Article
Materials Science, Multidisciplinary
Yaxiong Wang, Runda Guo, Ao Ying, Kaiyuan Di, Linya Chen, Honggang Gu, Shiyuan Liu, Yalei Duan, Hanrui Su, Shaolong Gong, Lei Wang
Summary: Due to the limitation of donor and acceptor group selection, efficient thermally activated delayed fluorescence (TADF) type sensitizers for blue organic light-emitting diodes (OLEDs) are rare. This study demonstrates the feasibility of using multiple resonance (MR) type TADF emitters as sensitizers, achieving efficient blue emission and significantly improving the external quantum efficiency by improving the photoluminescence quantum yield and utilizing triplet excitons.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Yalun Xu, Ao Ying, Jiali Peng, Fang Yao, Ruiming Li, Yao Tan, Shaolong Gong, Qianqian Lin
Summary: Metal halide perovskites have recently attracted great attention for ionizing radiation detection. In this study, hybrid devices coupled with excellent perovskite photodiodes were designed to fully utilize the incident X-rays. The use of a Cu(I)-containing thermally activated delayed fluorescent complex effectively achieved down-conversion luminescence and faster afterglow. This research has significant potential for X-ray detection and imaging.
SCIENCE CHINA-MATERIALS
(2023)
Article
Engineering, Environmental
Lisi Zhan, Yang Tang, Weimin Ning, Guohua Xie, Cheng Zhong, Shaolong Gong, Chuluo Yang
Summary: Humidity monitoring is important in daily life and industrial processes. A new class of humidity-responsive thermally activated delayed fluorescent material, AcHPM, is presented, which shows significant emission color changes and has good response time and reversibility. This study provides a new avenue for developing humidity sensors and exploring the mechanism of fluorescent-responsive processes.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Chenyue Zhao, Zhipeng Ding, Yibin Zhang, Zhigang Ni, Shijun Li, Shaolong Gong, Bo Zou, Kai Wang, Ling Yu
Summary: Different from conventional piezochromic materials, our designed molecule exhibits sensitive and tunable luminescence in response to hydrostatic pressure. The molecule possesses dual-emission and bidirectional shifting characteristics. Experimental studies reveal that the dual-emission behavior is attributed to intramolecular charge transfer and intermolecular excimer. The color change of the molecule from sky-blue to green to deep-blue is a result of intramolecular and intermolecular energy-transfer interactions.
Article
Chemistry, Multidisciplinary
Zhanxiang Chen, Manli Huang, Cheng Zhong, Xiaosong Cao, Guohua Xie, Shaolong Gong, Chuluo Yang
Summary: This study demonstrates the production of stable circularly polarized electroluminescence through cascade chirality transfer. Spectroscopic data and theoretical analysis reveal that diastereomeric interaction initiates this chirality transfer process. By utilizing this interaction and the excellent Forster resonance energy transfer ability to a known racemic emitter, circularly polarized OLEDs with a high electroluminescence dissymmetry factor (|g(EL)|) of 3.2 x 10(-3) and a high external quantum efficiency (EQE) of 32% are successfully fabricated. These devices also exhibit low efficiency roll-off at high brightness, maintaining an EQE of >= 20% at 128 000 cd m(-2). This study paves the way for future development of circularly polarized OLEDs through synergistic materials and device engineering.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Wei Yang, Jingsheng Miao, Fengping Hu, Yang Zou, Cheng Zhong, Shaolong Gong, Chuluo Yang
Summary: Currently, it is challenging to design MR-TADF emitters with emission wavelength over 550 nm. In this study, an effective approach toward yellow-to-orange MR-TADF emitters by integrating a strong electron-donating indolophenazine building block into the B/N-doped polycyclic aromatic hydrocarbons is proposed. These emitters exhibit excellent photophysical characteristics and achieve state-of-the-art device performances in yellow and orange OLEDs. Rating: 8 points.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Yuxuan Hu, Jingsheng Miao, Cheng Zhong, Yang Zeng, Shaolong Gong, Xiaosong Cao, Xue Zhou, Yu Gu, Chuluo Yang
Summary: The integration of heavy atoms into TADF molecules enhances the RISC process, but achieving high efficiency, small roll-off, narrowband emission, and good operational lifetime in OLEDs is challenging. In this study, a pure green multi-resonance TADF molecule BN-STO was synthesized by introducing a heavy atom selenium. The resulting OLED device showed excellent performance with high external quantum efficiency, power efficiency, suppressed efficiency roll-off, and pure green gamut.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Applied
Yajie Wang, Weimin Ning, Wei Yang, Lili Li, Nengquan Li, Tengxiao Liu, Shaolong Gong, Xiang Gao, Chuluo Yang
Summary: In this study, two novel emitters were constructed by incorporating phenothiazine dioxide into diphenyl sulfone derivatives, which can significantly improve the efficiency roll-off issue in organic light-emitting diodes (OLEDs) at high brightness. The heavy atom effect of the sulfur (S) atom enhances the spin-orbit coupling and accelerates the reverse intersystem crossing (RISC) process of the emitters, while promoting the intersystem crossing (ISC) channel. The emitters exhibit efficient thermally activated delayed fluorescence (TADF) properties and obvious aggregation-induced emission (AIE) property. The OLEDs fabricated with these emitters achieve a maximum quantum efficiency (EQE) of 11.7%, and even at a luminance of 1000 cd m(-2), the device based on PXZ-DPS-DOPTZ emitter shows extremely low efficiency roll-off with an EQE of 10.1%.
Article
Chemistry, Multidisciplinary
Lisi Zhan, Tianhao Chen, Cheng Zhong, Xiaosong Cao, Yuewei Zhang, Yang Zou, Zhengyang Bin, Jingsong You, Dongdong Zhang, Lian Duan, Chuluo Yang, Shaolong Gong
Summary: The control of excited states and emissive properties in gold(III) complexes is achieved through modulation of intramolecular electronic interactions. However, intermolecular electronic interactions in luminescent gold(III) systems have not been investigated. In this study, we demonstrate the use of gold(III) exciplexes based on a simple gold(III) complex, AuDPPy, as electron acceptors. The emissive properties of these exciplexes can be tuned by combining AuDPPy with different donors, resulting in efficient electroluminescence with high external quantum efficiencies (EQEs).
SCIENCE CHINA-CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Yaxun Wu, Fan Ni, Zhanxiang Chen, Wei Yang, Yepeng Xiang, Shaolong Gong, Xiaosong Cao, Chuluo Yang
Summary: In this study, two donor-acceptor-type TADF emitters with highly twisted conformation are synthesized. Through various experiments and analysis, it is discovered that X-aggregation supports aggregation-induced emission behavior, while H-aggregation leads to aggregation-caused quenching.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Ao Ying, Shaolong Gong
Summary: In recent years, coinage metal complexes, such as gold, silver, and copper, have been studied as luminescent materials in OLEDs, showing potential to replace noble metal complexes like iridium(III) and platinum(II). The use of carbene-metal-amide (CMA) complexes in OLEDs has emerged as a new class of luminescent materials with high radiative rates and reduced metal d-orbital participation. This concept article discusses the molecular design principles, structure-property correlations, and future prospects of CMA complexes in OLEDs.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Polymer Science
Maolin Yu, Yuhan Gao, Ao Ying, Lili Li, Guohua Xie, Shaolong Gong, Xiang Gao, Tao Wang, Chuluo Yang
Summary: In this study, we designed and synthesized a TSCT-based alternating TADF copolymer consisting of non-conjugated poly(maleimide-alt-styrene) as the backbone, acridine as the electron donor, and triazine as the electron acceptor. The solution-processed OLED using the alternating TADF copolymer as the emitter achieved a maximum external quantum efficiency of 20.9%, which was 2.8 times higher than that of the corresponding random copolymer. This highlights the superiority of alternating copolymerization in constructing TSCT-based TADF copolymers.
Article
Chemistry, Multidisciplinary
Ao Ying, Lisi Zhan, Yao Tan, Xiaosong Cao, Chuluo Yang, Shaolong Gong
Summary: This study successfully achieved efficient circularly polarized luminescence and thermally activated delayed fluorescence by introducing a typical planar chiral skeleton [2.2]paracyclophane into earth-abundant copper(I) complexes. Two pairs of proof-of-the-concept copper(I) enantiomers were developed, which not only exhibited significant mirror-image CPL signals but also displayed distinct TADF nature. The resultant OLEDs manifested efficient circularly polarized electroluminescence with excellent external quantum efficiencies, representing one of the best performances for CP-OLEDs based on earth-abundant organometallic complexes and the first example of CP-OLEDs from CMA complexes to our knowledge.
SCIENCE CHINA-CHEMISTRY
(2023)
Review
Polymer Science
Yihan Wang, Ao Ying, Shaolong Gong
Summary: The discovery of thermally activated delayed fluorescence (TADF) materials in the past decade has significantly advanced the development of organic light-emitting diode (OLED) technology. TADF dendrimers, with the combined advantages of TADF small molecules and polymers in achieving high efficiency, excellent solution processability, and precise molecular structures, have emerged as promising emitters for solution-processed OLEDs. In recent years, there have been important advances in the molecular design, mechanism exploration, and device performance of TADF dendrimers. This review provides an overview of solution-processable TADF dendrimers, focusing on their molecular design principles, structure-property correlations, and advanced device performances. The prospects and challenges in the development of TADF dendrimers are also discussed.
JOURNAL OF POLYMER SCIENCE
(2023)
Article
Chemistry, Multidisciplinary
Zhanxiang Chen, Manli Huang, Cheng Zhong, Shaolong Gong, Veaceslav Coropceanu, Jean-Luc Bredas, Chuluo Yang
Summary: It is a challenge to achieve high luminescence dissymmetry factor (g) in circularly polarized luminescence (CPL) materials. In this study, we investigated the role of molecular structure on CPL and found that delocalized transition density and optimized chromophore twisting are crucial for obtaining large g-factors. These findings provide molecular-level insights into CPL of organic emitters and have potential applications in the design of chiroptical materials and systems with strong CPL effects.
