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For the preparation of SiC nanowires (SiC NWs) by carbothermal reduction, it is of great significance to study the formation mechanism of sic nanowires for process optimization and the controllable preparation. Although first-principles molecular dynamics (FPMD) can simulate systems of hundreds of atoms on a picosecond time scale, the results of FPMD are still insufficient to elucidate the formation mechanism of core-shell SiC nanowires. To make up this deficiency, this article has conducted Deep Potential Molecular Dynamics (DPMD) simulation on nanoseconds timescales with near FPMD accuracy for systems containing thousands of atoms, the results more concretively show the formation process of core-shell SiC nanowires. DPMD simulation results show when CO molecules react with SiO molecules, CO molecules are wrapped by SiO molecules to form agglomerates, SiO molecules in the agglomerates that can come into contact with the wrapped CO molecules will react with wrapped CO molecules to form the SiC core, and SiO molecules that in the outer layer of the agglomerates will disproportionate into the amorphous SiO 2 shell. Furthermore, the formation mechanism of SiC nanowires was validated in combination with thermodynamics and experimental methods. Thermodynamic results show that vacuum conditions are favorable for the formation of SiO and CO and lower the temperature of SiC preparation. Finally, the core-shell structure of SiC NWs with good luminescence properties were successfully prepared by carbothermal reduction method using carbon black and silicon dioxide as raw materials under the pressure of less than 5 kPa. [ABSTRACT FROM AUTHOR]

Stacking faults (SFs) could be generated in aluminum (Al) via full dislocations extension under extreme stress. However, the extension behavior of the dislocations related to the stress conditions have not been studied comprehensively. In this study, SFs were generated solely under extreme stress condition in coarse–grained Al nanocomposites, where high content of Silicon Carbide nanowires (SiCnw) was introduced as reinforcement. Dislocation extension behaviors under normal and shear stress were predicted using an atomistic approach comparing with experiment methods. The extension ability of full dislocations was studied in terms of complex stress forced on partial dislocations and the relationship between stress condition and the SF width was established by stress analysis. The generated SFs were further proved to offer superb additional strengthening effect for the composites. This study provides a new idea and theory for designing of SF generation in coarse–grained Al based nanocomposites. [ABSTRACT FROM AUTHOR]

Metallic nanowires, particularly polyol-grown silver nanowires, exhibit a morphological instability at temperatures significantly lower than their bulk melting point. This instability is commonly named after Rayleigh's description of the morphological instability of liquid jets, even though it has been shown that its quantitative predictions are not consistent with experimental measurements. In 1996, McCallum et al. proposed a description of the phenomenon assuming a solid wire lying on a substrate. It is assumed that the latter description depicts more accurately the reality. Nanowires with varying diameters have been deposited on silicon wafers. Statistical analysis of their radius and the wavelength of their periodical instability have been performed. McCallum et al.'s model better aligns with experimental observations compared to Rayleigh's description. This validation provides a robust theoretical framework for enhancing the stability of nanowires, addressing a crucial aspect of their development. [ABSTRACT FROM AUTHOR]

Silicon, with its many advantages, is gaining attention in the field of lithium-ion battery anode materials. However, severe volume swelling, poor conductivity, and slow Li+ diffusion kinetics are major obstacles to enhancing the electrochemical properties of silicon anodes. One-dimensional silicon nanowires with a high aspect ratio can effectively ameliorate these issues, while the complexity of the synthesis method limits its development. Here, a three-dimensional flexible electrode of binary-phase Ni-silicide foam loaded with silicon nanowires (NixSiy@Si NWs) was constructed in two simple steps: preparation of metal catalyst nanoparticles using a chemical plating approach and production of silicon nanowires by the supercritical fluid-liquid–solid mechanism. Benefiting from the excellent anchoring ability and superior electrical conductivity of NixSiy as well as the extra space and favorable Li+ and electrolyte diffusion paths provided by the Si NWs network, the as-obtained anode exhibits a high initial Coulombic efficiency of 77% at 0.5 A g−1, excellent cycling performance (a reversible capacity of 1238 mAh g−1 after 200 cycles) and outstanding rate capability (2675, 2497, 2164, 1740, and 1222 mAh g−1 at 0.5, 1, 2, 4, and 8 A g−1, respectively). [ABSTRACT FROM AUTHOR]

Nanostructured silicon solar cells are designed to minimize costs through reduced material usage while enhancing power conversion efficiency via superior light trapping and shorter charge separation distances compared to traditional planar cells. This study identifies the optimal conditions for nanoimprinted silicon nanowire (SiNW) solar cells to achieve maximum efficiency under low sunlight concentration and evaluates their performance as bottom cells in III-V multijunction solar cell systems. The findings indicate that the SiNW solar cell reaches its peak performance at a concentration factor of 7.5 suns and a temperature of 40°C or lower. Specifically, the absolute conversion efficiency under these conditions is 1.05% higher than that under unconcentrated light. Compared to a planar silicon solar cell under identical conditions, the SiNW solar cell exhibits a 3.75% increase in conversion efficiency. Additionally, the SiNW single-junction solar cell, when integrated in series with a commercial latticematched InGaP/GaAs dual-junction solar cell, was tested under unconcentrated sunlight, specifically at one-sun, global air mass 1.5 condition, to assess its viability in one-sun multi-junction solar cell applications. The results suggest that a III-V upper subcell with a smaller active area than that of the SiNW subcell is optimal for maximizing current production, which is favorable to the cost reduction of the device. This hybrid configuration is particularly advantageous for terrestrial applications, such as electric vehicles, which demand lightweight, highperformance multijunction solar cell devices. Although the weight reduction of the characterized SiNW solar cell with a full silicon substrate compared to its planar solar cell counterpart is 1.8%, recommendations to increase this reduction to as much as 64.5% are discussed to conclude this paper. [ABSTRACT FROM AUTHOR]

Highlights: A new strategy for elaborate regulation of microstructure was successfully introduced by the ice template‑assisted 3D printing and chemical vapor deposition strategy, including graphene nanoplate/silicon carbide nanowires hierarchical porous structure and graphene nanoplate/boron nitride composite heterogeneous interface. The composite exhibits excellent electromagnetic wave absorption performance with an RLmin of -37.8 dB and an EABmax of 9.2 GHz (from 8.8 to 18.0 GHz) at 2.5 mm. And the high-temperature absorption stability makes it a promising absorber candidate under high temperature and oxidizing atmosphere. With vigorous developments in nanotechnology, the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers. Herein, a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity. The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires (SiCnws) grown in situ, while boron nitride (BN) interfacial structure is introduced on graphene nanoplates. The unique composite structure forces multiple scattering of incident EMWs, ensuring the combined effects of interfacial polarization, conduction networks, and magnetic-dielectric synergy. Therefore, the as-prepared composites present a minimum reflection loss value of − 37.8 dB and a wide effective absorption bandwidth (EAB) of 9.2 GHz (from 8.8 to 18.0 GHz) at 2.5 mm. Besides, relying on the intrinsic high-temperature resistance of SiCnws and BN, the EAB also remains above 5.0 GHz after annealing in air environment at 600 °C for 10 h. [ABSTRACT FROM AUTHOR]

Interband cascade lasers typically have significantly lower threshold current and power consumption than quantum cascade lasers. They can also have advantages regarding costs and compactness with the photonic integration onto silicon substrates by epitaxial growth. This research introduces a novel examination of the relative intensity noise and the modulation dynamics of a silicon-based Fabry–Perot interband cascade laser emitting at 3.5 μm. The investigation delves into crucial parameters, such as relaxation oscillation frequency, differential gain, gain compression, and K-factor. The resonance patterns identified in relative intensity noise curves can provide essential insights for the thorough characterization of high-defect mid-infrared semiconductor structures intended for high-speed applications. Moreover, this study demonstrates the feasibility of reaching 10 Gbit/s free-space transmission using a silicon-based interband cascade laser in conjunction with an interband cascade infrared photodetector. [ABSTRACT FROM AUTHOR]

In this article, we propose a novel natural light detector based on high-performance silicon nanowire (SiNW) arrays. We achieved a highly controllable and low-cost fabrication of SiNW natural light detectors by using only a conventional micromachined CMOS process. The high activity of SiNWs leads to the poor long-term stability of the SiNW device, and for this reason, we have designed a fully wrapped structure for SiNWs. SiNWs are wrapped in transparent silicon nitride and silicon oxide films, which greatly improves the long-term stability of the detector; at the same time, this structure protects the SiNWs from breakage. In addition, the SiNW arrays are regularly distributed on the top of the detector, which can quickly respond to natural light. The response time of the detector is about 0.015 s. Under the illumination of 1 W·m−2 light intensity, multiple SiNWs were detected together. The signal strength of the detector reached 1.82 μA, the signal-to-noise ratio was 47.6 dB, and the power consumption was only 0.91 μW. The high-intensity and highly reliable initial signal reduces the cost and complexity of the backend signal processing circuit. A low-cost and high-performance STM32 microcontroller can realize the signal processing task. Therefore, we built a high-performance SiNW natural optoelectronic detection system based on an STM32 microcontroller, which achieved the real-time detection of natural light intensity, with an accuracy of ±0.1 W·m−2. These excellent test performances indicate that the SiNW array natural light detector in this article meey the requirements of practicality and has broad potential for application. [ABSTRACT FROM AUTHOR]

Silicon monoxide nanowires have become ubiquitous in twenty-first century technology due to their superior photoelectric properties, widely utilized in semiconductor manufacturing and emerging energy fields. While numerous studies have concentrated on tailoring material properties, scant attention has been paid to the impact of process parameters on the productivity of silicon monoxide during synthesis. Through response surface methodology, the effects of holding time, heating temperature, and Si/SiO2 molar ratio on the volatilization ratio of silicon monoxide have been investigated. The optimization of silicon monoxide nanowire preparation via vacuum silicothermic reduction was aimed at achieving maximum efficiency. According to the established mathematical model, the volatilization ratio of silicon monoxide reaches 92.057% when the holding time is 126 min, the heating temperature is 1663 K, and the molar ratio is 1. A comprehensive analysis revealed that temperature is the most significant factor affecting silicon monoxide volatilization among the studied parameters. Furthermore, the reduction slag of the system was characterized and analyzed. The results indicate that vacuum conditions can lower the starting temperature of the silicothermic reduction, thereby promoting the volatilization of SiO(g). [ABSTRACT FROM AUTHOR]

This paper presents an integrated approach for a retinal prosthesis that overcomes the scalability challenges and limitations of conventional systems that use external cameras. Silicon nanowires (SiNWs) are utilized as photonic sensors due to their nanoscale dimensions and high surface-to-volume ratio. To enhance these properties and achieve high photoresponsivity, our research team developed a vertically stacked SiNW structure using a fabrication method entirely based on dry etching. The fabricated SiNW photodetector demonstrated excellent electrical and optical characteristics, including linear I–V characteristics that confirmed ohmic contact formation and high photoresponsivity exceeding 105 A/W across the 400–800 nm wavelength range. The SiNW photodetector, following its integration with a switched capacitor stimulator circuit, exhibited a proportional increase in stimulation current in response to higher light intensity and increased SiNW density. In vitro experiments confirmed the efficacy of the integrated system in inducing neural responses from retinal cells, as indicated by an increased number of neural spikes observed at higher light intensities and SiNW densities. This study contributes to sensor technology by demonstrating an approach to integrating nanostructures and electronic components, which enhances control and functionality. [ABSTRACT FROM AUTHOR]

Silicon is the most diffused material in the industry; thus, considering its high capacity for energy storage, silicon‐based materials are well studied as battery anodes and supercapacitors. Si nanowires (NWs) emerge due to the high surface to volume ratio, its compatibility with a wafer processing typical of microelectronics, and are studied as anodes for lithium batteries as well as coupled with other materials for supercapacitor application. In this article, the synthesis and application are reported as a lithium anode of 2D fractal arrays of ultrathin Si NWs obtained by a thin‐film metal‐assisted chemical etching (MACE). These Si NWs exhibit a density of about 1012 NWs cm−2, maximizing the surface to volume ratio compared to silver‐salts MACE and other NW fabrication approaches. By using 2.7 μm long NWs, a pseudo‐capacitor behavior with a specific capacitance of about 274.2 μF cm−2 at a scan rate of 50 mV s−1 is obtained. This specific capacitance is two orders of magnitude higher than the one obtained in the same condition by using NWs synthesized by silver‐salt MACE. In this result, the route is opened toward the application of these fractal arrays of ultrathin Si NWs as substrate for supercapacitors with improved efficiency. [ABSTRACT FROM AUTHOR]

Si 3 N 4 and SPEEK were simply mixed and used to prepare a Si 3 N 4 /SPEEK composite separator through electrospinning. The silicon nanowires formed at the interface between the Si 3 N 4 /SPEEK separator and the lithium anode result in the separator showing superior long-cycle performance. [Display omitted] • The Si 3 N 4 /SPEEK composite separator was prepared by electrospinning. • Si 3 N 4 in the Si 3 N 4 /SPEEK separator can be reduced by Li+ to form Si nanowires. • The Si 3 N 4 /SPEEK separator features a high specific surface area and abundant mesopores. • DFT calculations reveal that Si 3 N 4 has strong interactions with electrolyte molecules (EC and DMC). • Si 3 N 4 enhances the dimensional stability of separator at high temperatures and pressures. The uncontrolled lithium (Li) dendrite growth significantly impacts the safety performance of polymer separators. To mitigate this growth, this study introduces Si 3 N 4 into sulfonated poly(ether Ether Ketone) (SPEEK) and prepares Si 3 N 4 /SPEEK composite separators via electrospinning. At the interface between the Si 3 N 4 /SPEEK separator and the Li anode, the Si nanowires that form impede Li dendrite growth, thereby enhancing the electrochemical performance of lithium-ion batteries (LIBs). The Li deposition test of the 10 % Si 3 N 4 /SPEEK separator can operate for 1000 h without short-circuiting. Additionally, the LiFePO 4 ||Li cell with the 10 % Si 3 N 4 /SPEEK separator shows improved initial discharge capacity (157.8 mAh g−1 at 1C) and superior rate performance (125 mAh g−1 at 10C). Moreover, the nano-scale Si 3 N 4 endows the separator with robust thermal and mechanical properties. The FLIR observations reveal that the 10 % Si 3 N 4 /SPEEK separator maintains uniform thermal distribution and structural integrity even at 300 °C, ensuring safe battery operation at high temperatures. The additional load of the 10 % Si 3 N 4 /SPEEK separator can reach 10.2 mN, which enhances the puncture resistance of the separator. This work provides a solid approach for the application of SPEEK as a high-safety and high-rate LIB separator. [ABSTRACT FROM AUTHOR]

Dynamic nuclear polarization (DNP) has revolutionized the field of nuclear magnetic resonance spectroscopy, expanding its reach and capabilities to investigate diverse materials, biomolecules, and complex dynamic processes. Bringing high-efficiency DNP to the nanometer scale would open exciting avenues for studying nanoscale nuclear spin ensembles, such as single biomolecules, virus particles, and condensed matter systems. Combining pulsed DNP with nanoscale force-detected magnetic resonance measurements, we demonstrated a 100-fold enhancement in the Boltzmann polarization of proton spins in nanoscale sugar droplets at 6 kelvin and 0.33 tesla. Crucially, this enhancement corresponds to a factor of 200 reduction in the averaging time compared to measurements that rely on the detection of statistical fluctuations in nanoscale nuclear spin ensembles. These results substantially advance the capabilities of force-detected magnetic resonance detection as a practical tool for nanoscale imaging. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) single crystals have great prospects for high-temperature energy storage due to their robust structural stability, ultrahigh power output, and superior temperature stability. However, energy density is an essential challenge for SiC-based devices. Herein, a facile two-step strategy is proposed for the large-scale synthesis of a unique architecture of SiC nanowires incorporating MnO2 for enhanced supercapacitors (SCs), arising from the synergy effect between the SiC nanowires as a highly conductive skeleton and the MnO2 with numerous active sites. The SiC@MnO2 integrated electrode-based SCs with ionic liquid (IL) electrolytes were assembled and delivered outstanding energy and power density, as well as a great lifespan at 150 °C. This impressive work offers a novel avenue for the practical application of SiC-based electrochemical energy storage devices with high energy density under high temperatures. [ABSTRACT FROM AUTHOR]

a -axis-oriented AlN(100) films are identified as promising candidates for surface acoustic wave devices owing to their high transversal-acoustic velocity. Achieving uniform films across a wafer scale is crucial for enhancing device performance and minimizing manufacturing costs. In this study, we employ radio-frequency magnetron sputtering to deposit AlN(100) films on 2-in Si(100) wafers. We further examine the influence of various process parameters on the nonuniformity of film thickness and structural properties, including crystallite size, microstrain, and dislocation density. The optimization of parameters leads to the selection of a gas flow ratio of N 2 :Ar = 4:7, a sputtering power of 160 W, and a substrate temperature of 350 °C. Under these optimized conditions, the AlN films not only demonstrate a preferred (100) orientation and remarkable crystallinity, as indicated by a full width at half maximum of the X-ray diffraction peak of just 0.03°, but also achieve an optimal film thickness nonuniformity of 1.66 %. Our results offer valuable insights for the wafer-scale fabrication of AlN(100) films, potentially enhancing industrial production yields and reducing costs. [ABSTRACT FROM AUTHOR]

Recently, a great deal of interest has been focused on developing sensors that can measure both pressure and light. However, traditional sensors are difficult to integrate into silicon (Si)-based integrated circuits. Therefore, it is particularly important to design a sensor that operates on a new principle. In this paper, junction piezotronic transistor (JPT) arrays based on zinc oxide (ZnO) nanowire are demonstrated. And the JPT arrays show high spatial resolution pressure and light mapping with 195 dpi. Because ZnO nanowires are arranged vertically above the p-type Si channel's center of the transistor, the width of the heterojunction depletion region is constricted by the positive piezoelectric potential generated by strained ZnO. In addition, photogenerated charge carriers can be created in the Si channel when JPT is stimulated by light, which increases its electrical conductivity. Consequently, the external pressure and light distribution information can be obtained from the variation in the output current of the device. The prepared JPT arrays can be compatible with Si transistors, which make them highly competitive and make it possible to incorporate both pressure and light sensors into large integrated circuits. This work will contribute to many applications, such as intelligent clothing, human–computer interaction, and electronic skin. [ABSTRACT FROM AUTHOR]

This brief review covers the thermoelectric properties of one-dimensional materials, such as nanowires and nanotubes. The highly localised peaks of the electronic density of states near the Fermi levels of these nanostructured materials improve the Seebeck coefficient. Moreover, quantum confinement leads to discrete energy levels and a modified density of states, potentially enhancing electrical conductivity. These electronic effects, coupled with the dominance of Umklapp phonon scattering, which reduces thermal conductivity in one-dimensional materials, can achieve unprecedented thermoelectric efficiency not seen in two-dimensional or bulk materials. Notable advancements include carbon and silicon nanotubes and Bi3Te2, Bi, ZnO, SiC, and Si1−xGex nanowires with significantly reduced thermal conductivity and increased ZT. In all these nanowires and nanotubes, efficiency is explored as a function of the diameter. Among these nanomaterials, carbon nanotubes offer mechanical flexibility and improved thermoelectric performance. Although carbon nanotubes theoretically have high thermal conductivity, the improvement of their Seebeck coefficient due to their low-dimensional structure can compensate for it. Regarding flexibility, economic criteria, ease of fabrication, and weight, carbon nanotubes could be a promising candidate for thermoelectric power generation. [ABSTRACT FROM AUTHOR]

Context: Silicon carbide nanowires (SiCNWs) are considered a promising alternative material for application in lithium-ion batteries, with researchers striving to develop new electrode materials that exhibit high capacity and high charge/discharge rate performance. To gain a deeper understanding of the application of SiCNWs in semiconductor material science and energy supply fields, we investigated the effects of nanoscale and surface lithiation on the electrical and mechanical properties of SiCNWs grown along the [111] direction. First-principles calculation was used to study their geometries, electronic structures, and associated electrochemical properties. Herein, we considered SiCNWs with full hydrogen passivation, full lithium passivation, and mixed passivation at different sizes. The formation energy indicates that the stability of SiCNWs increases with the increasing diameter, and the surface-lithiated SiC nanowires (Li-SiCNWs) are found to be energetically stable. The mixed passivated SiCNWs exhibit the properties of indirect band gap with the increase of lithium atoms on the surface, while the fully lithium passivated nanowires exhibit metallic behavior. Charge analysis shows that a portion of the electrons on the lithium atoms are transferred to the surface atoms of the nanowires and electrons prefer to cluster more near the C atoms. Additionally, Li-SiCNWs still have good mechanical resistance during the lithiation process. The stable open-circuit voltage range and theoretical capacity of these SiCNWs indicate their suitability as anode materials. Method: In this study, Materials Studio 8.0 was used to construct the models of the SiCNWs. And all the density functional theory (DFT) calculations were performed by the Vienna ab initio Simulation Package (VASP). The self-consistent field calculations are performed over a Monkhorst–Pack net of 1 × 1 × 6 k-points. The energy convergence criteria for the self-consistent field calculation were set to 10−5 eV/atom with a cutoff energy of 400 eV. [ABSTRACT FROM AUTHOR]

Various electrocatalysts are extensively examined for their ability to selectively produce desired products by electrochemical CO2 reduction reaction (CO2RR). However, an efficient CO2RR electrocatalyst doesn't ensure an effective co‐catalyst on the semiconductor surface for photoelectrochemical CO2RR. Herein, Bi2S3 nanorods are synthesized and electrochemically reduced to Bi nanoplates that adhere to the substrates for application in the electrochemical and photoelectrochemical CO2RR. Compared with commercial‐Bi, the Bi2S3‐derived Bi (S‐Bi) nanoplates on carbon paper exhibit superior electrocatalytic activity and selectivity for formate (HCOO−) in the electrochemical CO2RR, achieving a Faradaic efficiency exceeding 93%, with minimal H2 production over a wide potential range. This highly selective S‐Bi catalyst is being employed on the Si photocathode to investigate the behavior of electrocatalysts during photoelectrochemical CO2RR. The strong adhesion of the S‐Bi nanoplates to the Si nanowire substrate and their unique catalytic properties afford exceptional activity and selectivity for HCOO− under simulated solar irradiation. The selectivity observed in electrochemical CO2RR using the S‐Bi catalyst correlates with that seen in the photoelectrochemical CO2RR system. Combined pulsed potential methods and theoretical analyses reveal stabilization of the OCHO* intermediate on the S‐Bi catalyst under specific conditions, which is critical for developing efficient catalysts for CO2‐to‐HCOO− conversion. [ABSTRACT FROM AUTHOR]

In recent decades, there has been a significant increase in the application of single‐molecule electrical analysis platforms in studying proteins and peptides. These advanced analysis methods have the potential for deep investigation of enzymatic working mechanisms and accurate monitoring of dynamic changes in protein configurations, which are often challenging to achieve in ensemble measurements. In this work, the prominent research progress in peptide and protein‐related studies are surveyed using electronic devices with single‐molecule/single‐event sensitivity, including single‐molecule junctions, single‐molecule field‐effect transistors, and nanopores. In particular, the successful commercial application of nanopores in DNA sequencing has made it one of the most promising techniques in protein sequencing at the single‐molecule level. From single peptides to protein complexes, the correlation between their electrical characteristics, structures, and biological functions is gradually being established. This enables to distinguish different molecular configurations of these biomacromolecules through real‐time electrical monitoring of their life activities, significantly improving the understanding of the mechanisms underlying various life processes. [ABSTRACT FROM AUTHOR]

Lithium ion batteries play an important role in various energy storage technologies due to their good safety performance. As an anode material, silicon has attracted attention for its higher theoretical capacity than commercial graphite. But large volume expansion and unstable solid electrolyte interface (SEI) during the cycling of silicon lead to rapid capacity decay, which limits the commercial application of silicon anode. In this article, Si/BiPO 4 anode materials were prepared by solvothermal reaction. After morphology analysis and constant current charge discharge cycle analysis of Si/BiPO 4 anode materials with different mass ratios, it was found that Si/BiPO 4 anode materials with the mass ratio of 7:3 exhibited more excellent electrochemical performance. The conversion reaction of BiPO 4 and Li generates Bi and Li 3 PO 4 , and the alloying reaction of Bi generates Li 3 Bi. Bi and Li 3 Bi reduce the internal resistance of the Si/BiPO 4 composite, and Li 3 PO 4 is distributed on the surface of Si material, participating in the formation of SEI film and improving the stability of the material. At a current density of 500 mA g−1, the first discharge specific capacity of the Si/BiPO 4 anode is 2672.1 mA h g−1. After 200 cycles, the discharge specific capacity remains at 1308.9 mA h g−1. The electrochemical impedances of pure Si and Si/BiPO 4 anode materials before and after cycling were analyzed. It was found that the resistance of the Si/BiPO 4 anode before and after 100 cycles was lower than that of pure Si materials, which further proved that the addition of BiPO 4 material helps to improve the charge transfer ability of pure silicon materials. [ABSTRACT FROM AUTHOR]

Perovskite SrVO 3 stands out as a promising anode material for lithium-ion batteries due to its inherent redox activity, excellent electrical conductivity, and structural adaptability. Despite these advantages, challenges persist, such as in achieving high tap density and volumetric specific capacity. In this study, we overcome these challenges by finely regulating particle size and constructing a tailored surface structure for SrVO 3. The implementation of ball milling during the synthesis process proves to be a simple yet highly efficient method for simultaneously tailoring particle size and in-situ creating an amorphous layer on SrVO 3 particles. The reduction in particle size not only facilitates enhanced electron and ion transport but also significantly improves the tap density of SrVO 3 , increasing it from 2.61 to 3.15 g cm−3. The in-situ construction of an amorphous layer introduces a multitude of defects and high valence V5+. These defects serve as active sites for lithium ions, while the V5+ species contribute to increased electron transfer, collectively resulting in a high gravimetric specific capacity. The engineered SrVO 3 anode delivers an impressive volumetric capacity of 1134 mAh cm−3 at 0.1 A g−1, surpassing both pristine SrVO 3 (733 mAh cm−3) and commercial graphite anode (∼460 mAh cm−3). [ABSTRACT FROM AUTHOR]

This work presents the pore defects repair of additively manufactured chopped carbon fibre reinforced silicon carbide (CCF/SiC) composites using a combination of chemical vapour deposition (with methyltrichlorosilane and hydrogen as the precursor material) and reactive melt infiltration. The in-situ generation of silicon carbide nanowires (SiC nws) in the CCF/SiC composites significantly reduced the initial pore defects size, while the secondary SiC and free Si filled and closed the pore defects. The X-CT shows that the CCF/SiC composite after pore defects repair was internally dense and no significant pore geometry was observed. The incorporation of micron-sized CCF and nano-sized SiC nws as reinforcing phases resulted in a synergistic toughening effect. Specifically, the CCF enhances toughness through fibre debonding and pull-out mechanisms, while the SiC nws contribute to toughening through nanowire bridging and pull-out mechanisms. This dual toughening mechanism significantly improved bending strength from 210.7 to 274.5 MPa and elevated the fracture toughness from 3.2 to 3.6 MPa m1/2. Another notable advantage of the SiC nws is their ability to form a space network and reduce the thermal expansion coefficient. Consequently, this novel microstructural pore defects repair approach further enhanced the overall performance and reliability of the CCF/SiC composites based on additive manufacturing. This innovative approach holds great promise for the development of high-performance complex-structure CCF/SiC composites with wide-ranging applications across various industries. [ABSTRACT FROM AUTHOR]

The silicon (Si) anode is prone to forming a high electric field gradient and concentration gradient on the electrode surface under high‐rate conditions, which may destroy the surface structure and decrease cycling stability. In this study, a ferroelectric (BaTiO3) interlayer and field polarization treatment are introduced to set up a built‐in field, which optimizes the transport mechanisms of Li+ in solid and liquid phases and thus enhances the rate performance and cycling stability of Si anodes. Also, a fast discharging and slow charging phenomenon is observed in a half‐cell with a high reversible capacity of 1500.8 mAh g−1 when controlling the polarization direction of the interlayer, which means a fast charging and slow discharging property in a full battery and thus is valuable for potential applications in commercial batteries. Simulation results demonstrated that the built‐in field plays a key role in regulating the Li+ concentration distribution in the electrolyte and the Li+ diffusion behavior inside particles, leading to more uniform Li+ diffusion from local high‐concentration sites to surrounding regions. The assembled lithium‐ion battery with a BaTiO3 interlayer exhibited superior electrochemical performance and long‐term cycling life (915.6 mAh g−1 after 300 cycles at a high current density of 4.2 A g−1). The significance of this research lies in exploring a new approach to improve the performance of lithium‐ion batteries and providing new ideas and pathways for addressing the challenges faced by Si‐based anodes. [ABSTRACT FROM AUTHOR]

To investigate the formation mechanism of wrinkle structures in imprinted resist masks generated by oxygen reactive ion etching (O2 RIE), we compared UV/ozone exposure (soft trimming) and O2 RIE (hard trimming) as oxidative trimming methods to tune the diameters of disk resist masks in ultraviolet nanoimprint lithography of Mie-resonant silicon nanodisks (Si NDs). Variations in the residual layer thicknesses of the imprinted resin patterns demonstrated that the wrinkle structures around the disk resist masks increased after the residual layer was removed completely. A comparison between soft and hard trimming indicated that the UV/ozone exposure maintained a relatively small edge roughness of the disk resist masks during a reduction in diameter from 370 to 160 nm, whereas O2 RIE caused a large edge roughness owing to wrinkle structures with diameters below 300 nm. The wrinkled structures are likely to have originated from the wrinkling instability caused by the formation of an ion-damaged layer near the resist surfaces via O2 RIE involving ion bombardment, which could be transferred to a monocrystalline Si layer on a synthetic quartz substrate. Microscopic optical measurements revealed that 230 nm-diameter Si-ND arrays with small and large edge roughnesses exhibited almost identical reflection spectra at visible wavelengths. [ABSTRACT FROM AUTHOR]

We conducted a simple solution-based method to fabricate Bi2S3 nanowire thin film solar cells by spin coating with varying sulfur-to-bismuth ratios. Spherical nanoparticles were observed in the thin film with low-concentration sulfur solution, with these nanoparticles gradually changing to nanorods. Finally, nanowires of Bi2S3 were observed in the thin film with a high sulfur concentration in solution. The band gap gradually decreased with the increase in sulfur concentration. The solar cell performance was significantly improved with the nanowire structure. During film fabrication, sulfur vacancy defects appeared primarily because of high annealing temperatures. These defects were somewhat reduced by the high concentration of sulfur in the solution, supported by the energy-dispersive x-ray spectroscopy (EDS) results. The elemental chemical composition of Bi2S3 material showed an increase in the sulfur-to-bismuth ratio, reaching saturation at almost 0.9. In this work, we systematically observed the effect on the optical properties, surface morphology, and photovoltaic properties by changing the concentration of sulfur in the precursor. The nanowire structure with a high concentration of sulfur in the solution is a promising way to improve the Bi2S3 thin film solar cell. [ABSTRACT FROM AUTHOR]

High‐quality liquid gate‐all‐around (LGAA) silicon nanowire (NW) field‐effect transistor (FET) biosensors are fabricated and studied their properties in 1 mm phosphate‐buffered saline solution with pH = 7.4 using transport and noise spectroscopy. At small VDS, the conventional current behavior of FET with a linear dependence on voltage is registered in the output current‐voltage (I‐VM) characteristics with M = 1. At drain‐source voltage VDS > 0.6 V, the I‐V characteristics with stronger power M are revealed. It is shown that the current in LGAA NW FETs follows current proportional to voltage in power M = 4 dependence on small liquid gate voltages. Transport and noise spectroscopy analyses demonstrate that the obtained results are associated with the space‐charge‐limited current (SCLC) effect. Moreover, a strong two‐level random telegraph signal (RTS) is found in the region corresponding to SCLC at VDS values exceeding 0.6 V. The RTS related to single trap phenomena results in a well‐resolved Lorentzian component of noise spectra. The results demonstrate that the SCLC and two‐level RTS phenomenon are correlated effects. They should be taken into account during the development of single‐trap‐based devices, including biosensors. [ABSTRACT FROM AUTHOR]

In the present study, we investigate the influence of boron (B) and phosphorus (P) (p- and n-type, respectively) doping on the electronic properties of ultra-thin silicon nanowires (SiNWs) by gradient-corrected density functional calculations with the Perdew–Burke–Ernzerhof (PBE) approximation. In the limit of very small diameters (5–8 Å), both pristine and highly active unsaturated SiNWs with orientations along the [001] and [111] directions exhibit electronic states around the Fermi level, indicative of conductive properties. Conduction is further enhanced by the introduction of doping atoms, as demonstrated by the relative change in the band structures of SiNWs with and without B and P doping. This investigation provides an important insight into the electronic states of SiNWs, which are candidates for future electronics or sensing applications. [ABSTRACT FROM AUTHOR]

Highlights: Extrinsic doping is proposed as a novel route to enhance the intrinsic properties of the two-dimensional oxidized Si nanosheet (namely, siloxene) anode for Li-ion batteries. Fabrication of P-doped n-type siloxene is revealed to be possible through selective nucleophilic substitution of Si atoms in siloxene with P atoms. Due to boosted charge transport kinetics, n-type siloxene (6.7 × 1019 P atoms cm-3) exhibits the excellent storage performance (594 mAh g-1 after 500 cycles) even at 2000 mA g-1. Doped two-dimensional (2D) materials hold significant promise for advancing many technologies, such as microelectronics, optoelectronics, and energy storage. Herein, n-type 2D oxidized Si nanosheets, namely n-type siloxene (n-SX), are employed as Li-ion battery anodes. Via thermal evaporation of sodium hypophosphite at 275 °C, P atoms are effectively incorporated into siloxene (SX) without compromising its 2D layered morphology and unique Kautsky-type crystal structure. Further, selective nucleophilic substitution occurs, with only Si atoms being replaced by P atoms in the O3≡Si–H tetrahedra. The resulting n-SX possesses two delocalized electrons arising from the presence of two electron donor types: (i) P atoms residing in Si sites and (ii) H vacancies. The doping concentrations are varied by controlling the amount of precursors or their mean free paths. Even at 2000 mA g−1, the n-SX electrode with the optimized doping concentration (6.7 × 1019 atoms cm−3) delivers a capacity of 594 mAh g−1 with a 73% capacity retention after 500 cycles. These improvements originate from the enhanced kinetics of charge transport processes, including electronic conduction, charge transfer, and solid-state diffusion. The approach proposed herein offers an unprecedented route for engineering SX anodes to boost Li-ion storage. [ABSTRACT FROM AUTHOR]

L10-FePt thin films with (111)-texture were deposited on Si(100) substrates at various atomic ratios and annealing temperatures to be used as a cover layer for magnetic force microscope (MFM) tips. Their microstructure and magnetic properties were systematically studied. The experimental results indicate that both atomic ratio and annealing temperature affect the disorder-order transformation of FePt films. In particular, when the atomic ratio approaches 1:1 (Fe: 51 at.%, Pt: 49 at.%) and the annealing temperature is 600 °C, the FePt film exhibits an ultra-high in-plane coercivity of 13.2 kOe. This is attributed to the formation of an L10-FePt phase with high order parameters. Based on the optimal preparation parameters, MFM tips were prepared by depositing FePt films on non-magnetic Si tips. Magnetic domain structures of magnetic tape and magnetic recording medium were successfully observed using these home-made FePt MFM tips. Therefore, the high coercivity L10-FePt films with (111)-texture prepared on Si substrates are expected to be potential materials for the fabrication of MFM tips. [ABSTRACT FROM AUTHOR]

Silicon qubits based on specific SOI FinFETs and nanowire (NW) transistors have demonstrated promising quantum properties and the potential application of advanced Si CMOS devices for future quantum computing. In this paper, for the first time, the quantum transport characteristics for the next-generation transistor structure of a stack nanosheet (NS) FET and the innovative structure of a fishbone FET are explored. Clear structures are observed by TEM, and their low-temperature characteristics are also measured down to 6 K. Consistent with theoretical predictions, greatly enhanced switching behavior characterized by the reduction of off-state leakage current by one order of magnitude at 6 K and a linear decrease in the threshold voltage with decreasing temperature is observed. A quantum ballistic transport, particularly notable at shorter gate lengths and lower temperatures, is also observed, as well as an additional bias of about 1.3 mV at zero bias due to the asymmetric barrier. Additionally, fishbone FETs, produced by the incomplete nanosheet release in NSFETs, exhibit similar electrical characteristics but with degraded quantum transport due to additional SiGe channels. These can be improved by adjusting the ratio of the channel cross-sectional areas to match the dielectric constants. [ABSTRACT FROM AUTHOR]

This document is a summary of an article titled "Abridging the CMOS Technology II" published in the journal Nanomaterials. The article discusses the advancements in nanosheet, forksheet, and CFET device structures, as well as 3D stacking techniques, that are expected to extend the lifespan of silicon CMOS devices. It also explores the challenges of achieving integration of 2D material ICs and the potential of innovative 2D materials for the future of integrated electronics. The article includes several review papers and regular papers on topics such as contact scaling, reliability concerns of FinFETs, carrier distribution in 2D quantized metal/insulator transition regions, flash memory technology, ZnO-based thin-film transistors, ESD protection strategies, and device innovation with emerging 2D semiconductor materials. The article concludes by stating that CMOS technology will remain the predominant integration technology for the foreseeable future, and the integration of innovative 2D materials into CMOS processes is expected to drive the next leap in technological advancement. [Extracted from the article]

Silicon nanowires were characterized by x-ray photoelectron spectroscopy with an Al Kα (1486.6 eV) excitation source. The sample was fixed to a stainless-steel sample holder with a copper double-sided adhesive tape. Survey spectrum and C 1s, O 1s, and Si 2p core-level spectra were acquired. [ABSTRACT FROM AUTHOR]

This computational research study will compare the specific charge capacity (SCC) between lithium ions inserted into crystallized silicon (c-Si) nanowires with that of sodium ions inserted into amorphous silicon (a-Si) nanowires. It will be demonstrated that the potential energy V(r) within a lithium–silicon nanowire supports a coherent energy state model with discrete electron particles, while the potential energy of a sodium–silicon nanowire will be discovered to be essentially zero, and, thus, the electron current that travels through a sodiated silicon nanowire will be modeled as a free electron with wave-like characteristics. This is due to the vast differences in the electric fields of lithiated and sodiated silicon nanowires, where the electric fields are of the order of 10 10 V/m and 10 − 15 V/m, respectively. The main reason for the great disparity in electric fields is the presence of optical amplification within lithium ions and the absence of this process within sodium ions. It will be shown that optical amplification develops coherent optical interactions, which is the primary reason for the surge of specific charge capacity in the lithiated silicon nanowire. Conversely, the lack of optical amplification is the reason for the incoherent optical interactions within sodium ions, which is the reason for the low presence of SCC in sodiated silicon nanowires. [ABSTRACT FROM AUTHOR]

We have observed spin splitting and band gap structure in the Si[110] direction by doping with impurities, which is manifested by a significant opening of the spin-splitting energy level in the localized states. Interestingly, the opening effect occurs such that the electronic spin states are embedded in the localized states on the surface. Here, the broken symmetry obviously appears in the system. In the simulation calculation, it is observed that the spin-splitting gap of the electronic spin levels can be opened over 500 meV in the localized states for the Si=O double bond for doped Si[110] nanowires with a diameter of 0.4 nm. Si[110] nanowire structures doped with oxygen were prepared on silicon wafers using a combination of nanosecond pulsed laser deposition (PLD) and coherent electron beam irradiation studied comparatively in experiments. By combining the experimental and computational results, the physical model on the coupling between the electronic spin states and the localized states was constructed, which will have good application potential in the fields of the electronic spin qubit, quantum information storage, and quantum information processing. [ABSTRACT FROM AUTHOR]

Biosensor-based devices are undergoing continuous advances in technology and design. Many studies on biosensor-based tunnel field-effect transistors have recently been published, but none of them has discussed the effect of the dual-drain technique with regard to the sensitivity of nanowire tunnel field-effect transistor-based biosensors. In this work, the role of a dual drain is investigated with respect to both the sensitivity and linearity performance of the device. To cover a vast range of enzymes, the permittivity of the cavities was varied from κ = 3 to κ = 25, and it was observed that a dual drain resulted in 85- and 2000-fold improved sensitivity, respectively. Along with the investigated nanowire, a sensitivity comparison with previous devices was carried out, which showed that for all the devices, the dual-drain technique significantly enhanced sensitivity; hence, in the future, this investigated technique can be used for improved sensing in biomedical devices. [ABSTRACT FROM AUTHOR]

Silicon is the most diffused material in the industry; thus, considering its high capacity for energy storage, silicon‐based materials are well studied as battery anodes and supercapacitors. Si nanowires (NWs) emerge due to the high surface to volume ratio, its compatibility with a wafer processing typical of microelectronics, and are studied as anodes for lithium batteries as well as coupled with other materials for supercapacitor application. In this article, the synthesis and application are reported as a lithium anode of 2D fractal arrays of ultrathin Si NWs obtained by a thin‐film metal‐assisted chemical etching (MACE). These Si NWs exhibit a density of about 1012 NWs cm−2, maximizing the surface to volume ratio compared to silver‐salts MACE and other NW fabrication approaches. By using 2.7 μm long NWs, a pseudo‐capacitor behavior with a specific capacitance of about 274.2 μF cm−2 at a scan rate of 50 mV s−1 is obtained. This specific capacitance is two orders of magnitude higher than the one obtained in the same condition by using NWs synthesized by silver‐salt MACE. In this result, the route is opened toward the application of these fractal arrays of ultrathin Si NWs as substrate for supercapacitors with improved efficiency.

The correction notice addresses errors in Figure 7b and Table 1 of the original publication regarding an ultrasensitive silicon nanowire biosensor for detecting the kidney failure biomarker Cystatin C. Textual corrections were made to the Abstract, Introduction, Results and Discussion, and Conclusions sections to rectify inaccuracies in the original publication. The scientific conclusions remain unaffected by these corrections, and the updated version of the publication has been approved by the Academic Editor. [Extracted from the article]

Highly selective etching of silicon nitride (Si3N4) and silicon dioxide (SiO2) has received considerable attention from the semiconductor community owing to its precise patterning and cost efficiency. We investigated the etching selectivity of Si3N4 and SiO2 in an NF3/O2 radio-frequency glow discharge. The etch rate linearly depended on the source and bias powers, whereas the etch selectivity was affected by the power and ratio of the gas mixture. We found that the selectivity can be controlled by lowering the power with a suitable gas ratio, which affects the surface reaction during the etching process. X-ray photoelectron spectroscopy of the Si3N4 and QMS measurements support the effect of surface reaction on the selectivity change by surface oxidation and nitrogen reduction with the increasing flow of O2. We suggest that the creation of SiOxNy bonds on the surface by NO oxidation is the key mechanism to change the etch selectivity of Si3N4 over SiO2. [ABSTRACT FROM AUTHOR]

Highlights: A novel photoelectrochemical (PEC) photosensor composed of GaN nanowire-on-Si platform demonstrates record-high responsivity of 247.8 mA W−1 with ultra-stable operation characteristics. Strategic internal and external band structure engineering of semiconductor nanowires promotes efficient PEC reaction via controlling carrier dynamics while preserving nanowires from material degradation. The glucose sensing system is constructed to successfully analyze blood glucose levels in real human serum samples, featuring a high sensitivity of 0.173 µA µM−1 cm−2 and a low detection limit of 0.07 µM. Photosensors with versatile functionalities have emerged as a cornerstone for breakthroughs in the future optoelectronic systems across a wide range of applications. In particular, emerging photoelectrochemical (PEC)-type devices have recently attracted extensive interest in liquid-based biosensing applications due to their natural electrolyte-assisted operating characteristics. Herein, a PEC-type photosensor was carefully designed and constructed by employing gallium nitride (GaN) p–n homojunction semiconductor nanowires on silicon, with the p-GaN segment strategically doped and then decorated with cobalt–nickel oxide (CoNiOx). Essentially, the p–n homojunction configuration with facile p-doping engineering improves carrier separation efficiency and facilitates carrier transfer to the nanowire surface, while CoNiOx decoration further boosts PEC reaction activity and carrier dynamics at the nanowire/electrolyte interface. Consequently, the constructed photosensor achieves a high responsivity of 247.8 mA W−1 while simultaneously exhibiting excellent operating stability. Strikingly, based on the remarkable stability and high responsivity of the device, a glucose sensing system was established with a demonstration of glucose level determination in real human serum. This work offers a feasible and universal approach in the pursuit of high-performance bio-related sensing applications via a rational design of PEC devices in the form of nanostructured architecture with strategic doping engineering. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by the accumulation of amyloid beta (Aβ) plaques in the brain. Aβ1–42 is the main component of Aβ plaque, which is toxic to neuronal cells. Si nanowires (Si NWs) have the advantages of small particle size, high specific surface area, and good biocompatibility, and have potential application prospects in suppressing Aβ aggregation. In this study, we employed the vapor–liquid–solid (VLS) growth mechanism to grow Si NWs using Au nanoparticles as catalysts in a plasma-enhanced chemical vapor deposition (PECVD) system. Subsequently, these Si NWs were transferred to a phosphoric acid buffer solution (PBS). We found that Si NWs significantly reduced cell death in PC12 cells (rat adrenal pheochromocytoma cells) induced by Aβ1–42 oligomers via double staining with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and fluorescein diacetate/propyl iodide (FDA/PI). Most importantly, pre-incubated Si NWs largely prevented Aβ1–42 oligomer-induced PC12 cell death, suggesting that Si NWs exerts an anti-Aβ neuroprotective effect by inhibiting Aβ aggregation. The analysis of Fourier Transform Infrared (FTIR) results demonstrates that Si NWs reduce the toxicity of fibrils and oligomers by intervening in the formation of β-sheet structures, thereby protecting the viability of nerve cells. Our findings suggest that Si NWs may be a potential therapeutic agent for AD by protecting neuronal cells from the toxicity of Aβ1–42. [ABSTRACT FROM AUTHOR]

[Display omitted] With the ever-growing demand for high-capacity energy storage technologies, lithium-ion batteries (LIBs) have drawn increasing attention. Ti 2 B 2 , a typical two-dimensional MBenes material, has been considered as a strong contender for anode materials of LIBs with significant performance. However, the limited Li storage capacity of MBenes has hindered its wide applications. To address this issue, we have functionalized Janus-structured MBenes, denoted as Ti 2 B 2 X a X b (X a /X b = N, O, S, Se). Employing first-principles simulations based on density functional theory, we have investigated the geometric characteristics and electrochemical properties of Ti 2 B 2 X a X b. Our results reveal that Ti 2 B 2 NO exhibits an exceptionally large theoretical specific capacity of 1091.17 mAh·g−1, improved by 2.4 times compared with the pristine Ti 2 B 2 (456 mAh·g−1). Li atoms on the O side of Ti 2 B 2 NO possess a low diffusion barrier of 0.33 eV, which is conducive to the rapid charging and discharging of the battery. Moreover, the open-circuit voltage of Ti 2 B 2 NO within the safe voltage range of 0–1 V ensures the safety of battery operation. Overall, our study sheds light on understanding the underlying mechanism of surface functionalization on the Li storage properties of Janus-structured MBenes from atomic-scale, laying the groundwork for future design of high-performance anode materials. [ABSTRACT FROM AUTHOR]

The article discusses the application of scanning thermal microscopy (SThM) for localizing and monitoring defects in electronics, emphasizing its role in thermal management, defect detection, and performance improvement of microelectronic technologies. It introduces the principle of SThM instruments, describes their operation in passive and active modes, and highlights their capabilities in detecting localized inhomogeneities and overheating in electronic components.

Artificial biomaterials with dynamic mechano-responsive behaviors similar to those of biological tissues have been drawing great attention. In this study, we report a TiO2-based nanowire (TiO2NWs) scaffolds, which exhibit dynamic mechano-responsive behaviors varying with the number and amplitude of nano-deformation cycles. It is found that the elastic and adhesive forces in the TiO2NWs scaffolds can increase significantly after multiple cycles of nano-deformation. Further nanofriction experiments show the triboelectric effect of increasing elastic and adhesive forces during the nano-deformation cycles of TiO2NWs scaffolds. These properties allow the TiO2NW scaffolds to be designed and applied as intelligent artificial biomaterials to simulate biological tissues in the future. [ABSTRACT FROM AUTHOR]

Many consumer products used daily contain sensors and image sensors (smartphones, cars, automated tools, etc.). There is a growing demand to enhance the capabilities of industrial products to probe their environment more efficiently, i.e., under difficult conditions (smoke, darkness, etc.). One solution is to extend the capabilities of image sensors to detect light toward the near-infrared and short-wave infrared (SWIR) regions. Because silicon has weak absorption properties in the infrared, especially in the SWIR region, manufacturers are investigating the use of new materials to build these sensors. To this end, colloidal quantum dot (QD) thin films made from the assembly of PbS nanoparticles have emerged as promising materials. They offer tunable bandgaps, favorable absorption properties, and scalability in production. However, patterning the active parts of photodiodes by plasma etching of this new material presents challenges. The etching chemistry must be selected to volatilize Pb and S without modifying the unetched active part of the PbS QD photodiode, and the etching profile should be anisotropic. In this study, we have screened several plasma operating conditions (power, pressure, and temperature) in various chemistries (H2, Cl2, HBr, and N2). To understand the etch mechanisms and profiles, ToF-SIMS and TEM/energy dispersive x-ray were employed. Our findings reveal that halogen-based plasmas cause QD material deterioration through Cl or Br diffusion deep in the film. While H2 plasmas are efficient to etch PbS QD films, they result in high roughness due to the removal of the carbonated ligands that separate PbS QDs. This ligand etching is followed by QD coalescence leading to significant roughness. However, the addition of N2 to H2 can prevent this phenomenon by forming a diffusion barrier at the surface, resulting in favorable etching characteristics. [ABSTRACT FROM AUTHOR]

In this paper, two experimental procedures are reported, namely electro-deposition in the ultrathin liquid layer and chemical micro-etching. Firstly, a large area quasi-two-dimensional periodic membrane with adjustable density is deposited on a Si substrate driven by half-sinusoidal voltage, which is composed of raised ridges and a membrane between the ridges. The smaller the voltage frequency is, the larger the ridge distance is. The height of a raised ridge changes synchronously with the amplitude. The grain density distribution of membrane and raised ridge is uneven; the two structures change alternately, which is closely related to the change of growth voltage and copper ion concentration during deposition. The structural characteristics of membrane provide favorable conditions for micro-etching; stable etching speed and microscope real-time monitoring are the keys to achieve accurate etching. In the chemical micro-etching process, the membrane between ridges is removed, retaining the raised ridges, thus a large scale ordered micro-nano wires array with lateral growth was obtained. This method is simple and controllable, can be applied to a variety of substrates, and is the best choice for designing and preparing new functional materials. This experiment provides a basis for the extension of this method. [ABSTRACT FROM AUTHOR]

The demand for the development of high-capacity, safe, and long-life secondary batteries and the interest in all-solid-state batteries are increasing. The cycle performance of solid-state batteries is limited by interfacial phenomena at the electrolyte–anode interface hindering the ion diffusions. A multifunctional aluminum oxide (specifically, Al2O3) coating was created for application on silicon-based anodes in all-solid-state lithium-ion batteries. In an all-solid-state lithium-ion battery, the electrochemical properties of Al2O3 coating were enhanced. The coating was applied to provide stable artificial solid electrolyte interphase (SEI) layers on the silicon-based anodes. Al2O3 layers not only promote the diffusion of Li+ through the Li–Al–O, but their intrinsically low electronic conductivity also limits the transmission of electrons at the contact between the anode and the electrolyte. A Si alloy–polyacrylonitrile anode was prepared using Al2O3 coating as an artificial SEI layer by radio-frequency (RF) plasma. Radio-frequency sputtering was used to create a simple and economical Al2O3 coating. The cycle properties of silicon-based anodes were enhanced by the addition of the thin amorphous aluminum oxide layer (i.e., Al2O3 coating). After 100 charge–discharge cycles, the half-cell with the Al2O3 layer delivered a discharge capacity of 502.08 mAh g−1 and a capacity retention ratio of 58.86%. After 100 cycles, the sample without the Al2O3 layer had a discharge capacity of 278.48 mAh g−1 and capacity retention of 34.34%. Cells with an Al2O3 -coated anode retained high capacity after 100 cycles. Thus, the Al2O3 -coated Si-based anodes were cycled successfully in all-solid-state half-cells to produce functional high-performance lithium-ion batteries. In this study, we employed the vacuum deposition method, radio-frequency sputtering, to deposit very thin layer of aluminum oxide on the surface of fully fabricated anodes for improved cycling properties of all solid-state battery. This layer of aluminum oxide was confirmed using advanced elemental analysis techniques. The aluminum oxide layer with 1-min coating had much-improved cycling characteristics compared with those of the sample with no coatings. Previous studies have used theoretical calculations to report that an aluminum oxide coating layer improves the stability characteristics for sulfide-based solid electrolytes. In this paper, the actual stability improvement of the sulfide-based solid electrolyte was demonstrated in terms of much improved cycling characteristics throughout the cycling test. The appropriate amount of aluminum oxide coating decreases the decomposition of solid electrolyte and also decreases the consumption of Li ions during lithiation and delithiation. This surface modification technique can be utilized to improve the cycling stability of solid-state batteries, which is one of the critical factors for the early adoption of solid-state batteries for electric vehicle applications. [ABSTRACT FROM AUTHOR]

Quantum random number generators employ the inherent randomness of quantum mechanics to generate truly unpredictable random numbers, which are essential in cryptographic applications. While a great variety of quantum random number generators have been realized using photonics, few exploit the high-field confinement offered by plasmonics, which enables device footprints an order of magnitude smaller in size. Here we integrate an on-chip nanowire plasmonic waveguide into an optical time-of-arrival based quantum random number generation setup. Despite loss, we achieve a random number generation rate of 14.4 Mbits s − 1 using low light intensity, with the generated bits passing industry standard tests without post-processing. By increasing the light intensity, we were then able to increase the generation rate to 41.4 Mbits s − 1 , with the resulting bits only requiring a shuffle to pass all tests. This is an order of magnitude increase in the generation rate and decrease in the device size compared to previous work. Our experiment demonstrates the successful integration of an on-chip nanoscale plasmonic component into a quantum random number generation setup. This may lead to new opportunities in compact and scalable quantum random number generation. [ABSTRACT FROM AUTHOR]

Colour centres in silicon carbide emerge as a promising semiconductor quantum technology platform with excellent spin-optical coherences. However, recent efforts towards maximising the photonic efficiency via integration into nanophotonic structures proved to be challenging due to reduced spectral stabilities. Here, we provide a large-scale systematic investigation on silicon vacancy centres in thin silicon carbide membranes with thicknesses down to 0.25 μm. Our membrane fabrication process involves a combination of chemical mechanical polishing, reactive ion etching, and subsequent annealing. This leads to highly reproducible membranes with roughness values of 3–4 Å, as well as negligible surface fluorescence. We find that silicon vacancy centres show close-to lifetime limited optical linewidths with almost no signs of spectral wandering down to membrane thicknesses of ~0.7 μm. For silicon vacancy centres in thinner membranes down to 0.25 μm, we observe spectral wandering, however, optical linewidths remain below 200 MHz, which is compatible with spin-selective excitation schemes. Our work clearly shows that silicon vacancy centres can be integrated into sub-micron silicon carbide membranes, which opens the avenue towards obtaining the necessary improvements in photon extraction efficiency based on nanophotonic structuring. [ABSTRACT FROM AUTHOR]