Silicon nanostructures exhibit promising application potentials in many fields comparison with their bulk counterpart or other semiconductor nanostructures. Therefore, the exploiting of controllable fabrication methods silicon nanostructures, and exploring further applications gain extensive attentions. In this review, recent advances metal-assisted chemical etching silicon, a low-cost versatile method enabling fine control over morphology feature are summarized. The overview concerning...

This study demonstrates a simple and highly reproducible method for fabricating well-defined nanostructured polymeric surfaces with aligned nanoembosses or nanofibers of controllable aspect ratios, showing remarkable structural similarity interesting natural biostructures such as the wing surface Cicada orni leaf Lotus. Our studies on present biomimetic revealed that wetting property given chemical composition could be systematically controlled by rendering nanometer-scale roughness. The...

Large-area high density silicon nanowire (SiNW) arrays were fabricated by metal-assisted chemical etching of silicon, utilizing anodic aluminum oxide (AAO) as a patterning mask thin metallic film on Si (100) substrate. Both the diameter pores in AAO and thickness metal affected SiNWs. The SiNWs decreased with an increase film. average diameters 20 nm down to 8 wire densities 10 (10) wires/cm (2) accomplished. These single crystalline vertically aligned It was revealed transmission electron...

In general, in thermoelectric materials the electrical conductivity σ and thermal κ are related thus cannot be controlled independently. Previously, to maximize figure of merit state-of-the-art materials, differences relative scaling between as dimensions reduced approach nanoscale were utilized. Here we present an using tin disulfide, SnS2, nanosheets that demonstrated a negative correlation κ. other words, thickness SnS2 decreased, increased whereas decreased. This leads increase 0.13 at...

Bimetallic nanotubes: Uniform arrays of metal nanotubes were prepared by the electrodeposition a thin metallic film on pore walls anodic aluminum oxide membranes decorated with nanoparticles. Multisegmented bimetallic stacking configuration along nanotube axis can be fabricated (see picture). The technique is applicable to wide variety conducting and semiconducting materials. Supporting information for this article available WWW under...

The self-ordering of nanoporous anodic aluminum oxide (AAO) in the course hard anodization (HA) sulfuric acid (H2SO4) solutions at voltages ranging from 27 to 80 V was investigated. Direct H2SO4-HA yielded AAOs with hexagonal pore arrays having interpore distances Dint 72 145 nm. However, were mechanically unstable and cracks formed along cell boundaries. Therefore, we modified procedure previously employed for oxalic HA (H2C2O4-HA) suppress development fabricate robust AAO films values 78...

Abstract Spatially separated ZnO pillars, typically 300 nm in diameter and 2 μm height, are fabricated via a template‐directed approach that leads to long‐range hexagonal order. The templates of Au nanodisk arrays obtained by using metal membranes as lithography mask. growth pillars is performed double‐tube system through vapor diffusion–deposition. mechanism the studied detail proposed be combination vapor–liquid–solid vapor–solid models. piezoelectric optical properties single...

The metal-assisted etching direction of Si(110) substrates was found to be dependent upon the morphology deposited metal catalyst. a substrate one two crystallographically preferred ⟨100⟩ directions in case isolated particles or small area mesh with nanoholes. In contrast, proceeded vertical [1̅1̅0] direction, when lateral size catalytic sufficiently large. Therefore, and resulting nanostructures obtained by can easily controlled an appropriate choice On basis this finding, generic method...

Au/Ag bilayered metal mesh with arrays of nanoholes were devised as a catalyst for metal-assisted chemical etching silicon. The present allows us not only to overcome drawbacks involved in conventional Ag-based processes, but also fabricate extended silicon nanowires (SiNWs) controlled dimension and density. We demonstrate that SiNWs different morphologies axial orientations can be prepared from wafers given orientation by controlling the conditions. explored phenomenological model explains...

Abstract Nanoporous anodic aluminum oxide is prepared by hard anodization of under potentiostatic conditions using 0.3 M H 2 C O 4 . Under unstirred electrolyte condition, spontaneous current oscillations are observed. The amplitude and period these observed to increase with time. As a consequence the oscillatory behavior, resulting alumina exhibits modulated pore structures, in which diameter contrast length modulation oscillations, respectively, peak profile determines internal geometry...

In this study, we present a review of the modeling void formation and unsaturated flow in liquid composite molding processes. We examine efforts considering all mechanisms involved such as transport, bubble compression, gas dissolution. particular, capillary number is identified key parameter for transport. Numerical simulation studies are reviewed, state-of-the-art presented. The influence microvoids on global resin also investigated. To model more accurately, suggest surface tension or...

A continuous process for the preparation of structurally well-defined uniform alumina (Al2O3) nanotubes was developed. The present nanofabrication approach is based on pulse anodization aluminum by using sulfuric acid and provides unique opportunity a facile tailoring length controlling duration.

Oxygen vacancies (VO) have profound effects on the physical and chemical performance of devices based oxide materials. This is particularly true in case oxide-based resistive random access memories, which memory switching operation under an external electrical stimulus closely associated with migration ordering oxygen material. In this paper, we report a reliable approach to situ control TiOx films. Our strategy for tight vacancy utilization plasma-enhanced atomic layer deposition titanium...

Wet-chemical etching of the barrier oxide layer anodic aluminum (AAO) was systematically investigated by using scanning electron microscopy (SEM), secondary ion mass spectrometry (SIMS), and a newly devised experimental setup that allows accurate in situ determination pore opening point during chemical layer. We found wet-chemical can be significantly influenced anodization time (tanodi). According to (SIMS) analysis, porous samples formed long-term contained lower level anionic impurity...

“Weyl’s theorem holds" for an operator <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper T"> <mml:semantics> <mml:mi>T</mml:mi> <mml:annotation encoding="application/x-tex">T</mml:annotation> </mml:semantics> </mml:math> </inline-formula> on a Banach space X"> <mml:mi>X</mml:mi> encoding="application/x-tex">X</mml:annotation> when the complement in spectrum of “Weyl spectrum" coincides with isolated points which are...

A new template-directed method for large-scale fabrication of hexagonally patterned and vertically aligned ZnO nanowires is demonstrated. The process involves a novel type metal membrane, gold catalyst templates produced using the membrane as deposition mask, catalyst-guided vapour-phase growth nanowires. membranes, composed hexagonal nanotube arrays, are electrochemically replicated from ordered porous alumina. obtained uniformly perpendicular to GaN surface have distribution according...

Stamp collection: Laser interference lithography can be used for the fabrication of master patterns with precise periodic nanostructures. Multiple copies Ni imprint stamps replicated from a single by an electrodeposition technique. The have been long-range-ordered anodic aluminum oxide membranes square or hexagonal pore arrangement (see schematic). Supporting information this article is available on WWW under http://www.wiley-vch.de/contents/jc_2296/2006/z600100_s.pdf author. Please note:...

A generic process for the preparation of curved silicon nanowires (SiNWs) with ribbon-like cross sections was developed. The present synthetic approach is based on chemical etching (100)-oriented wafers in mixture solutions HF and H(2)O(2) by using patterned thin gold films as catalyst provides a unique opportunity fabrication extended arrays zigzag SiNWs, ultrathin straight [111] SiNWs controlled turning angles. On basis our experiments performed under various conditions, factors governing...

A new anodization method for the preparation of nanoporous anodic aluminum oxide (AAO) with pattern-addressed pore structure was developed. The approach is based on pulse employing a series potential waves that consist two or more different pulses designated periods and amplitudes, provides unique tailoring capability internal alumina. Pores resulting AAOs exhibit high degree directional coherency along axes without branching, thus are suitable fabricating novel nanowires nanotubes, whose...