Recently, Professor Jun Ma from the Department of Electrical and Electronic Engineering at the Southern University of Science and Technology (SUSTech) demonstrated multi-channel nanowire devices for efficient power conversion, in collaboration with Professor Elison Matioli from École Polytechnique Fédérale de Lausanne (EPFL), Switzerland and Dr. Kai Cheng from Enkris Semiconductor Inc., China. The paper was published in the impact journal Nature Electronics, entitled “Multi-channel nanowire devices for efficient power conversion.” It reports this new technology that can significantly enhance power conversion efficiency, rendering a major step forward for wide-bandgap power electronics.

Semiconductor power devices are essential for power conversion. The higher the device breakdown voltage, the higher the power rating, and the lower on-resistance, the fewer losses. Conventional power devices feature a high on-resistance increasing with the breakdown voltage, therefore resulting in energy losses as well as increased carbon emission.

Figure 1. Schematics and SEM images of the multi-channel device

Figure 2. Impact of the multi-channels on the device breakdown voltage as well as the significant enhancement in breakdown thanks to the slanted tri-gate

In this project, novel multi-channel nanowire GaN devices were demonstrated based on a multi-channel GaN heterostructure with parallel conductive channels and slanted tri-gates that can effectively spread the electric field and enhances the breakdown voltage, shown 2x enhancement in figure-of-merit as compared to the best reported GaN devices in the literature.

Figure 3. Benchmark of the multi-channel device against other GaN devices in the literature, demonstrating tremendous prospects for efficient power conversion

Luca Nela of EPFL, Professor Jun Ma of SUSTech, Erien Catherine of EPFL were the first authors of this paper, and Professor Elison Matioli of EPFL is the corresponding authors. This work was supported by the European Research Council (ERC), the Swiss National Science Foundation (SNSF), and the ECSEL Joint Undertaking (JU).

Paper link: https://www.nature.com/articles/s41928-021-00550-8