Novel structure of GaAs-based interdigital-gated HEMT plasma devices for solid-state THz wave amplifier

Theoretical analysis of potential distribution in the interdigital-gated high electron mobility transistor (HEMT) plasma wave device was carried out. The dc I–V characteristics of capacitively coupled interdigital structure showed that uniformity of electric field under the interdigital gates was improved compared to the dc-connected interdigital gate structure. Admittance measurements of capacitively coupled interdigital gate structure in the microwave region of 10–40 GHz showed the conductance modulation by drain–source voltage. These results indicate the existence of plasma wave interactions.     

Building Elastic Solid Electrolyte Interphases for Stabilizing Microsized Antimony Anodes in Potassium Ion Batteries

Alloy anodes composed of microsized particles receive increasing attention recently, which outperform the nanostructured counterparts in both the manufacturing cost and volumetric energy density. However, the pulverization of particles and fracture of solid electrolyte interphase (SEI) during cycling brings about fast capacity degradation. Herein, it is shown how normally considered fragile SEI can become highly elastic through electrolyte chemistry regulation. Compared to the SEI constructed in classic carbonate electrolyte, the atomic force microscopy tests reveal that the one built in ether-based electrolyte doubles the maximum elastic strain to accommodate the repeated swelling-contracting. Such an SEI effectively encapsulates the microsized Sb anodes to prevent the capacity loss from particle isolation. Coupled with an intercalation-assisted alloying reaction mechanism, a sustained capacity of ≈573 mAh g⁻¹ after 180 cycles at 0.1 A g⁻¹ with outstanding initial Coulombic efficiency is obtained, which is among the highest values achieved in K-ion batteries. This study emphasizes the significance of building robust SEI, which offers the opportunity to enable stable microsized alloy anodes.     

彩色PDP动态假轮廓的改善方法

PDP发光在时间上的非线性和人眼平滑跟踪运动目标的自然倾向是彩色等离子体显示器产生动态假轮廓(DCF)的主要原因,文中详细介绍了目前改善DCF的主要方法和基本原理,并对各种方法的优缺点作了分析和评价.得出的结论是:在DCF和灰度级表现能力之间折衷是目前改善DCF最适合的方法,而运动补偿方法消除DCF是发展方向.     

聚乙二醇丁二酸酯对铝电解电容器工作电解液性能的影响

以聚乙二醇(400)和丁二酸酐为原料,合成了聚乙二醇丁二酸酯(PEGS).考察了所制PEGS的添加量和pH值对工作电解液的闪火电压.电导率以及铝电解电容器性能的影响.结果表明:PEGS可以提高工作电解液的闪火电压,并有效抑制电导率的降低:当添加PEGS的质量分数为3%时,工作电解液的闪火电压最大可升高45V,电导率只降...     

Armoring LiNi1/3Co1/3Mn1/3O2 Cathode with Reliable Fluorinated Organic–Inorganic Hybrid Interphase Layer toward Durable High Rate Battery

Ternary layered oxide materials have attracted extensive attention as a promising cathode candidate for high‐energy‐density lithium‐ion batteries. However, the undesirable electrochemical degradation at the electrode–electrolyte interface definitively shortens the battery service life. An effective and viable approach is proposed for improving the cycling stability of the LiNi_1/3Co_1/3Mn_1/3O₂ cathode using lithium difluorophosphate (LiPO₂F₂) paired with fuoroethylene carbonate (FEC) as co‐additives into conventional electrolytes. It is found that the co‐additives can greatly reduce the interface charge transfer impedance and significantly extend the life span of LiNi_1/3Co_1/3Mn_1/3O₂//Li (NMC//Li) batteries. The developed cathode demonstrates exceptional capacity retention of 88.7% and remains structural integrity at a high current of 5C after 500 cycles. Fundamental mechanism study indicates a dense, stable fluorinated organic–inorganic hybrid cathode‐electrolyte interphase (CEI) film derived from LiPO₂F₂ in conjunction with FEC additives on the surface of NMC cathode material, which significantly suppresses the decomposition of electrolyte and mitigates the dissolution of transition metal ions. The interfacial engineering of the electrode materials stabilized by the additives manipulation provides valuable guidance for the development of advanced cathode materials.     

Electrocatalytic Interlayer with Fast Lithium–Polysulfides Diffusion for Lithium–Sulfur Batteries to Enhance Electrochemical Kinetics under Lean Electrolyte Conditions

Lithium–sulfur batteries are promising energy‐storage devices because of their high theoretical energy densities. For practical Li–S batteries, reducing the amount of electrolyte used is essential for achieving the high energy densities. However, reducing the electrolyte amount leads to severe performance degradation, mainly because of sluggish deposition of discharge products (Li₂S) and the accompanying passivation issue that arise from the insulating nature of Li₂S. In this study, a lightweight, robust interlayer, with a 3D open structure and a low surface area is designed and fabricated. The structure facilitates electrolyte infiltration without trapping too much electrolyte. Moreover, the electrocatalytic Co nanoparticles embedded in the skeleton surface within the interlayer effectively promote Li ion diffusion, polysulfides conversion, and Li₂S deposition, and therefore enhance the electrochemical kinetics under lean electrolyte conditions. The mechanisms involved in the interlayer effects are investigated by microstructural characterizations, electrochemical performance tests, density functional theory calculations, and in situ X‐ray diffraction characterization. These results show the feasibility of using an interlayer strategy to improve the electrochemical performances of Li–S batteries under lean electrolyte conditions to potentially increase the practical energy densities of Li–S batteries.     

硼酸聚酯对铝电解电容器工作电解液性能的影响

选用乙二醇、二甘醇、聚乙二醇(200,400)和硼酸为原料,制备了一系列硼酸聚酯。考察了所制样品对铝电解电容器工作电解液的闪火电压、电导率、热稳定性及含水量的影响,并从机理方面进行了分析。结果表明:所制硼酸聚酯可以明显提高工作电解液的闪火电压和热稳定性,并能降低工作电解液的含水量;以硼酸乙二醇聚酯对工作电解液闪火电压提高贡献最大,其添加质量分数为6%时,可提高37.8V,电导率由1422×10–6S/cm降至1057×10–6S/cm,含水量(质量分数)降低51.3%;经过氨解后的硼酸聚酯的水解稳定性优于未氨解的产品。     

Performance enhancement of poly (vinylidene fluoride-co-hexafluoro propylene)/polyethylene oxide based nanocomposite polymer electrolyte with ZnO nanofiller for dye-sensitized solar cell

Nanocomposite polymer electrolytes (NCPEs) were prepared by blending poly (vinylidene fluoride-co-hexafluoro propylene) copolymer (PVdF-HFP) and polyethylene oxide (PEO) polymers and incorporation of ZnO inorganic nanofiller (PVdF-HFP:PEO:EC:PC:NaI:I₂:ZnO). The highest ionic conductivity value of 8.36 mS cm⁻¹ was recorded when 3 wt.% of ZnO inorganic nanofiller was incorporated into the NCPE system. Temperature-dependant ionic conductivity behaviour of NCPEs was analysed and proven to follow the Arrhenius thermal activated model. Structural studies of NCPEs were carried out using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy analysis. NCPEs were used to fabricate Dye-sensitized solar cells (DSSCs). Enhancements in the solar light to electricity conversion efficiency (η) of DSSCs were observed in the presence of ZnO inorganic nanofiller in the NCPE system and NCPE with 3 wt.% ZnO represented the highest η of 7.33% under full sun irradiation.     

Combined use of three-dimensional X-ray diffraction imaging and micro-Raman spectroscopy for the non-destructive evaluation of plasma arc induced damage on silicon wafers

The practicality of plasma etching, combined with low temperature and directional process capabilities make it an integral part of the IC manufacturing process. A significant cause of damage to wafers during plasma processing is arcing damage. Plasma arcing damage results in large pits and non-uniformities on the wafer surface which can lead to wafer breakage and high yield losses.Thus a non-destructive wafer damage metrology is crucial to the understanding of wafer failure mechanisms. We report on the successful use of a combined suite of non-destructive metrology techniques to locate the arc damage sites and examine the physical processes which have occurred as a result of the damage. These consist of 3D X-ray diffraction imaging (3D-XRDI), micro-Raman spectroscopy (μRS), and scanning electron microscopy (SEM).In the case of the two examples examined in this study the plasma induced damage on the wafer surface appears as regions of damage ranging from 100 μm to 1000 μm in diameter. 3D-XRDI shows that the strain fields propagate out from the damage site in all directions, with the damage penetrating up to ? of the way through the substrate. K-means clustering and false colouring algorithms are used to highlight the regions of interest in 3D-XRDI, and to enhance the analysis process. Sectioning of the 3D images has enabled non-destructive imaging of the internal damage in the samples at any location. Micro-Raman spectroscopy results indicate the presence of both crystalline and amorphous silicon. Strain measurements at the damage site show tensile strains as high as 500 MPa in certain situations, with strain levels increasing from the surface towards the bottom of the dislocation cell structures, which can be distinguished in the synchrotron X-ray topographs. 3D-XRDI and μRS results are in close correlation, proving the potential for 3D-XRDI as non-contact, non-destructive metrology particularly suited to these problems.     

Gel Polymer Electrolyte toward Large-Scale Application of Aqueous Zinc Batteries

Aqueous zinc batteries are promising candidates for energy storage and conversion devices in the “post-lithium” era due to their high energy density, high safety, and low cost. The electrolyte plays an important role in zinc batteries by conducting and separating the positive and negative electrodes. However, the issues of zinc dendrites growth, corrosion, by-product formation, hydrogen evolution and leakage, and evaporation of the aqueous electrolytes affect the commercialization of the batteries. Moreover, the widely used aqueous electrolytes result in large battery sizes, which are not conducive to the emerging smart devices. The intrinsic properties of gel polymer electrolytes (GPEs) can solve the above problems. In order to promote the wider application of GPEs-based zinc batteries, in this review, the working principle and the current problems of zinc batteries are first introduced, andthe merits of GPEs compared to aqueous electrolytes are then summarized. Subsequently, a series of challenges and corresponding strategies faced by GPE is discussed, and an outlook for its future development is finally proposed.