Every phone charger, electric car and power grid relies on semiconductor switches that control electricity. For decades those switches have been made of silicon, and silicon is nearing its physical limits. Engineers at The University of Hong Kong (HKU) now report a module built on a newer material, gallium oxide, that switched 1,000 volts and 1,000 amperes, a peak of one megawatt. According to HKU’s announcement, it is the first time a module made from this class of material has reached that power level.
Why gallium oxide is interesting
Gallium oxide belongs to a group called ultra-wide bandgap semiconductors. HKU says these materials can withstand extremely high electric fields, which makes them attractive for high-voltage jobs. Silicon struggles as systems demand more power and more complexity.
There is a catch. Gallium oxide does not conduct heat well, and putting several devices together in one package at high voltage and current has been hard. That gap between a promising material and a working high-power system is what this study addresses.
Designing the chip and the package together
The work was led by Professor Yuhao Zhang of HKU’s Department of Electrical and Computer Engineering and its Centre for Advanced Semiconductors and Integrated Circuits, with Dr Hehe Gong and PhD student Xin Yang. Collaborators included Professor Guo-Quan Lu of Virginia Tech and Professor Jiandong Ye of Nanjing University. The results appear in Nature Communications.
The central idea is a change of mindset. Instead of designing the semiconductor device and its package separately, the team designed them as one system. Zhang says this device-package co-design let them manage the electric field, the heat flow and the mechanical stress at the same time.
The two key tricks
First, the team created what it calls a junction-side cooling architecture. It places the heat-generating region closer to the cooling path, which tackles gallium oxide’s weak heat conduction directly.
Second, the module uses a high-permittivity insulating layer that redistributes the electric field around the device. Together, HKU says, the two features let the module handle extreme power while still working at temperatures above 250 degrees Celsius.
The result in numbers
The module repeatedly switched 1,000 V and 1,000 A at a frequency of 1 kHz, reaching one megawatt of peak power. HKU describes this as more than a hundred-fold increase over previous demonstrations using similar materials. Dr Gong calls it the first multi-chip ultra-wide bandgap module to reach the megawatt level and adds that it offers a scalable way to turn the material’s properties into practical high-power systems.
Where it could be used
HKU says the technology suits pulsed-power applications, where enormous energy must be delivered within microseconds. Listed possibilities include high-voltage protection for future power grids, particle accelerators, advanced medical systems and fusion energy facilities.
What it means
This is a laboratory demonstration, not a commercial part, and HKU does not give a product timeline. Its value is as proof that a hard material can be packaged into a robust, multi-chip module. For engineers in power electronics, the lesson is that packaging, cooling and insulation can matter as much as the semiconductor itself.
For energy and infrastructure planners, the longer-term significance is compact, high-voltage switching that could help grids and research facilities handle bursts of power more efficiently. Those benefits are possibilities named by the researchers, and further testing would be needed before they reach real equipment.
The bottom line
Silicon is not going away soon, but HKU’s megawatt gallium oxide module shows what comes next could be built differently: material, package and cooling designed as a single system. Watch for follow-up work on scaling up and reliability.