It's not often that I call a new development "disruptive," but there is one application of widebandgap semiconductors that has that potential. Here, I'm referring to the definition of disruptive as a technology that offers lower performance initially, but fills a market niche that the conventional technology is not filling. The market for the disruptive technology eventually exceeds the conventional one, sometimes completely displacing it.
The application I have in mind is for SiC or GaN devices for power management devices in hybrid and electric vehicles. Their use in these vehicles is not news, but it's easy to overlook the transformation that this technology can help bring to the auto industry.
Widebandgap devices can run hotter, switch faster, and are more efficient that equivalent devices based on silicon. They are more expensive too, but efficiency is very important in the power circuits in hybrid vehicles, and anyway, the price is coming down as volume increases. SiC devices are currently the market favorite, but GaN may be able to play here too.
What is really exciting is how the electric vehicle can truly transform our definition of a car. Once you eliminate the engine, transmission, and drive train, you can do many things very differently. (See, for example, this interview in Tech-On! with Yukitsugu Hirota, from the R&D Center of Calsonic Kansei.
It reminds me of the history of the electric motor, in the 1800s. The first thing that innovators did was to replace water wheels with large motors, driving everything off of a single, long shaft. This is what they knew how to do, since they were used to water wheels, not motors. Then they began to break up the workload into smaller pieces, each driven by its own motor. This process took time--about 30 years, in fact.
It's not difficult to see the same thing happening to the auto industry. Internal combustion engines won't go away, and electric golf carts are nothing new. But the auto industry will transform over the next few decades to a different type of vehicle, and it will need devices based on SiC and GaN.