS
(2021)