Silicon最新文献

Metal halide perovskites (MHPs) have garnered significant attention as promising luminescent candidates due to their tunable band gaps, high color purity with narrow emission linewidths, high carrier mobility, and high photoluminescence quantum yield (PLQY). To date, red and green perovskite light-emitting diodes (LEDs) have achieved remarkable efficiency, boasting external quantum efficiencies (EQEs) exceeding 20%. In contrast, blue perovskite LEDs have fallen behind in terms of both efficiency and stability, which poses a significant barrier to their application in lighting and display. Currently, a straightforward strategy for achieving blue light emission in perovskites involves using thin-film devices with a tunable bandgap based on a mixture of chlorine (Cl) and bromine (Br) halogens. However, this approach is challenged by phase separation under the influence of light and electric fields. In this study, we tackle the critical issue of phase separation by light-induced in hybrid halide perovskites. Furthermore, we demonstrate the spectrally stable in blue perovskite films with a broad emission wavelength range of 428 to 452 nm by introducing a simple and practical method that involves annealing all-inorganic halogen perovskite films in air at high temperatures. This temperature (350 °C) is much higher than the annealing temperature common in the current literature (80–120 °C). Moreover, we used N-type silicon with superior thermal conductivity as the substrate. Silicon with superior thermal conductivity not only mitigates the adverse effects in low-conductivity glass substrates at elevated temperatures, but also facilitates direct device integration for future applications. This high-temperature annealing process reduces grain boundaries and defect density, thereby inhibiting the migration of halogen ions and effectively preventing phase separation.

Ultrafast all-optical switching plays a critical role in the advancement of optical signal processing and sensing technologies, enabling high-speed, energy-efficient data transmission and real-time environmental monitoring. Recent progress in novel materials and structural innovations has significantly improved switching speed and efficiency. However, current designs often face challenges such as limited modulation depth, slow response times, reduced bandwidth, and a lower Extinction Ratio (ER). This work introduces a metamaterial-based optical switch that harnesses the insulator-to-metal phase transition of vanadium dioxide ((VO_2)) to overcome these challenges. The optical switch operates within the mid-infrared range (5.4-7 (mu m)), achieving a remarkable 97% absorption in the high state and just 10% in the low state. This performance delivers an outstanding ON / OFF contrast ratio of 9.7 and an extinction ratio of 37.45 dB. The innovative integration of a patterned (VO_2) layer with (SiO_2) and Cr substrates ensures precise resonant coupling and enables rapid modulation with sub-picosecond switching times (1.27 ps). By overcoming the limitations of previous designs, this switch offers high-speed, tunable optical performance with enhanced bandwidth, making it highly suitable for next-generation infrared sensors, reconfigurable photonic circuits, and high-speed optical communication systems. Its ability to achieve ultrafast modulation and strong contrast makes it a promising device for advanced infrared sensing, optical imaging, and environmental monitoring applications.

Titanium and its alloys are extensively utilized in aggressive environments like aviation and power generation sectors, where surface degradation through erosion plays a critical role in component performance and life. For this present study, TiO₂-SiC cermet coatings were coated on Ti base substrate using the High-Velocity Oxy-Fuel (HVOF) spraying technique with varying SiC reinforcement levels—uncoated alloy (Ti), TiO₂ coatings (T0), 5 wt.% SiC (T5), 10 wt.% SiC (T10), and 15 wt.% SiC (T15)—with the aim of improving erosion-resistant of the deposit. The coatings were examined through the solid particle erosion testing with considering the effect of particle velocity, particle flux rate, and impingement angle impacts on the erosion behavior of the coatings. Microstructural inspection showed a monotonic decrease in porosity from 6.4 vol.% of T0 to 2.1 vol.% for T10, accompanied by the corresponding increase in microhardness from 612 HV₀.₃ to 856 HV₀.₃. The T10 coating, specifically, showed better erosion resistance, with erosion rates decreased by 60.4% (from 0.48 mg/g to 0.19 mg/g) at 100 m/s particle velocity, 47.4% (from 2.75 mg/g to 2.22 mg/g) at an impingement angle of 90°, and 67.3% (from 0.55 mg/g 0.18 mg/g) at a particle flux of 5 g/m, as compared to T0. In addition, Atomic Force Microscopy (AFM) validated a denser and smoother surface with roughness reduced from 5.3 µm (T0) to 2.9 µm (T10). These results prove that TiO₂-SiC HVOF-sprayed coatings, when sprayed with optimized SiC reinforcement and spray parameters, improve erosion resistance, mechanical performance, and surface integrity substantially, and are hence ideal for high-temperature and erosive service applications.

Silicon based biosensors have emerged as a promising solution for real-time virus detection due to their high sensitivity and scalability. A new Triple Material Gate Nanosheet (TMGNS) MOSFETs-based biosensor for extremely sensitive SARS-CoV-2 detection is presented in this work for the first time. The suggested TMGNS MOSFETs enhances detection sensitivity and charge modulation by utilizing the special benefits of nanosheet MOSFETs, including improved electrostatic control, a high surface-to-volume ratio, and decreased short-channel effects. In this work, the S-protein and complementary DNA (c-DNA) of SARS-CoV-2 are two viral biomarkers that may be precisely detected. The device's exceptional performance is confirmed by Technology Computer-Aided Design (TCAD) simulations, which show notable threshold voltage shifts and drain current modulation in response to changes in the dielectric constant of biomolecules. The proposed biosensor has a quick response time of 4 ps and a high drain current sensitivity of 3.5 × 10⁶ at k = 12. It is appropriate for real-time viral detection due to its 10% improvement in the I_ON/I_OFF ratio and 6% improvement in subthreshold swing. Additionally, robust performance is confirmed by sensitivity analysis under various biomolecular charge densities, with a 22% improvement in threshold voltage for k = 12. A scalable, low-power, and highly effective method for identifying SARS-CoV-2 and other emerging viruses, the silicon based TMGNS MOSFETs is positioned as a prospective contender for next-generation point-of-care diagnostic applications due to its improved electrostatic coupling and charge sensing capabilities.

To address the excessive retardation of oil well cement caused by polycarboxylate dispersants (PCE), this study synthesized a zwitterionic polycarboxylate dispersant (DPC). Its molecular structure and weight were characterized using ¹H nuclear magnetic resonance and gel permeation chromatography, respectively. The dispersion effect of DPC in cement slurries was evaluated by analyzing microstates, particle size distribution, Zeta potential, and rheological properties, and compared with acetone formaldehyde sulfite condensates (AFS) and conventional anionic polycarboxylate dispersants (CPC). The influence of DPC on cement hydration was studied through thickening performance, compressive strength, semi-adiabatic calorimetry, and X-ray diffraction. DPC effectively disrupted particle flocculation in cement slurry, reducing the median particle size from 34.4 μm to 10.2 μm. At a dosage of 0.20%, the slurry with DPC exhibited superior flowability compared to CPC and AFS. DPC induced Newtonian fluid behavior with weaker thixotropy and significantly reduced retardation effects. The 24-h compressive strength of cement stones reached 39.7 MPa, the thickening time was about 83 min, and the hydration heat peak occurred earlier. Adsorption studies indicated that DPC disperses through steric hindrance and the synergistic anchoring effects of cations and anions. Overall, DPC demonstrates high dispersibility and lower retardation, making it a promising additive for oil and gas well cementing.

SiC—TiC—Al composite coatings were successfully deposited by preplacing paste of SiC, TiC and Al powder mixture on aluminum 6061 alloy substrate by TIG cladding process. The effect of process parameters on microstructure, microhardness and wear properties of the coatings was investigated by SEM and XRD, Vickers microhardness tester, and pin-on-disc type dry sliding wear tester respectively. The analysis demonstrated that the microstructure, microhardness and wear behaviour of the SiC—TiC—Al coatings were influenced by heat input, which was varied by different parametric combinations of current and scan speed during cladding. XRD result revealed the presence of Al, TiC and formation of compound such as Al₄SiC₄, which enhanced the microhardness values of the clad layers such that, the microhardness of the cladded surface was observed up to 168 HV_0.05, which was more than three times that of the substrate material. The developed coatings showed up to 4 times less in the wear loss value; under sliding abrasive conditions compared to the uncoated Al 6061 alloy, which validated the composite coating as a suitable option for the components requiring wear resistance.

This study explores the intriguing interaction between 1-(4-bromobenzyl)-2-(4-bromophenyl)-4-fluoro-1H-benzo[d]imidazole (BBFB) and silicon dioxide (SiO₂) nanoparticles, unveiling how functionalization enhances both the photophysical properties and antimicrobial efficacy of BBFB. Through absorption, fluorescence, and FT-IR spectroscopy, it is revealed that BBFB undergoes strong adsorption onto the surface of SiO₂nanoparticles, primarily driven by electron transfer interactions. The fluorescence quenching observed in BBFB is attributed to photo-induced electron transfer from the excited state of BBFB to the conduction band of SiO₂ nanoparticles. Functionalization of BBFB with SiO₂ nanoparticles significantly enhances its biocidal activity. Antibacterial assays indicate that the BBFB-functionalized SiO₂ nanoparticles exhibit superior efficacy against Staphylococcus aureus and Salmonella typhi, compared to unmodified BBFB. In antifungal testing, BBFB-functionalized SiO₂ nanoparticles also demonstrate improved performance against Aspergillus flavus and Candida albicans. The study highlights the potential of BBFB-functionalized SiO₂ nanoparticles as a promising antimicrobial agent, offering enhanced biological activity, reduced reaction times in synthesis, and improved efficiency, thus presenting a viable, eco-friendly alternative for various pharmaceutical applications.

Postoperative cognitive dysfunction (POCD) is a frequent neuroinflammatory complication in elderly patients, and dexmedetomidine has shown potential in reducing its incidence by modulating the CX3CL1/CX3CR1 signaling pathway. In this study, carboxymethyl chitosan (CMCS) was chemically modified with a silicon-based polymer (CPTMS) and a natural extract (compound 2) to construct a functionalized carrier material, CPTMS-CMCS-2. This hybrid platform was subsequently loaded with compound 1 and dexamethasone (Dex), yielding the electroactive nanocomposite CPTMS-CMCS-2@1@Dex. Electrochemical characterization revealed that the incorporation of π-conjugated structures and bioactive components enhanced the redox activity, electron transfer efficiency, and surface conductivity of the material, which are beneficial for stimuli-responsive drug release. A POCD rat model was established via abdominal surgery, followed by cognitive assessment using the Morris water maze and analysis of hippocampal CX3CL1 mRNA expression. The results showed that intervention with CPTMS-CMCS-2@1@Dex significantly improved the spatial learning ability of POCD model rats. This study provides new insights into the pathogenesis of POCD and highlights the potential of electroactive, functionalized polysaccharide-based nanocarriers in enhancing the therapeutic efficacy of dexmedetomidine through responsive delivery systems.