The Wide Bandgap (WBG) semiconductors silicon carbide (SiC) and gallium nitride (GaN) offering higher efficiency and higher power density compete against the dominating power semiconductor material silicon.
The advantages of WBG semiconductors on system level, higher voltage and temperature operation as well as higher switching frequency enabling volume and weight reduction, are related to fundamental material properties of these materials, e.g. electric field, energy gap, electron velocity, melting point and thermal conductivity.
Fast switching will become key in many applications because this will open a new generation of power electronics. Increasing the switching frequency enables the miniaturization of passive components for energy storage and filtering in power electronic systems. In a photovoltaic inverter, for example, the increase of switching frequency from 48 kHz to 250 kHz results in a weight and volume reduction by a factor of five.
After many years of research in SiC materials and device technology we see more and more devices entering the market from various suppliers in Europe, Japan and US. Now the research effort should focus on wide bandgap system integration involving all necessary technology steps along the value chain of WBG power electronics towards the systems and applications.