JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Chao Chen,Luoning Zhang,Xian He,Zuowei Zhang,Foxin Zhou,Cheng Zou,Yanzi Gao,Meina Yu,Huai Yang
Currently, thin polymer-dispersed liquid crystal (PDLC) films used in display applications have rarely been studied because the contrast ratio (CR) considerably decreases with decreasing thickness. Herein, the refractive index of the polymer matrix ( n p ) is adjusted by introducing bromine atoms and benzene rings into the acrylate, and the on-state transmittance is enhanced by improving the matching degree between n p and the ordinary refractive index of the liquid crystal. Simultaneously, the dissimilarity between n p and the average refractive index of LC is also elevated, which increases off-state scattering. This ultimately results in a 123 % increase in CR. Appropriate n p also broadens the viewing angle. In addition, further introduction of the methyl group on the acrylate monomer significantly increases the polymer pore size, resulting in a voltage reduction of 52 %. This study provides a new approach for enhancing the CR of PDLC films, expanding their potential applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Xiaoshuai Li,Meishan Zhang,Chi Zhang,Rui Niu,Hongmei Ma,Yubao Sun
Bistable liquid crystal devices, which require electricity only at the switching processes of the two states, have advantages in energy saving and safety compared with monostable liquid crystal devices. Due to electrohydrodynamic and dielectric effects, the ion-doped cholesteric liquid crystal can switch between a focal conic state and a planar state with different frequencies of the driving voltage. However, the cholesteric liquid crystal that self-assembles from the dynamic scattering state always has a poor focal conic state, resulting in a low contrast ratio. This paper presents a bistable polymer-stabilized ion-doped cholesteric liquid crystal device. The introduction of a small amount of polymer network can greatly enhance the light scattering capabilities of the focal conic state, endowing the device with excellent electro-optic performance. The electro-optical properties of the device are investigated with the various content of monomer and chiral dopant , and rotational viscosity of liquid crystal. Liquid crystal with a low rotational viscosity coefficient is beneficial to the formation of a good polymer network. The pitch induced by chiral dopant impacts the formation process of the polymer network, which subsequently affects the electro-optical properties. The bistable device has a low driving voltage and a high contrast ratio, making it ideal for use in smart windows.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
高影响因子
OPTICS EXPRESS
·
2024
·Vol. 32
·期 17
·29817-29829
·
IF 3.2
Zongtao Li,Zongtao Li,Jiayong Qiu,Xiujuan Liu,Jiasheng Li
To address challenges in enhancing color uniformity and ambient contrast ratio (ACR) in RGB light-emitting diodes (LEDs) without losing efficiency, we developed a scattering-enhanced magnetic manipulation (SEMM) bilayer structure. The effect of the TiO2 scattering layer on improving the LED’s angular intensity non-uniformity (AIN) was studied by ray-tracing simulations and optimized by varying the particle concentration. The magnetic manipulation technique formed the microcolumns and magnetic chains of the Fe3O4 anti-reflective layer, which was optimized by adjusting Fe3O4 particle size, magnetic field strength, and Fe3O4 concentration. The resulting bilayered device significantly increased the ACR by 11.38 times and reduced AIN by 63% compared to conventional graphite-based LEDs, while maintaining high brightness and consistent color quality across angles. This marks a pioneering application of magnetic manipulation in enhancing LED display quality.
研究领域:
光学工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
IEEE Photonics Journal
·
2025
·Vol. 17
·期 2
·1-7
·
IF 2.4
Zong-Tao Li,Yi-Hua Qiu,Jia-Sheng Li,Jin-Cheng Li,Bin-Hai Yu,Xin Zhu,Xin-Rui Ding
Highly light-absorbed encapsulation is generally used to eliminate the ambient light for light-emitting diode (LED) display devices, it is challenging to simultaneously achieve a high ambient contrast ratio (ACR) and high light output efficiency (LOE). To solve this problem, we propose an inverted packaging structure for LED display devices. The LED chips’ emitting surface is mounted on the transparent carrier board (TCB) while the backside is packaged by the composite encapsulation, causing that the substrate is inverted to the topside of devices. As a result, the chips can emit light directly from the TCB and avoid the absorption loss of the encapsulation, leading to the high ACR and LOE performances. Compared to traditional devices, the inverted device showed an average increase of over 800% in luminous flux (LF) and LOE, and an average increase of over 390% in ACR. Additionally, the devices exhibited excellent soldering performance, corrosion resistance, airtightness, and thermal stability. This novel device overcomes the bottleneck of achieving both high ACR and high LOE, providing new insights for the development of LED display technology. Future work can further optimize the structure and materials of the TCB and composite encapsulation to enhance device performance.
研究领域:
光学工程
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材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-10
·
IF 15.7
Li Shanlin,Chen Yingyu,Wang Zhen,Wang Mengmeng,Guo Xianglin,Tang Xueqing,Wang Xiaoyu,Lai Wende,Tong Meiyun,Wang Changhong,Cong Shan,Geng Fengxia,Chen Yong,Zhao Zhigang
Electrochromic materials were discovered in the 1960s when scientists observed reversible changes between the light and dark states in WO 3 thin films under different voltages. Since then, researchers have identified various electrochromic material systems, including transition metal oxides, polymer materials, and small molecules. However, the electrochromic phenomenon has rarely been observed in non-metallic elemental substances. Herein, we propose the development of non-metallic iodine electrodeposition-based electrochromic dynamic windows using a water-in-salt electrolyte containing iodine ions. The unique electrolyte environment and solvation structure of the water-in-salt electrolyte suppress the dissolution and shuttle effect of iodine, thereby achieving a different reaction pathway compared to traditional electrolytes. This pathway involves a reversible solid-liquid transition between solid iodine and solvated iodide ions. The iodine electrodeposition-based electrochromic dynamic window demonstrates a high optical contrast of 76.0% with near colour neutrality and excellent cycling stability. A practical 400 cm 2 complementary dynamic window is fabricated to demonstrate good electrochromic performance, including high optical contrast, a near colour-neutral opaque state, fast response time, uniform modulation, and polarity-switchable functionality.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 24
·48808
·
IF 2.188
Shuwei Cai,Haijun Niu
In this study, four novel triarylamine-based polyimides with different substituted groups (tert-butyl and -H) containing pyrrole moieties were successfully prepared by polycondensation reaction. The electrochemical and electrochromic properties of the polyimides were measured by cyclic voltammetry and spectro-electrochemistry. The polyimides exhibited obvious electrochromic behavior with good thermal stability (the 10% weight-loss temperatures were recorded in the range of 345-386°C), film-forming ability and reversible stability after 1000 s. The color of the polyimide films changed from colorless to light blue or yellow to blue on increasing the applied potential. The highest coloration efficiency reached up to 190 cm 2 C −1 . The polyimide films exhibited a stable response to the light (on or off) after 200 s. Especially, PyHBTPI displayed effective solubility, superior optical contrast (~30%) in the visible region, faster response time (1.19 s for coloring process), and obvious color change from yellow to blue with good stability, thus, confirming the potential use for high contrast displays. Overall, the study demonstrates the successful development of high-performance polyimides for electrochromic and optoelectronic behaviors. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48808.
研究领域:
材料科学
·
电化学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Hongbo Lu,Peng Huang,Tanyang Wu,Cuifen Chen,Jianzhou Shi,Miao Xu,Longzhen Qiu,Yunsheng Ding,Jun Zhu
A wavelength-selective, two-stage polymerization of acrylate-thiol for the formation of polymer dispersed liquid crystal (PDLC) films is developed. Via this method, the PDLC with microsphere polymer morphology was successfully prepared, which greatly improved the contrast ratio (CR) and adhesion without causing other performance degradation. The change of morphology from the porous to the microsphere structure could be controlled by adjusting the reaction time of the Michael addition reaction. Furthermore, the size and uniformity of the microsphere structure could be controlled by tuning the content of the free radical initiator. This work is expected to provide an effective method to control the microstructure of acrylate-thiol polymers in solution polymerization , and can possibly allow the fabrication of PDLCs with high CR and adhesion, which is of great significance in large, flexible displays, switchable windows, and light valves.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Guangyou Liu,Jie Liu,Qitian Fan,Yunhe Liu,Zheng Zeng,Zhuohang Li,Xinzao Wu,Mingyang Yang,Bo-Ru Yang
Smart windows can dynamically control the optical transmittance of natural light and efficiently reduce the energy consumption of buildings. Currently, the practical application of smart windows is limited by high power consumption, low transmittance, and complicated preparation process. Developing smart windows with fast response and high transmittance is challenging. Herein, we fabricated a smart window based on electrophoretic display (EPD) technology, which can switch between white and transparent states by changing the stacking states of the electrophoretic particles on electrodes. To further increase the transmittance of the smart window, the polyvinyl alcohol (PVA) hydrophilic layer was spin-coated on the electrode to reduce the adhesion of particles. Compared with other EPD smart window technologies, our device exhibits the fastest response time of up to 375 ms at 30 V, high transmittance of up to 78% at 632 nm, and a high contrast ratio of up to 89. In addition, to reduce the particle’s lateral diffusion and improve our device's stability, the microcup array was aligned on the interdigital electrode. The particles can be driven and stacked onto the side walls of the microcup to achieve a transparent state. This work demonstrated that the EPD device would provide a promising future for practical smart windows with high transmittance and fast response time.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2023
·
IF 4.5
Guangyou Liu,Xinzao Wu,Feng Xiong,Jinglan Yang,Tao Zhou,Qitian Fan,Jie Liu,Zhuohang Li,Zheng Zeng,Yunhe Liu,Bo-Ru Yang
As the Internet of Things (IoT) significantly improves people's lifestyles, flexible and low-power displays will become essential to real-time human-computer interaction. Electrophoretic display (EPD) has many advantages, such as low power consumption , flexibility, and high sunlight visibility, which is necessary for IoT terminal display. However, preparing electrophoretic particles with high charge and spatial resistance is difficult. Herein, dual-silane coupling agents, (3-Aminopropyl) trimethoxysilane (APS) and vinyltrimethoxysilane (VTS), were co-grafted on the black particles to optimize the electrophoretic particles' dispersity and charge. To evaluate the charge content and dispersity of particles, we measured the particles with zeta potential , dynamic light scattering, and long-term standing treatment. Fe 3 O 4 -APS 0.5 VTS 0.5 -PLMA, selected as the black particles for EPD, had an average particle size and zeta potential of 300 nm and 25 mV, respectively. Besides, the concentration of the black and white particle would significantly affect the EPD's performance. When optimizing the white and black particle concentration to 4:1, the contrast ratio of EPD was up to 13.2. In addition, the EPD has a response time of 200 ms and exhibits an invertible black and white state under ±15 V. Finally, to improve the stability of electrophoretic particles, the particles were encapsulated in microcups and driven to the black and white state under 30 V. This work demonstrated that dual-silane coupling agent particles have the potential to achieve the fast response and high contrast ratio EPD.
研究领域:
材料科学
·
显示技术
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2013
·
IF 3.777
Shi-Ming Wang,Lin Liu,Wei-Lin Chen,En-Bo Wang
Polyoxometalates (POMs) are a kind of metal oxide nanoclusters with excellent electrical properties, which have proved to be an excellent candidate for electrochromism (EC) materials. In this paper, we present a better performance POMs-based EC material on the TiO 2 substrate through adjusting the structure of the Well-Dawson type POMs with the electrodeposition method, which can overcome the high cost of the traditional methods such as vacuum evaporation or sputtering. The performance of the EC smart windows was fully tested. The maximum optical contrast for the K 10 [P 2 W 17 O 61 ]·20H 2 O (P 2 W 17 )-based EC smart window is 93.1% at the wavelength of 620 nm and for the K 6 [P 2 W 18 O 62 ]·14H 2 O (P 2 W 18 )-based EC smart window is 48.7% at 646 nm. The coloration time extracted for a 90% transmittance for the P 2 W 17 -based EC smart window is 0.9 s and for the P 2 W 18 -based smart window is 0.97 s; the coloration efficiency for the P 2 W 17 -based EC smart window is 205.3 cm 2 C −1 and the P 2 W 18 -based smart window is 176.8 cm 2 C −1 . Both of the P 2 W 17 - and P 2 W 18 -based EC smart windows have the feature of remarkable durability over 1000 cycles. The P 2 W 17 -based smart window has larger optical contrast and higher coloration efficiency than the P 2 W 18 -based smart window. More significantly, the near-infrared behavior of the P 2 W 17 under different applied potentials was recorded for the first time by using the smart window. We believe the performance of the P 2 W 17 -based smart window is the state-of-the-art among the POMs-based EC smart windows.
研究领域:
材料科学
·
纳米技术
·
能源与环境工程
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2019
·
IF 6.019
Jinming Zeng,Hui Li,Zhijun Wan,Lianghui Ai,Ping Liu,Wenji Deng
Poly(4-vinyltriphenylamine) (PVTPA) was synthesized, and cross-linked poly(4-vinyltriphenylamine) (PVTPA-CL n ) films with a thickness of 260 nm (CL1), 510 nm (CL2), and 680 nm (CL3) were prepared by electropolymerization . Using the PVTPA-CL2 and PVTPA-CL3 films as active materials, the electrochromic devices (ECDs) were fabricated. The structures of the devices were indium tin oxide (ITO) glass/gel electrolyte/PVTPA-CL2/ITO glass (ECD 1) and ITO glass/gel electrolyte/PVTPA-CL3/ITO glass (ECD 2). The electrochromic properties of the PVTPA, PVTPA-CL n films, and ECDs were investigated. Among them, the PVTPA-CL2 and PVTPA-CL3 films exhibited reversible color changes from colorless to gray-green and from colorless to black upon electrochemical doping and dedoping, respectively. The optical contrast of the PVTPA-CL2 and PVTPA-CL3 films were 81.0% and 84.3% at 750 nm, respectively. The ECD 1 could reversibly change between colorless and gray-green under different voltages, and it exhibited 78.3% optical contrast at 750 nm. Notably, ECD 2 could reversibly change between colorless and black under different voltages, and it exhibited 85.0% optical contrast at 750 nm. ECD 1 had shorter switching time than ECD 2, its coloring and bleaching times were 9.5 and 7.3 s, respectively. Both ECD 1 and ECD 2 exhibited reasonable electrochemical cyclic stability.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2018
·Vol. 47
·期 7
·2344-2351
·
IF 4.099
Xiao Zhu,Wan-Ying Zhang,Cheng Chen,Qiong Ye,Da-Wei Fu
Photoelectric dual-function features in bulk crystals or flexible thin films make them excellent candidates for important and thriving applications in storage, sensing and other information fields. Based on superior advantages such as easy and environmentally friendly processing, mechanical flexibility, and ability to fabricate films and bulk single crystals; we designed a type of molecular material with a photoelectric multi-function switch, [N(NH2CH2CH2)3]2Mn2Cl12 (compound 1), which exhibits intriguing temperature-dependent dielectric and red emission switchable characteristics. This material perfectly explains the advantages of molecular materials, while 1 can also be used to fabricate a transparent unidirectional film with ultra-flexibility. Moreover, this material shows the highest record in signal contrast of ∼5 (exceeding all the known molecular materials/crystalline switches, revealing its potential to obtain high-efficiency signal-to-noise ratio), sensitive dielectric bi-stability, and excellent switching anti fatigue. These features give it a high application value in integrated circuits, optoelectronic seamless integration devices and flexible multifunctional devices.
研究领域:
材料科学
·
光电子学
·
信息存储与传感
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）