Low-voltage Avalanche Breakdown in AlGaN Multi-quantum Wells

2006 ◽  
Vol 955 ◽  
Author(s):  
Shengkun Zhang ◽  
X. Zhou ◽  
Wubao Wang ◽  
R. R. Alfano ◽  
A. M. Dabiran ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Electric Fields ◽  
Impact Ionization ◽  
Low Voltage ◽  
Defect Density ◽  
Control Sample ◽  
Avalanche Breakdown ◽  
Ionization Coefficient ◽  
The Impact ◽  
Injection Modes

ABSTRACTIn this work, electro-luminescence (EL) of a AlGaN p-i-n diode have been investigated in both avalanche and injection modes. The active i-region of the diode consists of Al0.1Ga0.9N/Al0.15Ga0.85N MQWs. Strong interband luminescence from the Al0.1Ga0.9N active layers was observed when operating the device in both avalanche and injection modes. The threshold voltage for avalanche breakdown is as low as 9 V. This indicates that the impact ionization coefficient of electrons is greatly enhanced in these Al0.1Ga0.9N/Al0.15Ga0.85N MQWs comparing to AlGaN bulk materials. Polarization-induced electric fields in the Al0.1Ga0.9N well layers are believed to be responsible for the enhancement of the ionization coefficient. In a control sample that has higher defect density, the electroluminescence was dominated by long-wavelength emissions, which results from impact ionizations of the defect levels.

Comprehensive Study of Impact Ionization Coefficients of 4H-SiC

2004 ◽  
Vol 815 ◽  
Author(s):  
T. Hatakeyama ◽  
T. Watanabe ◽  
K. Kojima ◽  
N. Sano ◽  
T. Shinohe ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Impact Ionization ◽  
Avalanche Breakdown ◽  
Doping Density ◽  
Electric Field Dependence ◽  
Saturation Velocity ◽  
Large Anisotropy ◽  
Ionization Coefficients ◽  
The Impact ◽  
Comprehensive Study

AbstractThe electric field dependence and anisotropy of the impact ionization coefficients of 4H-SiC are investigated by means of the avalanche breakdown behavior of p+n diodes. The breakdown voltages as a function of doping density and the multiplication factors of a leakage current are obtained using p+n diode fabricated on (0001) and (1120) 4H-SiC epitaxial wafers. The obtained impact ionization coefficients show large anisotropy; the breakdown voltage of a p+n diode on (1120) wafer is 60% of that on (0001) wafer. We have shown that anisotropy of the impact ionization coefficients is attributable to the anisotropy of saturation velocity originated from the electronic structure of 4H-SiC.

scholarly journals The Barkhausen Method to Investigate Powerful Processes during Action of Piezoelectric Igniters

2020 ◽  
Vol 26 (3) ◽  
pp. 358-362
Author(s):  
Linas ARDARAVIČIUS ◽  
Skirmantas KERŠULIS ◽  
Oleg KIPRIJANOVIČ ◽  
Česlovas ŠIMKEVIČIUS ◽  
Steponas AŠMONTAS
Keyword(s):  
Electric Fields ◽  
High Voltage ◽  
Impact Ionization ◽  
Domain Switching ◽  
Practical Importance ◽  
Total Duration ◽  
High Amplitude ◽  
High Voltage Pulse ◽  
Pulse Generation ◽  
The Impact

The Barkhausen method is proposed to clarify the cause of radiation of electromagnetic (EM) pulses during high voltage pulse generation by piezoelectric igniters (PIs). Wide bandwidth of the experimental setup was narrowed for a simultaneous registration of electric and detected EM pulses by a two-channel oscilloscope. The PI was loaded on a high ohmic resistance and high voltage pulses of 8 – 17 kV amplitude and up to 150 ms in total duration were registered. These pulses contained a series of short pulses called Barkhausen type pulses. Duration of these pulses having the relatively high amplitude was 30 – 40 ns. The registration revealed that the radiating EM pulse series corresponded to Barkhausen type pulse series. Short non-radiating negative pulses appearing during the saturated voltage growth were also observed and they had relaxation tails. The analysis showed that the EM pulses are caused as a result of domain switching with high voltage spikes at the PZT cylinders bases, where high electric fields are created. The activity of these switchings weakens when the “age” of PIs increases. The non-radiated pulses resulted from fast internal screening processes in the volume of the cylinders, accompanied by the impact ionization. The increase of the saturation and PI’s “age” causes lengthening of the relaxation tails. The results of practical importance for PIs in monitoring systems are placed. It is concluded that the Barkhausen method in wideband configuration is a convenient experimental arrangement for investigation of powerful processes in ferro-piezoelectric ceramics.

Modeling of a Breakdown Voltage in GaN Rectifiers and SiC Rectifiers

2001 ◽  
Vol 680 ◽  
Author(s):  
You-Sang Lee ◽  
Min-Koo Han ◽  
Yearn-Ik Choi
Keyword(s):  
Breakdown Voltage ◽  
Epitaxial Layer ◽  
Doping Concentration ◽  
Impact Ionization ◽  
Accurate Approximation ◽  
Ionization Coefficient ◽  
Zinc Blende ◽  
The Impact

ABSTRACTThe breakdown voltage of wurtzite and zinc-blende GaN rectifiers as function of a doping concentration and the width of epitaxial layer were successfully modeled in the reach-through case. The breakdown voltage was derived by the impact ionization integral employing the effective impact ionization coefficient and an accurate approximation. Our model shows that the breakdown voltage of wurtzite GaN rectifier was larger than those of zinc-blende GaN rectifier and SiC rectifiers including 4H-SiC and 6H-SiC in the condition that both the thickness and doping concentration of epitaxial layer are identical.

The Closed-Form Solutions For The Breakdown Voltages Of 6H-SiC Reachthrough Diodes

1998 ◽  
Vol 512 ◽  
Author(s):  
You-Sang Lee ◽  
D.-S. Byeon ◽  
Y.-I. Choi ◽  
I.-Y. Park ◽  
Min-Koo Han
Keyword(s):  
Closed Form ◽  
Breakdown Voltage ◽  
Epitaxial Layer ◽  
Doping Concentration ◽  
Impact Ionization ◽  
Analytic Solutions ◽  
Ionization Coefficient ◽  
Closed Form Solutions ◽  
The Impact ◽  
Effective Ionization

ABSTRACTThe closed-form analytic solutions for the breakdown voltage of 6H-SiC RTD, reachthrough diode, having the structure of p+-n-n+, are successfully derived by solving the impact ionization integral using effective ionization coefficient in the reachthrough condition. In the region of the lowly doped epitaxial layer, the breakdown voltages of 6H-SiC RTD nearly constant with the increased doping concentration. Also the breakdown voltages of 6H-SiC RTD decrease, in the region of the highly doped epitaxial layer, which coincides with Baliga'seq. [1].

Avalanche Breakdown Due to 3-D Effects in the Impact-Ionization MOS (I-MOS) on SOI: Reliability Issues

2008 ◽  
Vol 55 (6) ◽  
pp. 1373-1378 ◽  
Author(s):  
FrÉdÉric Mayer ◽  
Cyrille Le Royer ◽  
Denis Blachier ◽  
Laurent Clavelier ◽  
Simon Deleonibus
Keyword(s):  
Impact Ionization ◽  
Avalanche Breakdown ◽  
The Impact

Spectroscopy of Impurities and Complex Defects in Silicon in Zlectric and Microwave Fields

1987 ◽  
Vol 104 ◽  
Author(s):  
M. Godlewski ◽  
H. Weman ◽  
F. P. Wang ◽  
B. Monemar ◽  
W. M. Chen ◽  
...  
Keyword(s):  
Electric Fields ◽  
Cyclotron Resonance ◽  
Impact Ionization ◽  
Simultaneous Recording ◽  
Pulsed Dc ◽  
Dc Excitation ◽  
Pl Intensity ◽  
Optically Detected ◽  
High Frequency Ac ◽  
The Impact

ABSTRACTWe report a detailed study of the photoluminescence (PL) intensity of bound excitons (BE:s) in silicon, related to shallow impurities and deep complex defects, as a function of DC and high frequency AC (9GHz) electric fields. Two experimental approaches are presented. The first involves a simultaneous recording of PL and photocurrent under pulsed DC excitation. The second utilizes the optically detected cyclotron resonance (ODCR) technique, which allows detection of cyclotron resonance (CR) via the resonancetransition- induced changes of BE PL intensity. The mechanism responsible for the PL changes is shown to be the impact ionization of BE:s by hot free carriers. Effects of sample inhomogeneities in these experiments are also discussed.

Mechanisms of exciton photoluminescence quenching in the electric field of a standing surface acoustic wave

2019 ◽  
Vol 33 (06) ◽  
pp. 1950032
Author(s):  
D. V. Gulyaev ◽  
K. S. Zhuravlev
Keyword(s):  
Acoustic Wave ◽  
Electric Field ◽  
Quantum Wells ◽  
Surface Acoustic Wave ◽  
Impact Ionization ◽  
Interface Roughness ◽  
Nonradiative Recombination ◽  
Recombination Centers ◽  
Subsequent Capture ◽  
The Impact

Mechanisms of exciton photoluminescence (PL) quenching in the longitudinal electric field of a standing surface acoustic wave (SAW) have been studied by the example of type II GaAs/AlAs superlattices (SLs). Such SLs with a long lifetime of nonequilibrium carriers have allowed examining the influence of the SAW electric field on the excitonic PL both under the continuous and impulse laser excitations. It has been found that the mechanisms of the interaction of excitons and a SAW electric field depend upon the kinetic energy of excitons and carriers. As for hot excitons and carriers, the standing SAW electric field causes the impact ionization of excitons with a subsequent capture of free carriers at the nonradiative recombination centers, which results in a decrease in the steady-state exciton PL. As for cold excitons and carriers, the impact of excitons with the carriers accelerated by the SAW electric field results mainly in exciton delocalization from the levels of quantum wells formed due to interface roughness with a subsequent capture of excitons at the nonradiative recombination centers, which leads to the acceleration of the PL kinetics.

DARK CURRENTS AND IMPACT IONIZATION COEFFICIENTS IN THE InP-InGaAsP DOUBLE HETEROSTRUCTURES

2006 ◽  
Vol 20 (29) ◽  
pp. 4929-4936
Author(s):  
M. OZER ◽  
M. AHMETOGLU ◽  
N. APRAILOV
Keyword(s):  
Electric Fields ◽  
Impact Ionization ◽  
Reverse Current ◽  
Tunneling Current ◽  
Double Heterostructures ◽  
Wide Range ◽  
Direct Energy ◽  
Ionization Coefficients ◽  
Dark Currents ◽  
The Impact

The dependence of reverse-biased leakage current on both voltage and temperature for InP - In x Ga 1-x As y P 1-y DH (double heterostructures) has been analyzed. We find that at the whole of the temperature range and at a wide range of reverse bias voltages, the reverse current varies exponentially with applied voltage, indicating that the band-to-band tunneling current mechanism prevails. An agreement is obtained between theory and experimental results. The tunneling current becomes substantial at peak junction electric fields as low as 105 V/m due to the small direct energy gaps and small effective masses of the structures tested. The process of breakdown in the investigated structures was of the avalanche type. The impact ionization coefficients in In x Ga 1-x As y P 1-y have been experimentally determined for composition x=0.68.

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