【国际学者无界讲堂】香港大学张宇昊教授：Multidimensional Power Devices in (Ultra-)Wide-Bandgap Semiconductors

Power electronics technologies provide electrical energy conversion using semiconductor devices and passive components. The global power semiconductor market reaches US$40 billion and is rapidly expanding, driven by applications like electric vehicles, data centers, consumer electronics, electric grids and renewable energy processing. Power device advances are driven by materials and device architectures. In addition to using wide-bandgap (WBG) or ultrawide-bandgap (UWBG) materials, multidimensional architectures – such as superjunction, multi-channel and multi-gate – can also improve device performance. These structures enable electrostatics engineering in additional dimensions and bring the benefits of geometrical scaling into power devices. This talk presents our efforts in developing multidimensional power devices in WBG and UWBG semiconductors, with the scope covering device and material innovation, packaging and thermal management, as well as circuit applications. These devices have achieved performance beyond the respective material limits of 1-D devices and hold great potential for advancing the speed, efficiency, and form factor of power electronics systems; some of them have reached initial commercialization. These devices also provide an exciting platform to explore the fundamental material properties and carrier transports under the concurrence of high electric field and high current density in sub-micron-second switching transients. Yuhao Zhang is currently a Full Professor with the Department of Electrical and Electronic Engineering of the University of Hong Kong (HKU). Before joining HKU, he was the Shirish S. Sathaye Associate Professor with Virginia Tech, leading the power semiconductor research at the Center for Power Electronics Systems, the largest academic research center in power electronics in the U.S. He received his Ph. D. and S. M., both in electrical engineering from Massachusetts Institute of Technology (MIT) in 2017 and 2013, respectively. He has authored over 200 papers (including 3 Nature-series papers, 21 IEDM papers, 20+ T-PEL papers as the corresponding author) and 2 book chapters and holds 7 granted U. S. patents. He is a co-author of over 10 highlight/feature/prize papers. His work has been cited over 11,000 times with a h-index of 57 and been widely covered by Nature Electronics, Semiconductor Today, Compound Semiconductors, EE Times, etc. over 100 times. He received the MIT Microsystems Technology Laboratories Doctoral Dissertation Award, two IEEE George Smith Awards (best paper award of the year in IEEE Electron Device Letters) in 2019 and 2023, four Technical Highlights of IEEE International Electron Devices Meeting in 2020, 2021, 2024 and 2025, the National Science Foundation CAREER Award, the Outstanding New Assistant Professor Award and Faculty Fellow Award of Virginia Tech, the Office of Naval Research Young Investigator Award, and the Compound Semiconductor Young Scientist Award. His students received the Ph.D. Thesis Talk Award of the IEEE Power Electronics Society and several APEC Best Presentation Awards. He is an Associate Editor of the IEEE Transactions on Power Electronics and the TPC member of many conferences (e.g., IEDM, APEC, ECCE, WiPDA).