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
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
Chemistry, Multidisciplinary
Kai Philipps, Yutaka Ie, Bas Zee, Rui-Qi Png, Peter K. H. Ho, Lay-Lay Chua, Esther del Pino Rosendo, Charusheela Ramanan, Gert-Jan A. H. Wetzelaer, Paul W. M. Blom, Jasper J. Michels
Summary: High-performance OLEDs based on novel TADF polymers that can be processed from a solution without vacuum processing are presented. The devices exhibit high external quantum efficiencies (EQEs) when using alkyl spacer-based TADF polymers, and the efficiency does not drop substantially upon dilution. In contrast, devices based on monomeric chromophores show significant efficiency losses upon dilution.
Article
Chemistry, Multidisciplinary
Yu Fu, Zecong Ye, Denghui Liu, Yingxiao Mu, Jingping Xiao, Dehua Hu, Shaomin Ji, Yanping Huo, Shi-Jian Su
Summary: In this study, a series of thermally activated delayed fluorescence (TADF) macrocycles are synthesized using a modularly tunable strategy by introducing xanthones as acceptors and phenylamine derivatives as donors. Detailed analysis of their photophysical properties reveals their characteristics of high performance. The corresponding devices exhibit record-high external quantum efficiencies of 31.6% and 26.9%, respectively, in the field of TADF macrocycles, owing to the high photoluminescence quantum yields and excellent dipole orientation of the macrocycles.
ADVANCED MATERIALS
(2023)
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, Applied
Taian Huang, Zhanxiang Chen, Yang Zou, Shaolong Gong, Chuluo Yang
Summary: A novel three-dimensional tetracoordinated organoboron acceptor, developed by direct borylation of pyridine derivatives, showed good stability, high PLQY, and TADF properties in the donor-acceptor emitter. By selecting different donors with varying electron donating abilities, two distinct electroluminescent devices achieved over 10% maximum external quantum efficiency with white and green emission.
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
Chemistry, Multidisciplinary
Yang Chen, Dongdong Zhang, Yuewei Zhang, Xuan Zeng, Tianyu Huang, Ziyang Liu, Guomeng Li, Lian Duan
Summary: The study developed a high-performance TADF emitter with controlled molecular orientation and optoelectronic properties, achieving high quantum yield and fast intersystem crossing rate. The corresponding OLED device demonstrated impressive efficiency performance, pushing the device efficiency towards theoretical limits.
ADVANCED MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Wei Li, Mengke Li, Wenqi Li, Zhida Xu, Lin Gan, Kunkun Liu, Nan Zheng, Chengyun Ning, Dongcheng Chen, Yuan-Chun Wu, Shi-Jian Su
Summary: This study investigates the importance of energy level relationships between spiral donors and luminophores on the photoluminescent quantum yields of materials, and proposes the use of quantum chemistry simulations to accurately predict these relationships. The optimized molecular structure and energy alignment play a key role in enhancing the performance of TADF emitters. Ultimately, the TADF emitter DspiroS-TRZ achieved remarkable results with 99.9% PLQY and 38.4% EQE, the highest reported among all blue TADF emitters to date.
ACS APPLIED MATERIALS & INTERFACES
(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, 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
Materials Science, Multidisciplinary
Tong Yang, Jixiong Liang, Yuanyuan Cui, Zhiqiang Li, Xiaomei Peng, Shi-Jian Su, Yue Wang, Chenglong Li
Summary: A pair of red thermally activated delayed fluorescence (TADF) isomers were developed through isomer engineering, achieving high photoluminescence quantum efficiency, small singlet-triplet energy split, and large horizontal emitting dipole ratio. The red electroluminescent device based on TPA-APQDCN-C achieved the highest external quantum efficiency of 34.3% with an emission peak at 610 nm among red TADF-OLEDs with emission maximum beyond 600 nm ever reported.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Youngnam Lee, Jong-In Hong
Summary: Halogen-substituted multiple-resonance (MR) thermally activated delayed fluorescence emitters, Cl-MR and Br-MR, were synthesized and their performance was studied. Cl-MR showed a decreased delayed fluorescence lifetime and an enhanced reverse intersystem crossing rate, leading to high photoluminescence quantum yield and external quantum efficiency. However, Br-MR did not exhibit any enhancement in these properties.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Review
Chemistry, Multidisciplinary
Ming Zhang, Cai-Jun Zheng, Hui Lin, Si-Lu Tao
Summary: Research has shown that exciplex emitters hold great potential for applications in OLEDs, contributing to the development of high-performance TADF emitters. The design principles for efficient TADF exciplex emitters are systematically categorized into three systems, indicating significant progress in this field.
MATERIALS HORIZONS
(2021)
Article
Chemistry, Organic
Megan Amy Bryden, Francis Millward, Tomas Matulaitis, Dongyang Chen, Marco Villa, Andrea Fermi, Sultan Cetin, Paola Ceroni, Eli Zysman-Colman
Summary: In this study, an alternative donor-acceptor TADF structure, pDTCz-DPmS, was reported as a photocatalyst. It exhibited better ground state reducing agent and photoreductant properties compared to 4CzIPN. The increased conjugation of pDTCz-DPmS resulted in enhanced light absorption, and prompt and delayed emission lifetimes confirmed its TADF nature. These properties made pDTCz-DPmS useful in a variety of photocatalysis reactions, including photoredox oxidative and reductive quenching reactions, dual Ni(II) cocatalyst reactions, and energy transfer processes.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Callum Prentice, James Morrison, Andrew D. Smith, Eli Zysman-Colman
Summary: The donor-acceptor thermally activated delayed fluorescent compounds DiKTa and Mes(3)DiKTa were found to have comparable or better product yields than 4CzIPN in a range of photocatalytic reactions. Among them, DiKTa stands out due to its lower cost, making it a valuable addition to any chemist's collection of photocatalysts.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Jeannine Gruene, Giacomo Londi, Alexander J. Gillett, Basil Staehly, Sebastian Lulei, Maria Kotova, Yoann Olivier, Vladimir Dyakonov, Andreas Sperlich
Summary: The development of non-fullerene acceptors (NFAs) in organic photovoltaics (OPV) has led to a significant progress in power conversion efficiencies, reaching nearly 20%. However, triplet states have been found to negatively affect device performance, leading to non-radiative losses and device degradation. A study using various spin-sensitive methods and quantum-chemical calculations identified the presence of triplet excitons in OPV blends, providing insights into the pathways for triplet formation and suggesting potential for improved charge generation to enhance OPV efficiencies.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Tao Wang, Abhishek Kumar Gupta, Sen Wu, Alexandra M. Z. Slawin, Eli Zysman-Colman
Summary: We discovered a general design principle for materials that exhibit multiple room-temperature phosphorescence (RTP) processes. By modulating the hybridization between donor and acceptor groups, we achieved multiple RTP processes in sp3 C-linked donor-acceptor compounds. However, in sp2 C-linked counterparts, only one locally excited triplet state phosphorescence was observed due to enhanced excitonic coupling. Our findings provide insights into the dynamics of higher-lying triplet excited states and offer a fundamental design principle for compounds with multiple RTP.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Multidisciplinary
Subeesh Madayanad Suresh, Le Zhang, Tomas Matulaitis, David Hall, Changfeng Si, Gaetano Ricci, Alexandra M. Z. Slawin, Stuart Warriner, David Beljonne, Yoann Olivier, Ifor D. W. Samuel, Eli Zysman-Colman
Summary: Two multiresonant thermally activated delayed fluorescence (MR-TADF) emitters are demonstrated. The borylation of a deep-blue MR-TADF emitter, DIDOBNA-N, results in a new near-UV MR-TADF emitter, MesB-DIDOBNA-N, with a blueshifted and narrowed emission. DIDOBNA-N emits bright blue light with high efficiency, while the OLED based on MesB-DIDOBNA-N shows the highest efficiency and the bluest emission among MR-TADF OLEDs reported to date.
ADVANCED MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Dongyang Chen, Francisco Tenopala-Carmona, Julius A. Knoeller, Andreas Mischok, David Hall, Subeesh Madayanad Suresh, Tomas Matulaitis, Yoann Olivier, Pierre Nacke, Frank Giesselmann, Sabine Laschat, Malte C. Gather, Eli Zysman-Colman
Summary: The use of TADF emitters and emitters with preferential horizontal TDM orientation are two emerging strategies to enhance OLED efficiency. In this study, a liquid crystalline MR-TADF emitter, DiKTa-LC, was introduced. The spin-coated film of DiKTa-LC exhibited a preferential horizontal TDM orientation with an anisotropy factor of 0.28. Green-emitting solution-processed OLEDs based on DiKTa-LC achieved an EQE(max) of 13.6%. This study demonstrates how self-assembly of a liquid crystalline TADF emitter can control the orientation of the transition dipole in solution-processed films, which is relevant for high-performance OLEDs.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Eimantas Duda, Subeesh Madayanad Suresh, David Hall, Sergey Bagnich, Rishabh Saxena, David B. Cordes, Alexandra M. Z. Slawin, David Beljonne, Yoann Olivier, Anna Koehler, Eli Zysman-Colman
Summary: This study introduces a molecular design that gradually increases the number of quasi-degenerate states to enhance the efficiency of thermally activated delayed fluorescence (TADF) using the oligomer approach. By selecting and arranging benzonitrile (BN) acceptors and amine donors, connected together via repetitive donor-acceptor units, the number of quasi-degenerate states is gradually increased. It is found that increasing the size of the oligomer enhances the rates of intersystem crossing and reverse intersystem crossing.
CHEMISTRY OF MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Kenneth Chu, Jonathan R. Adsetts, Zackry Whitworth, Shiv Kumar, Eli Zysman-Colman, Zhifeng Ding
Summary: The electrochemistry, electrochemiluminescence (ECL), and chemiluminescence (CL) properties of a thermally activated delayed fluorescence (TADF) emitter TPA-ace-TRZ and its analogues were investigated. TPA-ace-TRZ exhibited delayed onset of ECL and long-persistent luminescence, attributed to the formation of an aggregate excited state in excimer or exciplex form. The presence of this aggregate excited state was observed in both ECL annihilation and coreactant pathways as well as in CL. TPA-ace-TRZ showed high absolute ECL efficiency using benzoyl peroxide (BPO) as a coreactant and high absolute CL quantum efficiency.
Article
Materials Science, Multidisciplinary
Tao Wang, Abhishek Kumar Gupta, David B. Cordes, Alexandra M. Z. Slawin, Eli Zysman-Colman
Summary: This study reports the observation of emission directly from the T-2 state in multi-resonant thermally activated delayed fluorescence (MR-TADF) emitters for the first time by modulating the conjugation between the emissive center and donor substituent. Theoretical and photophysical investigations reveal that the Delta E-S1T2 difference influences the reverse intersystem crossing rate. Therefore, designing MR-TADF emitters with degenerate S-1 and T-2 states provides a possible solution to mitigate device efficiency roll-off.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Shi Tang, John Marques dos Santos, Joan Rafols-Ribe, Jia Wang, Eli Zysman-Colman, Ludvig Edman
Summary: In this study, narrowband and efficient electroluminescence from multi-resonance thermally activated delayed fluorescence (MR-TADF) organic semiconductors in light-emitting electrochemical cells (LECs) is achieved by carefully selecting materials and developing the devices. The aggregation tendency of the MR-TADF emitter is inhibited by dispersing it into a compatible blend host and an ionic-liquid electrolyte. The designed metal-free active MR-TADF material exhibits a high external quantum efficiency of 3.8% with a narrow emission profile.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Changfeng Si, Tao Wang, Abhishek Kumar Gupta, David B. Cordes, Alexandra M. Z. Slawin, Jay S. Siegel, Eli Zysman-Colman
Summary: Corannulene-derived materials have been extensively studied in energy storage and solar cells. However, their potential as emitters in light-emitting sensors and OLEDs has been largely unexplored. In this study, a family of multi-D-A motifs, TCzPhCor, TDMACPhCor, and TPXZPhCor, were developed by using corannulene as the acceptor and different donors. These materials exhibit multiple phosphorescence and show promise in temperature sensing and OLED applications.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Correction
Chemistry, Organic
Kang Yuan, Abhishek Kumar Gupta, Changfeng Si, Marina Uzelac, Eli Zysman-Colman, Michael James Ingleson
Article
Chemistry, Organic
Kang Yuan, Abhishek Kumar Gupta, Changfeng Si, Marina Uzelac, Eli Zysman-Colman, Michael James Ingleson
Summary: Bromo-functionalized B(1)-polycyclic aromatic hydrocarbons (PAHs) were synthesized and utilized in cross-couplings for the formation of donor-acceptor materials. These materials exhibited a range of S-1 energies, with some showing thermally activated delayed fluorescence and significant emission in the near-infrared region. The B-1-PAHs are a valuable family of readily synthesized and functionalized acceptors.
Article
Chemistry, Multidisciplinary
Liuqing Yang, Lihui Dong, David Hall, Mahdi Hesari, Yoann Olivier, Eli Zysman-Colman, Zhifeng Ding
Summary: The electrochemiluminescence (ECL) behavior of a multiresonance thermally activated delayed fluorescence molecule has been investigated for the first time. The compound, Mes(3)DiKTa, exhibits complex ECL behavior including delayed onset time and long-persistent ECL. The absolute ECL efficiencies of Mes(3)DiKTa are superior to those of most other organic ECL materials, suggesting the potential importance of similar ECL materials in various applications.