scholarly journals Prospects of 4H-SiC Double Drift Region IMPATT Device as a Photo-Sensitive High-Power Source at 0.7 Terahertz Frequency Regime

2008 ◽  
Vol 2008 ◽  
pp. 1-9 ◽  
Author(s):  
Moumita Mukherjee ◽  
Nilratan Mazumder ◽  
Sitesh Kumar Roy
Keyword(s):  
High Power ◽  
Dynamic Performance ◽  
Negative Resistance ◽  
Wide Bandgap ◽  
Drift Region ◽  
Terahertz Frequency ◽  
Impatt Diode ◽  
Terahertz Region ◽  
Frequency Regime ◽  
First Time

The dynamic performance of wide-bandgap 4H-SiC based double drift region (p++ p n n++) IMPATT diode is simulated for the first time at terahertz frequency (0.7 Terahertz) region. The simulation experiment establishes the potential of SiC based IMPATT diode as a high power (2.5×1011 Wm−2) terahertz source. The parasitic series resistance in the device is found to reduce the RF power output by 10.7%. The effects of external radiation on the simulated diode are also studied. It is found that (i) the negative conductance and (ii) the negative resistance of the diode decrease, while, the frequency of operation and the quality factor shift upward under photoillumination. Holes in 4H-SiC based IMPATT are found to dominate the modulation activities. The inequality in the magnitude of electron and hole ionization rates in the semiconductors may be correlated with these findings.

scholarly journals Study of p-SiC/n-GaN Hetero-Structural Double-Drift Region IMPATT Diode

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 919
Author(s):  
Yang Dai ◽  
Qingsong Ye ◽  
Jiangtao Dang ◽  
Zhaoyang Lu ◽  
Weiwei Zhang ◽  
...  
Keyword(s):  
Impact Ionization ◽  
Wide Bandgap ◽  
Drift Region ◽  
Rf Power ◽  
Large Signal ◽  
Impatt Diode ◽  
Signal Characteristics ◽  
Design And Manufacture ◽  
First Time ◽  
Ddr Impatt

Nowadays, the immature p-GaN processes cannot meet the manufacturing requirements of GaN impact ionization avalanche transit time (IMPATT) diodes. Against this backdrop, the performance of wide-bandgap p-SiC/n-GaN heterojunction double-drift region (DDR) IMPATT diode is investigated in this paper for the first time. The direct-current (DC) steady-state, small-signal and large-signal characteristics are numerically simulated. The results show that compared with the conventional GaN single-drift region (SDR) IMPATT diode, the performance of the p-SiC/n-GaN DDR IMPATT proposed in this design, such as breakdown voltage, negative conductance, voltage modulation factor, radio frequency (RF) power and DC-RF conversion efficiency have been significantly improved. At the same time, the structure proposed in this design has a larger frequency bandwidth. Due to its greater potential in the RF power density, which is 1.97 MW/cm2 in this study, indicates that the p-SiC/n-GaN heterojunction provides new possibilities for the design and manufacture of IMPATT diode.

scholarly journals Study on Electric Field Modulation and Avalanche Enhancement of SiC/GaN IMPATT Diode

Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2180
Author(s):  
Yang Dai ◽  
Jiangtao Dang ◽  
Qingsong Ye ◽  
Zhaoyang Lu ◽  
Shi Pu ◽  
...  
Keyword(s):  
Electric Field ◽  
Impact Ionization ◽  
Wide Bandgap ◽  
Electron Velocity ◽  
Drift Region ◽  
Rf Power ◽  
Impatt Diode ◽  
Field Modulation ◽  
P Type ◽  
Lower Electric Field

This paper proposes a 6H-materials silicon carbide (SiC)/gallium nitride (GaN) heterogeneous p-n structure to replace the GaN homogenous p-n junction to manufacture an impact-ionization-avalanche-transit-time (IMPATT) diode, and the performance of this 6H-SiC/GaN heterojunction single-drift-region (SDR) IMPATT diode is simulated at frequencies above 100 GHz. The performance parameters of the studied device were simulated and compared with the conventional GaN p-n IMPATT diode. The results show that the p-SiC/n-GaN IMPATT performance is significantly improved, and this is reflected in the enhanced characteristics in terms of operating frequency, rf power, and dc-rf conversion efficiency by the two mechanisms. One such characteristic that the new structure has an excessive avalanche injection of electrons in the p-type SiC region owing to the ionization characteristics of the SiC material, while another is a lower electric field distribution in the drift region, which can induce a higher electron velocity and larger current in the structure. The work provides a reference to obtain a deeper understanding of the mechanism and design of IMPATT devices based on wide-bandgap semiconductor materials.

scholarly journals Interleaved, Switched Inductor and High-Gain Wide Bandgap Based Boost Converter Proposal

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 800
Author(s):  
David Marroqui ◽  
Ausias Garrigós ◽  
Cristian Torres ◽  
Carlos Orts ◽  
Jose M. Blanes ◽  
...  
Keyword(s):  
Power Density ◽  
High Power ◽  
Low Voltage ◽  
High Gain ◽  
Wide Bandgap ◽  
High Power Density ◽  
Boost Converters ◽  
Proposal A ◽  
Current Ripples ◽  
Current Ripple

Many applications (electric vehicles, renewable energies, low-voltage DC grids) require simple, high-power density and low-current ripple-boost converters. Traditional step-up converters are limited when large transformation ratios are involved. In this work is proposed a step-up converter that brings together the characteristics of high gain, low ripple, and high-power density. From the converter proposal, a mathematical analysis of its operation is first performed, including its static transfer function, stress of components, and voltage and current ripples. Furthermore, it provides a design example for an application of Vin = 48 V to Vo = 270 V and 500 W. For its implementation, two different wide bandgap (WBG) semiconductor models have been used, hybrid GaN cascodes and SiC MOSFETs. Finally, the experimental results of the produced prototypes are shown, and the results are discussed.

12 kV 4H-SiC p-IGBTs with Record Low Specific On-Resistance

2008 ◽  
Vol 600-603 ◽  
pp. 1187-1190 ◽  
Author(s):  
Q. Jon Zhang ◽  
Charlotte Jonas ◽  
Joseph J. Sumakeris ◽  
Anant K. Agarwal ◽  
John W. Palmour
Keyword(s):  
Carrier Lifetime ◽  
Drift Region ◽  
Gate Bias ◽  
Enhancement Layer ◽  
Channel Mobility ◽  
Dc Characteristics ◽  
Blocking Voltage ◽  
High Carrier ◽  
P Type ◽  
First Time

DC characteristics of 4H-SiC p-channel IGBTs capable of blocking -12 kV and conducting -0.4 A (-100 A/cm2) at a forward voltage of -5.2 V at 25°C are demonstrated for the first time. A record low differential on-resistance of 14 mW×cm2 was achieved with a gate bias of -20 V indicating a strong conductivity modulation in the p-type drift region. A moderately doped current enhancement layer grown on the lightly doped drift layer effectively reduces the JFET resistance while maintains a high carrier lifetime for conductivity modulation. A hole MOS channel mobility of 12.5 cm2/V-s at -20 V of gate bias was measured with a MOS threshold voltage of -5.8 V. The blocking voltage of -12 kV was achieved by Junction Termination Extension (JTE).

Fleeing the Soviet Union, Dancing on the West Coast

Experiment ◽  
2014 ◽  
Vol 20 (1) ◽  
pp. 297-316
Author(s):  
Lorin Johnson ◽  
Donald Bradburn
Keyword(s):  
Soviet Union ◽  
Los Angeles ◽  
High Power ◽  
West Coast ◽  
Southern California ◽  
The West ◽  
The Arts ◽  
The Soviet Union ◽  
First Time

In the 1970s and 1980s, Los Angeles audiences saw Soviet defectors Mikhail Baryshnikov, Alexander Godunov, Natalia Makarova, and Rudolf Nureyev in the prime of their careers at the Hollywood Bowl, The Dorothy Chandler Pavilion and the Greek Theater. Dance photographer Donald Dale Bradburn, a local Southern California dancer describes his behind-the-scenes access to these dancers in this interview. Perfectly positioned as Dance Magazine’s Southern California correspondent, Bradburn offers a candid appraisal of the Southern California appeal for such high-power Russian artists as well as their impact on the arts of Los Angeles. An intimate view of Russian dancers practicing their craft on Los Angeles stages, Bradburn’s interview is illustrated by fourteen of his photographs, published for the first time in this issue of Experiment.

Epitaxial growth of β-Ga2O3 (-201) thin film on fourfold symmetry CeO2 (001) substrate for heterogeneous integrations

2021 ◽  
Author(s):  
Xiao Tang ◽  
Kuanghui Li ◽  
Che-Hao Liao ◽  
Dongxing Zheng ◽  
chen Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Epitaxial Growth ◽  
Gas Sensors ◽  
High Power ◽  
Wide Bandgap ◽  
Semiconductor Material ◽  
Uv Detectors ◽  
Wide Bandgap Semiconductor ◽  
Fourfold Symmetry

β-Ga2O3 is a wide bandgap semiconductor material promising for many fields such as gas sensors, UV detectors, and high power electronics. Until now, most epitaxial β-Ga2O3 thin films could only...

LD-pumped high-power continuous-wave Pr3+:YLF deep red lasers at 718.5 and 720.8 nm

Laser Physics ◽  
2021 ◽  
Vol 32 (2) ◽  
pp. 025801
Author(s):  
Xiangrui Liu ◽  
Zhuang Li ◽  
Chengkun Shi ◽  
Bo Xiao ◽  
Run Fang ◽  
...  
Keyword(s):  
Output Power ◽  
High Power ◽  
Slope Efficiency ◽  
Laser Emission ◽  
Continuous Wave ◽  
Optical Glass ◽  
Maximum Output Power ◽  
Glass Plate ◽  
Maximum Output ◽  
First Time

Abstract We demonstrated 22 W LD-pumped high-power continuous-wave (CW) deep red laser operations at 718.5 and 720.8 nm based on an a-cut Pr3+:YLF crystal. The output power of both polarized directions reached the watt-level without output power saturation. A single wavelength laser operated at 720.8 nm in the π-polarized direction was achieved, with a high output power of 4.5 W and high slope efficiency of approximately 41.5%. To the best of our knowledge, under LD-pumped conditions, the laser output power and slope efficiency are the highest at 721 nm. By using a compact optical glass plate as an intracavity etalon, we suppressed the π-polarized 720.8 nm laser emission. And σ-polarized single-wavelength laser emission at 718.5 nm was achieved, with a maximum output power of 1.45 W and a slope efficiency of approximately 17.8%. This is the first time that we have achieved the σ-polarized laser emission at 718.5 nm generated by Pr3+:YLF lasers.

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