Wide Bandgap – Advancing Power Electronics

­Wide bandgap (WBG) materials, characterized by a larger energy bandgap (typically greater than 2.0 eV), are revolutionizing the field of power electronics. They are also the cornerstone of next-generation RF and optoelectronic devices.

Endowed with unique – and beneficial – properties, WBG devices like Silicon Carbide (SiC) and Gallium nitride (GaN) enable operation in high-power, high-frequency and high-temperature environments that would challenge silicon semiconductors. Compared with silicon, their larger bandgap allows WBG devices to sustain higher electric fields without breaking down, making them ideal for high-voltage applications. They also exhibit higher thermal conductivity, facilitating efficient heat dissipation and enhancing device reliability. Their ability to function at elevated temperatures without significant performance degradation also reduces the need – and cost – of using elaborate cooling systems.

WBG devices are also notable for their inherent resistance to radiation, making them particularly attractive for aerospace and defense applications. This robustness enables longer operational lifespans in environments where conventional materials might fail. (This feature has gained interest since it’s almost impossible to get a reliable supply of Rad-hard silicon MOSFETS these days). But WBG offers the most promise for volume markets like electric vehicles (EVs), renewable energy systems and some industrial power supplies.

Watching the differing product marketing strategies around WBG vs. silicon devices at semiconductor companies is interesting. From the start, WBG devices offered real benefits in actual circuit applications; however, many early predictions about their evolution in the industry were simply wrong, as such projections usually are. For instance, companies offering GaN usually market their parts as replacing silicon and SiC. Those with SiC devices say their parts replace GaN. Those with only silicon say something like: The market really isn’t there yet, we are looking for a business case, or We’re still studying WBG. And those offering silicon, GaN and SiC don’t say much at all. Today there are still plenty of uses for silicon devices – so the three technologies are not mutually exclusive. As it always does, the market will eventually decide which technologies will prevail.

Wide bandgap devices represent a step forward for the power electronics industry, paving the way for innovative solutions. Their increased radiation resistance, size and weight reduction and efficiency are key for powering AI servers, 6G and beyond and are spurring defense industries and speeding the electrification of transportation. By enabling devices that are smaller, lower R_DS(on), faster switching, lower capacitance and more efficient, WBG materials are not only driving progress in critical industries but also contributing to a more sustainable and energy-efficient future. In addition to GaN and SiC, emerging WBG materials like diamond and aluminum nitride, which are still in the development stage for commercial use, hold promises for ultra-high-power and high-frequency applications. As time goes on, more benefits of WBG will emerge.