Silicon最新文献

The cost of bifacial monocrystalline silicon passivated emitter and rear contact solar cells at the module level can be decreased by optimizing the wafer size. This research work has studied electrical and optical loss analysis for 180–90 µm wafer sizes. The solution of thinned 90 µm PERC solar cells to the module level, its performance, and comparison to the reference (180 µm) and undesigned (90 µm) PERC cells have been addressed through SunSolve simulations. A 72-cell bifacial c-Si PERC solar module was simulated with an optimized wafer thickness of 90 µm. The cell performance at a longer wavelength was improved by depositing Al₂O₃/SiN_x/SiO_x films on the rear of PERC solar cells. SiO_x, SiN_x, SiN_y, and SiO₂ films were deposited on the front side of the PERC solar cell to improve light absorption at shorter wavelengths. The present simulation design with optimized performance led to an average increase of open circuit voltage of 24.7 mV from 699.3 mV to 724 mV, an average increase of fill factor of 0.89% from 79.06% to 79.95%, and an average increase of packing conversion efficiency of 0.96% from 21.78% to 22.74%, as compared to the designed (90 µm) and reference (180 µm) cells. The simulation results showed that the designed cell absolute efficiency has improved compared to the reference cell. The optimized PERC solar cell and its parameters simulated a 72-cell bifacial solar module. The module showed average values of 51.75 V, 9.181 A, 384.3 W, 80.9% and 19.72% for V_oc, I_sc, P_mp, FF and efficiency. The bifaciality factor of the present module was 78.4% under standard test conditions (STC).

Nanostructured silicon is a promising material for many recent applications. In this work, inverted pyramidal porous silicon is synthesized by two stages metal assisted etching followed by PECVD rebuilding. At first, nanowires are obtained by conventional Ag assisted chemical etching at the surface of monocrystalline silicon wafer. Then, Inverted pyramidal (IP) macroporous structure is obtained by dipping the sample in HNO₃: Ni solution after nanowire harvesting. Finally, PECVD is used to build deep holes on the porous surface template. The depth of the pyramidal holes can be tuned by deposition time and silane pressure. The macroporous structure characteristics are investigated by many techniques such as XRD, SEM, FTIR, reflectivity and impedance. Sensing tests of IP layers for different gases show their selectivity for NO₂.

In this work, the interaction of K₂SiF₆ with LiCl–KCl-CsCl chloride melts was studied using cyclic voltammetry and atomic emission spectroscopy analysis, depending on their cationic composition in the temperature range from 550 to 665 °C. It has been determined that an increase in the CsCl/LiCl ratio leads to a decrease in the rate of decomposition of the K₂SiF₆ additive due to the formation of compounds with greater stability due to the replacement of the cation and the predominance of the corresponding reactions. Based on the results of ICP-AES, a decrease in the concentration of silicon ions in the melt during electrolysis was detected, and its final values in the melts at the end of the 12-h exposure were determined. During electrolysis, the silicon concentration also decreases, and in the case of a short electrolysis duration (up to 4 h), it is possible to maintain a sufficient concentration to be carried out without introducing additional K₂SiF₆ in the process. The optimal composition for electrodeposition was also determined, and it was found that a high LiCl content in the melt leads to the formation of lithium fluoride and its inclusion in the deposit.

Photocatalyzed hydrosilication has the advantages of high reaction efficiency and environmental friendliness. However, the cost of photosensitive platinum catalysts is very high, hindering their applications. In this work, a novel and cost-effective photosensitive platinum catalyst is synthesized and can effectively catalyze the hydrosilylation reaction under ultraviolet light. It is found that Pt catalysts exhibit catalytic activity under ultraviolet light when the ratio of Platinum chloride bonding and cyclopentadienyl (Pt-Cl:Cp) is higher than 1:1.2. The cost is reduced by 50%. The structure of this platinum catalyst is characterized using FTIR and NMR techniques. Under ultraviolet light, the new photosensitive platinum catalyst’s catalytic efficiency increases from approximately 5% to 60%. The viscosity of prepared silicone rubber was measured. Results show that the prepared silicone rubber has a storing time of over 30 days in shaded environments, and can be completely cured within 2 min under ultraviolet light. The thermal decomposition residual mass of photocured silicone rubber products is as high as 70%, having good thermal stability. As the content of the platinum catalyst increases from 20 to 100 ppm, the reaction conversion rate of the hydrosilylation reaction increases from 43 to 60%. The hardness of the silicone rubber also increases from the initial 11 degrees to 20 degrees. This novel photosensitive platinum catalyst has potential applications in 3D printing and electronic packaging.

The research aims to characterize a melt-quenched sodium silicate glass doped with different concentrations of copper oxide (CuO) as an optical filter material. Sodium oxide (Na₂O) was fixed at 45 mol%, whereas CuO was introduced to the glass network at the expense of Na₂O, from 0.2 to 0.8 mol%. The silicate network comprises Si–O–Si vibrations in symmetrical and assymmetrical modes, with the formation of non-bridging oxygens (NBOs) as a result of the presence of the modifiers NaO₆ and distorted tetragonal CuO₆ units. The optical transmittance was zero in the UV region and in the visible region starting from 600–900 nm, depending on the glass composition and the CuO ratio. The glass containing 0.6 mol% CuO had a maximum transmittance peak (T = 0.64) at 450 nm, whereas the glass containing 0.8 mol% CuO exhibited a low transmittance peak (T = 0.28) at 450 nm. The optical parameters were discussed in terms of the effect of CuO, in which the optical band gap varied from 3.168 eV to 2.819 eV as the CuO changed from 0 to 0.8 mol%. Other important parameters like Urbach energy, refractive index, and their related variables were determined and discussed. The glass density of sodium silicate glass is 2.478 g/cm³, which has been slightly increased to 2.491 g/cm³ due to the effect of the CuO dopant. Furthermore, as the CuO content increased, the optical basicity increased from 1.222 to 1.237, indicating that the glass was thermodynamically stable.

Gas sensors are critical topics, attracting scientists and industries for their ability to work in different environments for safety and environmental monitoring applications. The impact of various concentrations of silicon nitride (Si₃N_4[Y%]) (Y = 0.2, 2.2, and 4.2%) compact with synthesis graphene oxide (GO_[0.8%]) as (GO_[0.8%]@Si₃N_4[Y%]) hybrid nanomaterials loaded into newly ternary blend polyethylene oxide, carboxymethyl cellulose, and nano polyaniline (PEO_[60%]-CMC_[30%] -PANI_[x%]) to fabricated newly nanocomposites for nanochemical NO₂ gas sensor. Sol–gel and ultrasonic mixing methods were used to make nanocomposites, which were then dried out on glass slides using thermal evaporation to characterize the sensors. Images from field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) showed that the shape and porosity of the surface changed a lot. These changes, along with the attachment of nanomaterials, are key to how well it can sense gases. The Fourier-transform infrared spectroscopy (FTIR) spectra showed that the sample components had strong physical and network interactions. X-ray diffraction (XRD) indicated a semi-crystalline behavior in all samples. Dialectical constant and loss were reduced, whereas AC electrical conductivity improved with the increase in the content of Si3N4. The gas sensor ran at three temperatures (RT, 100 °C, and 200 °C). All of the nanofilm sensors behaved like p-type semiconductors, and when the oxidized gas NO₂ was turned on, the electrical resistance went down. The best sensitivity to NO₂ was (6.89%) at RT, with a response time of (16 s) and a recovery time of (19 s) for a loading ratio of 3 wt.% hybrid nanomaterials. The study provides an excellent nanochemical gas sensor for NO₂ gas for manufacturing applications.

Numerous abiotic and biotic stresses threaten sustainable agriculture under limited resources. Agriculture productivity is disrupted by these unpredictable environmental fluctuations, posing a serious threat to food security. As a beneficial nutrient, silicon (Si) application enhances biological functions, crop development and productivity. Silicon application has garnered attention for its ability to mitigate various stresses and has shown a highly significant response under conditions such as water scarcity, salinity, metal toxicity, thermal stress and nutrients deprivation. Additionally, it enhances defense mechanisms against fungal, bacterial and pest attacks. High crops production can be achieved by incorporating Si into the agricultural system to replace synthetic fertilizers. This approach can help overcome limitations in crop production posed by limited resources and unpredictable environmental conditions. The environmentally friendly Si application is replacement of synthetic toxic chemicals for sustainable agriculture to get maximum yield under limited resources and unpredictable environmental conditions, as well regulate the genes expression to mitigate the biotic and abiotic stresses. The keys genes involved in different metabolic pathways under Si application have discussed in this study, which will be more beneficial to develop stress resilient crops through CRISPR/CAS technology to overcome the food threat and agriculture sustainability.

Graphical Abstract

Using molecular dynamics simulation on sodium silicate glass we have investigated the sodium motion through Voronoi Si and O polyhedrons. The result shows that Na atoms are almost not present in Si polyhedrons, and sodium number density in non-bridging oxygen and free oxygen polyhedrons is larger by 2.5 – 10.5 times than in bridging oxygen polyhedrons. The volume of space occupied by non-bridging oxygen and free oxygen polyhedrons varies from 25 to 66% of total volume of system. The simulation reveals that Na atoms move frequently along non-bridging oxygen and free oxygen polyhedrons and rarely along bridging oxygen polyhedrons. Moreover, they often leave and comeback to starting polyhedron. Such movement is responsible for decreasing the correlation factor F. The system contains unconnected sodium mobile regions which consists of polyhedrons connected with each other by preferential moving paths. With decreasing SiO₂ content the system possesses long diffusion pathways. We have established the expression for sodium diffusion constant D via the rate of hops ξ, average square distance per visiting polyhedron ({d}^{2}) and factor F. We find that as the temperature or SiO₂ content changes, the variation of F is significantly larger either than ξ or ({d}^{2}). Moreover, the dependence of D on F is found linear.

In this work, the capacities of Si₆₀, C₆₀, B₃₀N₃₀, Sc-Si₆₀, Sc-C₆₀, Sc-B₃₀N₃₀ to deliver the Dacarbazine are examined. The E_adoption of Sc-Si₆₀, Sc-C₆₀ and Sc-B₃₀N₃₀ are -4.45, -4.57 and -4.70 eV. The E_cohesive of Si₆₀, C₆₀ and B₃₀N₃₀ nanocages are -6.23, -6.51 and -6.86 eV, respectively and so the Si₆₀, C₆₀ and B₃₀N₃₀ nanocages are stable nanostructures. Results shown than the Sc-B₃₀N₃₀ has acceptable potential to adsorb and deliver the Dacarbazine. Results shown that the Sc-Si₆₀, Sc-C₆₀ and Sc-B₃₀N₃₀ nanocages have higher capacitates and abilities to deliver and transfer of the Dacarbazine as anticancer drug than other nanostructures in previous works. The adsorption of Dacarbazine on Si₆₀, C₆₀, B₃₀N₃₀, Sc-Si₆₀, Sc-C₆₀, Sc-B₃₀N₃₀ nanocages have the τ values ca 48.8, 51.1, 54.2, 54.9, 57.5 and 62.1 s, respectively. Finally, the Sc-B₃₀N₃₀ is proposed to adsorb and deliver the Dacarbazine.

Enormous advantages can be brought by using silicon as a substrate for III-V photonic integrated circuit quantum dot (QD) lasers, such as a low cost, high bandwidth transmission data, on-chip light sources, etc. However, several difficulties arise when III-V QD lasers are grown directly on Si-substrate, mainly due to high lattice mismatching between the III-V components and the silicon wafer. In fact, a highly thermal expansion coefficient difference, threading dislocation densities (TDDs), and antiphase boundaries (APBs) are the crucial obstacles for developing a high-performance semiconductor laser on Si. In this regard, many approaches and strategies have been devoted to tolerantly grow III-V on Si. In this review, the history of QD laser diodes directly grown on Si-substrate is demonstrated. The benefits and the problems of III-V semiconductor materials epitaxially grown on Si are discussed. The recent progress in QD lasers grown in silicon is reviewed, focusing on InAs-QD lasers in terms of threshold current density, output optical power, emission wavelengths, and operation temperatures. The future of QD lasers monolithically grown on Si-substrate and their application are also discussed in this review.