Search results for "ELECTRONICS"
showing 10 items of 4340 documents
3D superconducting hollow nanowires with tailored diameters grown by focused He+ beam direct writing
2020
Currently, the patterning of innovative three-dimensional (3D) nano-objects is required for the development of future advanced electronic components. Helium ion microscopy in combination with a precursor gas can be used for direct writing of three-dimensional nanostructures with a precise control of their geometry, and a significantly higher aspect ratio than other additive manufacturing technologies. We report here on the deposition of 3D hollow tungsten carbide nanowires with tailored diameters by tuning two key growth parameters, namely current and dose of the ion beam. Our results show the control of geometry in 3D hollow nanowires, with outer and inner diameters ranging from 36 to 142 …
Growth of low-density vertical quantum dot molecules with control in energy emission
2010
This article is distributed under the terms of the Creative Commons Attribution Noncommercial License.-- This article is part of the series 8th International Workshop on Epitaxial Semiconductors on Patterned Substrates and Novel Index Surfaces.
Spectral characterization of bulk and nanostructured aluminum nitride
2009
Spectral characteristics including photoluminescence (PL) spectra and its excitation spectra for different AlN materials (AlN ceramics, macro size powder and nanostructured forms such as nanopowder, nanorods and nanotips) were investigated at room temperature. Besides the well known UV-blue (around 400 nm) and red (600 nm) luminescence, the 480 nm band was also observed as an asymmetric long-wavelength shoulder of the UV-blue PL band. This band can be related to the luminescence of some kind of surface defects, probably also including the oxygen-related defects. The mechanisms of recombination luminescence and excitation of the UV-blue luminescence caused by the oxygen-related defects were …
Single Out-of-Resonance Dielectric Nanoparticles as Molecular Sensors.
2021
Light scattering from single nanoparticles and nanostructures is a commonly used readout method for nanosensors. Increasing the spectral sensitivity of resonant nanosensors to changes in their local surrounding has been the focus of many studies. Switching from spectral to intensity monitoring allows one to investigate nonresonant or out-of-resonance dielectric nanoparticles. Here, we systematically compared such dielectric silica nanoparticles with plasmonic gold nanorods by deriving analytical expressions and by performing experiments. The experiments show a similar sensitivity for the detection of an adsorbate layer for both particle types, which is in good agreement with theory. The fla…
Mapping of local conductivity variations on fragile nanopillar arrays by scanning conductive torsion mode microscopy.
2010
A gentle method that combines torsion mode topography imaging with conductive scanning force microscopy is presented. By applying an electrical bias voltage between tip and sample surface, changes in the local sample conductivity can be mapped. The topography and local conductivity variations on fragile free-standing nanopillar arrays were investigated. These samples were fabricated by an anodized aluminum oxide template process using a thermally cross-linked triphenylamine-derivate semicondcutor. The nanoscale characterization method is shown to be nondestructive. Individual nanopillars were clearly resolved in topography and current images that were recorded simultaneously. Local current−…
Toward Single Electron Nanoelectronics Using Self-Assembled DNA Structure
2016
DNA based structures offer an adaptable and robust way to develop customized nanostructures for various purposes in bionanotechnology. One main aim in this field is to develop a DNA nanobreadboard for a controllable attachment of nanoparticles or biomolecules to form specific nanoelectronic devices. Here we conjugate three gold nanoparticles on a defined size TX-tile assembly into a linear pattern to form nanometer scale isolated islands that could be utilized in a room temperature single electron transistor. To demonstrate this, conjugated structures were trapped using dielectrophoresis for current-voltage characterization. After trapping only high resistance behavior was observed. However…
ZnO Thin films doped with Erbium: Elaboration, Characterization and nonlinear optical properties measurements
2011
In this paper, we investigate NLO properties of ZnO nanostructures for optoelectronics applications. It is shown that carefully designed and fabricated nanostructured ZnO films posses some advantageous for practical use and to generate more and short wavelengths and, when combined with TiO , produce a core–shell structure that 2 reduces the combination rate. The limitations of ZnO-based DSCs are also discussed and several possible methods are suggested in order to expand the basic knowledge of ZnO to TiO , motivating further improvement 2 in the power-conversion efficiency of third harmonic generation THG.
Structural characterization of one-dimensional ZnO-based nanostructures grown by MOCVD
2010
Various one-dimensional (1D) ZnO-based nanostructures, including ZnO nano-wires (NWs) grown using vapour-liquid-solid (VLS) process, ZnO/ZnSe core/shell, nitrogen-doped ZnO and ZnMgO NWs were grown by metalorganic chemical vapour deposition (MOCVD). Transmission electron microscopy (TEM) analysis is presented. For all the samples, a high crystalline quality is observed. Some features are emphasized such as the gold contamination of ZnO wires grown under the metal droplets in the VLS process. It is concluded that MOCVD is a suitable technique for the realization of original ZnO nanodevices.
Combustion Formation of Novel Nanomaterials: Synthesis and Cathodoluminescence of Silicon Carbide Nanowires
2009
This paper presents the combustion synthesis and characterization of one-dimensional silicon carbide nanostructures (nanowires of 3C-SiC polytype with zincblend structure) by means of cathodoluminescence technique. Cathodoluminescence spectra of nano-SiC samples and, as a reference, of a commercially available SiC micropowder are compared. It is shown that the emission band at 1.97 eV which is slightly evidenced in the spectrum of the commercial SiC under 10 keV electron beam irradiation becomes the prevailing band in CL of the purified silicon carbide nanowires.
Surface waves in plasmonic anisotropie media
2012
We investigate the spatial dispersion of hybrid-polarized surface waves excited at the boundary of a semi-infinite layered metal-dielectric nanostructure. We put emphasis in the case that the thickness of a metal layer becomes of the order of the metal skin depth. We demonstrate that the use of the so-called effective medium approximation (EMA) is not justified, in general. For that purpose, we compare the results using the EMA model and numerical simulations based on the finite-element method. We include an analysis of the influence of metallic losses.