scholarly journals Высоковольтные (1600 V) размыкатели тока с субнаносекундным (150 ps) быстродействием на основе 4H-SiC

Author(s):  
П.А. Иванов ◽  
О.И. Коньков ◽  
Т.П. Самсонова ◽  
А.С. Потапов

AbstractHigh-voltage (1600 V) diodes based on epitaxial 4 H -SiC p ^++– p ^+– n _0– n ^+ structures are tested as fast current breakers included in a special pulsed circuit. The measured current-breakdown time is about 150 ps. This is a record short time for high-voltage (above 1000 V) silicon-carbide diode breakers. The saturated hole-drift velocity in 4 H -SiC of p type is experimentally estimated for the first time: v _ sp = 3 × 10^6 cm/s.

RSC Advances ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 3009-3013 ◽  
Author(s):  
Tuan-Khoa Nguyen ◽  
Hoang-Phuong Phan ◽  
Jisheng Han ◽  
Toan Dinh ◽  
Abu Riduan Md Foisal ◽  
...  

This paper presents for the first time a p-type 4H silicon carbide (4H-SiC) van der Pauw strain sensor by utilizing the strain induced effect in four-terminal devices.


2021 ◽  
pp. 67-73
Author(s):  
Vitaliy Zotin ◽  
Alexander Drakin ◽  
Sergei Rybalka ◽  
Andrey Demidov ◽  
Evgeniy Kulchenkov

This paper describes a developed automated research measuring complex that allows one to determine the parameters of currents, voltages and power of silicon carbide Schottky diodes when applied reverse voltage impulses with amplitudes from 400 to 1000 V. The research measuring complex was tested on DDSH411A91 («GRUPPA KREMNY EL») and C3D1P7060Q (Cree/Wolfspeed) silicon carbide Schottky diodes and allows to determine their maximum values of the rate of rise of reverse voltage dV/dt (877 V/ns and 683 V/ns). Also, the maximum values of the current rise rate dI/dt were determined for DDSH411A91 (3.24 A/ns) and C3D1P7060Q (3.72 A/ns) diodes. For the first time it was established that, when a reverse voltage impulse with an amplitude of 1000 V is applied, the maximum values of instantaneous fullpower reach 1419 VA for the DDSH411A91 diode and 1638 VA for the C3D1P7060Q diode.


1995 ◽  
Vol 403 ◽  
Author(s):  
T. S. Hayes ◽  
F. T. Ray ◽  
K. P. Trumble ◽  
E. P. Kvam

AbstractA refined thernodynamic analysis of the reaction between molen Al and SiC is presented. The calculations indicate much higher Si concentrations for saturation with respect to AkC 3 formation than previously reported. Preliminary microstructural studies confirm the formation of interfacial A14C3 for pure Al thin films on SiC reacted at 9000C. The implications of the calculations and experimental observations for the production of ohmic contacts to p-type SiC are discussed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lan N. Truong ◽  
Brayden D. Whitlock

AbstractControlling infections has become one of the biggest problems in the world, whether measured in lives lost or money spent. This is worsening as pathogens continue becoming resistant to therapeutics. Antimicrobial surfaces are one strategy being investigated in an attempt to decrease the spread of infections through the most common route of transmission: surfaces, including hands. Regulators have chosen two hours as the time point at which efficacy should be measured. The objectives of this study were to characterize the new antimicrobial surface compressed sodium chloride (CSC) so that its action may be understood at timepoints more relevant to real-time infection control, under two minutes; to develop a sensitive method to test efficacy at short time points; and to investigate antifungal properties for the first time. E. coli and Candida auris are added to surfaces, and the surfaces are monitored by contact plate, or by washing into collection vats. An improved method of testing antimicrobial efficacy is reported. Antimicrobial CSC achieves at least 99.9% reduction of E. coli in the first two minutes of contact, and at least 99% reduction of C. auris in one minute.


Author(s):  
Daniele Tognetto ◽  
Marco R. Pastore ◽  
Gian Marco Guerin ◽  
Giuliana Decorti ◽  
Martina Franzin ◽  
...  

Abstract Purpose In the era of antibiotic resistance, there is an increased interest in antiseptic solutions that might represent a reliable option for ocular surface disinfection. The objective of this study is to compare for the first time three different antiseptic ophthalmic preparations to assess their in vitro antimicrobial activity. Methods The antiseptic activity of three commercial ophthalmic solutions, IODIM (povidone-iodine 0.6% in hyaluronic acid vehicle—Medivis, Catania, Italy), OZODROP (nanoemulsion with ozonated oil—concentration not specified—FBVision, Ophthalmic Pharmaceuticals, Rome, Italy), and DROPSEPT (chlorhexidine 0.02% and vitamin E 0.5% Tocopherol Polyethylene Glycol 1000 Succinate—TPGS, Sooft Italia, Montegiorgio, Italy), was tested in vitro on six reference strains by time-killing assays. Viable cells were evaluated after 1, 15, 30 min; 2, 6, and 24 h exposure by seeding 100 µl of the suspension (or appropriate dilutions) on LB agar or Sabouraud-dextrose agar. All plates were incubated at 37 °C for 24 h and evaluated by manually counting the colonies. Results IODIM solution showed a very rapid microbicidal activity: the number of viable cells for all the tested strains was under the detection limit (less than 10 CFU/ml) already after 1 min exposure, and this result was maintained at every incubation time. The rapid antimicrobial activity of povidone-iodine was not replicated when testing the other two antiseptics. Conclusions The study reports the great efficacy in reducing bacterial load in a very short time of povidone-iodine 0.6% compared with other antiseptic preparations.


2014 ◽  
Vol 989-994 ◽  
pp. 1273-1277
Author(s):  
Chang Ming Li ◽  
Bao Zhong Han ◽  
Long Zhao ◽  
Chun Peng Yin

Nonlinear insulated materials can uniform electric field distribution in non-uniform electric field. In order to inhibit the electric tree initiation and propagation inside high-voltage cross-linked polyethylene (XLPE) insulated cable, a kind of 220kV high-voltage XLPE insulated cable with new structure is designed by embedding nonlinear shielding layer into XLPE insulation layer of high-voltage cable with traditional structure in this study. Experimental and simulation results indicate that the nonlinear shielding layer can effectively inhibit electrical tree propagation inside the XLPE specimens, and obviously extend the breakdown time caused by electric tree propagation. When the electrical tree propagates into the nonlinear shielding layer sandwiched between insulation layers of cable, the electric field distribution near the tip of electrical tree is obviously improved. These findings prove the feasibility and the effectivity of inhibiting electrical tree propagation inside high-voltage cable by adding nonlinear shielding layer into the insulation layer.


2008 ◽  
Vol 600-603 ◽  
pp. 1187-1190 ◽  
Author(s):  
Q. Jon Zhang ◽  
Charlotte Jonas ◽  
Joseph J. Sumakeris ◽  
Anant K. Agarwal ◽  
John W. Palmour

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).


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