ZnS Nanowire Arrays Research Articles

Novel ZnO–ZnS nanowire arrays with heterostructures and enhanced photocatalytic properties

The graphical abstract exhibits the SEM images and schematic representation of ZnO–ZnS heterostructure NW arrays, the schematic energy band diagram and the rates of the photocatalytic H2at different temperatures.

Highly ordered ZnS nanowire arrays embedded in anodic alumina membrane by a hydrothermal method with double diffusion

A new synthesis method of anodic alumina membrane (AAO) template with double diffusion through hydrothermal has been studied. Highly ordered ZnS nanowire arrays were fabricated through this method, using Zn(CH3COO)2·2H2O and Na2S2O3·5H2O as zinc source and sulfur source. The characterization results from X-ray diffraction, scanning electron microscope and transmission electron microscopy showed that ZnS nanowires which were only obtained in the holes of the AAO template have a uniform diameter of about 60nm, with regular spread. It was in accord with the size of the AAO holes, which confirmed the significant spatial limitations induced by the AAO template on the nanorod arrays.

Dense and vertically-aligned centimetre-long ZnS nanowire arrays: ionic liquid assisted synthesis and their field emission properties

Based on the self-ordering behavior of ionic liquids on solid surface, a gold ion containing ionic liquid was employed to obtain a uniform pattern of gold nanoparticles on Si substrate. Using this catalytic pattern, super-dense, centimetre long, well-crystallized and vertically-aligned ZnS nanowire arrays were then generated. It was found that the densely-packed gold nanoparticles played a key role in the nanowire alignment. Furthermore, the field-emission measurements show that the present ultralong ZnS nanowires arrays possess a low turn-on field of 3.69 V μm(-1) and a high field-enhancement factor of 1215.4, indicating they are valuable field emitters.

The epitaxial growth of ZnS nanowire arrays and their applications in UV-light detection

Compared to random nanowires, vertically aligned nanowire arrays (NWAs) are especially useful as functional parts in future nanowire based devices. Here, vertically aligned ZnS NWAs have been grown on the GaAs (111)B substrates by metal–organic chemical vapor deposition. Ga was chosen as the catalyst and dopant of the ZnS nanowires during growth. The density of nanowires was controlled and their diameter was slightly tuned. The NWAs have been assembled into a photodetector by a low cost and effective method. An individual ZnS nanowire photodetector has also been fabricated for comparison. The two photodetectors are sensitive to UV but not to visible light. Under the same conditions, the photocurrent of the NWA photodetector is more stable, and five orders larger than that of the nanowire photodetector. In addition, the ZnS NWA photodetector has a fast response and an excellent repeatability, showing its potential for fast, visible-blind, UVA detection.

Self-assembled ZnS nanowire arrays: synthesis, in situ Cu doping and field emission

Well-aligned single-crystalline ZnS nanowire arrays have been grown on highly conductiveCu substrates through controlling the morphology evolution of self-patternedZnS nanoparticles. The ZnS nanowires have sharp tips with an average size of ∼ 30 nm and alength of ∼ 3 µm. Field emission measurements demonstrated that the aligned ZnS nanowiresgrown on Cu substrates are excellent field emitters having a turn-on field as low as2.92 V µm − 1 and a field-enhancement factor as high as 3400. The use of highly conductive metalsubstrate may promote the commercial applications of ZnS-based emitters in flat paneldisplays and other optoelectronic devices.

Orientation and Structure Controllable Epitaxial Growth of ZnS Nanowire Arrays on GaAs Substrates

Single-crystalline, well-aligned ZnS nanowire arrays were epitaxially grown on GaAs substrates by metal−organic chemical vapor deposition using Ag and Au nanoparticles as catalysts. Au nanoparticle...

Direct Growth of Quasi-Aligned Ultrafine ZnS Nanowire Arrays on Conducting Zinc Foils and Their Field Emission Properties

Quasi-aligned ultrafine ZnS nanowire arrays have been grown directly on zinc substrates via a simple hydrothermal method. The morphology, structure, and composition are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectroscopy. The single-crystalline ultrafine ZnS nanowires have a hexagonal structure with typical diameters of 5-15 nm and lengths of up to micrometers. A possible growth mechanism is proposed. Since the Zn foil serves as both the Zn source and substrate, direct synthesis and assembly of ZnS nanowires on an electrically conductive Zn substrate are accomplished in one step. Optical properties of the product are studied by photoluminescence. Field emission measurements disclose that the synthesized nanostructures possess good electron emission properties with a low turn-on field of about 5.4 V/microm at a current density of 10 microA/cm2. The materials are potentially useful as cathode materials in field emission devices.

Synthesis and Growth Mechanism of Quasialigned Ultrafine ZnS Nanowire Arrays Fabricated Directly on Zinc Foils

Quasialigned ZnS nanowire arrays have been synthesized directly on zinc substrates via a simple and mild one-step solvothermal method. The morphology, structure, and composition of the synthesized materials are evaluated by scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. These ultrafine nanowire arrays fabricated directly on a zinc foil have diameters of 5−15 nm and grow along the [001] direction. The influence of the reaction time, temperature, and solvent on the morphology and composition of the products is investigated systematically and the growth mechanism of the ultrafine nanowire arrays is proposed. This growth model may enable better design and assembly of other chalcogenide nanowire arrays on the appropriate metal substrates for nanodevice applications.

Density-Controlled Homoepitaxial Growth of ZnS Nanowire Arrays

In this paper, single-crystal ZnS column arrays are prepared on the ZnS wafer. The ZnS column arrays are then utilized as a transition layer to achieve large-scale homoepitaxial growth of ZnS nanowire arrays. Through annealing ZnS columns coated with Au films at different temperatures, the Au particle density is controlled, and the ZnS nanowire density is controlled via a vapor−liquid−solid process ranging from 0.33 to 3.04 wires/μm2. This universal method can be easily applied to homoepitaxially grow nanowire arrays of other materials and tune the nanowire density.

ZnO−ZnS Heterojunction and ZnS Nanowire Arrays for Electricity Generation

Vertically aligned ZnO-ZnS heterojunction nanowire (NW) arrays were synthesized by thermal evaporation in a tube furnace under controlled conditions. Both ZnO and ZnS are of wurtzite structure, and the axial heterojunctions are formed by epitaxial growth of ZnO on ZnS with an orientation relationship of [0001](ZnO)//[0001](ZnS). Vertical ZnS NW arrays have been obtained by selectively etching ZnO-ZnS NW arrays. Cathodoluminescence measurements of ZnO-ZnS NW arrays and ZnS NW arrays show emissions at 509 and 547 nm, respectively. Both types of aligned NW arrays have been applied to convert mechanical energy into electricity when they are deflected by a conductive AFM tip in contact mode. The received results are explained by the mechanism proposed for nanogenerator.

ZnS Nanowire Arrays: Synthesis, Optical and Field Emission Properties

Nanowire arrays of cubic zinc sulfide are synthesized on zinc foil by a simple thermal evaporation route at relatively low temperature (<500 °C). A self-catalytic liquid–solid growth is proposed for the formation of the nanowires. Influence of the synthesis temperatures on the morphological features of the ZnS nanowires is studied. Growth sequence of the nanowires with synthesis time is also studied through scanning electron microscopy. These nanowires grow along the [111] direction and remain perpendicular to the surface of the Zn substrate. Room temperature photoluminescence measurement exhibit UV and blue emission peaks at around 350 and 397 nm, respectively. These ZnS nanowires exhibited good field emission properties similar to those of conventional field emitters.

Fabrication and photoluminescence properties of highly ordered ZnS nanowire arrays embedded in anodic alumina membrane

ZnS nanowire arrays embedded in anodic alumina membranes (AAM) were fabricated from an electrolyte containing ZnCl2 and elemental S in dimethylsulfoxide. Photoluminescence (PL) measurements show a broadband with three peaks centered at about 353, 425, and 520 nm that are attributed to vacancies or interstitial, sulfur vacancy, and point defects respectively.

High-symmetry ZnS hepta- and tetrapods composed of assembled ZnS nanowire arrays

Sixfold symmetry heptapodlike and threefold symmetry tetrapodlike ZnS structures have been fabricated by thermal evaporation of a ZnS and SiO mixture source in N2 at 1300°C. Both the heptapods and tetrapods have been formed by the self-assembly of ZnS nanowires with the preferred (0001) orientations. Structures and morphologies of the obtained heptapods and tetrapods are thoroughly studied using x-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. Room-temperature photoluminescence spectra taken from the nanostructures show a strong green emission centered at 550nm.

Heteroepitaxial growth and optical properties of ZnS nanowire arrays on CdS nanoribbons

The authors present the results of heteroepitaxial growth of single-crystalline ZnS nanowire arrays on CdS nanoribbon substrates by the metal-catalyzed vapor-liquid-solid growth method. ZnS nanowire arrays were vertically or crosswise aligned to the surface of CdS nanoribbon substrates. Room-temperature lasing from ZnS nanowire arrays was demonstrated. The present synthesis provides a new approach to the rational design of building blocks for nanodevices.

Homoepitaxial Growth and Lasing Properties of ZnS Nanowire and Nanoribbon Arrays

Orientation-dependent cathodoluminescence has been found in crossed nanowire arrays (see figure). ZnS crossed nanowire arrays and aligned nanoribbons are grown on micrometer-wide single-crystal ZnS ribbon substrates, which leads to bandgap lasing emission in two specific directions. The reported results present a new route to synthesize II–VI semiconducting nanostructures with attractive photoelectronic properties.

Preparation and formation mechanism of ZnS semiconductor nanowires made by theelectrochemical deposition method

ZnS nanowire arrays have been prepared for the first time by direct-currentelectrodeposition into the nanopores of porous anodic alumina membranes (AAMs),and the growth mechanism is that metal cations are firstly reduced and thenreact with elemental S to form ZnS nanowire arrays in the nanopores of AAMs.The nanopores of AAMs are of benefit to the formation of sulfide nanowires.