RII Track-4: NSF: Advancing High Density and High Operation Temperature Traction Inverter by Gallium Oxide Packaged Power Module

Electric vehicles (EVs) offer a crucial pathway to reduce carbon emissions in the transportation sector and mitigate global climate change. The traction inverter powers the vehicle’s movement and is considered the “heart” of an EV’s powertrain. A smaller, lighter, and more efficient traction inverter saves energy and extends the driving range of EVs.

Additionally, high-temperature capability is essential to ensure reliable EV operation across a wider range of temperatures without damage or failure, reducing the need for bulky cooling systems. The aim of this project is to enhance the power density and operating temperature range of traction inverters by utilizing gallium oxide packaged power modules.

Gallium oxide, an emerging ultra-wide bandgap semiconductor, has the potential to revolutionize power electronics with higher efficiency and superior operational temperatures due to its exceptional material properties. By eliminating technical barriers to gallium oxide device integration, this project will foster the development of the next generation of high-density, high-temperature power converters and promote the use of gallium oxide technology in automotive and other harsh environment applications.

The fellowship will strengthen the PI’s multi-disciplinary research capabilities in semiconductor devices, multiphysics analysis, power module packaging, and high-performance power electronics. It will also provide hands-on laboratory experience to educate and train the next generation of electrical engineers in the field of wide and ultra-wide bandgap semiconductor devices, power electronics packaging, and conversion.

This Research Infrastructure Improvement Track-4 EPSCoR Research Fellows (RII Track-4) project would provide a fellowship to an Assistant professor and training for a graduate student at the University of Arkansas. This work would be conducted in collaboration with researchers at the National Renewable Energy Laboratory. High-density, lightweight power electronics converters, especially those capable of operation at high ambient temperatures, are compellingly needed for automotive, aerospace, and space exploration applications.

Gallium oxide emerges as a promising ultra-wide bandgap semiconductor material with a larger bandgap energy compared to conventional silicon and wide bandgap semiconductors. This advantageous characteristic enables high breakdown electrical strength, low intrinsic carrier concentration, and corresponding high operating temperatures, making it an ideal candidate for high-temperature, high-density power electronics.

However, the low thermal conductivity of gallium oxide impedes efficient heat dissipation from the device junction, increasing thermal resistances in conventional packaging designs. In collaboration with researchers at the National Renewable Energy Laboratory, the PI will overcome these challenges associated with gallium oxide power module packaging and advance its application in high-power density and high-temperature power electronics converters.

This project has three research objectives: (1) Innovate power module packaging techniques that optimize thermal resistances, minimize parasitic inductances, and enhance high-temperature operation capability; (2) Explore reliable gallium oxide power device gate driving and protection strategies to maximize device potential and increase reliability; and (3) Demonstrate a gallium oxide-based high-density and high-temperature traction inverter to validate and expedite the adoption of gallium oxide technology. The success of the project promises empirical insights into gallium oxide device modeling, packaging, gate driving, protection, and its application in power converters.

Consequently, it will catalyze advancements in transport electrification and the deployment of gallium oxide technology within challenging environments.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.