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Dynamic performance of 6.5 kV SiC MOSFET body diodes and anti‑parallel Schottky barrier diodes
Yujie Du,Xinling Tang,Xiaoguang Wei,Shuai Sun,Fei Yang,Zhibin Zhao 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.6
For a silicon carbide (SiC) metal–oxide–semiconductor fi eld-eff ect transistor (MOSFET), both the body diode of the MOSFET and an anti-parallel diode can function as a freewheeling diode that carries reverse current. Selecting a suitable freewheeling method is particularly important to fully exploit the performance of high-voltage SiC MOSFET devices. In this study, based on the 6.5 kV SiC MOSFET and the Schottky barrier diode (SBD) developed by our research group, the dynamic characteristics of the MOSFET body diode, the SBD, and the parallel connection of the two are investigated. In addition, the influence of capacitive current on the dynamic characteristics is analyzed by establishing an equivalent circuit model. Test results show that when compared with the body diode, the SBD has an extremely low reverse recovery current, a lower capacitive current, and better reverse recovery temperature stability. Thus, the SBD is regarded as the most suitable freewheeling diode for the 6.5 kV SiC MOSFET. Finally, a package solution for the 6.5 kV SiC MOSFET and SBD is proposed.
Shuai Ji,Yujie Wang,Shikai Gao,Xian Shao,Wei Cui,Yan Du,Mengzhe Guo,Daoquan Tang 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.80 No.-
Lots of minor constituents in herbal medicines have shown great potential to devolve into leadcompounds, and their extraction is attracting more and more attention in pharmaceutical industry. Thisstudy provided an example that showed efficient and selective extraction of minor bioactive naturalproducts (prenylatedflavonoids with anti-cancer activities) from an herbal medicine (licorice) using pureionic liquids as green solvents. After investigation of a variety of hydrophobic ionic liquids withultrasonic-assisted extraction, we found that [C8MIM]BF4 (1-octyl-3-methylimidazolium tetrafluor-oborate) was the most effective one for extraction offive representative compounds (isoangustone A,glycycoumarin, licoisoflavanone, licoricidin and glabridin), and solvent to solid ratio, extraction time,extraction temperature and soaking time were then optimized through single-factor experiments andresponse surface methodology. As a result, the established method had significantly higher extractionselectivity than conventional organic solvents, which could be attributed to significant physical change oflicorice microstructures after extraction, as well as strong interactions (especially hydrogen bondinteractions) between [C8MIM]BF4 and prenylatedflavonoids by mechanism study. In addition, 78.92% ofthe extracted prenylatedflavonoids could be readily recovered from [C8MIM]BF4 by using reversed-phasesolid phase extraction, and the recyclability of [C8MIM]BF4 was also confirmed.
Haifeng Bian,Guoli Zhang,Qingxi Zhai,Yanyan Du,Yujie Ma,Beibei Yang,Shaochun Tang,Duan Bin,Xiangkang Meng,Hongbin Lu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.122 No.-
Stainless steel (SS) is a promising material for designing bipolar plates (BPs), but their further applicationis limited by serious corrosion problems in the acidic environment. Ti3C2Tx is expected to be used for SSBPs coatings, while galvanic corrosion will occur after the damage of Ti3C2Tx coating. Herein, a PPY/Ti3C2Tx-AE double-layer coating (DC) is well-designed and prepared on 304SS BP, which is composedof an inner electropolymerized PPY layer and an outer Ti3C2Tx-acrylic epoxy layer. When tested in0.2 M HCl solution, the corrosion potential and corrosion current density of the DC are 38 mV and0.00927 lA cm2 respectively, which are superior to those of the PPY coating and the Ti3C2Tx coating. Moreover, the DC presents the best long-term stability among the three coatings. The excellent corrosionresistance is attributed to the barrier and anodic protection effects as well as the solution of galvanic corrosion. The new coating system provides a new insight into the design of DC coatings of SS BPs.