scholarly journals Index of refraction from the near-ultraviolet to the near-infrared from a single crystal microwave-assisted CVD diamond

2017 ◽  
Vol 7 (3) ◽  
pp. 855 ◽  
Author(s):  
Giorgio Turri ◽  
Scott Webster ◽  
Ying Chen ◽  
Benjamin Wickham ◽  
Andrew Bennett ◽  
...  
Keyword(s):  
Single Crystal ◽  
Near Infrared ◽  
Cvd Diamond ◽  
Index Of Refraction ◽  
Microwave Assisted ◽  
Near Ultraviolet

An Infrared Microscope for Use on a Focused Ion Beam for Circuit Edit and Backside Edit Applications

2015 ◽  
Author(s):  
Alexander Richards ◽  
Matthew Weschler ◽  
Michael Durller
Keyword(s):  
Focused Ion Beam ◽  
Near Infrared ◽  
Ion Beam ◽  
Visible Spectrum ◽  
Camera System ◽  
Buried Structures ◽  
Ir Camera ◽  
Area Of Interest ◽  
Near Ultraviolet ◽  
Infrared Microscope

Abstract To help solve the navigational problem, i.e., being able to successfully locate a circuit for probing or editing without destroying chip functionality, a near-infrared (NIR), near-ultraviolet (NUV), and visible spectrum camera system was developed that attaches to most focused ion beam (FIB) or scanning electron microscope vacuum chambers. This paper reviews the details of the design and implementation of the NIR/NUV camera system, as instantiated upon the FEI FIB 200, with a particular focus on its use for the visualization of buried structures, and also for non-destructive real time area of interest location and end point detection. It specifically considers the use of the micro-optical camera system for its benefit in assisting with frontside and backside circuit edit, as well as other typical FIB milling activities. The quality of the image obtained by the IR camera rivals or exceeds traditional optical based imaging microscopy techniques.

scholarly journals Pyrene Carboxylate Ligand Based Coordination Polymers for Microwave-Assisted Solvent-Free Cyanosilylation of Aldehydes

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1101
Author(s):  
Anirban Karmakar ◽  
Anup Paul ◽  
Elia Pantanetti Sabatini ◽  
M. Fátima C. Guedes da Silva ◽  
Armando J. L. Pombeiro
Keyword(s):  
Coordination Polymer ◽  
Single Crystal ◽  
Coordination Polymers ◽  
Metal Ion ◽  
Solvent Free ◽  
Lewis Acidity ◽  
Carboxylate Ligand ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microwave Assisted

The new coordination polymers (CPs) [Zn(μ-1κO1:1κO2-L)(H2O)2]n·n(H2O) (1) and [Cd(μ4-1κO1O2:2κN:3,4κO3-L)(H2O)]n·n(H2O) (2) are reported, being prepared by the solvothermal reactions of 5-{(pyren-4-ylmethyl)amino}isophthalic acid (H2L) with Zn(NO3)2.6H2O or Cd(NO3)2.4H2O, respectively. They were synthesized in a basic ethanolic medium or a DMF:H2O mixture, respectively. These compounds were characterized by single-crystal X-ray diffraction, FTIR spectroscopy, thermogravimetric and elemental analysis. The single-crystal X-ray diffraction analysis revealed that compound 1 is a one dimensional linear coordination polymer, whereas 2 presents a two dimensional network. In both compounds, the coordinating ligand (L2−) is twisted due to the rotation of the pyrene ring around the CH2-NH bond. In compound 1, the Zn(II) metal ion has a tetrahedral geometry, whereas, in 2, the dinuclear [Cd2(COO)2] moiety acts as a secondary building unit and the Cd(II) ion possesses a distorted octahedral geometry. Recently, several CPs have been explored for the cyanosilylation reaction under conventional conditions, but microwave-assisted cyanosilylation of aldehydes catalyzed by CPs has not yet been well studied. Thus, we have tested the solvent-free microwave-assisted cyanosilylation reactions of different aldehydes, with trimethylsilyl cyanide, using our synthesized compounds, which behave as highly active heterogeneous catalysts. The coordination polymer 1 is more effective than 2, conceivably due to the higher Lewis acidity of the Zn(II) than the Cd(II) center and to a higher accessibility of the metal centers in the former framework. We have also checked the heterogeneity and recyclability of these coordination polymers, showing that they remain active at least after four recyclings.

High-performance near-infrared photodetectors based on C3N quantum dots integrated with single-crystal graphene

2021 ◽  
Author(s):  
Yun Zhao ◽  
Xiaoqiang Feng ◽  
Menghan Zhao ◽  
Xiaohu Zheng ◽  
Zhiduo Liu ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Electric Field ◽  
Single Crystal ◽  
High Performance ◽  
Near Infrared ◽  
Fast Response ◽  
Local Electric Field ◽  
Infrared Photodetectors ◽  
Photocurrent Response

Employing C3N QD-integrated single-crystal graphene, photodetectors exhibited a distinct photocurrent response at 1550 nm. The photocurrent map revealed that the fast response derive from C3N QDs that enhanced the local electric field near graphene.

Development of Diamond-Based X-ray Detection for High Flux Beamline Diagnostics

2009 ◽  
Vol 1203 ◽  
Author(s):  
Jen Bohon ◽  
John Smedley ◽  
Erik M. Muller ◽  
Jeffrey W. Keister
Keyword(s):  
Single Crystal ◽  
Linear Response ◽  
Voltage Dependence ◽  
Cvd Diamond ◽  
High Flux ◽  
National Synchrotron Light Source ◽  
X Ray ◽  
Single Crystal Diamond ◽  
Synchrotron Light ◽  
Pulse Structure

AbstractHigh quality single crystal and polycrystalline CVD diamond detectors with platinum contacts have been tested at the white beam X28C beamline at the National Synchrotron Light Source under high-flux conditions. The voltage dependence of these devices has been measured under DC and pulsed-bias conditions, establishing the presence or absence of photoconductive gain in each device. Linear response has been achieved over eleven orders of magnitude when combined with previous low flux studies. Temporal measurements with single crystal diamond detectors have resolved the ns scale pulse structure of the NSLS.

scholarly journals Joint Measurements of PM<sub>2.5</sub> and light-absorptive PM in woodsmoke-dominated ambient and plume environments

2017 ◽  
Author(s):  
K. Max Zhang ◽  
Bo Yang ◽  
Geng Chen ◽  
Jiajun Gu ◽  
James Schwab ◽  
...  
Keyword(s):  
Near Infrared ◽  
Uv Light ◽  
Operating Conditions ◽  
Infrared Range ◽  
Wood Combustion ◽  
Near Ultraviolet ◽  
Linear Relationships ◽  
Saranac Lake ◽  
Near Infrared Range ◽  
Strong Linear Relationship

Abstract. DC, also referred to as Delta-C, measures enhanced light absorption of particulate matter (PM) samples at the near-ultraviolet (UV) range relative to the near-infrared range, which has been proposed previously as a woodsmoke marker due to the presence of enhanced UV light absorbing materials from wood combustion. In this paper, we further evaluated the applications and limitations of using DC as both a qualitative and semi-quantitative woodsmoke marker via joint continuous measurements of PM2.5 (by nephelometer pDR-1500) and light-absorptive PM (by 2-wavelength and 7-wavelength Aethalometer®) in three Northeastern U.S. cities/towns including Rutland, VT, Saranac Lake, NY and Ithaca, NY. We compared the pDR-1500 against a FEM PM2.5 sampler (BAM 1020), and identified a close agreement between the two instruments in a woodsmoke-dominated ambient environment. The analysis of seasonal and diurnal trends of DC, BC (880 nm) and PM2.5 concentrations supports the use of DC as an adequate qualitative marker. The strong linear relationships between PM2.5 and DC in both woodsmoke-dominated ambient and plume environments suggest that DC can reasonably serve as a semi-quantitative woodsmoke marker. We proposed a DC-based indicator for woodsmoke emission, which was then shown to exhibit relatively strong linear relationship with heating demand. While we observed reproducible PM2.5-DC relationships in similar woodsmoke-dominated ambient environments, those relationships differ significantly with different environments, and among individual woodsmoke sources. DC correlated much more closely with PM2.5 than EcoChem PAS2000-reported PAH in woodsmoke-dominated ambient environments. Our analysis also indicates the potential for PM2.5-DC relationships to be utilized to distinguish different combustion and operating conditions of woodsmoke sources, and that DC-Heating demand relationships could be adopted to estimate woodsmoke emissions. However, future studies are needed to elucidate those relationships.

A spectroscopic study of optical centers in diamond grown by microwave-assisted chemical vapor deposition

1990 ◽  
Vol 5 (11) ◽  
pp. 2507-2514 ◽  
Author(s):  
A. T. Collins ◽  
M. Kamo ◽  
Y. Sato
Keyword(s):  
Chemical Vapor Deposition ◽  
Radiation Damage ◽  
Single Crystals ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Edge Emission ◽  
Microwave Assisted ◽  
Bright Blue ◽  
Methane Concentrations

Absorption and cathodoluminescence spectra have been recorded for single crystals of diamond and polycrystalline films of diamond, grown by microwave-assisted chemical vapor deposition (CVD) using methane and hydrogen. The investigation has been carried out to see to what extent the properties of CVD diamond are similar to those of conventional diamond, and to what extent they are unique. Studies have been made of the as-grown material, which has not been intentionally doped, and also samples that have been subjected to radiation damage and thermal annealing. The single crystals grown using methane concentrations of 0.5 to 1.0% exhibit bright blue “band A” emission and also intense edge emission, similar to the cathodoluminescence spectra of some natural type IIa diamonds. This implies that the crystals are relatively free from structural and chemical defects, a conclusion which is reinforced by the absence of any zero-phonon lines in the absorption spectra of crystals which have been subjected to radiation damage and annealing at 800 °C. Before radiation damage the spectrum does, however, reveal an absorption which increases progressively to higher energies, and which may be associated with sp2-bonded carbon. The Cathodoluminescence spectra after radiation damage indicate that the crystals contain some isolated nitrogen, and the detection of H3 luminescence, following thermal annealing at 800 °C, demonstrates for the first time that these samples contain small concentrations of nitrogen pairs. All of the polycrystalline films, grown using methane concentrations between 0.3 and 1.5%, have an absorption which increases progressively to higher energies, and which again is attributed to sp2-bonded carbon. This absorption is stronger in the films grown using higher methane concentrations. Films grown at a methane concentration of 0.3% also exhibit bright blue cathodoluminescence, although the edge emission is undetectably weak. The use of higher methane concentrations produces films with evidence in the cathodoluminescence spectra of nitrogen + vacancy and nitrogen + interstitial complexes, as well as optical centers unique to CVD diamond. One particular defect produces an emission and absorption line at 1.681 eV. By implanting conventional diamonds with 29Si ions it has been confirmed that this center involves silicon, and it has been shown that the 1.681 eV luminescence is relatively more intense in implanted diamonds which have a high concentration of isolated nitrogen.

scholarly journals Solar radius determined from PICARD/SODISM observations and extremely weak wavelength dependence in the visible and the near-infrared

2018 ◽  
Vol 616 ◽  
pp. A64 ◽  
Author(s):  
M. Meftah ◽  
T. Corbard ◽  
A. Hauchecorne ◽  
F. Morand ◽  
R. Ikhlef ◽  
...  
Keyword(s):  
Inflection Point ◽  
Near Infrared ◽  
Solar Limb ◽  
Wavelength Dependence ◽  
Uncertainty Budget ◽  
Solar Radius ◽  
Absolute Calibration ◽  
Point Position ◽  
Near Ultraviolet ◽  
Venus Transit

Context. In 2015, the International Astronomical Union (IAU) passed Resolution B3, which defined a set of nominal conversion constants for stellar and planetary astronomy. Resolution B3 defined a new value of the nominal solar radius (R⊙N = 695 700 km km) that is different from the canonical value used until now (695 990 km). The nominal solar radius is consistent with helioseismic estimates. Recent results obtained from ground-based instruments, balloon flights, or space-based instruments highlight solar radius values that are significantly different. These results are related to the direct measurements of the photospheric solar radius, which are mainly based on the inflection point position methods. The discrepancy between the seismic radius and the photospheric solar radius can be explained by the difference between the height at disk center and the inflection point of the intensity profile on the solar limb. At 535.7 nm (photosphere), there may be a difference of ∼330 km between the two definitions of the solar radius. Aims. The main objective of this work is to present new results of the solar radius in the near-ultraviolet, the visible, and the near-infrared from PICARD space-based and ground-based observations. Simulations show the strong influence of atmosphere effects (refraction and turbulence) on ground-based solar radius determinations and highlight the interest of space-based solar radius determinations, particularly during planet transits (Venus or Mercury), in order to obtain more realistic and accurate measurements. Methods. Solar radius observations during the 2012 Venus transit have been made with the SOlar Diameter Imager and Surface Mapper (SODISM) telescope on board the PICARD spacecraft. We used the transit of Venus as an absolute calibration to determine the solar radius accurately at several wavelengths. Our results are based on the determination of the inflection point position of the solar limb-darkening function (the most common solar radius definition). A realistic uncertainty budget is provided for each solar radius obtained with the PICARD space-based telescope during the 2012 Venus transit. The uncertainty budget considers several sources of error (detection of the centers of Venus and Sun in PICARD images, positions of Sun and Venus from ephemeris (planetary theory), PICARD on-board timing, PICARD spacecraft position, and optical distortion correction from PICARD images). Results. We obtain new values of the solar radius from the PICARD mission at several wavelengths and in different solar atmosphere regions. The PICARD spacecraft with its SODISM telescope was used to measure the radius of the Sun during the Venus transit in 2012. At 535.7 nm, the solar radius is equal to 696 134 ± 261 km (combined standard uncertainty based (ξ) on the uncertainty budget). At 607.1 nm, the solar radius is equal to 696 156 ± 145 km (ξ), and the standard deviation of the solar radius mean value is ±22 km. At 782.2 nm, the solar radius is equal to 696 192 ± 247 km (ξ). The PICARD space-based results as well as PICARD ground-based results show that the solar radius wavelength dependence in the visible and the near-infrared is extremely weak. The differences in inflection point position of the solar radius at 607.1 nm, 782.2 nm, and 1025.0 nm from a reference at 535.7 nm are less than 60 km for the different PICARD measurements.

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