$\beta$-Ga₂O₃ in Power Electronics Converters: Opportunities & Challenges

In this work, the possibility of using different generations of $\beta$ -Ga ₂ O ₃ as an ultra-wide-bandgap power semiconductor device for high power converter applications is explored. The competitiveness of $\beta$ -Ga ₂ O ₃ for power converters in still not well quantified, for which the major determining factors are the on-state resistance, $R_{{\rm ON}}$ , reverse blocking voltage, $V_{{\rm BR}}$ , and the thermal resistance, $R_{{\rm th}}$ . 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 $\beta$ -Ga ₂ O ₃ devices are made against contemporary SiC-FET and Si-IGBTs. The results have indicated that although the early $\beta$ -Ga ₂ O ₃ devices are not competitive to incumbent Si-IGBT and SiC-FET modules, the latest experimental measurements on NiO _X / $\beta$ -Ga ₂ O ₃ and $\beta$ -Ga ₂ O ₃ /diamond significantly surpass the performance of incumbent modules. Furthermore, parameters derived from semiconductor-level simulations indicate that the $\beta$ -Ga ₂ O ₃ /diamond in superjunction structures delivers even superior performance in these power converters.