Emerging wide bandgap technologies
We are reaching the theoretical limits for power device innovations using
conventional silicon (Si), but new Wide Bandgap
(WBG) materials are emerging which offer opportunities to the electronics power industry that we previously couldn’t even imagine!
- Silicon Carbide (SiC) offers significant advantages over Si in power devices, including increased durability in harsh environments, higher switching frequencies which enable more compact designs, higher breakdown voltages and lower losses, which translates into higher efficiency. Of the WBG emerging technologies, SiC is the most developed and SiC-based power electronics are becoming more widely available.
- Gallium Nitride (GaN) is generally more cost-effective than SiC but is not yet so widely available. It is not as thermally conductive as Silicon Carbide but offers outstanding reliability and high voltage operations. GaN is basically bonded over a SiC or Si substrate.
These new materials are allowing designers to push the boundaries and deliver step changes in power efficiency. They are expected to feature massively in the future development of electric and hybrid vehicles. As an example, Toyota is working on delivering a 10% improvement in fuel efficiency whilst reducing the size of its power control unit by 80%. This is being achieved by making the semiconductor wafers with SiC instead of silicon.