Zn3P2 Nanowires Research Articles

Large-scale synthesis and in situ functionalization of Zn3P2 and Zn4Sb3 nanowire powders

A simple method for the large-scale synthesis of gram quantities of compound semiconductor nanowires without the need for any external catalysts or templates is presented. This method is demonstrated using zinc phosphide (Zn3P2) and zinc antimonide (β-Zn4Sb3) nanowires as example systems. Large-scale synthesis of Zn3P2 and Zn4Sb3 nanowire powders was accomplished using a hot-walled chemical vapor deposition chamber by transporting phosphorus and antimony, respectively, via the vapor phase onto heated zinc foils. The zinc foils were rolled concentrically into coils to maximize the substrate surface area, and consequently, the nanowire yield. Using this method, 250 mg of Zn3P2 nanowires were obtained on 480 cm(2) of zinc foil in a span of 45 minutes. Furthermore, a process of exposing the synthesized nanowires to a vapor of organic functional molecules immediately after their synthesis and before their removal from the vacuum chamber was developed to obtain large quantities of surface functionalized nanowire powders. This in situ vapor-phase functionalization procedure passivated the nanowire surfaces without adversely affecting their morphology or dimensions. Our studies revealed that both 4-aminothiophenol and 3-propanedithiol functionalized Zn3P2 nanowires were stable over a 120 day duration without any agglomeration or degradation. This method of mass producing nanowires can also be extended to other binary semiconductors.

(Invited) Thermoelectric Properties of Bulk Synthesized Zn3P2 Nanowire and Quantum Wire Powders

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Low-temperature synthesis of Zn3P2 nanowire

Abstract

Novel Type-II Zn3P2/ZnO Core/Shell Nanowires: Synthesis, Characteristic, and Photoluminescence Properties

Novel type-II Zn3P2/ZnO core/shell nanowires were synthesized for the first time. First, Zn3P2 nanowires with high yield were synthesized via a catalyst-free chemical vapor deposition method. Then, a facile low-cost surface oxidization process was used to obtain the ZnO nanocrystalline shells. Field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), and high-angle angular darkfield scanning transmission electron microscopy (HAADF-STEM) were used to characterize the morphologies, crystal structures, and element composition of the as-fabricated core/shell nanowires. Room-temperature photoluminescence properties of them were studied. A possible growth mechanism was proposed. The heterostructure fabrication approach developed here may be extended to other functional heterostructure material systems. The experimental results together with the energy band analysis demonstrated that the type-II Zn3P2/ZnO core/shell nanowire heterostructures have substantial potential for future photovoltaic nanodevice applications.

Fast-speed and high-gain photodetectors of individual single crystalline Zn3P2 nanowires

We report high-performance photodetectors of individual single crystalline Zn3P2 nanowires. A facile catalyst-free physical evaporation process was developed to synthesize high-quality single crystalline Zn3P2 nanowires (NWs) with high yield. A typical individual Zn3P2 NW photodetector exhibited fast speeds (the response and recovery times were less than 25 and 26 μs, respectively) and high gain (∼470), which is an excellent result towards getting a balance in the speed and gain trade-off of the semiconductor nanostructure-based photodetectors. In addition, the device had the advantages of high photosensitivity (Iphoto − Idark/Idark ≈ 100) and small device size (constructed on an individual nanowire). All these merits substantiate that the Zn3P2 nanowires can serve as excellent photoconductive materials, and the Zn3P2 NW photodetectors are very promising for practical applications.

Three-dimensional Structure of Twinned and Zigzagged One-dimensional Nanostructures Using Electron Tomography

AbstractElectron tomography and high-resolution transmission electron microscopy were used to characterize the unique 3-dimensional (3D) structures of twinned Zn3P2 (tetragonal) and InAs (zinc blende) nanowires synthesized by the vapor transport method. The Zn3P2 nanowires adopt a unique superlattice structure that consists of twinned octahedral slice segments having alternating orientations along the axial [111] direction of a pseudocubic unit cell. The apices of the octahedral slice segment are indexed as six equivalent <112> directions at the [111] zone axis. At each 30 degrees turn, the straight and zigzagged morphologies appear repeatedly at the <112> and <011> zone axes, respectively. The 3D structure of the twinned Zn3P2 nanowires is virtually the same as that of the twinned InAs nanowires. In addition, we analyzed the 3D structure of zigzagged CdO (rock salt) nanowires and found that they include hexahedral segments, whose six apices are matched to the <011> directions, linked along the [111] axial direction. We also analyzed the unique 3D structure of rutile TiO2 (tetragonal) nanobelts; at each 90 degree turn, the straight morphology appears repeatedly, while the in-between twisted form appears at the [011] zone axis. We suggest that the TiO2 nanobelts consist of twinned octahedral slices whose six apices are indexed by the <011>/<001> directions with the axial [010] direction.

Single-Crystalline and Twinned Zn3P2 Nanowires: Synthesis, Characterization, and Electronic Properties

We describe the synthesis of zigzag-shaped single-crystalline or twinned Zn3P2 nanowires via a thermochemical method. The single-crystalline nanowires possessed two different kinds of kink angles and were formed via a vapor−solid process by using ZnS and GaP as source materials, whereas the twinned nanowires were synthesized via a vapor−liquid−solid process under additional introduction of In2S3 nanoparticles as the catalyst precursors. The products were characterized in detail by using X-ray diffraction, a scanning electron microscope, and a transmission electron microscope equipped with an energy-dispersive X-ray spectrometer. Field-effect transistors based on individual zigzag nanowires were fabricated and their electronic transport at different temperatures was analyzed. The results showed that these unusual structures are p-type semiconductors and that the thermal activation with a 49.7 meV energy is the dominant transport mechanism.

Synthesis of high quality p-type Zn3P2 nanowires and their application in MISFETs

Single-crystalline Zn3P2nanowires (NWs) have been synthesized on silicon (Si) substrates via a vapor phase transport method. Zn (99.99%) powder and InP (99.99%) fragments were used as the sources, and 10 nm thick thermal evaporated gold (Au) film was used as the catalyst. The as-prepared Zn3P2 NWs have diameters of 100–200 nm and lengths of more than 10 μm. Single NW metal–insulator–semiconductor field-effect transistors (MISFETs) based on Zn3P2 NWs were fabricated. Electrical transport measurements show that the as-grown Zn3P2 NWs are of p-type. The hole concentrations and mobilities of the p-type Zn3P2 NWs are about 5.6 × 1016 cm−3 and 42.5 cm2V−1 s−1, respectively. The on–off ratio of the MISFET is about 4 × 104, and its threshold voltage and transconductance are 2.5 V and 35 nS, respectively. These parameters indicate that the p-type Zn3P2 NWs are of high quality, and may have potential applications in nanoscale electronic and optoelectronic devices.

Single-Crystalline Branched Zinc Phosphide Nanostructures: Synthesis, Properties, and Optoelectronic Devices

Hierarchical tree-shaped nanostructures, nanobelts, and nanowires of Zn3P2 were synthesized in a thermal assisted laser ablation process. All nanostructures are tetragonal phased Zn3P2 with excellent crystallinity and are free from an oxidization layer according to electron microscopy and X-ray diffraction analyses. Optical measurement revealed a strong absorption from the ultraviolet to near-infrared regions. Optoelectronic devices fabricated using individual nanowires demonstrate a high sensitivity and rapid response to impinging light. A crossed heterojunction of an n-type ZnO nanowire and a p-type Zn3P2 nanowire has been characterized, and it offers a great potential for a high efficient spatial resolved photon detector.

Single-crystalline trumpetlike zinc phosphide nanostructures

Single-crystalline trumpetlike Zn3P2 nanostructures composed of hollow cones supported by nanowires have been prepared via a simple thermochemical method, which utilized ZnS and GaP as the source materials. The as-synthesized nanostructures are composed of single-crystalline Zn3P2 nanowires with diameters of ∼50nm and large diameter hollow cones with diameters increasing from 50nm at the bottom to 600nm at the top. Photoluminescence study of the trumpetlike Zn3P2 nanostructures shows a broad emission centered at ∼585nm at room temperature.