In recent years, the presence of numerous xenobiotic substances, such as antibiotics, has been detected in water environments. They can be considered environmental contaminants, even if their effect on human health yet to totally understood. Several approaches have studied for removal these kinds pollutants. Among compounds, tetracycline (TC), a broad-spectrum antibiotic, is one most commonly found due its widespread use. context reducing TC aqueous solution, this contribution, composite...

High-speed metal-semiconductor-metal (MSM) photodetectors based on Schottky-contacted core/shell GaAs/AlGaAs and bare GaAs nanowires were fabricated characterized. The measured temporal response has a ∼10 ps full-width at half-maximum an estimated corrected value less than 5 ps. devices exhibit slower (∼35 ps) along with slow decaying persistent photocurrent (∼80 s). significantly improved dc high-speed performance over comparable to planar MSM photodetectors. picosecond response, coupled...

Gold nanoparticles heavily functionalized with oligonucleotides have been used in a variety of DNA detection methods. The optical properties three-dimensional aggregates Au solution or deposited onto suitable surfaces analyzed to detect hybridization processes specific sequences as possible alternatives fluorescent labeling This paper reports on the preparation gold directly surface silicon (Si) and sapphire (Al2O3) substrates by physical methodology, consisting thermal evaporation thin film...

Au-catalyzed self-assembly of GaAs nanowires on (1¯1¯1¯)B by metalorganic vapor phase epitaxy is reported between 375 and 500°C, using tertiarybutylarsine trimethylgallium in H2. The are [1¯1¯1¯]B aligned kink-free. Below 425°C the have narrow base diameter distributions, closely matching size (∼60nm) Au nanoparticles at their tip (no tapering). Above show a hexagonal-based pyramidal shape with edges normal to ⟨2¯11⟩ in-plane substrate directions diameters which increase exponentially...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Zongquan Gu, Paola Prete, Nicola Lovergine, Bahram Nabet; On optical properties of GaAs GaAs/AlGaAs core-shell periodic nanowire arrays. J. Appl. Phys. 15 March 2011; 109 (6): 064314. https://doi.org/10.1063/1.3555096 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers...

Direct epitaxial growth of WS₂ isolated crystals and continuous films onto epitaxial- CVD-graphene providing a homogeneous narrow PL peak.

Low-temperature chemical vapor deposition (LT-CVD) of graphene using liquid aromatic hydrocarbons holds technological advantages over conventional growth from methane. However, the nature decomposition mechanisms such precursors and their effectiveness in a LT-CVD process is still debated. We investigate by means density functional theory adsorption energies first steps on Cu(111) single-ring hydrocarbons, as benzene toluene. Our results confirm stronger stability with respect to methane...

Coherent gold nanoislands were prepared directly on (100)-oriented Si substrates by a physical methodology, consisting of the thermal evaporation very thin Au film $(t\ensuremath{\sim}2\text{ }\text{nm})$ and its successive annealing in temperature range $350\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}<T<814\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$. We found that at $814\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ presence residual oxygen during process,...

Electron holographic tomography (EHT), the combination of off-axis electron holography with tomography, is a technique, which can be applied to quantitative 3-dimensional (3D) mapping electrostatic potential at nanoscale. Here, we show results obtained in EHT investigation GaAs and GaAs-AlGaAs core-shell nanowires grown by Au-catalysed metalorganic vapor phase epitaxy. The unique ability disentangling materials mean inner (MIP) from specimen projected thickness allows reconstruction nanowire...

The non-destructive characterization of nanoscale devices, such as those based on semiconductor nanowires, in terms functional potentials is crucial for correlating device properties with their morphological/materials features, well precisely tuning and optimizing growth process. Electron holographic tomography (EHT) has been used the past to reconstruct total potential distribution 3D but hitherto lacked a quantitative approach separate variations due chemical composition changes (mean...

We investigate the photodetection properties of individual core/shell GaAs/AlGaAs nanowires (NWs) and, in particular, their behavior under linearly polarized light. The NWs are grown by Au-assisted metalorganic vapor phase epitaxy and electrical contacts defined on electron beam induced deposition. spectral photocurrent single NW is measured dependence polarization anisotropy ρ (varying from ∼0.1 to ∼0.55) absorption wavelength found be clearly affected structure. High quantum efficiency...

We report on the development of electron holographic tomography towards a versatile potential measurement technique, overcoming several limitations, such as limited tilt range, previously hampering reproducible and accurate electrostatic reconstruction in three dimensions. Most notably, tomographic is performed optimally sampled polar grids taking into account symmetry other spatial constraints nanostructure. Furthermore, series acquisition alignment have been automated adapted to...

We report on the first Au-catalyzed growth of CdTe nanowires by metalorganic vapor phase epitaxy. The were obtained a separate precursors flow process in which (i) di-isopropyl-telluride (iPr2Te) was flowed through reactor to ensure formation liquid Au-Te alloy droplets, and (ii) after purging with pure H2 remove unreacted iPr2Te molecules from surface, (iii) dimethylcadmium (Me2Cd) supplied so that Cd atoms could enter catalyst leading nanowire self-assembly. grown between 485 515 °C...

Dense arrays of core–shell nanowires possess great potential as superabsorptive media for the fabrication efficient solar cells. We report on GaAs near-band-edge absorption properties free-standing GaAs–AlGaAs having different shell thicknesses, by detailed line-shape analyses room-temperature photoreflectance (PR) spectra, employing first-derivative Gaussian and Lorentzian models complex dielectric function. Line-shape nanowire PR spectra returned a doublet resonance lines at energies...

Excitonic properties of high-quality ZnS layers grown by low-pressure metal-organic vapor-phase epitaxy have been investigated using photoluminescence and absorption spectroscopy. Comparison with theoretical models has provided accurate information on eigenstates, broadening, strain, temperature dependence heavy-hole, light-hole, split-off-band exciton transitions. Finally, radiative recombination due to inelastic exciton-polariton scattering is shown under strong injection rates.

The electronic transport and gating characteristics in GaAs Ge nanowires (NWs) are altered significantly following either indirect or direct exposure to a focused Ga+ ion beam (FIB), such as that used produce Pt electrical contacts NWs. While these results challenge the assumptions made some previously reported work relating properties of semiconductor NWs using FIB-assisted production and/or their leads, local electron induced deposition is shown be reliable facile route for producing...

Abstract We report on the Au‐catalysed synthesis of GaAs nanowires hetero‐structured GaAs/(111)Si substrates by metalorganic vapour phase epitaxy. It is demonstrated that deposition a 40‐50 nm thin epilayer onto Si guarantees high percentage straight and vertically‐aligned nanowires. epilayers were grown at 400 °C subsequently annealed 700 °C. Growth experiments performed 4°‐miscut exactly‐oriented (111)Si show higher yield (close to 90%) vertical obtained using miscut substrates, an effect...

Abstract Many strategies have been adopted to improve the photoinduced features of zinc oxide nanostructures for different application fields. In this work, has synthesised and decorated by plasmonic metal nanoparticles enhance its photocatalytic activity in visible range. Furthermore, an insulating layer SiO 2 grown between surface nanoflakes silver nanoparticles. A synthetic procedure that allows accurate modulation thickness range 5–40 nm developed. Evidences highlight crucial role...