Researchers at EPFL (École Polytechnique Fédérale de Lausanne) in Switzerland have developed a new gallium nitride (GaN) transistor with a breakdown voltage approaching 4,000 volts - more than five times that of current commercial GaN power devices, which typically operate at 600–650V. The device also maintains a low on-resistance. The findings were published in the latest issue of Nature Electronics.
To overcome the high-voltage limitation, the team developed a novel GaN transistor called an "intrinsic polarization superjunction." The device is built from multiple layers of GaN material on a low-cost silicon substrate. By leveraging GaN's inherent polarization properties, a layer of positive charge naturally forms alongside the electron layer. By tuning the thickness of the material layers, the researchers achieved a balance between positive and negative charges. As a result, when the transistor is switched off, the voltage is distributed more evenly across the device rather than concentrating at a single point - significantly reducing the risk of breakdown caused by localized high electric fields.
Tests show that the new transistor can withstand nearly 4,000 volts while maintaining a low on-resistance, which helps reduce energy loss and heat generation during power conversion. Additionally, the device does not require traditional chemical doping to control charge, a design that is expected to improve stability under high-temperature and high-electrical-stress conditions.
This breakthrough is expected to have significant applications in high-voltage power electronics, including AI data centers, renewable energy systems, and electric vehicles.