Effect of Electric Field and Current Injection on the Main Electron Trap in Bulk GaAs

1980 ◽  
Vol 2 ◽  
Author(s):  
S. Makram–Ebeid
Keyword(s):  
Impact Ionization ◽  
Electron Trap ◽  
Hot Electron ◽  
Tunneling Model ◽  
Bulk Gaas ◽  
Low Field ◽  
Assisted Tunneling ◽  
High Fields ◽  
Franck Condon ◽  
Good Agreement

ABSTRACTThe dark capacitive transients related to the main electron trap in bulk and VPE GaAs have been studied in detail. The low temperature low field transients are induced by electrons injected from the metal counter electrode. Both hot electron capture and impact ionization effects are observed. At high fields, a phonon assisted tunneling model accounts for the observations and yields the values of the Franck Condon Shift Sw and the energy w of the phonon coupled to the level. These values are found to be in good agreement with other independent estimates.

Modelling of Drift Mobility Experiments on a-Si:H

1999 ◽  
Vol 557 ◽  
Author(s):  
Wen Chao Chen ◽  
Louis-André Hamel ◽  
Mathieu Kemp ◽  
Arthur Yelon
Keyword(s):  
Monte Carlo ◽  
Simple Model ◽  
Reasonable Agreement ◽  
Drift Mobility ◽  
Low Field ◽  
Comparison With Experiment ◽  
Multiple Trapping ◽  
Apparent Inconsistency ◽  
High Fields ◽  
Good Agreement

AbstractWe present recent results of a study of the behavior of electronic carriers in a-Si:H, using the model of multiple trapping (MT) in an exponential density of states. In previous publications, using Monte Carlo simulations, we showed that the standard low field MT model gives reasonable agreement with experiment particularly if the Meyer-Neldel effect is included in the model. We report here on the results of including two other effects. First, we have included a simple model of field assisted detrapping, to take account of the effect of high fields. We obtain very good agreement with the results of measurements on both electrons and holes, from a number of laboratories. In addition, we show here that the validity of an effective temperature approach can be checked easily by comparison with experiment. Second, we have presented a simple model of rapid relaxation of trapped carriers. This model offers the possibility of removing the apparent inconsistency between these measurements, and other experiments.

Temperature Dependence of Hole Impact Ionization Coefficient in 4H-SiC Photodiodes

2009 ◽  
Vol 615-617 ◽  
pp. 311-314 ◽  
Author(s):  
W.S. Loh ◽  
J.P.R. David ◽  
B.K. Ng ◽  
Stanislav I. Soloviev ◽  
Peter M. Sandvik ◽  
...  
Keyword(s):  
Phonon Scattering ◽  
Impact Ionization ◽  
Positive Temperature Coefficient ◽  
Positive Temperature ◽  
Different Temperatures ◽  
Ionization Coefficients ◽  
Increasing Temperature ◽  
The Impact ◽  
Good Agreement ◽  
Ionization Rates

Hole initiated multiplication characteristics of 4H-SiC Separate Absorption and Multiplication Avalanche Photodiodes (SAM-APDs) with a n- multiplication layer of 2.7 µm were obtained using 325nm excitation at temperatures ranging from 300 to 450K. The breakdown voltages increased by 200mV/K over the investigated temperature range, which indicates a positive temperature coefficient. Local ionization coefficients, including the extracted temperature dependencies, were derived in the form of the Chynoweth expression and were used to predict the hole multiplication characteristics at different temperatures. Good agreement was obtained between the measured and the modeled multiplication using these ionization coefficients. The impact ionization coefficients decreased with increasing temperature, corresponding to an increase in breakdown voltage. This result agrees well with the multiplication characteristics and can be attributed to phonon scattering enhanced carrier cooling which has suppressed the ionization process at high temperatures. Hence, a much higher electric field is required to achieve the same ionization rates.

Disorientation of Cs(62P1/2) atoms, induced in collisions with noble gases

1976 ◽  
Vol 54 (7) ◽  
pp. 748-752 ◽  
Author(s):  
B. Niewitecka ◽  
L. Krause
Keyword(s):  
Cross Sections ◽  
Noble Gas ◽  
Zero Magnetic Field ◽  
Zero Field ◽  
Buffer Gas ◽  
Resonance Fluorescence ◽  
Circularly Polarized ◽  
Low Field ◽  
Good Agreement ◽  
Gas Pressures

The disorientation of 62P1/2 cesium atoms, induced in collisions with noble gas atoms in their ground states, was systematically investigated by monitoring the depolarization of cesium resonance fluorescence in relation to noble gas pressures. The Cs atoms, contained together with a buffer gas in a fluorescence cell and located in zero magnetic field, were excited and oriented by irradiation with circularly polarized 8943 Å resonance radiation, and the resonance fluorescence, emitted in an approximately backward direction, was analyzed with respect to circular polarization. The experiments yielded the following disorientation cross sections which have been corrected for the effects of nuclear spin: Cs–He: 4.9 ± 0.7 Å2; Cs–Ne: 2.1 ± 0.3 Å2; Cs–Ar: 5.6 ± 0.8 Å2; Cs–Kr: 5.8 ± 0.9 Å2; Cs–Xe: 6.3 ± 0.9 Å2. The results are in good agreement with most of the available zero-field and low-field data.

scholarly journals The Electron Impact Ionization Cross Sections of Methanol, Ethanol and 1-Propanol

Atoms ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 60 ◽  
Author(s):  
Yogesh Kumar ◽  
Manoj Kumar ◽  
Sachin Kumar ◽  
Rajeev Kumar
Keyword(s):  
Electron Impact ◽  
Cross Sections ◽  
Impact Ionization ◽  
Experimental Results ◽  
Oscillator Strengths ◽  
Ionization Cross ◽  
Total Ionization ◽  
Plane Wave Born Approximation ◽  
Ionization Cross Sections ◽  
Good Agreement

In the present investigation, the plane-wave Born approximation was employed to calculate the total ionization cross sections by electron impact of methanol, ethanol and 1-propanol from the threshold of ionization to 10 MeV. This method requires continuum generalized oscillator strengths (CGOSs). The two different semi-phenomenological expressions of CGOS, given by Mayol and Salvat and Weizsacker and Williams, along with approximated form of the continuum optical oscillator strength (COOS) by Khare et al. were used. Furthermore, the average of the above two CGOSs was also used. The calculated ionization cross sections were compared to the available previous theoretical results and experimental data. Out of three CGOSs, the present results with the average CGOS were found in good agreement with the available experimental results for all the considered molecules. Collision parameters CRP were also calculated from 0.1 to 100 MeV and the calculations were found to be in excellent agreement with the experimental results of Reike and Prepejchal.

Photoexcited hot electron relaxation processes in n-HgCdTe through impact ionization into traps

1991 ◽  
Author(s):  
D. G. Seiler ◽  
J. R. Lowney ◽  
C. L. Littler ◽  
I. T. Yoon ◽  
M. R. Loloee
Keyword(s):  
Impact Ionization ◽  
Relaxation Processes ◽  
Hot Electron ◽  
Electron Relaxation

Impact Ionization, Degradation, and Breakdown in SiO2

1992 ◽  
Vol 284 ◽  
Author(s):  
D. J. Dimaria ◽  
E. Cartier ◽  
D. Arnold
Keyword(s):  
Silicon Dioxide ◽  
Temperature Dependence ◽  
Impact Ionization ◽  
Charge Trapping ◽  
Oxide Thickness ◽  
Bandgap Energy ◽  
Strongly Correlated ◽  
Hot Electron ◽  
Defect Production ◽  
Oxide Degradation

ABSTRACTDestructive breakdown in silicon dioxide is shown to be strongly correlated to the oxide degradation caused by hot-electron-induced defect production and charge trapping ner the interfaces of the films. Two well defined transitions in the chargc-to-breakdown data as a function of field and oxide thickness are shown to coincide with the onset of mechanisms due to trap creation and impact ionization by electrons with energies exceeding 2 and 9 eV (the SiO2 bandgap energy), respectively. The temperature dependence of charge-to-breakdown is also shown to be consistent with that of these two defect-producing mechanisms.

A Discussion on photoelectron spectroscopy - Franck-Condon factors and autoionization in the photoelectron spectra of diatomic molecules

1970 ◽  
Vol 268 (1184) ◽  
pp. 159-162 ◽  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Photoionization Cross Section ◽  
Resonance Wavelength ◽  
Exciting Radiation ◽  
Vibrational Structure ◽  
Photoelectron Spectra ◽  
Condon Factors ◽  
Franck Condon ◽  
Characteristic Manner ◽  
Good Agreement

Distributions of calculated Franck-Condon factors for autoionizing transitions are used to illustrate the way in which the vibrational structure of the photoelectron spectrum may be extended in a characteristic manner when the wavelength of the exciting radiation coincides with a resonance in the photoionization cross section of a diatomic gas. The calculations are found to be in good agreement with resonance wavelength photoelectron spectra from O2.

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