The power electronics industry has reached the theoretical limit of silicon devices and must go to another semiconductor material whose performance matches today’s newer systems. The solution is wide bandgap (WBG) semiconductors.
Semiconductor Energy Bands
Selection of the optimum Semiconductor material depends on its energy bands. The key band is where no electron states can exist: the bandgap, which refers to the energy difference between the top of a semiconductor’s valence band and the bottom of its conduction band.
WBG Device Characteristics
The bandgap is a major factor in a semiconductor’s electrical conductivity. With enhanced conductivity and electron mobility compared to silicon, a wide bandgap semiconductor provides the benefits of:
• Higher temperature operation
• Higher switching frequencies
• Lower thermal resistivity, dissipating power faster
• Excellent reverse recovery (low switching losses)
• Higher efficiency than present Si devices.
• Higher breakdown voltages, reducing the need for parallel connection of devices for high power applications.
Current WBG Device Challenges
• Reducing WBG material production costs
• Producing new compatible circuits, passive components and gate drivers consistent with WBG device assets
• Diamond is the ultimate material for power devices, but it may take at least 20 years before diamond power devices can be expected to be available.
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