Ashley Jian is working to improve the efficiency of high-power electronics for better energy security and sustainability

As our world becomes increasingly dependent on power electronics, which enable everything from data servers to high-speed trains, the need for efficient, reliable energy usage is crucial. This is also known as “energy security,” meaning the availability of energy sources at an affordable price to sustain modern economies and life.

“Energy security is one of the biggest concerns in our century,” said PhD student Ashley Jian. “I want to help develop high-efficiency power devices to solve this kind of problem.”

Jian focuses on the design, modeling, fabrication, and characterization of gallium oxide-based high-power devices. Her recent research uses high-quality dielectrics to enable high performance beta phase gallium oxide (β-Ga₂O₃) field-effect transistors. This method achieves high-quality semiconductor-dielectric interface and low leakage current, which is important for device efficiency and reliability.

“Power electronics are used everywhere,” Jian said. “If we can improve their energy efficiency, that will benefit our Earth very much.”

Power electronics are used everywhere.

ECE PhD student Ashley Jian

Traditional silicon-based power systems are relatively inefficient, but β-Ga₂O₃ has become a promising semiconductor for high-power applications, such as electric vehicles. In this research, Jian experimented with aluminum-silicon-oxide dielectrics, which have a record-high breakdown strength. This means they can hold a very high voltage and support higher power devices.

“The most fascinating thing about my research is everything is quite new and challenging,” Jian said. “Gallium oxide is a very new and promising material for high-power applications. I enjoy learning something new every day.”

Jian’s research, published in “Electrical properties of MOCVD-grown AlSiO gate dielectric on (001) β-Ga₂O₃,” won the Best Presentation Award from the 63rd Electronic Materials Conference. The research was performed in part in the Lurie Nanofabrication Facility (LNF) and in collaboration with Dr. Islam Sayed and Wenjian Liu at the University of California, Santa Barbara.

Jian received her B.S. in Electrical Engineering at the Beihang University, China, and M.S. in Electrical and Computer Engineering at the University of Michigan. She is advised by Prof. Elaheh Ahmadi.