EPFL researchers develop high-voltage GaN transistor

Researchers at the Ecole Polytechnique Federale de Lausanne (EPFL) have developed a new class of Gallium Nitride (GaN) transistor known as the intrinsic polarisation superjunction (iPSJ). The chip-sized device, constructed from GaN layers on a low-cost silicon base, can withstand nearly 4 kV before breakdown, setting a record for this technology.

By exploiting a natural polarisation effect unique to GaN, the team at the Power and Wide-band-gap Electronics Research Lab (POWERlab) engineered the transistor layers to create matched positive and negative charge sheets. This prevents the charge imbalance found in conventional GaN transistors, which typically causes intense electric fields and device breakdown.

The iPSJ maintains low resistance, which minimizes energy loss as heat. This combination of high-voltage capability and efficiency is considered essential for power conversion in renewable energy systems and AI data centres.