β-Ga2O3 in Power Electronics Converters: Opportunities & Challenges

In this work, the possibility of using different generations of β-Ga2O3 as an ultra-wide-bandgap power semiconductor device for high power converter applications is explored. The competitiveness of β-Ga2O3 for power converters in still not well quantified, for which the major determining factors are the on-state resistance, RON, reverse blocking voltage, VBR, and the thermal resistance, Rth. We have used the best reported device specifications from literature, both in terms of reports of experimental measurements and potential demonstrated by computer-aided designs, to study power converter performance for different device generations. Modular multilevel converter-based voltage source converters are identified as a topology with significant potential to exploit these device characteristics. The performance of MVDC & HVDC converters based on this topology have been analysed, focusing on system level power losses and case temperature rise at the device level. Comparisons of these β-Ga2O3 devices are made against contemporary SiC-FET and Si-IGBTs. The results have indicated that although the early β-Ga2O3 devices are not competitive to incumbent Si-IGBT and SiC-FET modules, the latest experimental measurements on NiOX / β-Ga2O3 and β-Ga2O3 /diamond significantly surpass the performance of incumbent modules. Furthermore, parameters derived from semiconductor-level simulations indicate that the β-Ga2O3 /diamond in superjunction structures delivers even superior performance in these power converters.