Move over Silicon, here comes Silicon Carbide, the Power Player!

Silicon, the work horse of the electronics and electrical industry might have to be put out to pasture soon. Recent advancements in devices have pushed silicon semiconductors to the limits of performance of the material. Current needs of power electronics, especially in emerging new energy sources, demand criteria that cannot be met by silicon. Some of these are larger blocking voltages, wider frequencies, higher efficiencies and greater reliability. Conventional silicon devices are seen to suffer avalanche kind of breakdowns and inability to handle peak performance at higher temperatures. Silicon based power devices like diodes, thyristors, IGBT and MOSFET are hard put to function in the present high power handling applications without breakdown.

The main factor leading to this situation is the band gap between the conduction band and the valence band. Silicon has a relatively small band gap, which means that less energy is required to kick up electrons from the valence band into the conduction band. This leads to the avalanche breakdown of silicon based devices operating at high power and voltage conditions. Any marginal shift leads to a failure.

With the massive surge in the demand for electrical energy devices will be called on to handle gigawatts of power at very high voltages in the very near future. Because of the small band gap for silicon many devices will have to be series connected to handle this with the attendant energy losses and poor reliability.

Silicon Carbide, Gallium Nitride and Diamond are some of the Wide Band Gap (WBG) materials being considered for the next generation power electronic devices. Of these SiC is easily ahead as SiC diodes and other devices are already in service. SiC has three times the band gap energy of silicon. A SiC device of the same size as the current Silicon based device can have ten times the blocking voltage of the silicon device.

We can see the writing is on the wall.

“Move over Silicon. SiC is here. Take a well earned rest.”

This paper on ‘Wide Bandgap Semiconductors for Utility Applications’ compares all these WBG materials with regard to their promise, performance and applicability:
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This item from ieee Spectrum deals with SiC as the torch bearer of the WBG brigade:
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This link from II-IV Inc., gives a list of reference publications on WBG materials:
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All in all WBG Materials in general and SiC in particular are poised to be a contender to the throne of power electronics in the near future.
There is no more ‘If’. It is ‘When’.

It may be worthwhile for people in the Electrical and Electronic field to jump on the Band(gap) Wagon.