Silicon最新文献

This research utilized powder metallurgy technology to create three layers of functionally graded composites (FGCs) based on aluminum alloy (Al6061). It is enhanced with mono and hybrid ceramics, specifically silicon nitride (Si₃N₄) and granite waste. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were employed to examine the microstructure of the produced FGC powder layers and the sintered samples. Subsequently, the sintered composites' physical, thermal, tribological, and mechanical properties were investigated. The results indicated that incorporating mono and hybrid ceramics positively influenced the refinement of milled powder, reducing the particle size of the Al6061 alloy from 79.18 nm to 36.43 nm, which represents a decrease of approximately 54.39% after reinforcement with 2.5% granite + 5% Si₃N₄. Furthermore, both mechanical and tribological properties showed significant improvement. The highly reinforced sample (FGC6), which comprised 1.25% granite + 2.5% Si₃N₄ in the second layer and 2.5% granite + 5% Si₃N₄ in the third layer, the compressive strength, Young's modulus, and wear rate improved by about 26.13%, 13.66%, and 16.19%, respectively, compared to the sample without reinforcements (FGC1). Notably, the coefficient of thermal expansion (CTE) for FGC6 samples decreased to 15.1 × 10^–6/°C, an increase of approximately 35.15% compared to the FGC1 sample (23.3 × 10^–6/°C). Finally, the addition of reinforcements to the layers harmed the thermal conductivity of the FGC layers.

The multi-crystalline silicon (mc-Si) grown by directional solidification (DS) system is a suitable candidate for fabricating the Si parts used for the semiconductor etching application, which requires less SiC precipitates and low thermal stress in the bulk ingot. In this paper, we employed a global simulation model to analyze the influence of crucible covers on the distribution of carbon impurities during the DS process. The entire process, including impurity generation, penetration, transport, and incorporation, has been characterized during crystal growth using both traditional uncoated crucible covers and those coated with W, Mo, and SiN layers, respectively. The protective effect of the coating layer is primarily attributed to two mechanisms. A noticeable isolation effect of the coating materials in the impurity generation process has been found, inhibiting the reaction between SiO gas and the graphite components along the crucible cover surface at high temperatures. Moreover, a detaining effect of impurity transport during the transport process occurs, where the C atoms are detained in the natural convection-dominated region of the Si melt, depending strongly on the melt temperature gradient. Therefore, fewer C atoms can be incorporated into the grown Si ingot. Through comparative investigation, Mo is an optimal coating material for crucible covers due to its lower emissivity, resulting in a 18.4% decrease in SiC content in the Si ingot compared to that of the traditional uncoated crucible cover. Thus, coating a Mo layer on the crucible cover surface is an effective solution for fabricating the bulk mc-Si ingot for semiconductor etching applications.

We report a comprehensive numerical study of single-junction photovoltaic devices incorporating linearly graded Si_1-x-yGe_ySn_x absorber layers, performed using the SCAPS-1D simulator. Four compositional profiles—Si_0.75-xGe_0.25Sn_x, Si_0.70-xGe_0.30Sn_x, Si_0.65-xGe_0.35Snₓ, and Si_0.60Ge_0.40Sn_x—were engineered over a 1 μm thickness to achieve graded bandgaps from 1.28 eV down to 1.19 eV, extending the absorption edge from 970 nm to 1,040 nm. Optimization of absorber thickness, doping densities (10¹²–10¹⁸ cm⁻³ acceptors), trap densities (10¹⁰–10¹⁵ cm⁻³), and capture cross Sects. (10^–20–10^–10 cm²) yielded peak power conversion efficiencies of 26.02%, 26.37%, 26.25%, and 25.77%, respectively. Corresponding short-circuit current densities (27.95–30.60 mA/cm²) and open-circuit voltages (1.00–1.08 V) highlight the trade-off between photocurrent enhancement and voltage retention. External quantum efficiency profiles exhibited gradual roll-off beyond the critical wavelength, with peak spectral responses of 0.510 A/W (750 nm), 0.542 A/W (800 nm), 0.539 A/W (790 nm), and 0.519 A/W (770 nm). Impedance spectroscopy (10^–12–10¹² Hz) demonstrated reduced charge-transfer resistance with thicker absorbers and a resistive-to-capacitive transition between 10^–2 and 10² Hz, beyond which capacitive bypassing dominates. Johnson-Nyquist noise analysis revealed series noise attenuation at low frequencies and parallel noise emergence at high frequencies, elucidating charge-transport regimes. These findings establish a robust theoretical framework for SiGeSn ternary alloys, providing critical design guidelines for bandgap engineering, interface optimization, and noise management in next-generation high-efficiency photovoltaic technologies.

This study addresses the challenge of accurately predicting the density of liquid siloxanes, which are widely used as working fluids in systems designed for recovering waste heat from low-temperature and minor-scale origins such as solar energy, biomass, geothermal energy, and turbine exhaust. Accurate modeling of transport properties, including density, is essential for improving the performance of these systems. In this research, several machine learning algorithms were created and assessed to predict siloxane density based on temperature, pressure, boiling point, and molar mass. The methods include decision trees, ensemble methods, boosting techniques, random forest, convolutional neural networks, support vector machines, k-nearest neighbors, and multilayer perceptron artificial neural networks. A sensitivity assessment was performed to evaluate the influence of each input variable, and an outlier detection method was applied to enhance data reliability. The multilayer perceptron model outperformed all other algorithms, achieving a coefficient of determination (R²) of 0.982 and an average absolute relative error of 0.58% on the testing dataset. Furthermore, temperature exhibited a negative correlation with density, while pressure was identified as the most influential factor.

In this paper, a novel ultra-light SiC ceramic with double-layer hollow interconnected skeleton (SSC_i) was successfully synthesized by combining controllable CVI technology with an oxidation process. Pyrolytic carbon of CVI was the key technology to introduce into porosity. The pore structure, XRD, microstructure, compression properties, and thermal insulation performance of the prepared SSC_i were investigated. The effect of the number of hollow layers on the SiC ceramics was also studied, which provided certain guidance for the optimization of parameters and properties of porous SiC ceramic materials. SSC_i exhibited ultra-light characteristics with a density of 92 mg·cm⁻³. Benefiting from the double-layer hollow structure, the specific surface area of SSC_i reached 906 m²·g⁻¹. SEM results indicated that the double-layer hollow structure was successfully fabricated. SSC_i consisted of two layers of SiC, and the double-layer hollow skeleton ensured the continuity of SSC_i. Due to the synergistic strengthening effect of the double-layer structure, the compression strength of SSC_i was enhanced. The compression strength of SSC_i reached 2.55 MPa, with a specific strength of 27.72 MPa·g⁻¹·cm³. The hierarchical energy dissipation mechanism delayed the overall failure of SSC_i, and strain hardening enhanced the load-bearing capacity of the matrix. The thermal conductivity of SSC_i increased most slowly with temperature. The high crystallinity of the outer SiC layer gave it strong infrared radiation reflection capability, reducing radiative heat transfer. The ultra-high specific surface area of the double-layer hollow structure also caused multiple reflections of thermal radiation, significantly hindering radiative heat transfer. SSC_i exhibited potential applications in the field of high-temperature thermal insulation.

A successful attempt has been done to use conventional gas metal arc welding (GMAW) to increase the melt-pool sledding in width using SiC-reinforced with AISI304 stainless steel (ASS) clad layer on low carbon steel (LCS) substrate. Defect-free melt-pool sledding width was observed at voltages greater than 24 V, with a feed rate of 5 m/min to 6 m/min. Additionally, a uniformly distributed fine SiC-reinforced clad layer with improved clad dilution on the LCS substrate was found. SiC-reinforced clad layer showed hard-intermetallic phases such as Cr₇C₃, Fe₅C₂, Fe₂C, Mn₃Ni₂Si, and CrSi₂. Additionally, the hardened phases in the SiC-ASS clad layer enhanced the hardness to 519 HV0.5, compared to 177 HV0.5 for the LCS substrate. The SiC-ASS clad layer also improved wear resistance up to eight times that of the LCS substrate.

Diabetic nephropathy (DN), a progressive microvascular complication of diabetes, is primarily driven by chronic hyperglycemia-induced inflammation, fibrosis, and cell cycle dysregulation. Recent studies identified mitotic arrest deficient 2-like protein B (MAD2B) as a critical regulatory protein in DN, markedly upregulated in high-glucose-treated human glomerular mesangial cells (HGMCs), accompanied by a 2.8-fold increase in IL-6 expression, highlighting its pathological relevance. To achieve targeted therapy and real-time monitoring, we designed a silica-based hybrid nanoplatform incorporating a lanthanide coordination polymer [Sm(L)₃·CH₃OH] (CP1) with a well-defined tricapped trigonal prismatic geometry (confirmed by SCXRD). CP1 was loaded with a lipophilic bioactive molecule—Compound 1, a diterpenoid quinone derived from Salvia miltiorrhiza known for anti-inflammatory and anti-fibrotic properties—and subsequently coated with carboxymethyl chitosan (CMCS) and 3-aminopropyltrimethoxysilane (APTMS) to yield CMCS-APTMS@CP1@1. The resulting nanoplatform exhibited enhanced aqueous stability, biocompatibility, and sustained-release capability under physiological conditions. Notably, CMCS-APTMS@CP1@1 also demonstrated robust fluorescence responsiveness toward MAD2B, enabling sensitive detection with a linear response in the 0–40 μM range (R² = 0.998) and a detection limit of 58 nM. Fluorescence lifetime and UV–vis analyses revealed a Förster resonance energy transfer (FRET)-mediated quenching–recovery mechanism. Molecular docking confirmed strong hydrogen bonding (∼1.7 Å) between the imide moiety of the Sm complex and the hydroxyl group of TYR-280 in MAD2B. These findings underscore the dual functionality of CMCS-APTMS@CP1@1 as both a smart therapeutic carrier and a MAD2B-responsive fluorescence probe, offering promising potential for precision DN treatment and monitoring.

This study presents an optimized high-sensitivity Surface Plasmon Resonance (SPR) sensor based on Group-IV materials integrated with a CaF(_{2}) prism in the Kretschmann configuration. The research aims to enhance sensor performance by leveraging the high refractive index(RI) and strong plasmonic coupling of Group-IV materials with silver. The proposed structure consists of CaF(_{2})/Ag/Group-IV materials/Analyte and operates at a wavelength of 633 nm. Through systematic optimization, a silicon configuration of seven monolayers (total thickness 2.31nm) yielded the best performance, achieving a maximum sensitivity(S) of 472(^circ )/RIU, a Figure of Merit (FoM) of 140.89, a Limit of Detection (LoD) of (0.636 times 10^{-5}), and a Full Width at Half Maximum (FWHM) of (3.35^circ ) for a refractive index range of 1.331 to 1.336. Compared to conventional SPR sensors, the proposed design demonstrates superior plasmonic confinement and reduced damping losses, as evidenced by strong field localization at the metal–dielectric interface and a narrower reflectance dip (FWHM = 3.35(^circ )), leading to enhanced sensing accuracy. These findings highlight the sensor’s potential for highly precise chemical and biochemical detection.

In this paper, a novel structure, double gate with inverted T-shaped TFET (DG-IT-TFET has been proposed and studied with and without charge plasma technique. We have further studied the DG-IT-TFET structures on three different substrate namely, Silicon-based, Germanium-based and hetero Silicon–Germanium based. In this novel structure we have used 15 nm gate thickness for both gates. Lateral length (L_T) has been optimized as 1 nm that gives vertical tunneling and enhanced the subthreshold slope (SS). The novel structure with dual gate provides flexibility over electrostatics control, improved ON current, lowers subthreshold swing and improves ON-current to OFF-current ratio. One has also studied and analyzes the digital and analog parameters of novel structure DG-IT-TFET with and without charge plasma. In this charge plasma concept, apply appropriate work function to both electrodes. Our comparative study shows that Si-DG-IT-TFET(without charge plasma) structure has most significant improvement in ON current of value 2.2 × 10⁻⁴A/μm, very low leakage current 6.8 × 10⁻¹⁷A/μm, and very low SS with a value of (13.5 mV/dec). Si-DG-IT-TFET structure produces improved I_ON/I_OFF with the peak value of 10¹². Comparative results with charge plasma and without charge plasma of DG-IT-TFET structure listed are Tables 2 and 3. The Ge based DG-IT-TFET(without charge plasma) structure shows promising results for analog circuits. Thus our proposed DG-IT-TFET structure is good electrical characteristics. Thus this structure is most promising candidate for extremely low power digital and analog chips.

Recently introduced nanosheet field-effect transistors (NS FETs) are cutting-edge technology in the foundry business. Compared to conventional FinFETs, NS FETs exhibit superior gate controllability and output current. However, NS FETs are still limited by the presence of a substrate parasitic n-type metal–oxide–semiconductor (NMOS), which increases off-state current (I_OFF) and impacts overall device reliability. Trench gate (TG) NS FETs have been proposed as a solution, but the process for source/drain (S/D) formation in TG NS FETs remains unclear. This study focuses on optimizing the junction depth (X_j) in TG NS FETs, which is a key factor to enhancing device performance. A shallow X_j increases the effective gate length (L_G.EFF) of the substrate parasitic NMOS, effectively suppressing short-channel effects (SCEs). To guide the development of these TG NS FETs, both device fabrication and electrical characteristics were simulated using 3-dimensional (3-D) technology computer-aided design (TCAD), with various design parameters considered.