VACUUM
·
2020
·
IF 2.906
Han Wu,Siqi Shen,Jun Li,Xiaohong Chen,Zhejuan Zhang,Wei Ou-Yang
Boosted field emission (FE) cathodes of silicon carbide nanowires (SiC NWs) filled with polyaniline (PANI) and polypyrrole (PPY) coatings were prepared via cyclic voltammetry method, which is facile, feasible and capable to control the coating-thickness. As compared to pristine SiC, the average turn-on field ( E on ) of SiC/PANI and SiC/PPY under several of repeat experiment decreased from 1.84 to 1.44 and 1.04 V/μm, respectively. The lowest E on of SiC/PPY even dropped down to 0.95 V/μm with raised field enhancement-factor and conductivity, identifying that the FE properties have been improved by depositing PANI and PPY due to enhanced conductivity. However, the conductivity would be saturated with the continuously increasing depositing-thickness and overly thick coatings would block the efficient FE points and reduce the effective electric field between cathode and anode, causing a worse FE performance instead. Besides, the optimal FE performance was obtained in SiC/PPY, which not only had a much lower E on , but also reinforced the stability. The synergy of conductivity effect and thickness effect found in this study indicates SiC/PPY to be a promising candidate for FE applications in vacuum electronic devices.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Xianwen Yan,Jin Li
Organic photodetectors with bulk heterojunctions were constructed with a structure of ITO/ZnO/P3HT:PC 61 BM/MoO 3 /Al. The effect of the thickness of the ZnO layer on the properties of the device were investigated by fabricating photodetectors with different ZnO layer thicknesses: 20, 40, 50, 60, and 80 nm. The 40 nm-thick ZnO electron transport layer provided the device with a low dark current density (1.7 × 10 −9 A/cm 2 ), high specific detectivity (2.7 × 10 13 Jones), wide linear dynamic range (78.9 dB), and fast response speed ( τ r / τ f = 0.61/0.75 μs). The results show that an optimal thickness of the ZnO electron transport layer can effectively block hole injection into the active layer, which is a promising strategy to improve the performance of organic photodetectors.
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 2
·777-784
·
IF 3.9
Shi-Kuan Sun,Jin-Hao Yuan,Wei-Ming Guo,Xiao-Ming Duan,De-Chang Jia,Hua-Tay Lin
This study aimed to investigate the effects of the original thickness on the densification, microstructure, and nanoindentation hardness of silicon carbide (SiC) ceramics prepared by the spark plasma sintering (SPS) process. The densification of SiC ceramics with different initial thicknesses ranging from 50 to 2000 µm was investigated in combination with varying SPS sintering temperature at 1700–1900°C. The results indicated that the densification of SiC sample with the initial thickness of 50 µm was complete after sintering at 1700°C. On the contrary, when the initial thickness exceeded 50 µm, it resulted in a porous microstructure. When the initial thickness varied from 50 to 100 µm, dense SiC monolithic could be obtained after sintering at 1800°C. All the samples were fully densified after sintering at 1900°C. The predominant factors for the thickness effect were mainly derived from the unique characteristics of SPS. The hardness of SiC ceramics was measured using nanoindentation, and it was found to have a strong correlation with the initial thickness, mainly attributed to the densification status. The dense SiC product demonstrated nanoindentation hardness with high values of ∼28.0 GPa.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
Ceramics-Switzerland
·
2024
·Vol. 7
·期 1
·29-38
·
IF 2.7
Wenfeng Yue,Yali Cai,Quansheng Guo,Dawei Wang,Tingting Jia
The pursuit of low-power/low-voltage operation in devices has prompted a keen interest in the mesoscale effects within ferroelectric thin films. The downsizing of ferroelectrics can significantly influence performance; for instance, the remanent polarization and coercive field are susceptible to alterations based on thickness. In this study, randomly oriented Bi3.25La0.75Ti3O12thin films were fabricated on Pt/Ti/SiO2/Si substrates using the sol–gel method, and SEM observations revealed rod-like grains in all thin films. The investigation delved into the correlation between dielectric and ferroelectric properties with thin film thickness. The thin film exhibited an increased remanent polarization and a reduced coercive electric field. Additionally, the ferroelectric domain structure was scrutinized through PFM, and the resistor properties of the BLT4 thin film were studied, which shows the potential of BLT thin films in non-volatile memory and memristor.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2024
·Vol. 16
·期 19
·2709
·
IF 4.7
Bochu Du,Chenghao Lee,Ying Ji
Enhancing the degradability of polyethylene plastics could provide a potential solution to the overwhelming crisis of plastic waste. Conventional studies have focused on the degradation of polyethylene thin films. This study investigated UV-induced photo-degradation according to ASTM D5208-14 in polyethylene sheets with thicknesses ranging from 0.4 to 1.2 mm. The impacts of sample thickness, metal pro-oxidants, polyethylene resin types and foaming were explored through the characterization of the carbonyl index, molecular weight, tensile properties and crystallinity. As pro-oxidants, single iron or manganese stearate demonstrated a concentration-dependent trend in accelerating the photo-degradation of polyethylene sheets. The thickness, foaming and resin type—such as low-density polyethylene (LDPE) and high-density polyethylene (HDPE)—significantly impacted the rate of photo-oxidation. Thick polyethylene sheets (1.2 mm) exhibited a heterogenous and depth-dependent degradation profile. As the photo-degradation progressed, the enhanced crystallinity, reduced UV transmittance and formation of crosslinks were able to prevent further oxidative cleavage of the polyethylene chain. This study investigated the time course and factors affecting the photo-degradation of polyethylene sheets, which could provide insights into the formulation design of photo-degradable polyethylene plastics.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NANOTECHNOLOGY
·
2020
·Vol. 31
·期 35
·355201
·
IF 3.551
Xiaojing Lv,Xinjia Xu,Yujian Zhang,Dominic S Wright,Yongfu Zhang,Cheng Zhang
TiO2 nanowires with high transparency and good ion storage capacity were explored as the charge-balancing layers for assembling electrochromic devices (ECDs). Increase thickness of TiO2 nanowires layer lowers the driving potential of the entire ECDs accompanied with reduced potential at the EC layer electrode, which further leads to decreased optical contrast and switching speed of the ECDs. Meanwhile, it can be found that the EC layer electrodes possess larger charge densities than those of TiO2 nanowire electrodes during the electrochemical redox process of these ECDs. However, the intrinsic injection and extraction charge densities of each single electrode are similar, which appears that the intrinsic charge balance of EC layer and TiO2 nanowires electrodes play more important role in the cycling stability of the ECDs. ECD with an optimum thickness of the TiO2 nanowires layer exhibits good electrochromic properties in term of high optical contrast (∼45%), fast switching speed (3.23 s) and excellent cycling stability (which has nearly no decay after 5000 cycles). This study explores the effects of thickness of TiO2 Nanowires layer on electrode potentials and electrochromic properties of electrochromic devices (ECDs), providing a potentially new direction for the preparation of ECDs with good integrated performance.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2014
·Vol. 26
·期 2
·884-890
·
IF 1.966
Li Rui,Wang Yan-ze,Mao Zhi-yong,Wang Da-Jian
A remote phosphor coating by using Sr 3 (Al,Si)(O, F) 5 :Ce 3+ (SASF:Ce 3+ ) on glass substrate was prepared by a simple and convenient screen printing method. The crystalline phase and the distribution of SASF:Ce 3+ crystals in coating were investigated by XRD and SEM, respectively. The scattering light and absorption light properties of remote phosphor coating with different thicknesses were discussed through Lambert–Beer’s law. The relationship between luminous efficiency and absorption coefficient was demonstrated. White light emitting diode prototype fabricated with blue chip and the prepared patterned SASF:Ce 3+ remote phosphor in this work showed excellent performances, opening a cost-effective process to generate planar white light.
研究领域:
材料科学
·
光学工程
·
发光材料
·
固态照明
·
功能涂层
✓ 已验证
DOI
高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
·
2025
·
IF 3.6
Danqing Yu,Xiaoqiang Zhang,Jianmei Han,Xingjie Zan,Yan Guo,Xuyang Chen
Microcapsules are considered as one of the most promising drug carriers due to their exceptional characteristics. The cellular uptake of microcapsules is determined by physicochemical properties, yet comprehensive studies on thickness and shape effects are limited. In this study, we developed single-layered poly(amidoamine) (PAMAM) dendrimer microcapsules with tunable thicknesses and morphologies to systematically investigate their cellular internalization. By varying PAMAM generations (G2–G8), the wall thickness can be tuned within the range of 19.3–53.7 nm, while the microcapsule shapes can be determined by the distinct morphologies of the CaCO3 templates (spherical, peanut-like, dumbbell-like). Cellular uptake studies in DC2.4 cells revealed significant thickness- and shape-dependent trends: among spherical microcapsules, OPC/PAMAM-G6 microcapsules with a thickness of 43.5 nm exhibited higher internalization efficiency than their counterparts, while among OPC/PAMAM-G6 microcapsules, dumbbell-like microcapsules outperformed spherical and peanut-like microcapsules. Notably, dumbbell-shaped microcapsules with negative surface charge (−11.8 mV) demonstrated superior biocompatibility and uptake kinetics. This study demonstrates the structural diversity and functional versatility of PAMAM microcapsules by utilizing oligomeric proanthocyanidins (OPC), proposing a simple and universal method for preparing polyphenol/polymer microcapsules that can be applied to practical drug delivery systems.
研究领域:
生物医学工程
·
纳米技术
·
药学
·
材料科学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）