Interaction Between EL5 and EL6 in Bulk GaAs

1995 ◽  
Vol 378 ◽  
Author(s):  
Hiroyuki Shiraki ◽  
Yutaka Tokuda ◽  
Koichi Sassa
Keyword(s):  
Pulse Duration ◽  
Carrier Density ◽  
Initial Value ◽  
Bulk Gaas ◽  
Single Level ◽  
Wide Range ◽  
Capacitance Voltage ◽  
Voltage Transient ◽  
Transient Spectroscopy ◽  
Electron Occupation

AbstractThe interaction between EL5 and EL6 in the n-type bulk GaAs have been observed by using isothermal constant-capacitance voltage transient spectroscopy (CCVTS). Each CCVTS spectrum of EL5 and EL6 was broader than a theoretical one expected for a single level, and was found to be consistently interpreted by two main trap components. With the increase of the filling pulse duration in a wide range, one component of EL6 decreased to about 50 % of its initial value, while one component of EL5 increased and saturated. This variation in peak heights could be reversed by controlling electron occupation fractions of EL5 and EL6 by application of two adjacent filling pulses. Such interaction between both levels was commonly observed in n-type bulk GaAs independent of carrier density.

Relationship between Constant Voltage and Constant Capacitance DLTS

1983 ◽  
Vol 20 (2) ◽  
pp. 145-149
Author(s):  
W. S. Lau ◽  
Y. W. Lam ◽  
C. C. Chang
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Constant Voltage ◽  
Unified Approach ◽  
Deep Traps ◽  
Capacitance Voltage ◽  
Voltage Transient ◽  
Transient Spectroscopy ◽  
Capacitance Transient ◽  
The Relationship

A unified approach is presented in the derivation of equations for the constant-voltage capacitance transient and constant-capacitance voltage transient in deep-level transient spectroscopy (DLTS), and for the relationship between them. The validity of these equations is independent of the device and nature of deep traps.

scholarly journals Universal mobility characteristics of graphene originating from charge scattering by ionised impurities

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jonathan H. Gosling ◽  
Oleg Makarovsky ◽  
Feiran Wang ◽  
Nathan D. Cottam ◽  
Mark T. Greenaway ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carrier Density ◽  
Carrier Mobility ◽  
Carrier Transport ◽  
Analytical Models ◽  
Pristine Graphene ◽  
High Electron ◽  
Boltzmann Transport ◽  
Transport Parameters ◽  
Wide Range

AbstractPristine graphene and graphene-based heterostructures can exhibit exceptionally high electron mobility if their surface contains few electron-scattering impurities. Mobility directly influences electrical conductivity and its dependence on the carrier density. But linking these key transport parameters remains a challenging task for both theorists and experimentalists. Here, we report numerical and analytical models of carrier transport in graphene, which reveal a universal connection between graphene’s carrier mobility and the variation of its electrical conductivity with carrier density. Our model of graphene conductivity is based on a convolution of carrier density and its uncertainty, which is verified by numerical solution of the Boltzmann transport equation including the effects of charged impurity scattering and optical phonons on the carrier mobility. This model reproduces, explains, and unifies experimental mobility and conductivity data from a wide range of samples and provides a way to predict a priori all key transport parameters of graphene devices. Our results open a route for controlling the transport properties of graphene by doping and for engineering the properties of 2D materials and heterostructures.

Structural and Magneto-Electric Properties of Pulsed Laser Deposited Ferroelectric/Ferromagnetic Heterostructure

2009 ◽  
Vol 1199 ◽  
Author(s):  
Ricardo Martinez ◽  
Ashok Kumar ◽  
Ratnakar Palai ◽  
Ram S. Katiyar
Keyword(s):  
Elevated Temperatures ◽  
High Strain ◽  
Ferroelectric Properties ◽  
Pulsed Laser ◽  
Ferromagnetic Behavior ◽  
Asymmetric Behavior ◽  
Normal Behavior ◽  
Wide Range ◽  
Capacitance Voltage ◽  
Voltage Relationship

AbstractAsymmetric superlattices (SLs) with ferromagnetic La0.7Sr0.3MnO3 (LSMO) and ferroelectric Ba0.7Sr0.3TiO3 (BST) as constitutive layers were fabricated on conducting LaNiO3 (LNO) coated (001) oriented MgO substrates using pulsed laser deposition (PLD). The crystallinity, ferroelectric and magnetic properties of the SLs were studied over a wide range of temperatures and frequencies. The structure exhibited ferromagnetic behavior at 300K, and ferroelectric behavior over a range of temperatures between 100K and 300K. The dielectric response as a function of frequency obeys normal behavior below 300 K, whereas it follows Maxwell–Wagner model at elevated temperatures. The effect of ferromagnetic LSMO layers on ferroelectric properties of the SL indicated strong influence of the interfaces. The asymmetric behavior of ferroelectric loop and the capacitance-voltage relationship suggest development of a built field in the SLs due to high strain across the interfaces.

Evaluation of Sub-Gap States in Amorphous In-Ga-Zn-O Thin Films Treated with Various Process Conditions

2014 ◽  
Vol 1633 ◽  
pp. 55-60 ◽  
Author(s):  
Kazushi Hayashi ◽  
Aya Hino ◽  
Hiroaki Tao ◽  
Yasuyuki Takanashi ◽  
Shinya Morita ◽  
...  
Keyword(s):  
Thin Films ◽  
Peak Position ◽  
Process Conditions ◽  
Charge Densities ◽  
Capacitance Voltage ◽  
Time Regime ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Gap States ◽  
Capacitance Transient

ABSTRACTIn the present study, the sub-gap states of amorphous In-Ga-Zn-O (a-IGZO) thin films treated with various process conditions have been evaluated by means of capacitance-voltage (C-V) characteristics and isothermal capacitance transient spectroscopy (ICTS). It was found that the space-charge densities of the a-IGZO decreased as the oxygen partial pressure was increased during the sputtering of a-IGZO thin films. The ICTS spectra for the 4, 8, and 12 % samples were similar and the peak positions were found to be around 1 × 10-2 s at 180 K. On the other hand, the peak position for the 20 % sample shifted to a longer time regime and was located at around 2 × 10-1 s at 180 K. The total densities of the traps for the 4, 8, and 12 % samples were calculated to be 5−6 × 1016 cm-3, while that for 20 % was one order of magnitude lower than the others. From Thermal desorption spectrometer, it was found that desorption of Zn atoms started at a temperature higher than 300 °C for the 4 % sample, while desorption of Zn was not observed for the 20 % sample. The introduction of the sub-gap states could be attributed to oxygen-rich and/or Zn-deficient defects in the a-IGZO thin films formed during thermal annealing.

scholarly journals Влияние нейтронного облучения на спектр дефектов с глубокими уровнями в GaAs, изготовленном методом жидкофазной эпитаксии в атмосфере водорода и аргона

2022 ◽  
Vol 56 (1) ◽  
pp. 53
Author(s):  
М.М. Соболев ◽  
Ф.Ю. Солдатенков
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Experimental Studies ◽  
Shallow Donor ◽  
Defect Clusters ◽  
Deep Traps ◽  
Capacitance Voltage ◽  
Before And After ◽  
Transient Spectroscopy ◽  
Different Doses

The results of experimental studies of capacitance– voltage characteristics, spectra of deep-level transient spectroscopy of graded high-voltage GaAs p+−p0−i−n0 diodes fabricated by liquid-phase epitaxy at a crystallization temperature of 900C from one solution–melt due to autodoping with background impurities, in a hydrogen or argon ambient, before and after irradiation with neutrons. After neutron irradiation, deep-level transient spectroscopy spectra revealed wide zones of defect clusters with acceptor-like negatively charged traps in the n0-layer, which arise as a result of electron emission from states located above the middle of the band gap. It was found that the differences in capacitance–voltage characteristics of the structures grown in hydrogen or argon ambient after irradiation are due to different doses of irradiation of GaAs p+−p0−i−n0 structures and different degrees of compensation of shallow donor impurities by deep traps in the layers.

Capacitance-voltage and deep-level-transient spectroscopy characterization of defects near SiO2/SiC interfaces

2011 ◽  
Vol 109 (6) ◽  
pp. 064514 ◽  
Author(s):  
A. F. Basile ◽  
J. Rozen ◽  
J. R. Williams ◽  
L. C. Feldman ◽  
P. M. Mooney
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Capacitance Voltage ◽  
Transient Spectroscopy

Optical and Electrical Properties of TiO2 Nanotubes Grown by Titanium Anodization

2009 ◽  
Vol 1178 ◽  
Author(s):  
Yahya Alivov ◽  
Vladimir Kuryatkov ◽  
Mahesh Pandikunta ◽  
Gautam Rajanna ◽  
Daniel Johnstone ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electrical Properties ◽  
Tio2 Nanotubes ◽  
Anatase Phase ◽  
Rutile Phase ◽  
Electrochemical Anodization ◽  
Voltage Range ◽  
Wide Range ◽  
Transient Spectroscopy ◽  
Tio2 Nts

AbstractIn this work we investigated the structural, electrical, and optical properties of titanium dioxide (TiO2) nanotubes (NTs) formed by electrochemical anodization of Ti metal sheets in NH4F+glycerol electrolyte at different anodization voltages (Va) and acid concentrations. Our results revealed that TiO2 NTs can be grown in a wide range of anodization voltages from 10 V to 240 V. The maximum NH4F acid concentration, at which NTs can be formed, decreases with the anodization voltage, which is 0.7% for Va<60V, and decreases to 0.1% at Va =240 V. Glancing angle X-ray diffraction (GAXRD) experiments show that as-grown amorphous TiO2 transforms to anatase phase after annealing at 400 oC, and further transforms to rutile phase at annealing temperatures above 500 oC. Samples grown in 30-120 voltage range have higher crystal quality as seen from anatase (101) peak intensity and reduced linewidth. The electrical resistivity of the NTs varies with Va concentration and increases by eight orders of magnitude when Va increases from 10 V to 240 V. This is consistent with cathodoluminescense studies which showed improved optical properties for samples grown in this voltage range. Optical properties of samples were also studied by low temperature photoluminescence. Temperature dependent I-V and photo-induced current transient spectroscopy were employed to analyze electrical properties and defect structure on NT samples.

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