Speaker: Yuji Zhao
Affiliation: Arizona State University
Abstract: More than two decades after the first demonstration, gallium nitride (GaN) wide bandgap (WBG) semiconductors are revolutionizing an increasing number of applications from power electronics, RF communications, to light-emitting diode (LED) lighting, photovoltaic solar cells, integrated nanophotonics, and more. For example, GaN WBG power devices technology is presently making a significant impact on energy efficiency and on transforming the electric grid from a passive one to an actively controlled physical-cyber system. This impact is not only economic (over $40B in annual electricity savings), or environmental (equivalent of 300 coal fired power plants worth of energy), but critical for new device concepts and system architectures which will radically change the way people generate, distribute, and consume electricity every day. At the heart of all these exciting applications is the GaN WBG materials, the unique electronic and optical properties of which have enabled and will continue to enable new paradigms in electronic and photonic technologies. In this talk, I will review our progress on GaN materials research, and discuss their applications in kV-class power transistors (supported by APRAe) and high temperature solar cells (supported by NASA). For future outlook, I will further present and argue the possibilities of new WBG devices based on AlN and diamond materials (supported by DTRA and AFOSR), and emerging UV/visible GaN integrated photonics for biochemical sensing, nonlinear optics, quantum photonics, and THz applications (supported by ARO and SFAz).
Biography: Yuji Zhao is an Assistant Professor at Arizona State University (ASU) and leads the MOCVD GaN Laboratory. He received the Ph.D degree from University of California Santa Barbara (UCSB) in 2012 under the supervision of Nobel Laureate Professor Shuji Nakamura. He received the B.S. degree from Fudan University in China in 2008. Dr. Zhao’s research interests are centered around the MOCVD growth and applications of GaN WBG semiconductor hetero- and nano- structures to electronic and photonic devices. He has authored/co-authored more than 80 journal and conference publications, 2 book chapters, and over 10 patents. His research achievements include the demonstration of the first “low droop” semipolar InGaN blue LEDs (reported by Science, May 2012), elucidating the basic growth modes and defect generation for “green gap” InGaN quantum well LEDs and lasers (reported by Nature Photonics, July 2013), demonstration of the first nonpolar InGaN solar cells with high carrier collection efficiency (reported by Semiconductor Today, May 2017), and the first AlN power diode with over 1 kV breakdown voltage (reported by Semiconductor Today, August 2017). Dr. Zhao is the receipt of 2017 ASU Fulton Outstanding Assistant Professor Award, 2016 DTRA Young Investigator Award, 2015 NASA Early Career Faculty Award, 2015 SFAz Bisgrove Scholar Faculty Award, and 2010–2013 UCSB SSLEC Outstanding Research Award.
Date(s) - Nov 15, 2017
1:00 pm - 2:30 pm
E-IV Tesla Room #53-125
420 Westwood Plaza - 5th Flr., Los Angeles CA 90095