Si Structures Research Articles

Relationship between viscosity, foaming, and structure of CaO–SiO2–Al2O3–MgO–FeO slag with the addition of SiO2 and Al2O3

Optimizing the foaming characteristics of slag in electric arc furnaces (EAF) presents a challenging task, affecting electrode heating efficiency and increasing smelting cost. This study explores the impact of adding silicon dioxide (15–35 wt%) and a small quantity of alumina (5–10 wt%) on the viscosity and foaming properties of CaO–SiO2–Al2O3–MgO–FeO slag. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) were employed to investigate structural changes in the slag melt. The findings reveal that higher levels of silica or a slight increase in alumina content enhance slag polymerization and foaming efficiency. Specifically, a 10 wt% alumina content, in contrast to 5 wt%, leads to high silica content, leading to faster polymerization but relatively lower viscosity. Structural analysis confirms that increasing alumina content, particularly when silica content is high, results in a less stable Al–O–Si structure, causing a shift from Q0 and Q1 units to Q2 and Q3 units, which ultimately reduces viscosity. When the alumina content remains at 5 wt% and silica content increases from 15 wt% to 35 wt%, foaming efficiency improves from 13.06 cm min to 94.97 cm min, a remarkable 627% rise. Moreover, when silica content is 30 wt% and alumina is slightly increased by 5 wt%, there is a notable enhancement in foaming efficiency, rising from 47.11 cm min to 89.16 cm min, while the effect on viscosity is not prominent.

Structural phase transition and resistive switching properties of Cu x O films during post-thermal annealing

We studied the phase change and resistive switching characteristics of copper oxide (Cu x O) films through post-thermal annealing. This investigation aimed to assess the material’s potential for a variety of electrical devices, exploring its versatility in electronic applications. The Cu x O films deposited by RF magnetron sputtering were annealed at 300, 500, and 700 °C in ambient air for 4 min by rapid thermal annealing (RTA) method, and then it was confirmed that the structural phase change from Cu2O to CuO occurred with increasing annealing temperature. Resistive random-access memory (ReRAM) devices with Au/Cu x O/p+-Si structures were fabricated, and the ReRAM properties appeared in CuO-based devices, while Cu2O ReRAM devices did not exhibit resistive switching behavior. The CuO ReRAM device annealed at 500 °C showed the best properties, with a on/off ratio of 8 × 102, good switching endurance of ∼100 cycles, data retention for 104 s, and stable uniformity in the cumulative probability distribution. This characteristic change could be explained by the difference in the grain size and density of defects between the Cu2O and CuO films. These results demonstrate that superior and stable resistive switching properties of RF-sputtered Cu x O films can be obtained by low-temperature RTA.

Circular disk solar absorber heater design for industrial heaters based on Fe2O3–Si structure

Industrial heaters nowadays work on renewable energy concepts and one of the important green energy sources is solar energy and we have used solar energy to design industrial heaters. The solar absorber converts the solar energy into heat which is used for industrial heaters. We developed a new solar absorber construction with three different layers by using different materials for each layer construction. Aluminium (Al) is for the top (resonator) layer, iron (III) oxide (Fe2O3) is for the middle (substrate), and silicon is used in the ground (based) layer respectively. A thin graphene layer is constructed between the Al resonator and the Fe2O3 substrate sections to develop better absorption by this design. In the wavelength range (μm) of 1.86 and 3, the explored absorption rate is 95.43 % with a 1740 nm bandwidth. The absorption rate performs above 97 % (97.23 %) at a 540 nm bandwidth with a wavelength (μm) difference between 1.96 and 2.5. The overall absorption for design explores 91.23 % (greater than 90 %) with a 2800 nm bandwidth range by the wavelength contribution from 0.2 to 3 μm. To highlight the explored amounts in variation, the four high wavelengths (in micrometers) are selected with λ1 = 0.45, λ2 = 1.1, λ3 = 2.1, and λ4 = 2.5 respectively. Concerning the presentation of this design, the construction steps from the beginning to the complete stage distribution, Air Mass (AM) exploration and equations, parameter analysis with the respective color extractions, polarization situation by changing incident angle (degree) from 0 to 80, electric and magnetic field analysis section, and a comparison table will be included in this work. This design can be achieved in the development of renewable energy such as the large amount of electricity generation by solar energy (green energy) systems, the process of heating and cooling systems of water, and multiple transportation systems.

Dislocations in Crystalline Silicon Solar Cells

Dislocation is a common extended defect in crystalline silicon solar cells, which affects the recombination characteristics of solar cells by forming deep‐level defect states in the silicon bandgap, thereby reducing the lifetime of minority carrier. Hence, reducing the impact of defects on device performance is an effective strategy to optimize the performance of photovoltaic devices. This article reviews the observation and engineering of dislocation in Si solar cell. The structure and deformation of Si can be directly observed by chemical etching combined with electron microscopy. Also, more information about dislocation is obtained indirectly by monitoring the electrical and optical properties of Si. The classification, density, distribution of dislocations, and their interactions with other defects in Si can affect the lifetime of minority carriers and thereby reduce the performance of Si solar cells. In order to achieve higher cell efficiency, crystals with less or even no dislocation should be obtained. In addition to the specification of controlling the relevant parameters during the growth of silicon ingots to obtain the minimum dislocation density, it is necessary to study the behavior of dislocation in Si wafers under the combined action of external stress, temperature, and other defects.

Comprehensive Recovery of Point Defect Displacement Field Function in Crystals by Computer X-ray Diffraction Microtomography

In the case of the point defect in a crystal, the inverse Radon’s problem in X-ray diffraction microtomography has been solved. As is known, the crystal-lattice defect displacement field function f(r) = h·u(r) determines phases − (±h)-structure factors incorporated into the Takagi–Taupin equations and provides the 2D image patterns by diffracted and transmitted waves propagating through a crystal (h is the diffraction vector and u(r) is the displacement field crystal-lattice-defects vector). Beyond the semi-kinematical approach for obtaining the analytical problem solution, the difference-equations-scheme of the Takagi–Taupin equations that, in turn, yield numerically controlled-accuracy problem solutions has been first applied and tested. Addressing the inverse Radon’s problem solution, the χ2-target function optimization method using the Nelder–Mead algorithm has been employed and tested in an example of recovering the Coulomb-type point defect structure in a crystal Si(111). As has been shown in the cases of the 2D noise-free fractional and integrated image patterns, based on the Takagi–Taupin solutions in the semi-kinematical and difference-scheme approaches, both procedures provide the χ2-target function global minimum, even if the starting-values of the point-defect vector P1 is chosen rather far away from the reference up to 40% in relative units. In the cases of the 2D Poisson-noise image patterns with noise levels up to 5%, the figures-of-merit values of the optimization procedures by the Nelder–Mead algorithm turn out to be high enough; the lucky trials number is 85%; and in contrast, for the statistically denoised 2D image patterns, they reach 0.1%.

Paramagnetic Point Defect in Fluorine-Doped Silica Glass: The E^{'}(F) Center.

Fluorine-doped silica is a key material used in all low-loss and/or radiation-resistant optical fibers. Surprisingly, no fluorine-related radiation-induced point defects have been identified. By using electron paramagnetic resonance, we report the first observation of F-related defects in silica. Their fingerprint is a doublet with 10.5mT splitting due to hyperfine coupling (hfc) to ^{19}F nuclear spins. An additional 44.4mT hfc to the ^{29}Si nucleus indicates that this defect belongs to the "E^{'} center" family and has a structure of a fluorine-modified Si dangling bond: 3-coordinated Si atoms with an unpaired electron in an sp^{3} orbital, bonded to a glass network by 2 bridging oxygen atoms and to a F atom.

Coordination Structure of Si(II) Ions in Binary Melts (LiF-KF, LiF-NaF, and NaF-KF) and Ternary Melt (LiF-NaF-KF).

The formation of Si(II) by the comproportionation reaction between electrodeposited silicon and Si(IV) ions [Si(IV) + Si0 ⇄ 2Si(II)] in fluoride melts has been discussed in many previous reports on the electrochemical processing of silicon. In this study, the coordination structure of Si(II) ions in LiF-KF, LiF-NaF, NaF-KF, and LiF-NaF-KF melts was investigated by high-temperature Raman spectroscopy and quantum chemical calculation based on density functional theory. The formation of Si(II) ions was induced by mixing metallic silicon powder as the source of Si0, with the melts containing hexafluoro silicate or silicon dioxide as the source of Si(IV) ions. The simulated vibrational modes of the Si(II) species and the experimental Raman bands showed good agreement. It was found that both Si(II) and Si(IV) species were detected in either fluoride melt, demonstrating that the proposed comproportionation reaction between Si0 and Si(IV) occurred. In addition, the interaction between Si(II) and F-, O2-, Li+, Na+, and K+ ions significantly changed depending on the composition of fluoride melts. The coordination structure of the Si(II) ions reported in this study will provide clues for controlling the electrodeposition process of silicon in fluoride melts.

Quasi-deterministic localization of Er emitters in thin film TiO2 through submicron-scale crystalline phase control

With their shielded 4f orbitals, rare-earth ions (REIs) offer optical and electron spin transitions with good coherence properties even when embedded in a host crystal matrix, highlighting their utility as promising quantum emitters and memories for quantum information processing. Among REIs, trivalent erbium (Er3+) uniquely has an optical transition in the telecom C-band, ideal for transmission over optical fibers, making it well suited for applications in quantum communication. The deployment of Er3+ emitters into a thin film TiO2 platform has been a promising step toward scalable integration; however, like many solid-state systems, the deterministic spatial placement of quantum emitters remains an open challenge. We investigate laser annealing as a means to locally tune the optical resonance of Er3+ emitters in TiO2 thin films on Si. Using both nanoscale x-ray diffraction measurements and cryogenic photoluminescence spectroscopy, we show that tightly focused below-gap laser annealing can induce anatase to rutile phase transitions in a nearly diffraction-limited area of the films and improve local crystallinity through grain growth. As a percentage of Er:TiO2 is converted to rutile, the Er3+ optical transition blueshifts by 13 nm. We explore the effects of changing laser annealing time and show that the amount of optically active Er:rutile increases linearly with laser power. We additionally demonstrate local phase conversion on microfabricated Si structures, which holds significance for quantum photonics.

New Crystal Photodiode Combination for Environmental Radiation Measurement

Here, a new design will be introduced to detect radiation in the environment with high efficiency. The designed structure consists of placing ZnS–Si APD and PIN photodiodes at the ends of conventional crystals such as NaI(Tl) and CsI(Tl). Since ZnS is transparent to photons with wavelengths between 340 and 10000 nm, photons coming from the crystals are absorbed directly in the depletion region and generate primary particles. With an increase in the number of generated primary particles, a stronger and cleaner signal is obtained. In the simulation work, the light generated by 30 keV–3 MeV gamma rays in the crystals was obtained using the Geant4 simulation code. The single-particle Monte Carlo technique was used to calculate the photodiode output signal for the crystal emission spectrum. The simulation results showed that the crystals and ZnS–Si photodiode structures formed a good combination. The high quantum efficiency and low excess noise factor make the ZnS–Si structure an excellent choice for scintillating light detection.

Electronic structure, optical and elastic properties of Si doped Strontium Selenide: A theoretical investigation

The structural, electronic, optical, and elastic properties of Silicon doped Strontium Selenide binary and ternary semiconductor alloys with the general form of Sr(1-x)SixSe, 0 ≤ x ≤ 1 in B1 and B3 phases have been figured adopting augmented plane wave plus local orbital methods within density functional theory, Structural properties summarize the crystal structure, relevant atomic positions, lattice constant, bulk modulus minimum energy E0 and minimum volume V0. Elastic constants conform to the structure stability of the B1 and B3 phases. Band gap is found to shift from indirect to direct and in some materials with initial direct band gap, the gap width increased which increased the range of applicability of these binary and ternary semiconductor compounds. Whereas optical properties which include the study of zero frequency limit of static dielectric constant ε0(ω) with its real and imaginary parts, static refractive index n(0), optical reflectivity (R), optical absorption coefficient (α), and loss function (L) studied comprehensively to get real electrical and optical properties of these materials and give semiconductor market best alternative candidate which shows its effectiveness in the visible, ultraviolet and infrared region of the electromagnetic spectrum. The obtained results were compared together and with the available experimental along with theoretical work on these binary and ternary Silicon doped Alkaline earth chalcogenides.

Atomic understanding of the evolutionary mechanism of fused glass densification generation during single particle scratching

The densification of fused glass during processing has a significant impact on the performance and application of fused glass components. However, the precise atomic mechanisms underlying densification remain elusive. In this study, we explore the atomic mechanisms responsible for densification in fused glass during single particle scratching, with a focus on the scratching depths and environmental humidity. We employ reactive force field molecular dynamics (ReaxFF MD) simulations for our investigation. We subjected models to scratching under various humidity conditions using a spherical virtual indenter with a 20 Å radius. The scratching depths were set at 10 Å and 15 Å, respectively, with a constant scraping speed of 40 m/s. Our findings indicate that water molecules impede lateral atom movement on the fused glass surface while enhancing vertical flow. Furthermore, water molecules facilitate the volume recovery of fused glass following scratching. The transfer of hydrogen (H) atoms within the fused glass, facilitated by Si–O–H⋯O–Si structures, plays a crucial role in promoting volume recovery. The ultimate density distribution of fused glass results from a combination of atomic displacement during scratching and subsequent volume recovery. This study enhances our atomic-level understanding of densification generation in fused glass.

The Effect of Silica Sol on the Stain Resistance of Exterior Wall Latex Coatings through Natural Exposure to Sunlight

Stain resistance is one of the important characteristics of exterior wall latex coatings in cities. Adding silica sol to the coating can increase its stain resistance. However, there is currently limited research on the long-term natural exposure test of latex coatings. This paper first investigates the influence of different amounts of silica sol on the elongation, water absorption, and stain resistance of coatings and obtains a better percentage of silica sol addition. Then, heat storage tests were conducted to obtain the viscosity and pH changes of the coating. Afterwards, outdoor natural exposure tests were conducted for up to 12 months to obtain the stain resistance of the coating with the addition of silica sol. The results indicate that the stain resistance value of the coating with added silica sol was significantly better than that without added silica sol after 12 months of natural exposure to sunlight, increasing by 65.8%. The formation of a network structure of Si O-Si bonds in the silica sol enhances the hardness and rigidity of the coating while also allowing it to enter the capillary tubes of the coating caused by prolonged exposure to sunlight, avoiding cracking of the coating and preventing the entry of dust and impurities. Therefore, the stain resistance of the coating is improved. These research results will contribute to the better application of exterior wall latex coatings in architecture.

Annealing behavior of AlSi10Mg alloy fabricated by laser powder bed fusion

The AlSi10Mg alloy fabricated by laser powder bed fusion was subjected to isochronal annealing for 2h at temperatures in the range of 100–520 °C. Recovery and grain growth of the annealed samples were investigated by combining EBSD and in situ TEM techniques. A bimodal grain size distribution with grain sizes of 0.9 μm and 2.3 μm was developed in the initial sample, where large grains were found in the interiors of melt pools and most of small grains were distributed along melt pool boundaries. In-situ TEM investigations revealed that nucleation that occurs at the melt pool boundaries is as a consequence of migration of high angle boundaries during annealing. A slight increase in grain sizes was discovered during high-temperature heat treatment, indicating the remarkable thermal stability of the alloy compared to conventional cast Al-Si alloys. This is explained by the fact that the stable eutectic Si structure, which was originally formed during rapid solidification, can effectively retard grain boundary migration during recrystallization.

Effect of rare earth La2O3 on the microstructure and tribological properties of laser-clad CoCrFeNiMoSi high-entropy alloy coatings

In this study, CoCrFeNiMoSi and CoCrFeNiMoSi + 0.5 % La2O3 High entropy alloy (HEA) coatings were prepared by laser cladding. The microstructure was consisted mainly of body-centered cubic structure, face-centered cubic structure and intermetallic compounds of Si. The addition of rare earth La2O3 resulted in the refinement and uniformity of the CoCrFeNiMoSi + 0.5 % La2O3 HEA coating grains, leading to an increase in microhardness from 430 HV to 520 HV. Additionally, the friction coefficient decreased by 0.15 and the wear rate decreased by 2/3. These findings indicate that the appropriate addition of La2O3 has significant potential in enhancing the friction and wear performance of HEA coatings.

Building Three-Dimensional Network Structures of Silicon–Graphite/Carbon Nanotube Composite Anode for High-Energy Lithium-Ion Batteries

As the increasing demand for high-energy-density lithium-ion batteries (LIBs), silicon-based anodes have become an excellent alternative to conventional graphite anodes owing to their high theoretical capacities. In this study, a three-dimensional (3D) electric network structure was developed using an aqueous carbon nanotube (CNT) suspension to improve the specific capacity and cyclability of Si–graphite electrodes. Field-emission scanning electron microscopy demonstrated that longer single-walled CNTs (SWCNTs) effectively covered and interconnected the entire surface of the Si and graphite particles, thereby providing electric conduction networks and facile access to Li ions in the electrode and structural strength with flexibility. As a result, 3D networks structure of Si–graphite/SWCNTs (Si-G-SW) exhibited the highest specific capacity (829.7 mAh g−1 at 0.1 A g−1), rate capability, and cycle stability (>79% after 100 cycles). We expect this robust 3D network electrode system to provide a new route for high-energy-density LIB anodes.

On the Possibility of Realizing a 2D Structure of Si─N Bonds by Metal‐Organic Chemical Vapor Deposition

On the Possibility of Realizing a 2D Structure of Si─N Bonds by Metal‐Organic Chemical Vapor Deposition

A Physics-Based Model of Charge Trapping Behavior of Si FeFET With Metal/Ferroelectric/Interlayer/Si Structure

A Physics-Based Model of Charge Trapping Behavior of Si FeFET With Metal/Ferroelectric/Interlayer/Si Structure

Investigation of the Surface Structure of Si, Ge, GaAs, GaP by the Method of Ion Bombarding When Growing Solid Solutions from a Liquid Phase

Investigation of the Surface Structure of Si, Ge, GaAs, GaP by the Method of Ion Bombarding When Growing Solid Solutions from a Liquid Phase

Highly regular laser-induced periodic silicon surface modified by MXene and ALD TiO2 for organic pollutants degradation

The co-catalytic ability of surface groups in MXene renders MXene-based composites efficient photocatalysts for organic dye photodegradation. In this study, we introduce a novel approach combining highly-regular laser-induced periodic surface Si structures (Si nanoripples - SiNR) with MXene and TiO2, deposited through atomic layer deposition (ALD), to achieve stable, repeatable, and highly efficient photocatalytic materials. The ternary system, SiNR/MXene/TiO2, exhibits high light absorption across the entire spectrum. Furthermore, the photodegradation efficiency of SiNR/MXene/TiO2 is approximately 2.6 times higher than that of SiNR/TiO2 samples. This remarkable enhancement in photocatalytic activity can be attributed to two main factors: increased separation of photogenerated charge carriers and enhanced light absorbance through the light trapping effect. The synergistic combination of SiNRs, MXene, and TiO2 in the ternary nanocomposite structure enables efficient separation of photogenerated charge carriers, thereby minimizing recombination and enhancing the degradation of organic dyes. Moreover, the introduction of a laser-patterned surface and its ALD modification significantly enhances light absorbance, ensuring effective utilization of a wider range of the solar spectrum for photocatalysis. Therefore, SiNR/MXene/TiO2 ternary nanocomposites hold great promise for developing high-performance photocatalysts for water purification applications, offering improved stability, repeatability, and enhanced photocatalytic efficiency.

On the Possibility of Realizing a 2D Structure of Si─N Bonds by Metal‐Organic Chemical Vapor Deposition

2D SiN honeycomb monolayer structures predicted theoretically have been the focus of interest in materials science for a long time, most recently for their semiconducting and ferromagnetic properties. Herein, by investigating metal‐organic chemical vapor deposition processes and direct heat treatment of epitaxial graphene in ammonia flow, the possibility of realizing a certain periodic 2D structure via Si─N bonds under epitaxial graphene on SiC (0001) is reported. The result is of interest because it is compatible with semiconductor material deposition technologies and future use in nanoscience and nanotechnology.