Article
Crystallography
Sangwok Bae, Dong-Sun Park, Suk-Won Choi
Summary: A prototype opaque-type colored silicon-based solar cell integrated with liquid crystalline cholesteric layers was developed using only organic components and wet processes, without the need for complicated vacuum processes. However, the evaluated performance of the prototype solar cells was found to be inferior to other types of colored solar cells due to limitations of the cholesteric layers, including limited reflectance (~50%), narrow color gamut, and viewing angle-dependent color changes. Strategies for improving the performance of colored solar cell modules integrated with cholesteric layers are proposed.
Article
Chemistry, Physical
Sangwok Bae, Young Wook Noh, Dong-Sun Park, Myoung Hoon Song, Suk-Won Choi
Summary: This study developed a new type of liquid crystal reflective filter (ChRFs) for colored perovskite solar cells, which has adjustable reflective properties that can control hue, power conversion efficiency, and chromaticity by tuning different parameters. ChRFs are suitable for large and flexible PeSCs, and are constructed using only organic components and wet processes.
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
Energy & Fuels
Qurat Ul Ain, Jianxing Xia, Hiroyuki Kanda, Imanah Rafieh Alwani, Xiao-Xin Gao, Habib Ur Rehman, Guang Shao, Vygintas Jankauskas, Kasparas Rakstys, Ammar Ahmed Khan, Mohammad Khaja Nazeeruddin
Summary: Hexakis(hexyloxy)triphenylene (HAT6) discotic liquid crystal is used as a transparent hole-transporting material (HTM) for perovskite solar cells (PSCs), achieving a power conversion efficiency (PCE) of 15.7%, the highest among HAT6 HTMs. Despite lower PCE than spiro-OMeTAD-based devices (20.3%), HAT6-based PSCs show much higher ambient and thermal stability.
Article
Chemistry, Multidisciplinary
Meizi Wu, Hongyan Wang, Yong Li, Ran Chen, Hui Zhou, Shaomin Yang, Dongfang Xu, Kun Li, Zhongwei An, Shengzhong (Frank) Liu, Zhike Liu
Summary: The disordered growth of the bottom perovskite film affects the buried interface of perovskite solar cells (PSCs), but using a new material to modify the interface can improve the photovoltaic performance. In this study, a new ionic liquid crystal (ILC) was developed to modify the buried interface of PSCs, promoting preferential growth of the perovskite film and passivating defects. The ILC-modified PSC achieved a high efficiency of 24.92% and maintained 94% of its original value after 3000 hours of storage.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Nanoscience & Nanotechnology
Mengqi Cui, Na Li, Yuying Wang, Yuting Li, Xia Tian, Xingchen Zhang, Wenting Wang, Zhongmin Liu, Qikun Rong, Xingsen Gao, Guofu Zhou, Li Nian
Summary: This study demonstrates an effective and simple approach to optimize the performance of both cathode and anode interlayers in organic solar cells by doping them with 4-heptyl-4'-cyanobiphenyl (7CB). Devices with 7CB-doped interlayers show increased short-circuit current density, fill factor, and power conversion efficiency compared to undoped interlayers, regardless of whether it is the anode or cathode interlayer, which is a rare phenomenon in the field of interlayer modification.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Physical
Shengbo Zhu, Wei Li, Bingyang Lu, Ran Chen, Yongliang Liu, Weixing Chen, Xiaoling Niu, Wenzhi Zhang, Xinbing Chen, Zhongwei An
Summary: In this study, three organic fluorine-containing dyes were designed and synthesized, and it was found that the introduction of fluorine can significantly broaden the absorption spectra of the dyes, but does not improve the light-harvesting capability of solar cells. One of the dyes, with fluorine substitution at the 3-position, showed a relatively high open-circuit photovoltage compared to the fluorine-free dye, and when co-sensitized with other dyes, it achieved a remarkably high power conversion efficiency and long-term stability. This work suggests that judicious molecular engineering and co-sensitization are promising strategies for highly efficient and stable solar cells.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Multidisciplinary
Fowzia S. Alamro, Hoda A. Ahmed, Sobhi M. Gomha, Mohamed Shaban
Summary: New asymmetrical Schiff base series containing lateral methoxy groups in the central core were synthesized and characterized in terms of their optical and mesomorphic properties. The position of the methoxy group affected the mesophase type and stability. The electric resistance and optical properties of the series can be tuned by adjusting the length of the terminal alkyl chains, making them potentially useful for solar energy applications.
FRONTIERS IN CHEMISTRY
(2021)
Article
Chemistry, Physical
Shallu Dhingra, Feng-Rong Chen, Iram Siddiqui, Santosh Prasad Gupta, Ching-Wu Wang, Jwo-Huei Jou, Santanu Kumar Pal
Summary: By engineering a molecular structure with a tri-alkynyl benzene core, we have developed a room-temperature stable discotic nematic material, which also shows excellent performance in organic light-emitting diodes.
JOURNAL OF MOLECULAR LIQUIDS
(2023)
Article
Engineering, Electrical & Electronic
Indu Bala, Harpreet Kaur, Madhusudan Maity, Rohit Ashok Kumar Yadav, Joydip De, Santosh Prasad Gupta, Jwo-Huei Jou, Upendra Kumar Pandey, Santanu Kumar Pal
Summary: This study presents the synthetic design and emissive and semiconducting properties of aggregation-induced emission (AIE)-active columnar discotic liquid crystals. The materials demonstrated enantiotropic mesomorphic behavior and ambipolar charge transport. They also exhibited promising light-emitting properties in solution-processed organic light-emitting devices.
ACS APPLIED ELECTRONIC MATERIALS
(2022)
Article
Energy & Fuels
Xia Yang, Hanjun Yang, Meng Su, Jianming Zhao, Xiangchuan Meng, Xiaotian Hu, Tangyue Xue, Zengqi Huang, Ying Lu, Yuzhan Li, Zhou Yang
Summary: This study introduces a liquid crystal 6OBA as an additive for printable and crystalline templates of scalable perovskite films. The optimized perovskite solar cells show high power conversion efficiency values and outstanding bending resistance.
Article
Chemistry, Multidisciplinary
Guillaume Bousrez, Olivier Renier, Brando Adranno, Volodymyr Smetana, Anja-Verena Mudring
Summary: The study found that 1,3-dialkyltriazolium iodides exhibit high chemical and thermal stability, with significant changes in electrolyte properties upon addition of different iodine content, where iodine addition usually leads to a decrease in melting point and an increase in conductivity. Compared to imidazolium iodides, triazolium compounds show higher efficiency and longer battery life, possibly due to their non-hygroscopic nature.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2021)
Review
Polymer Science
Yong Ye, Li Guo, Tingjun Zhong
Summary: Polymer-stabilized liquid crystals (PSLCs) are versatile materials with polymer networks providing anchoring energy for liquid crystals. This review details various improvements in PSLCs, including polymer-stabilized nematic, cholesteric, blue phase, smectic, ferroelectric, and antiferroelectric liquid crystals. PSLCs offer multiple functionalities, such as reorientation in smart windows and manual tuning of reflection bandwidth in broadband reflectors. PSBPLCs open up new possibilities for displays, modulators, sensors, lasers, lenses, and photonics applications. Polymer networks in PSFLCs or PSAFLCs enhance grayscale memories for flexible displays and energy-saving smart cards. The remaining challenges and research opportunities in PSLCs are also discussed.
Article
Materials Science, Multidisciplinary
Kelum Perera, Nilanthi Haputhantrige, Md Sakhawat Hossain Himel, Md Mostafa, Alex Adaka, Elizabeth K. Mann, Oleg D. Lavrentovich, Antal Jakli
Summary: This work presents electrically tunable microlenses based on a polymer-stabilized chiral ferroelectric nematic liquid crystal, which exhibit unique properties and lens deformation performance different from traditional liquid crystal lenses. The technology is of great significance in various application fields.
ADVANCED OPTICAL MATERIALS
(2023)
Article
Chemistry, Physical
Wajid Ali, Wei Qin, Hao Tian, Junxue Guo, Zhaochi Feng, Can Li
Summary: The lattice structure has a significant impact on the photoelectronic properties of metal halide perovskites, but the correlation between crystallography and photogenerated charge carriers is still unclear. This study reveals that a preferred crystal orientation can be established under direct current (DC)-poling, leading to domain boundary evolution and enhanced light scattering, thereby improving light absorption and solar cell performance.
ACS ENERGY LETTERS
(2023)
Article
Nanoscience & Nanotechnology
Jiali Li, Huihui Li, Zhongjie Ren, Shouke Yan, Xiaoli Sun
Summary: This study introduces a new technology to improve electrical properties during stretching by using oriented P3HT films and PDMS layers. It was found that the electrical stability of P3HT films during stretching is better when stretched perpendicular to the c-axis. In addition, the evolution of the multiscale structure of P3HT films under stretching conditions was explored.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Jia Zhou, Wen Li, Ye Chen, Yen-Hung Lin, Mingdong Yi, Jiayu Li, Yangzhou Qian, Yun Guo, Keyang Cao, Linghai Xie, Haifeng Ling, Zhongjie Ren, Jiangping Xu, Jintao Zhu, Shouke Yan, Wei Huang
Summary: Memristors are a promising device concept for neuromorphic computing, but the assembly of large memristive arrays often faces heat dissipation issues. Organic materials can be tailored for neuromorphic applications but are susceptible to heat. A study demonstrated a high-temperature organic memristive synapse resembling biological neurons' ion movement, showcasing potential for practical organic neuromorphic devices.
ADVANCED MATERIALS
(2021)
Article
Engineering, Environmental
Yuchao Liu, Shouke Yan, Zhongjie Ren
Summary: This study explores deep-blue conjugated polymer light emitting diodes with TADF mechanism, demonstrating PCzDD-50 and PTDD-50 as efficient emitters with sky-blue emission. Molecular simulations and photophysical analysis reveal high-efficiency reverse intersystem crossing process in PCzDD-50, leading to superior device performance with the highest EQE values reported for TADF conjugated polymers with sky-blue emission.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Polymer Science
Chensen Li, Yuchao Liu, Zhennan Zhao, Junteng Liu, Zhongjie Ren, Shouke Yan
Summary: Anisotropic 1D nanostructures, such as TADF polymer nanofibers produced by electrospinning, exhibit polarized photoluminescent properties due to high orientation degree and superior molecular arrangement. These nanofibers show enhanced TADF characteristics compared to spin-coated films, including longer-lived excited states, higher photoluminescence quantum efficiency, lower internal conversion decay rate, and higher reverse intersystem crossing rate constant.
MACROMOLECULAR RAPID COMMUNICATIONS
(2021)
Article
Nanoscience & Nanotechnology
Yuchao Liu, Xingwen Tong, Xinrui Chen, Yafei Wang, Shian Ying, Zhongjie Ren, Shouke Yan
Summary: This study successfully designed conjugated TADF polymers with superior photophysical properties and stable device performance using an intramolecular sensitization strategy, achieving high photoluminescence quantum yield and stable device performance.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Zhennan Zhao, Yuchao Liu, Lei Hua, Shouke Yan, Zhongjie Ren
Summary: This study proposes a strategy to improve the light-emitting performance of conjugated polymers by adjusting the local electronegativity of the polymer backbone. It also demonstrates the impact of strongly electronegative atoms on the charge-transfer properties of TADF polymers, leading to a rapid reverse intersystem crossing process through vibronic coupling.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Chensen Li, Alastair K. Harrison, Yuchao Liu, Zhennan Zhao, Cheng Zeng, Fernando B. Dias, Zhongjie Ren, Shouke Yan, Martin R. Bryce
Summary: The mechanism of thermally activated delayed fluorescence (TADF) in dendrimers is not clear. This study focuses on fully-conjugated or fully-nonconjugated structures and their impact on TADF efficiency. The researchers synthesized asymmetrical half-dendronized and half-dendronized-half-encapsulated emitters to eliminate degenerate excited states and enhance the spin-flip process. By utilizing a encapsulating tricarbazole unit, nonradiative decay is reduced and TADF performance is improved. The non-doped solution-processed devices achieved high external quantum efficiency (EQE) with low efficiency roll-off at different brightness levels.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Polymer Science
Ruru Wan, Xiaoli Sun, Zhongjie Ren, Haijun Wang, Huihui Li, Shouke Yan
Summary: Poly(vinylidene fluoride) (PVDF) films with polymorphic crystal structure were prepared and the effects of heat treatment on the crystal morphology and properties were studied. The results provide a useful way to induce the formation of polar PVDF phases.
Article
Engineering, Environmental
Chensen Li, Alastair K. Harrison, Yuchao Liu, Zhennan Zhao, Fernando B. Dias, Cheng Zeng, Shouke Yan, Martin R. Bryce, Zhongjie Ren
Summary: A novel thermally activated delayed fluorescence (TADF) dendronized polymer was designed and synthesized. The synthesized polymer, PDCDC, exhibited blue or greenish-blue emission and showed unique fluorescence and delayed fluorescence behavior in the presence of oxygen. The PDCDC-based organic light-emitting diodes (OLEDs) achieved a maximum external quantum efficiency of 9.0%, making them the most efficient dendronized polymer devices with blue or greenish-blue emission. These findings are significant for the development of efficient organic light-emitting diode devices.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Polymer Science
Silu Liu, Quanwei Li, Lei Hua, Zhennan Zhao, Zhongjie Ren, Shouke Yan
Summary: In this study, blue-emitting polysiloxanes with TADF properties were successfully designed and synthesized. The photophysical properties of two different structures of copolysiloxanes were compared, and it was found that order-controlled copolysiloxanes can improve the light-emitting efficiency.
MACROMOLECULAR RAPID COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Yuchao Liu, Yanchao Xie, Lei Hua, Xingwen Tong, Shian Ying, Zhongjie Ren, Shouke Yan
Summary: Polymer-based light-emitting diodes (PLEDs) with thermally activated delayed fluorescence (TADF) have gained significant attention for their potential use in large-area and low-cost flexible display equipment. This study provides a valid strategy to enhance the photophysical properties and efficiency of PLEDs by modifying the TADF units and employing an intramolecular sensitizing strategy. The results demonstrate that a rational regulation of component proportions can achieve high photoluminescence quantum yield and low nonradiative decay rate, while suppressing the efficiency roll-off. This work addresses the imperative need for PLEDs with high EQE and low efficiency roll-off.
Article
Chemistry, Multidisciplinary
Zhennan Zhao, Cheng Zeng, Xiaomei Peng, Yuchao Liu, Haisong Zhao, Lei Hua, Shi-Jian Su, Shouke Yan, Zhongjie Ren
Summary: A series of ultrapure-blue thermally activated delayed fluorescence (TADF) emitters featuring through-space charge transfer (TSCT) have been constructed, which exhibit accelerated radiative transition, diminished vibrionic relaxation, reduced Stokes shift, and narrow emission. The corresponding OLEDs based on AC-BO and QAC-BO demonstrate excellent performance with EQE(max) of 19.3% and 15.8%, respectively.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Engineering, Environmental
Yuchao Liu, Yanchao Xie, Yannan Cheng, Xi Tian, Lei Hua, Shian Ying, Shouke Yan, Zhongjie Ren
Summary: By covalently linking thermally activated delayed fluorescence (TADF) groups to phosphorescent iridium (III) complexes, the performance of solution-processed phosphorescent organic light-emitting diodes (PhOLEDs) can be enhanced by effectively utilizing triplet excitons. The prepared complex TriTADF-Ir (dFppy)3 shows a high photoluminescence quantum yield of nearly 73%. The solution-processed PhOLEDs using TriTADF-Ir (dFppy)3 as a light emitter achieve an external quantum efficiency value over 20% and maintain around 16% at 1000 cd/m2.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Multidisciplinary Sciences
Lei Hua, Yuchao Liu, Binbin Liu, Zhennan Zhao, Lei Zhang, Shouke Yan, Zhongjie Ren
Summary: By designing emitters with different TADF units on a TNP core, concentration quenching of TADF units is reduced in the stacking structure of TNPs, resulting in high-efficiency orange-red emission and increased photoluminescence quantum yield. This study provides a universal strategy for designing high-performance TADF emitters.
NATURE COMMUNICATIONS
(2022)
Article
Materials Science, Multidisciplinary
Ling Peng, Yumiao Huo, Shuyao He, Yuchao Liu, Zhongjie Ren, Shian Ying, Shouke Yan
Summary: In this work, a novel linear deep-blue hybrid fluorphore (P2MPC) with good thermal stability and balanced bipolar transporting properties is developed. It can be used for constructing high efficiency and low efficiency roll-off monochromatic and hybrid white OLEDs. P2MPC can serve as a neat emitter to develop non-doped OLEDs and act as a universal host to sensitize green, yellow and red phosphors. High-performance complementary-color and three-color hybrid white OLEDs are achieved using P2MPC as the emitter and host.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
