Silicon最新文献

In the present study, a theoretical model that interconnects plasma waves, thermal dynamics, and elastic vibrations has been applied to examine the propagations of waves in semiconductors as a result of photo-thermal effects. A study was conducted on a semiconducting material that is both isotropic and elastic, displaying uniform thermoelastic properties. This research looked into how plasma, thermal, and elastic waves, which are produced by a sharply focused laser beams with modulated intensity, interact within the material. Using Laplace transform methods, the analytical solutions obtained through the eigenvalues approach in the transformed domains were observed. To do the numerical calculations, a semiconductor resembling silicon was used.

Perovskite/Silicon tandem solar cells have earned substantial attention in the field of photovoltaics (PVs) due to their potential high-efficiency energy conversion. The provided TCAD simulation in the current work aims at delivering a novel design for a 4-T Perovskite/PERL p-type Si tandem solar cell. The main structure consists of ITO/CuSCN/Perovskite/PC60PM/AZO/AgNW as the top cell and a conventional PERL p-Si as the bottom cell. Simulation results showed that the proposed top cell structure achieves a significant performance after substituting Zn(O_0.3,S_0.7) for AZO and PC60PM electron transport layers (ETLs), while replacing CuSCN with CuI as a suitable alternative for the hole transport layer (HTL). These modifications achieved an efficiency of 19.81% for the top cell. The bottom cell also attained a noteworthy level of performance by using bifacial dual-side-textured construction with efficiencies reaching 29.11% and 14.08% for bare and filtered cells, respectively. With these combined modifications, the PCE (power conversion efficiency) reached 33.89%, showing significant improvement compared to the base structure.

Bioactive glasses containing boron oxide have attracted substantial attention owing to their unique attributes and the promising prospects they offer for biomedical uses. The study explores boro calcium fluoro alumino silicate (BCFAS) glass containing boron oxide, highlighting its potential in biomedical applications. The glass was synthesized through melt-water quenching with varying B₂O₃ ratios, utilizing CaO from clam shell and SiO₂ from soda lime silica glass waste. The investigation examined the physical and mechanical properties of the resulting samples. Results showed that increasing B₂O₃ content caused a reduction in crystallinity, as confirmed by XRD analysis. The incorporation of B₂O₃ into the glass structure was further supported by the emergence of B‒O‒B and Si‒O‒B bonds observed in FTIR spectroscopy, which may potentially influence the glass's dissolution and degradation characteristics. However, higher B₂O₃ content also reduced density, impacting the mechanical properties. Vickers microhardness and compressive strength decreased due to the introduction of the BO₃ unit, which increased the fragility of the glass. While enhancing glass-like behavior and potentially increasing bioactivity, the addition of B₂O₃ adversely affected its mechanical attributes.

Silicon nanowalls atop the (100) – oriented boron doped P-type (1–10 Ω-cm) single crystalline silicon wafers were prepared using a metal assisted chemical etching route for different durations 1, 5, 15, and 30 min. The scanning electron microscopy results revealed that the structure evolved up on etching is in the form of vertical silicon nanowalls with mean wall thickness of 70 nm. It can be observed that as the etching time increases, the height of the SiNWs increases linearly at an etching rate of ~ 301 nm per minute. The transmission electron microscopy results combined with FTIR spectroscopy results indicate that about one nanometer thick Si–O-Si- bonded amorphous layer formed at the surface of the grown silicon nanowalls. A defect sensitive Variable energy positron beam Doppler broadening technique used to study the etched silicon wafers confirms that the defect structures that are evolved in the silicon nanowalls with etching are different from that of planar Silicon. Analysis of the Doppler broadened line-shape profiles shows that the effective positron diffusion length and height of the silicon nanowalls are related logarithmically with a scaling exponent of—1/2, indicating that the implanted positrons that are thermalized in the silicon nanowalls diffuse back to the wall surfaces and are annihilated at the defects linked (Si–O-Si)/Si interface region. The present positron experimental results abound with literature reports suggest that understanding the microstructure of the surface layer in SiNWs is significantly important in determining their performance for producing efficient solar cells.

In this article, a novel model was studied that explains the interaction between the equations governing the photo-thermoelasticity theory in the case of the presence of the diffusion of moisture of the semiconductor medium with the electromagnetic field. The photo-thermoelasticity theory is used to investigate the photothermal excitation process for an elastic semiconductor medium in a one-dimensional deformation. This article discusses the effect of the magnetic field on conductive moisture diffusivity. The coupling interactions between magneto-thermo-elastic stresses and moisture diffusivity are investigated. According to some initial conditions, the governing equations are investigated using the Laplace transform technique to calculate the numerical solution of the key physical field contribution in the Laplace domain. The basic quantities for the process in the Laplace domain are calculated using all mechanical stresses, thermal conditions, and plasma boundary surface conditions. To obtain complete solutions in the time domain for the main problems, the numerical method approach is used to invert the Laplace transform. Some comparisons are made under the influence of different parameters to show the wave propagation of the main fields.

Herein, a novel magnetic mesoporous silica nanocomposite with a core–shell structure modified with IL/Cu complex (MMS@IL/Cu) is prepared through the template-directed hydrolysis of tetramethyl orthosilicate (TMOS) over Fe₃O₄@RF composite followed by grafting of propyl-imidazolium chloride/copper complex. The MMS@IL/Cu nanocomposite was characterized by PXRD, FT-IR, TGA, VSM, EDX, SEM and TEM techniques. The MMS@IL/Cu was employed as a robust nanocatalyst to successfully promote the Chan-Lam coupling reaction in EtOH at 50 °C. High yields of the desired products were obtained within a relatively short time. The designed magnetic catalyst could retain its high efficiency for at least eight runs under applied conditions.

Because of their desirable characteristics, ceramic-based scaffolds have emerged as prominent candidates for artificial bone replacements in bone regeneration procedures. Bredigite (Ca₇MgSi₄O₁₆) ceramic has demonstrated favorable bioactivity, bone growth, and mechanical qualities, making it a viable candidate for replacing bone defects. This review presents the main techniques employed for the synthesis of bredigite. It was also mentioned how combining bredigite ceramic with other materials might increase the quality of composites. Because of the presence of magnesium in bredigite, it has higher mechanical properties and chemical stability than calcium silicates such as wollastonite, dicalcium silicate, and tricalcium silicate. The density and elastic modulus of bredigite is 3.4 gr/cm3 and 43 GPa, respectively. Higher mechanical properties of bredigite compared to polymers, and its biocompatibility, bioactivity, and osteoconductivity, can cause to higher quality of polymer-bredigite composite than that of polymer. Based on findings derived from many investigations conducted in in-vitro and in-vivo contexts, bredigite has great promise as a flexible and efficient material for bone tissue engineering. Additional research is needed to maximize the clinical applications of bredigite bioceramics.

The molecular graph of a chemical compound can be measured using a topological index, which helps us to understand its physical and chemical characteristics. Topological indices play a crucial role in characterizing the different chemical properties of substances, such as (SiO_{4}), within the field of chemical graph theory. (SiO_{4}) is an important compound owing to its versatility, accessibility, and quantifiability. In this study, we developed the methodology for calculating various temperature indices for a linear molecular graph of (SiO_{4}). We compare and find the correlation of temperature indices of silicate chain. In the last section of the paper, we present an application of benzenoid hydrocarbons to elucidate the significance of temperature indices.

Impurities in low-grade silicon ore, particularly iron and aluminum, can significantly influence the quality of subsequent products. Therefore, it is vital to eliminate these impurities to improve the purity of low-grade silicon ore. This study introduces a method for removing iron and aluminum impurities from silicon ore. The silicon ore samples were analyzed through X-ray diffraction, scanning electron microscopy, and potential-pH diagram. The results confirmed that after direct roasting, the quartz crystal transformed from α-quartz to β quartz, causing an increase in quartz volume. After quenching, cracks and pits formed on the quartz surface, facilitating the diffusion and oxidation of impurities. Subsequent pressure leaching enabled the leaching agent to effectively penetrate the quartz interior, thereby removing impurities from the quartz sand. The experimental results revealed that the optimal conditions for removing impurities through direct roasting and quenching involved using a mixed acid solution containing 3% hydrochloric acid and 6 g/L oxalic acid. The leaching process was conducted at a temperature of 200 ℃ for 4 h in a reactor. Under these conditions, the silicon ore exhibited residual Fe and Al contents of 85 and 320ppmw, respectively, achieving the highest removal rates of 97.98% and 97.85%, the SiO₂ content in silicon ore increased from 94.08% to 99.42%. Compared with leaching under atmospheric pressure leaching, pressure leaching resulted in a 30% increase in the removal rate of impurities. This study provides valuable practical guidance for purifying low-grade silicon ore used in silicon smelting raw materials.

Globally, heavy metals especially arsenic (As) toxicity in staple crops like wheat has posed serious threats to human health, necessitating conducting fresh studies to find out biologically viable As toxicity mitigation strategies. Therefore, this study aimed to investigate the impact of foliar-applied silicon nanoparticles (SiNPs) at the tillering stage on the activation of physiological and antioxidant regulation in wheat to induce tolerance against varying As toxicity levels. The trial comprised two promising wheat cultivars (Anaaj and Ghazi) and five SiNPs regimes including 0, 30, 60, 90, and 120 ppm doses against As toxicity levels of 0 and 25 ppm. The recorded findings depicted that SiNPs regimes significantly improved morphological characteristics such as root length, fresh and dry weight, as well as shoot length, and fresh and dry weight of wheat cultivars. Additionally, the levels of chlorophyll pigments, including chlorophyll a, chlorophyll b, and total chlorophyll contents, were significantly increased in SiNPs-treated plants, indicating improved photosynthetic activity. The enhanced antioxidant enzyme activities, such as ascorbate peroxidase (APX), superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), played a vital role in combating oxidative stress induced by As toxicity. Moreover, SiNPs application resulted in a significant reduction in As concentration in both leaves and roots, highlighting the ability of SiNPs to regulate the uptake and accumulation of arsenic and mitigate its toxic effects. In conclusion, the foliar application of SiNPs during the tillering stage of wheat effectively activated physiological and antioxidant regulation, leading to enhanced tolerance against As toxicity.