Low resistivity metal silicide nanowires with extraordinarily high aspect ratio for future nanoelectronic devices

Revealing Seed-Mediated Structural Evolution of Copper-Silicide Nanostructures: Generating Structured Current Collectors for Rechargeable Batteries

Metal silicide thin films and nanostructures typically employed in electronics have recently gained significant attention in battery technology, where they are used as active or inactive materials. However, unlike thin films, the science behind the evolution of silicide nanostructures, especially 1D nanowires (NWs), is a key missing aspect. Cux Siy nanostructures synthesized by solvent vapor growth technique are studied as a model system to gain insights into metal silicide formation. The temperature-dependent phase evolution of Cux Siy structures proceeds from Cu>Cu0.83 Si0.17 >Cu5 Si>Cu15 Si4 . The role of Cu diffusion kinetics on the morphological progression of Cu silicides is studied, revealing that the growth of 1D metal silicide NWs proceeds through an in situ formed, Cu seed-mediated, self-catalytic process. The different Cux Siy morphologies synthesized are utilized as structured current collectors for K-ion battery anodes. Sb deposited by thermal evaporation upon Cu15 Si4 tripod NWs and cube architectures exhibit reversible alloying capacities of 477.3 and 477.6 mAh g-1 at a C/5 rate. Furthermore, Sb deposited Cu15 Si4 tripod NWs anode tested in Li-ion and Na-ion batteries demonstrate reversible capacities of ≈518 and 495 mAh g-1 .

Advances in Si and SiC Materials for High-Performance Supercapacitors toward Integrated Energy Storage Systems

Silicon (Si), as the second most abundant element on Earth, has been a central platform of modern electronics owing to its low mass density and unique semiconductor properties. From an energy perspective, all-in-one integration of power supply systems onto Si-based functional devices is highly desirable, which inspires significant study on Si-based energy storage. Compared to the well-known Si-anode Li-ion batteries, Si-based supercapacitors possess high power density, long life, and simple working mechanisms, which enables their ease of integration onto a wide range of devices and applications. Besides Si, silicon carbide (SiC), as a physicochemically stable wide-bandgap semiconductor, also attracts research attention as an energy storage material in harsh environments. In this review, a detailed overview of latest advances in materials design, synthesis methods, and performances of Si-based and SiC-based supercapacitors will be provided. Some successful integrated devices, future perspectives, and potential research directions are also highlighted and discussed.

Millimeters long super flexible Mn5Si3@SiO2 electrical nanocables applicable in harsh environments

Providing high performance electrical nano-interconnects for micro-nano electronics that are robust in harsh environments is highly demanded. Today, electrical nano-interconnects based on metallic nanowires, e.g. Ag and Cu, are limited by their positive physicochemical reactivity and ductility under large strain (i.e. irreversible dislocations and local necking-down elongation) at high temperatures or in strong oxidizing and acidic environments. Herein, to overcome these limitations, high-quality millimetre-sized soft manganese-based silicide (Mn₅Si₃@SiO₂) nanowire nanocables are designed via a glassy Si–Mn–O matrix assisted growth. The proposed nanocables exhibit good electrical performance (resistivity of 1.28 to 3.84×10^-6 Ωm and maximum current density 1.22 to 3.54×10⁷ A cm⁻²) at temperatures higher than 317°C in air atmosphere, strongly acidic (HCl, PH=1.0) and oxidizing (H₂O₂, 10%) ambient, and under complex electric field. The proposed Mn₅Si₃@SiO₂ nanocables, which withstand a strain of 16.7% free of failure, could be exploited for diverse applications in flexible electronics and complex wiring configurations.

Though high performance electrical interconnects are required for micro/nano electronics, existing metallic nanowires lack structural and electrical stability. Here, the authors report soft manganese-based silicide nanowires with high electrical and structural performance in harsh environments.

Solid-State Limited Nucleation of NiSi/SiC Core-Shell Nanowires by Hot-Wire Chemical Vapor Deposition

This work demonstrated a growth of well-aligned NiSi/SiC core-shell nanowires by a one-step process of hot-wire chemical vapor deposition on Ni-coated crystal silicon substrates at different thicknesses. The NiSi nanoparticles (60 to 207 nm) acted as nano-templates to initially inducing the growth of these core-shell nanowires. These core-shell nanowires were structured by single crystalline NiSi and amorphous SiC as the cores and shells of the nanowires, respectively. It is proposed that the precipitation of the NiSi/SiC are followed according to the nucleation limited silicide reaction and the surface-migration respectively for these core-shell nanowires. The electrical performance of the grown NiSi/SiC core-shell nanowires was characterized by the conducting AFM and it is found that the measured conductivities of the nanowires were higher than the reported works that might be enhanced by SiC shell layer on NiSi nanowires. The high conductivity of NiSi/SiC core-shell nanowires could potentially improve the electrical performance of the nanowires-based devices for harsh environment applications such as field effect transistors, field emitters, space sensors, and electrochemical devices.

Growth of single-crystalline nickel silicide nanowires with excellent physical properties

Single-crystalline NiSi₂, Ni₂Si and Ni₃₁Si₁₂ nanowires with outstanding characteristics were synthesized through a nickel transport chemical vapor deposition method.