Progress in semiconductor technologies have been so consequent these last years that theoretical limits of silicon, speci cally in the eld of high power, high voltage and high temperature have been achieved. At the same time, research on other semiconductors, and es- pecially wide bandgap semiconductors have allowed to fabricate various power devices reliable and performant enough to design high eciency level converters in order to match applications requirements. Among these wide bandgap materials, SiC is the most advanced from a techno- logical point of view: Schottky diodes are already commercially available since 2001, JFET and MOSFET will be versy soon. SiC-based switches Inverter eciency bene ts have been quite established. Considering GaN alternative technology, its driving force was mostly blue led for optical drive or lighting. Although the GaN developments mainly focused for the last decade on optoelectronics and radio frequency, their properties were recently explored to design devices suitable for high power and high eciency applications. As inferred from various studies, due to their superior material properties, diamond and GaN should be even better than SiC, silicon (or SOI) being already closed to its theoretical limits. Even if the diamond maturity is still far away from GaN and SiC, laboratory results are encouraging speci cally for very high voltage devices. Apart from packaging considerations, SiC, GaN and Diamond o ers a great margin of progress. The new power devices o er high voltage and low on-resistance that enable important reduction in energy consumption in nal applications. Applications for wide bandgap materials are the direction of high voltage but also high temperature. As for silicon technology, WBG-ICs are under development to take full bene ts of power and drive integration for high temperature applications.