Sensitive, Nonintrusive,In-SituMeasurement of Temporally and Spatially Resolved Plasma Electric Fields

1984 ◽  
Vol 52 (7) ◽  
pp. 538-541 ◽  
Author(s):  
Cameron A. Moore ◽  
Glenn P. Davis ◽  
Richard A. Gottscho
Keyword(s):  
Electric Fields ◽  
Spatially Resolved

Ultralow-Energy Excitations and Prospects for Spatially Resolved Spectroscopy

2004 ◽  
Vol 10 (1) ◽  
pp. 28-33 ◽  
Author(s):  
A. Howie
Keyword(s):  
Electric Fields ◽  
Electron Beams ◽  
Condensed Matter ◽  
Intermediate Energy ◽  
X Ray ◽  
Ultralow Energy ◽  
Spatially Resolved ◽  
Direct Excitation ◽  
Spatially Resolved Spectroscopy ◽  
Electron Energy Loss

The key contribution of electron microscopy methods to condensed matter spectroscopy is undoubtedly spatial resolution. So far this has mainly been manifest through electron energy loss spectroscopy in the 1-eV to 10-keV energy range and has not seriously challenged the dominance of optical, X-ray, and neutron spectroscopy methods over most of the vast field at lower energies. At frequencies up to a few megahertz, corresponding to energies of a few nanoelectron volts and below, direct excitation by pulsed electron beams or electric fields has proved effective. Prospects are discussed for extending spatially resolved spectroscopy to the intermediate energy region, mainly by combining the advantages of electrons with those of photons.

Unravelling charge separation via surface built-in electric fields within single particulate photocatalysts

2017 ◽  
Vol 198 ◽  
pp. 473-479 ◽  
Author(s):  
Ruotian Chen ◽  
Jian Zhu ◽  
Hongyu An ◽  
Fengtao Fan ◽  
Can Li
Keyword(s):  
Electric Fields ◽  
Charge Separation ◽  
Energy Conversion Efficiency ◽  
Single Particles ◽  
Kelvin Probe ◽  
Force Microscopy ◽  
Transfer Processes ◽  
Spatially Resolved ◽  
P Type

Kelvin Probe Force Microscopy (KPFM) and spatially resolved surface photovoltage (SRSPV) techniques were employed to reveal built-in electric fields and surface photogenerated charge distribution on single particulate photocatalysts. The photogenerated holes and electrons spread over the whole surface of the particulate photocatalyst are imaged on n-type BiVO4 and p-type Cu2O single particles, respectively. It is demonstrated that the built-in electric field in the surface Space Charge Region (SCR) dictates the charge separation/transfer processes and allows the drift of one kind of the photogenerated carriers to the surface, while holding another kind of the carriers in the bulk. The results emphasize the role of the SCR played in the unidirectional charge transport between the bulk and surface in the particulate photocatalyst, which may be the crucial reason for low solar energy conversion efficiency.

scholarly journals Spatially Resolved Electroluminescence of InGaN-MQW-LEDs

2000 ◽  
Vol 5 (S1) ◽  
pp. 22-27
Author(s):  
Veit Schwegler ◽  
Matthias Seyboth ◽  
Christoph Kirchner ◽  
Marcus Scherer ◽  
Markus Kamp ◽  
...  
Keyword(s):  
Electric Fields ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Spatially Resolved ◽  
Band Emission ◽  
Substrate Side ◽  
Local Fluctuations ◽  
Current Densities ◽  
Significant Measure ◽  
Spectrally Resolved

Electroluminescence (EL) is the most significant measure for light-emitting diodes since it probes the most relevant properties of the fully processed device during operation. In addition to the information gained by conventional spectrally resolved EL, scanning micro-EL provides spatially resolved information. The devices under investigation are InGaN/GaN-LEDs with single peak band-band emission at about 400 nm grown by MOVPE on sapphire substrates.The µ-EL-characterization is performed as a function of injection current densities and the emission is investigated from the epitaxial layer as well as from substrate side. Spatially resolved wavelength images reveal emission peaks between 406 nm and 417 nm, corresponding either to In fluctuations of 1 %−1.5 % or local fluctuations of piezo electric fields. Beside the information on the emission wavelength fluctuations µ-EL is used to determine the temperature distribution in the LEDs and to investigate transparent contacts.

Spatially Resolved Electroluminescence of InGaN-MQW-LEDs

1999 ◽  
Vol 595 ◽  
Author(s):  
Veit Schwegler ◽  
Matthias Seyboth ◽  
Christoph Kirchner ◽  
Marcus Scherer ◽  
Markus Kamp ◽  
...  
Keyword(s):  
Electric Fields ◽  
Light Emitting ◽  
Sapphire Substrates ◽  
Spatially Resolved ◽  
Band Emission ◽  
Substrate Side ◽  
Local Fluctuations ◽  
Current Densities ◽  
Significant Measure ◽  
Spectrally Resolved

AbstractElectroluminescence (EL) is the most significant measure for light-emitting diodes since it probes the most relevant properties of the fully processed device during operation. In addition to the information gained by conventional spectrally resolved EL, scanning micro-EL provides spatially resolved information. The devices under investigation are InGaN/GaN-LEDs with single peak band-band emission at about 400 nm grown by MOVPE on sapphire substrates.The μ-EL-characterization is performed as a function of injection current densities and the emission is investigated from the epitaxial layer as well as from substrate side. Spatially resolved wavelength images reveal emission peaks between 406 nm and 417 nm, corresponding either to In fluctuations of 1%–1.5% or local fluctuations of piezo electric fields. Beside the information on the emission wavelength fluctuations ν-EL is used to determine the temperature distribution in the LEDs and to investigate transparent contacts.

scholarly journals Polarization Stark spectroscopy for spatially resolved measurements of electric fields in the sheaths of ICRF antenna

2019 ◽  
Vol 90 (12) ◽  
pp. 123101
Author(s):  
A. Kostic ◽  
K. Crombé ◽  
R. Dux ◽  
M. Griener ◽  
R. Ochoukov ◽  
...  
Keyword(s):  
Electric Fields ◽  
Stark Spectroscopy ◽  
Spatially Resolved

scholarly journals Characterization of electron beam propagation through foils by innershell X-ray spectroscopy

2001 ◽  
Vol 19 (1) ◽  
pp. 91-97 ◽  
Author(s):  
G. PRETZLER ◽  
TH. SCHLEGEL ◽  
E. FILL
Keyword(s):  
Electron Beam ◽  
Electric Fields ◽  
Rear Side ◽  
X Rays ◽  
Hot Electron ◽  
X Ray ◽  
Spatially Resolved ◽  
High Intensity Laser ◽  
Electron Propagation

Characteristic X-rays generated by high-intensity laser interaction with solids were investigated and used for determining the resulting hot electron populations. Spectrally as well as spatially resolved data are evaluated for this purpose. The experimental data were compared with Monte Carlo simulations to determine the electron energy distribution and geometric features of the electron beam. These results are in good agreement with PIC simulations. The self-generated low-resistivity channel of the electron beam results in a distinct difference in the generated rear-side X-ray spot when the electron beam propagates in an insulator rather than a metal. Self-generated electric fields prevent electron propagation into the vacuum. This fact is used for demonstrating photopumping of cobalt with copper Kα radiation, an experiment relevant to innershell X-ray laser schemes. The emission of cobalt is compared with that of nickel, which is not photopumped by copper Kα, and is found to be enhanced by a factor of 2.5.

Control of Metal Alloy Oxidation with Electric Fields

1973 ◽  
Vol 31 ◽  
pp. 164-165
Author(s):  
R. R. Dils ◽  
P. S. Follansbee
Keyword(s):  
Electric Fields ◽  
Oxidation Process ◽  
Base Alloy ◽  
Oxide Surface ◽  
Platinum Electrodes ◽  
Insulating Layer ◽  
Iron Base Alloy ◽  
Alloy Oxidation ◽  
Aluminum Oxide Layer ◽  
And Control

Electric fields have been applied across oxides growing on a high temperature alloy and control of the oxidation of the material has been demonstrated. At present, three-fold increases in the oxidation rate have been measured in accelerating fields and the oxidation process has been completely stopped in a retarding field.The experiments have been conducted with an iron-base alloy, Pe 25Cr 5A1 0.1Y, although, in principle, any alloy capable of forming an adherent aluminum oxide layer during oxidation can be used. A specimen is polished and oxidized to produce a thin, uniform insulating layer on one surface. Three platinum electrodes are sputtered on the oxide surface and the specimen is reoxidized.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

Sign in / Sign up

Export Citation Format

Share Document