New nanotransistors keep their cool at high voltages

Designing novel power transistors to improve the converters' efficiency is the aim of the team of EPFL engineers. With their entirely new transistor design, based on the counterintuitive application of nanoscale structures for high voltage applications, much less heat is lost during the conversion process, making the transistors especially well-suited to high-power applications like electric vehicles and solar panels. Their findings have just been published in Nature Electronics. The heat dissipation in converters is caused by the high electrical resistance, among other factors, which is the biggest challenge in power electronic devices.

They have developed a transistor that can substantially reduce the resistance and cut the amount of heat dissipation in high-power systems. More specifically, it has less than half as much resistance as conventional transistors, while holding voltages of over 1,000 V. The EPFL technology incorporates two key innovations.

• The first involves building several conductive channels into the component so as to distribute the flow of current—much like new lanes that are added to a highway to allow traffic to flow more smoothly and prevent traffic jams. "Our multi-channel design splits up the flow of current, reducing the resistance and overheating," says Nela.
• The second innovation involves using nanowires made of gallium nitride, a semiconducting material ideal for power applications. Nanowires are already used in low-power chips, such as those in smartphones and laptops, not in high voltage applications. The POWERlab demonstrated nanowires with a diameter of 15 nm and a unique funnel-like structure enabling them to support high electric fields, and voltages of over 1,000 V without breaking down.

https://techxplore.com/news/2021-03-nanotransistors-cool-high-voltages.html