scholarly journals Guided CdSe Nanowires Parallelly Integrated into Fast Visible-Range Photodetectors

ACS Nano ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 213-220 ◽  
Author(s):  
Erga Shalev ◽  
Eitan Oksenberg ◽  
Katya Rechav ◽  
Ronit Popovitz-Biro ◽  
Ernesto Joselevich
Keyword(s):  
Visible Range ◽  
Cdse Nanowires

Structural aspects of silicon diffusion in quaternary III-V thin-film semiconductors

1991 ◽  
Vol 49 ◽  
pp. 850-851
Author(s):  
F. A. Ponce ◽  
R. L. Thornton ◽  
G. B. Anderson
Keyword(s):  
Semiconductor Lasers ◽  
Wide Bandgap ◽  
Semiconductor Diode ◽  
Visible Range ◽  
P System ◽  
Misfit Dislocations ◽  
Lattice Match ◽  
Semiconductor Diode Laser ◽  
Thin Film Semiconductors ◽  
Silicon Diffusion

The InGaAlP quaternary system allows the production of semiconductor lasers emitting light in the visible range of the spectrum. Recent advances in the visible semiconductor diode laser art have established the viability of diode structures with emission wavelengths comparable to the He-Ne gas laser. There has been much interest in the growth of wide bandgap quaternary thin films on GaAs, a substrate most commonly used in optoelectronic applications. There is particular interest in compositions which are lattice matched to GaAs, thus avoiding misfit dislocations which can be detrimental to the lifetime of these materials. As observed in Figure 1, the (AlxGa1-x)0.5In0.5P system has a very close lattice match to GaAs and is favored for these applications.In this work, we have studied the effect of silicon diffusion in GaAs/InGaAlP structures. Silicon diffusion in III-V semiconductor alloys has been found to have an disordering effect which is associated with removal of fine structures introduced during growth. Due to the variety of species available for interdiffusion, the disordering effect of silicon can have severe consequences on the lattice match at GaAs/InGaAlP interfaces.

Formation of Luminescent Si Nanocrystals by High-Temperature Annealing of Ion-Beam-Sputtered Si/SiO2 Multilayers

2003 ◽  
Vol 775 ◽  
Author(s):  
Suk-Ho Choi ◽  
Jun Sung Bae ◽  
Kyung Jung Kim ◽  
Dae Won Moon
Keyword(s):  
Quantum Confinement ◽  
Radiative Recombination ◽  
Ion Beam ◽  
Quantum Confinement Effect ◽  
Visible Range ◽  
Ion Beam Sputtering ◽  
Transmission Electron ◽  
Si Nanocrystals ◽  
Beam Sputtering ◽  
Microscopy Images

AbstractSi/SiO2 multilayers (MLs) have been prepared under different deposition temperatures (TS) by ion beam sputtering. The annealing at 1200°C leads to the formation of Si nanocrystals in the Si layer of MLs. The high resolution transmission electron microscopy images clearly demonstrate the existence of Si nanocrystals, which exhibit photoluminescence (PL) in the visible range when TS is ≥ 300°C. This is attributed to well-separation of nanocrystals in the higher-TS samples, which is thought to be a major cause for reducing non-radiative recombination in the interface between Si nanocrystal and surface oxide. The visible PL spectra are enhanced in its intensity and are shifted to higher energy by increasing TS. These PL behaviours are consistent with the quantum confinement effect of Si nanocrystals.

Estimation of precipitation intensity due to image processing from the camera of the visible range

2018 ◽  
Vol 1 (3) ◽  
pp. 282-296
Author(s):  
V. N. Garmash ◽  
◽  
D. M. Korobochkin ◽  
S. A. Matveev ◽  
Y. V. Petrov ◽  
...  
Keyword(s):  
Image Processing ◽  
Precipitation Intensity ◽  
Visible Range

Fluorescence of BODIPY Dyes in Gas Phase at near Ambient Conditions

2020 ◽  
Author(s):  
Kseniya A. Mariewskaya ◽  
Denis Larkin ◽  
Yuri Samoilichenko ◽  
Vladimir Korshun ◽  
Alex Ustinov
Keyword(s):  
Gas Phase ◽  
Molecular Interactions ◽  
Atmospheric Pressure ◽  
Fluorescence Spectra ◽  
Visible Range ◽  
Intrinsic Properties ◽  
Ambient Conditions ◽  
Ideal Model ◽  
Molecular Fluorescence ◽  
Tesla Coil

Molecular fluorescence is a phenomenon that is usually observed in condensed phase. It is strongly affected by molecular interactions. The study of fluorescence spectra in the gas phase can provide a nearly-ideal model for the evaluation of intrinsic properties of the fluorophores. Unfortunately, most conventional fluorophores are not volatile enough to allow study of their fluorescence in the gas phase. Here we report very bright gas phase fluorescence of simple BODIPY dyes that can be readily observed at atmospheric pressure using conventional fluorescence instrumentation. To our knowledge, this is the first example of visible range gas phase fluorescence at near ambient conditions. Evaporation of the dye in vacuum allowed us to demonstrate organic molecular electroluminescence in gas discharge excited by electric field produced by a Tesla coil.

First-Principles Evaluation of the Potential of Borophene as a Monolayer Transparent Conductor

2017 ◽  
Author(s):  
Lyudmyla Adamska ◽  
Sridhar Sadasivam ◽  
Jonathan J. Foley ◽  
Pierre Darancet ◽  
Sahar Sharifzadeh
Keyword(s):  
First Principles ◽  
Density Functional ◽  
State Of The Art ◽  
Transparent Electrode ◽  
Visible Range ◽  
Two Dimensional ◽  
Transparent Conductor ◽  
Many Body ◽  
Functional Theory ◽  
Many Body Perturbation Theory

Two-dimensional boron is promising as a tunable monolayer metal for nano-optoelectronics. We study the optoelectronic properties of two likely allotropes of two-dimensional boron using first-principles density functional theory and many-body perturbation theory. We find that both systems are anisotropic metals, with strong energy- and thickness-dependent optical transparency and a weak (<1%) absorbance in the visible range. Additionally, using state-of-the-art methods for the description of the electron-phonon and electron-electron interactions, we show that the electrical conductivity is limited by electron-phonon interactions. Our results indicate that both structures are suitable as a transparent electrode.

Determination of the profile of the temperature field of material heated by continuous laser radiation

2020 ◽  
pp. 51-10
Author(s):  
B.A. Lapshinov ◽  
◽  
N.I. Timchenko ◽  
Keyword(s):  
Temperature Field ◽  
Optical Fiber ◽  
Prolonged Exposure ◽  
Radiation Spectrum ◽  
Visible Range ◽  
Continuous Laser ◽  
Surface Temperature Distribution ◽  
Continuous Radiation ◽  
Spectral Pyrometry

Spectral pyrometry was used to determine the surface temperature distribution of Si, Nb, Cu, and graphite samples when they were locally heated by continuous radiation of an Nd:YAG laser (λ = 1.064 μm). With prolonged exposure to radiation, a stationary temperature field was established in the samples. The thermal spectra were recorded with a small spectrometer in the visible range in the temperature range above 850 K. The optical fiber used to transmit the radiation spectrum to the spectrometer had an additional diaphragm with a diameter of 1 mm located at a certain distance from the fiber end, which ensured the locality of the recorded spectra. The optical fiber moved continuously along the sample, and the spectrometer recorded up to 100 spectra with a frequency of 5-10 Hz. The temperature profile of the samples was calculated based on the results of processing the spectra using the Spectral Pyrometry program.

Green synthesis of iron nanoparticles using flower extract of Piliostigma thonningii and their antibacterial activity evaluation

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Antibacterial Activity ◽  
Environmental Remediation ◽  
Iron Nanoparticles ◽  
Reduction Process ◽  
Xrd Analysis ◽  
Visible Range ◽  
Magnetic Storage ◽  
Ferrous Chloride ◽  
Flower Extract ◽  
Piliostigma Thonningii

Iron nanoparticles have gained tremendous attention due to their application in magnetic storage media, ferrofluids, biosensors, catalysts, separation processes, environmental remediation and antibacterial activity. In the present paper, iron nanoparticles were synthesized using aqueous flower extract of Piliostigma thonningii, a natural nontoxic herbal infusion. Iron nanoparticles were generated by reaction of ferrous chloride solution with the flower extract. The reductants present in the flower extract acted as reducing and stabilizing agents. UV-vis analysis of the iron nanoparticles showed continuous absorption in the visible range suggesting the iron nanoparticles were amorphous. This was confirmed by X-ray diffraction (XRD) analysis which did not have distinct diffraction peaks. Scanning electron microscopy (SEM) analysis revealed that the synthesized iron nanoparticles were aggregated as irregular clusters with rough surfaces. FT-IR studies showed the functional groups that participated in the bio-reduction process to include a C-H stretch (due to alkane CH3, CH2 or CH), C=O stretch (due to aldehydes), O-H bend (due to tert-alcohol or phenol), C-O stretch (due to aldehydes or phenols) and C-O stretch (due to alcohols) corresponding to absorptions at 2929.00, 1721.53, 1405.19, 1266.31 and 1030.02 cm-1 respectively. The iron nanoparticles showed significant antibacterial activity against Escharichia coli and Staphylococcus aureus suggesting potential antibacterial application.

Phototherapy is a pathogenetic method in the treatment of acute sinusitis

2020 ◽  
pp. 34-39
Author(s):  
Arsen Korkmazov
Keyword(s):  
Nasal Mucosa ◽  
Local Effect ◽  
Nasal Secretion ◽  
Visible Range ◽  
Neutrophil Granulocytes ◽  
Physical Treatment ◽  
Local Immunity ◽  
Acute Rhinosinusitis ◽  
Therapeutic Measures ◽  
Effect Of Light

Currently, physical treatment methods, in particular use of photochromotherapy in the treatment of sinusitis, are of interest. Is to investigate the local effect of light in the visible range (450 nm) on the factors of local infection protection of the nasal mucosa. The study involved 50 patients with a diagnosis of acute rhinosinusitis at the age of 27.23±3.29 years. Exposure of the mucous membrane of the nasal cavity was carried out in accordance with the parameters: 450 nm wavelength (monochromatic non-polarized blue light), during 5 minutes for each nostril. Sessions of photochromotherapy were carried out according to the "Sanitary norms and rules for the design and operation of lasers" No. 5804-91. Inclusion of photochromotherapy in the complex of therapeutic measures for patients with acute rhinosinusitis helps to reduce the total number of neutrophils in nasal secretion, normalize their lysosomal activity, NBT-reducing activity, activity and intensity of phagocytosis. Restoration of local immunity factors in nasal mucosa, expressed in normalizing the functional and metabolic status of neutrophil granulocytes of the nasal secretion, can serve as one of the criteria for the effectiveness of treatment using photochromotherapy

Reaction of organolithium compounds with 1-substituted 2,4,6-triphenylpyridinium perchlorates

1989 ◽  
Vol 54 (7) ◽  
pp. 1880-1887 ◽  
Author(s):  
Marián Schwarz ◽  
Josef Kuthan
Keyword(s):  
Visible Range ◽  
Molecular Spectra ◽  
Organolithium Compounds ◽  
Phenylmagnesium Bromide

The reaction of organolithium compounds with 1-substituted 2,4,6-triphenylpyridinium perchlorates Ia-Ic produces mixtures of 1,4-dihydropyridines IIa-IIe and 1,2-dihydropyridines IIIa-IIIe. Analogous reactions of phenylmagnesium bromide with compounds Ia-Ic proceed with very low conversions (less than 1%). Photochromism in visible range is observed only with the compounds II which have two aromatic substituents at 4-position, whereas compounds III and IId show no visible photochromism. The molecular spectra of the compounds newly prepared are discussed.

Optical constants of PbI2 in the visible range

1980 ◽  
Vol 60 (2) ◽  
pp. K153-K157 ◽  
Author(s):  
C. de Blasi ◽  
S. Galassini ◽  
C. Manfredotti ◽  
R. Murri ◽  
R. Piccolo
Keyword(s):  
Optical Constants ◽  
Visible Range
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