Cathodoluminescence Study of Hydrothermal Zn1-xMgxO Alloy Crystals

2006 ◽  
Vol 957 ◽  
Author(s):  
Julio Mass ◽  
Manuel Avella ◽  
Juan Jiménez ◽  
Michael Callahan ◽  
E. Grant ◽  
...  
Keyword(s):  
Depth Distribution ◽  
Energy Shift ◽  
High Energy ◽  
Growth Sector ◽  
Spectral Parameters ◽  
Luminescence Emission ◽  
Acceleration Voltage ◽  
Marked Dependence ◽  
Excitonic Luminescence ◽  
Cathodoluminescence Study

ABSTRACTHydrothermal ZnMgO crystals were studied by cathodoluminescence. The high energy shift of the excitonic luminescence demonstrates the Mg incorporation in the ZnO lattice in at a few percent. The spectral parameters of the luminescence emission show a marked dependence of the incorporation of defects and Mg on the growth facet. This growth sector selectivity shows similar trends to those observed in hydrothermal ZnO crystals. The in depth distribution of Mg was studied varying the acceleration voltage of the excitation e-beam, showing a slight accumulation of Mg close to the surface.

High energy resolution spectrometer for the dedicated STEM

1984 ◽  
Vol 42 ◽  
pp. 558-559 ◽  
Author(s):  
P.E. Batson
Keyword(s):  
Collection Efficiency ◽  
Core Loss ◽  
Beam Current ◽  
High Energy ◽  
High Energy Resolution ◽  
Acquisition Time ◽  
Good Definition ◽  
Loss Analysis ◽  
Definition Of ◽  
Acceleration Voltage

Use of the STEM to obtain precise electronic information has been hampered by the lack of energy loss analysis capable of a resolution and accuracy comparable to the 0.3eV energy width of the Field Emission Source. Recent work by Park, et. al. and earlier by Crewe, et. al. have promised magnetic sector devices that are capable of about 0.75eV resolution at collection angles (about 15mR) which are great enough to allow efficient use of the STEM probe current. These devices are also capable of 0.3eV resolution at smaller collection angles (4-5mR). The problem that arises, however, lies in the fact that, even with the collection efficiency approaching 1.0, several minutes of collection time are necessary for a good definition of a typical core loss or electronic transition. This is a result of the relatively small total beam current (1-10nA) that is available in the dedicated STEM. During this acquisition time, the STEM acceleration voltage may fluctuate by as much as 0.5-1.0V.

Analysis of Voltage Contrast in Secondary Electron Images Using a High-Energy Electron Spectrometer

2019 ◽  
Author(s):  
Natsuko Asano ◽  
Shunsuke Asahina ◽  
Natasha Erdman
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Sample Surface ◽  
High Energy ◽  
Secondary Electrons ◽  
Analysis Technique ◽  
Quantitative Understanding ◽  
Voltage Contrast ◽  
Acceleration Voltage ◽  
Failure Localization

Abstract Voltage contrast (VC) observation using a scanning electron microscope (SEM) or a focused ion beam (FIB) is a common failure analysis technique for semiconductor devices.[1] The VC information allows understanding of failure localization issues. In general, VC images are acquired using secondary electrons (SEs) from a sample surface at an acceleration voltage of 0.8–2.0 kV in SEM. In this study, we aimed to find an optimized electron energy range for VC acquisition using Auger electron spectroscopy (AES) for quantitative understanding.

Si2p Core Level Absorption and Photoemission Spectra of Porous Si

1992 ◽  
Vol 283 ◽  
Author(s):  
Hisao Nakashima ◽  
Koichi Inoue ◽  
Kenzo Maehashi
Keyword(s):  
Synchrotron Radiation ◽  
Electronic Structures ◽  
Energy Shift ◽  
Blue Shift ◽  
Photo Luminescence ◽  
High Energy ◽  
Core Level ◽  
Oxidation States ◽  
Porous Si ◽  
The Core

ABSTRACTSi2p core level absorption and photoemission spectra are taken for different porous Si layers using synchrotron radiation, toknow the electronic structures of porous Si. The core level absorption spectra show the high energy shift of the conduction band which correlates with the photo-luminescence blue shift. The oxidation states of porous Si are clarified from the photoemission spectra.

scholarly journals X-ray Spectral Evolution of High Energy Peaked Blazars

Galaxies ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 62
Author(s):  
Haritma Gaur
Keyword(s):  
High Energy ◽  
Energy Interval ◽  
Spectral Studies ◽  
Parabolic Model ◽  
Spectral Evolution ◽  
Spectral Variability ◽  
Spectral Parameters ◽  
X Ray ◽  
Wide Energy ◽  
Energy Dependent

The synchrotron hump of the high energy peaked blazars generally lies in the 0.1–10 keV range and such sources show extreme flux and spectral variability in X-ray bands. Various spectral studies showed that the X-ray spectra of high energy peaked blazars are curved and better described by the log-parabolic model. The curvature is attributed to the energy dependent statistical acceleration mechanism. In this work, we review the X-ray spectral studies of high energy peaked blazars. It is found that the log-parabolic model well describes the spectra in a wide energy interval around the peak. The log-parabolic model provides the possibility of investigating the correlation between the spectral parameters derived from it. Therefore, we compiled the studies of correlations between the various parameters derived from the log-parabolic model and their implications to describe the variability mechanism of blazars.

scholarly journals QCD PRECISION MEASUREMENTS AND STRUCTURE FUNCTION EXTRACTION AT A HIGH STATISTICS, HIGH ENERGY NEUTRINO SCATTERING EXPERIMENT: NuSOnG

2010 ◽  
Vol 25 (05) ◽  
pp. 909-949 ◽  
Author(s):  
T. ADAMS ◽  
P. BATRA ◽  
L. BUGEL ◽  
L. CAMILLERI ◽  
J. M. CONRAD ◽  
...  
Keyword(s):  
Standard Model ◽  
Energy Shift ◽  
High Energy ◽  
Structure Functions ◽  
Distribution Functions ◽  
Neutrino Beam ◽  
Model Parameters ◽  
Parton Distribution Functions ◽  
Neutrino Scattering ◽  
Scattering Experiment

We extend the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering On Glass) to address a variety of issues including precision QCD measurements, extraction of structure functions, and the derived Parton Distribution Functions (PDF's). This experiment uses a Tevatron-based neutrino beam to obtain a sample of Deep Inelastic Scattering (DIS) events which is over two orders of magnitude larger than past samples. We outline an innovative method for fitting the structure functions using a parametrized energy shift which yields reduced systematic uncertainties. High statistics measurements, in combination with improved systematics, will enable NuSOnG to perform discerning tests of fundamental Standard Model parameters as we search for deviations which may hint of "Beyond the Standard Model" physics.

Interface and Luminescence Properties of Pulsed Laser Deposited MgxZn1-xO/ZnO Quantum Wells with Strong Confinement

2006 ◽  
Vol 957 ◽  
Author(s):  
Susanne Heitsch ◽  
Gregor Zimmermann ◽  
Alexander Müller ◽  
Jörg Lenzner ◽  
Holger Hochmuth ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Stark Effect ◽  
Pulsed Laser ◽  
Energy Shift ◽  
High Energy ◽  
Interface Roughness ◽  
Force Microscopy ◽  
Quantum Confined Stark Effect ◽  
Barrier Layers ◽  
Atomic Force

ABSTRACTMgxZn1-xO/ZnO/MgxZn1-xO quantum wells (QWs) (0.12 ≤ x ≤ 0.15) have been grown on a-plane sapphire substrates by pulsed laser deposition. The nominal ZnO well layer thickness lies between 1.2 nm and 6 nm. Atomic force microscopy (AFM) investigations at ZnO/MgxZn1−xO heterostructures show the film-like structure of the ZnO layers. Their root mean square surface roughness of ∼ 0.5 nm gives information about the interface roughness in the QWs. AFM results from the MgxZn1−xO barrier layers show the same surface structure and roughness. We confirmed the lateral homogeneity of the Mg distribution in the MgxZn1−xO barrier layers by scanning cathodoluminescence measurements. The QWs show a bright and laterally homogeneous luminescence, suggesting good crystalline quality of the ZnO wells. The measured QW photoluminescence energies agree well with calculated values and display the presence of the quantum-confined Stark effect. As a result of quantum confinement a high-energy shift of the ZnO excitonic photoluminescence of 222 meV is observed in the thinnest QW.

Depth distribution of defects and impurities in diamond and cubic boron nitride after high-energy ion implantation

1989 ◽  
Vol 115 (2) ◽  
pp. 427-435 ◽  
Author(s):  
A. F. Burenkov ◽  
V. S. Varychenko ◽  
A. M. Zaitsev ◽  
F. F. Komarov ◽  
G. G. Konoplyanik ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Ion Implantation ◽  
Depth Distribution ◽  
Cubic Boron Nitride ◽  
High Energy ◽  
Defects And Impurities

Spectrally Resolved Cathodoluminescence (SRCL) of Hydrothermal ZnO crystals

2005 ◽  
Vol 878 ◽  
Author(s):  
J. Mass ◽  
M. Avella ◽  
J. Jiménez ◽  
M. Callahan ◽  
E. Grant ◽  
...  
Keyword(s):  
High Energy ◽  
Luminescence Spectra ◽  
Growth Sector ◽  
High Energy Part ◽  
Spectral Signatures ◽  
Energy Part ◽  
Good Crystalline Quality ◽  
Recombination Centers ◽  
Band Tailing ◽  
Spectrally Resolved

AbstractLarge hydrothermal ZnO crystals were grown using 3N NaOH, 1N KOH and 0.5N Li2CO3mineralizer. The crystals were studied by cathodoluminescence (CL), showing a good crystalline quality. Different growth regions were identified by CL imaging. These regions were characterized by their corresponding luminescence spectra, showing that the incorporation of impurities and non radiative recombination centers depend on the growth sector. The surface is shown to introduce band tailing modifying the high energy part of the spectrum. The main spectral signatures of each sector are discussed.

Ultraviolet Light Emitting Devices Using AlGdN

2011 ◽  
Vol 1342 ◽  
Author(s):  
Takashi Kita ◽  
Shinya Kitayama ◽  
Tsuguo Ishihara ◽  
Hirokazu Izumi ◽  
Yoshitaka Chigi ◽  
...  
Keyword(s):  
Ultra Violet ◽  
High Energy ◽  
Radio Frequency Magnetron Sputtering ◽  
Excitation Process ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
High Energy Electrons ◽  
Rare Earth Nitrides ◽  
Phosphor Film ◽  
Acceleration Voltage

ABSTRACTWe developed ultra-violet field-emission devices using rare-earth nitrides of Al1-xGdxN grown by a reactive radio-frequency magnetron sputtering technique. The Al1-xGdxN phosphor film excited by high-energy electrons shows a resolution limited, narrow intra-orbital luminescence from Gd3+ ions at 318 nm. The devise characteristics depend on injected current and acceleration voltage, which were analyzed by considering multiple excitation process of injected high-energy electrons.

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