HKU Engineers Build World-First Power Module Using Emerging Semiconductor Material

Every time you charge a phone, drive an electric car, or turn on a light, a hidden layer of technology is at work: power semiconductor devices, the electronic switches that control and convert electricity across modern life. For decades, silicon has been the material of choice. But as demand for power grows and systems become more complex, we are approaching the physical limits of what silicon semiconductors can do.

A research team at The University of Hong Kong has now demonstrated that a newer class of material can go much further. In a study published in Nature Communications, the team developed a gallium oxide power module capable of repeatedly switching 1,000 volts and 1,000 amperes at a frequency of 1 kHz, reaching a peak power of one megawatt. It is the first time an ultra-wide bandgap semiconductor module has achieved this power level, representing a more than hundred-fold increase over previous demonstrations using similar materials.

The research was led by Professor Yuhao Zhang of HKU’s Department of Electrical and Computer Engineering and the Centre for Advanced Semiconductors and Integrated Circuits (CASIC), together with Dr Hehe Gong and PhD student Xin Yang, in collaboration with Professor Guo-Quan Lu of Virginia Tech and Professor Jiandong Ye of Nanjing University.

Gallium oxide, part of an emerging class of materials known as ultra-wide bandgap (UWBG) semiconductors, can withstand extremely high electric fields, making it promising for high-voltage applications. But it does not conduct heat well, and packaging multiple devices together at high voltage and current has proved difficult. The HKU team’s breakthrough lay in treating the semiconductor device and its packaging as a single integrated system rather than designing them separately.

“Instead of treating the semiconductor device and its package separately, we designed them together as a single system,” said Professor Zhang. “This device-package co-design allowed us to simultaneously manage the electrical field, heat flow and mechanical stress.”

The team developed a “junction-side cooling” architecture that places the heat-generating region closer to the cooling path, along with a high-permittivity insulating layer that redistributes the electric field around the device. Together, these innovations allow the module to handle extreme power levels while remaining functional at temperatures exceeding 250°C.

The technology is particularly suited to pulsed-power applications, where enormous amounts of energy must be delivered within microseconds. Potential uses include high-voltage protection for future power grids, particle accelerators, advanced medical systems, and fusion energy facilities.

“This is the first time that an UWBG multi-chip module has reached the megawatt power level,” said Dr Gong. “More importantly, the result provides a scalable approach for translating the exceptional material properties of UWBG semiconductors into practical high-power systems.”