Silicon最新文献

Decreased carrier mobility in the junctionless field-effect transistors (JLFETs) channel limits their performance for applications in high-frequency electronics. This paper presents a drain doping technique based on CMOS technology is offered for the first time to improve the analog/RF performance and high-frequency noise parameters of a CONV-shell doped channel- JLFET (CONV-SDCHJLFET). The proposed device is called DG-JLFET with T-shape drain doping (DG-JLFET with TSDD), in which two main drain regions (regions d₁ and d₂) are crucial to achieve the desired results. By fine-tuning various influencing factors within these two regions, the DG-JLFET with TSDD achieves a transconductance (g_mmax) of 4.41 mS/um, a cut-off frequency (f_T) of 813 GHz, a minimum noise figure (NF_min) of 0.6 dB and an available associated gain (Gma) of 19.92 dB. g_mmax, f_T, NF_min, and Gma of the SDCh-JLFET increased by 78%, 30%, 53%, and 19.2%, respectively, compared to the CONV-SDCHJLFET with similar dimensions. This device is excellent for analog/RF applications and performs well in high-frequency noise, making it an ideal choice for demanding next-generation telecommunications applications.

Many research is underway in the semiconductor industry. Conventional MOSFETs are getting replaced with emerging devices such as junctionless field-effect-transistor (JLTFET) to increase the efficiency and performance of the devices. The incorporation of junctionless mechanism in JLTFET has significantly reduced fabrication complexity because of independency with the pn junction formed at source and drain regions. JLTFET has shown promising electrical behavior with the improvement in the ON-state current, reduction in ambipolar conduction, and reduced short channel effects. The significant enhancement in OFF-state current resulting in improved I_ON/I_OFF drain current ratio which in turn result in comparatively steeper subthreshold slope. In this review paper, the significance of JLTFET has been analysed in terms of its working principle and considering its electrical behavior such as architectural, dielectric, semiconductor material, oxide thickness, gate workfunction, source workfunction engineering and its performance at higher temperature.

Experiments on directional solidification were carried out to investigate how purification of metallurgical-grade silicon in cast furnaces is affected by changes in heat extraction from and heat supply to their melts. A reference condition analogous to that in the block-casting process was established using top/side heaters to supply heat and a water-cooled base to extract heat from the bottom of a graphite-clay crucible. This condition was modified by (a) changing the crucible bottom material to graphite, (b) increasing the length of the resulting ingot from 100 to 130 mm, and (c) turning off the heaters. Temperatures were measured within the melt and in the furnace environment. The grain macro-microstructures and the macrosegregation of impurities of the ingots were revealed. The cooling rates and solid–liquid interface velocity calculated with a mathematical model increase relative to the reference experiment when the graphite crucible bottom is used or when the top/side heaters are absent. The vertical temperature gradients also increase with the graphite bottom, but significantly decrease without the heaters. Most of the ingots exhibit a purified lower region of columnar grains with straight boundaries, free from intermetallic particles, and an upper region with mixed long and short columnar grains with serrated boundaries, precipitated particles, and higher impurity concentrations. Changing the crucible bottom material from graphite-clay to graphite increases the length of the purified region from 70 (reference condition) to 97 mm, whereas turning off the heaters completely eliminates this region. Although the graphite crucible bottom (with the top/side heaters) yields the longest purified region, the graphite-clay bottom (also with the heaters) gives the lowest impurity concentrations.

Silicon oxide has become promising negative electrode materials for lithium-ion batteries due to its high specific capacity, abundant reserve, and moderate lithiation potential. However, the cyclic stability and high-rate capacity are unsatisfied due to the large volume change during charging/discharging and poor electrical conductivity of both silicon and silicon oxides. Herein, a novel hierarchical structure composed of SiO_x, NiO and carbon nanotubes (CNTs) is proposed and prepared in a facile ball-milling and hydrothermal method. The interlaced CNTs network and NiO nanoparticles coated outside the SiO_x particles act as highly conductive porous shell and prevent crack and pulverization of SiO_x. Benefiting from this structure, the SiO_x/NiO/CNTs composites demonstrate excellent rate capacity and cyclic performance of 916.3 mAh g⁻¹ after 200 cycles at 0.5 A g⁻¹.

This study proposes energy-efficient smart windows based on one-dimensional photonic crystal structures that operate without an external power source and discuss the design and analysis of the proposed smart window which is composed of SiO2/Vo2 layers, their interaction with light and heat, the effect of the incident waves angles and their potential to reduce energy consumption and radiation exposure. The proposed window proves the performance of blocking harmful rays of ultraviolet and infra-red region even the temperature, polarization and the incident wave angles change and transmitting visible light except the green color that the window appears with, which adds a beauty view to it.

This study explores the in-situ incorporation of silica (SiO₂) microparticles into a hard-soft segmented polyurethane (PU) matrix to enhance its properties for potential coating applications. The structural characterization of the material was conducted using Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), and Field Emission Scanning Electron Microscopy (FE-SEM) studies. In the FTIR spectra, the C = O absorption peaks in urethane at 1707 and 1726 cm⁻¹ for PU-Neat film shift to 1702 and 1716 cm⁻¹ in PU-SiO₂, indicating H-bonding between polyurethane and SiO₂. The optical, thermal, and mechanical properties of the material were evaluated through transmittance, haze measurement, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and mechanical analysis. The results demonstrated that adding SiO₂ microparticles significantly improved the thermal stability, and the glass transition temperature (T_g) increased from 2.52 °C to 3.0 °C due to the incorporation of SiO₂ particles, as analyzed from DSC; these results are supported by DMA findings. The silica-incorporated polyurethane demonstrated significantly higher resistance to scratching, with a threshold load of 1800 g compared to PU-Neat (1000 g). The PU-SiO₂ composite exhibited a higher maximum decomposition temperature (T_max, 393.9 °C) and increased tensile strength (21.21 MPa) compared to neat PU. Enhanced thermal conductivity (1913.91 W/cm.^oC) and mechanical properties were attributed to the uniform dispersion of silica microparticles within the matrix, as confirmed by FE-SEM analysis. These findings indicate that SiO₂-incorporated polyurethane composites are promising candidates for hard coating applications requiring enhanced durability and performance under mechanical stress.

Mustard (Brassica juncea) is a major oilseed and medicinal crop and its consumption has considerably increased with growing human population, leading to greater demand than supply. Increasing production and productivity of oilseed brassica to meet out the projected demand of edible oils, crop management strategies need to be fabricated and implemented. The two varieties of mustard, RH 725 and RH 0749 display superior performance for yield and are recommended for farmers’ fields in north India. The present study evaluated the efficacy of silicon applied in the form of orthosilicic acid (OSA) for improving the physiological and biochemical performances, growth, and yield of recommended mustard varieties under field conditions, as a function of variety, stage, dose, and application time. OSA was applied as a foliar spray at 20, 30, and 40 ppm during vegetative and flowering stages to analyse its influence on plant growth, physiology, enzymatic and non-enzymatic antioxidant enzymes, and yield attributes. Application of OSA at 30 ppm at vegetative stage and 20 ppm at flowering stage, increased activity of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POX) and metabolites, ascorbic acid and glutathione; and decreased the levels of hydrogen peroxide (H₂O₂), malondialdehyde (MDA), and relative stress injury (RSI), as compared to the respective untreated controls. The increase in antioxidant enzyme activity and ascorbic acid and glutathione content and protein content was greater in RH 0749 than RH 725. Photosynthetic rate, stomatal conductance, transpiration rate, and chlorophyll fluorescence and protein content improved with the application of 20 ppm OSA, where RH 0749 responded more at the vegetative stage whereas RH 725 showed better responses at flowering stage. The growth and yield related attributes also enhanced with the foliar application of 20 ppm and 30 ppm OSA in both the varieties. RH 725 displayed an increase of 15% and RH 0749 displayed an increase of 18% in seed yield with 20 ppm OSA. Single foliar application of OSA could yield pronounced effects on growth, physiological and biochemical responses and yield of Brassica varieties. The present study indicates the ability of OSA in low dosesto modulate crop physiological and biochemical responses under field conditions can contribute to bridging the productivity gap of brassica to meet consumer demand for establishing a sustainable cropping system.

Graphical Abstract

Diagrammatic overview of Brassica juncea varieties subjected to OSA treatments during the vegetative and flowering stages for the experiment. 20 ppm OSA was found to be optimum dosage for improving crop productivity, according to the analysis of specific growth, physio-biochemical and yield parameters.

This paper proposes a new approach on the processing of silicon production waste (microsilica) as a raw material for metallurgical processing. It is known from practice that the granulometric composition of microsilica does not allow its use in metallurgical processing. The authors of this work propose its use together with a reductant as part of a briquetted charge. In this work, the optimal composition of the charge mixture for briquetting is determined. The main focus is on assessing the strength characteristics of the briquettes and analyzing their efficiency in the silicon smelting process. The strength of the briquettes was studied by the dropping method. As a result, in terms of strength and other characteristics, it is highly advisable to use briquettes consisting of 65% of microsilica and 35% special coke screenings. The obtained batches of high-strength briquettes were tested for the smelting of metallurgical grade silicon in a large-scale laboratory ore-thermal furnace to replace the traditional charge mixtures (high-quality quartzites, petroleum coke, wood chips, etc.) with briquettes. It was established that the briquetted monocharge ensures more intensive reduction processes and improves melting conditions compared to the traditional charge. This leads to higher silicon recovery rates, which was confirmed by tests, during which the maximum recovery rate reached 83.1% with a 30% replacement of the charge with briquettes. The batch of metallurgical silicon with 95-96% of Si content was obtained.

Porous silicon (PS) was produced by the metal-induced chemical etching of p-type Si wafers. Patterned platinum dots (~ 300 μm) were deposited on a Si wafer by DC magnetron sputtering for 15 s. When the H₂O₂ fraction in the etchants consisting of HF and H₂O₂ was increased from 0.3 to 24%, the etching behavior changed from “pore formation” to “electropolishing.” The etching reaction activation energy also changed from 0.20 to 0.36 eV in the ln J–K(current–etchant temperature) relationships. The etched morphologies exhibited different structures, such as nano-scaled sponge-like and 3D micro-scaled pore structures, according to the H₂O₂ ratio. The etched layers contained a Si quantum structure, amorphous Si phase, and SiO_x. These phase ratios changed according to the etching behavior. The Si nanocrystallite size changed from ~ 3.0 to 4.6 nm, emitting optical features in the band gap range of 1.73 to 1.88 eV. The fluorescence region varied according to the H₂O₂ contents. The fluorescence preferentially occurred at the interface between the metal circle and Si wafer in the case of etched PS by an etchant containing a lower hydrogen peroxide ratio. In contrast, the fluorescence increased in the non-coated region from 19.5 to 24.0%.

In this paper, Zinc Oxide nanoparticles (ZnO NPs) have been successfully synthesized for the first time by electrochemical deposition on silicon nanowires (SiNWs) produced using silver-assisted chemical etching method. The as-prepared nanowires were pre-coated with ZnO seed layer to initialize the uniform growth of ZnO nanoparticles from aqueous solutions using the electrochemical deposition. The SEM images showed a homogenous distribution of dense ZnO nanoparticles on silicon nanowires. X-ray diffraction pattern indicated that the electrodeposited ZnO NPs have hexagonal wurtzite structure. Current–voltage characteristics pointed that ZnO NPs significantly improved the diode parameters such as ideality factor (n), series resistance (({R}_{s})), energy barrier (({varphi }_{b})) and saturation current (({I}_{s})). As a result, a rectifying behavior of the ZnO NPs/SiNWs structure has been exhibited by a factor of 2.7 compared to pure SiNWs structures. The values of the saturation current ({I}_{s}) and the series resistance ({R}_{s}) of these heterostructures decrease indicating an improvement in junction quality which can be due to the reduction of dangling bonds and surface defects. Significantly, ZnO nanoparticles @SiNWs increased the minority carrier lifetime from 9.11 (mu s) to 14.89 (mu s) and consequently reduced the surface recombination activities, further revealing the efficient surface passivation role of ZnO nanoparticles. Good anti-reflectance abilities up to 10% and 15% are observed for pure SiNWs and SiNWs/ZnO NPs, respectively, as compared to 40% for bare Silicon. Based on these findings, SiNWs/ZnO NPs can be considered as potential candidate for optoelectronic devices, photovoltaics and nanoelectronics.