Multidimensional Power Devices in (Ultra-)Wide-Bandgap Semiconductors

Abstract:

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.

Bio:

Yuhao Zhang is an assistant professor leading the power semiconductor research at the Center for Power Electronics Systems (CPES) of Virginia Tech, one of the largest power electronics research centers in the U.S. universities. Before joining VT in 2018, he worked as a postdoctoral associate at the Massachusetts Institute of Technology (MIT) from 2017 to 2018. He received his Ph. D. and S. M., both in electrical engineering from MIT in 2017 and 2013, respectively. Before joining MIT, he received his B. S. in physics from Peking University in 2011. He has authored over 150 journal papers and conference proceedings and holds 5 granted U. S. patents. He received the MIT Microsystems Technology Laboratories Doctoral Dissertation Award in 2017, the IEEE George Smith Award in 2019, the National Science Foundation CAREER Award in 2021, the Outstanding New Assistant Professor Award and Faculty Fellow Award of Virginia Tech Engineering in 2021 and 2022, and the Office of Naval Research Young Investigator Award in 2023. His students received the Ph.D. Thesis Talk Award of the IEEE Power Electronics Society, the Virginia Tech Graduate Student of the Year Award, and several APEC Best Presentation Awards.