By Josh Perry, Editor
[email protected]

The National Renewable Energy Laboratory (NREL) in Lakewood, Colo. released the findings from a technoeconomic study of gallium oxide as a potential material for future power electronics and determined that it could be three to five times cheaper to manufacture than silicon carbide (SiC).

NREL researchers Timothy Remo (left), Samantha Reese, Andriy Zakutayev, and Johney Green used technoeconomic analysis to determine "How Much Will Gallium Oxide Power Electronics Cost?" (Dennis Schroeder/NREL)

While there has been plenty of research into wide bandgap semiconductors because of their ability to operate at higher heat than silicon in compact spaces, the report from the NREL explained, most of the discussion has been about SiC and gallium nitride (GaN).  Gallium oxide isn’t currently used commercially but there are several companies working on devices composed of the material.

“For the gallium oxide analysis, a bottoms-up cost model created around the manufacturing process considered such factors as crystal growth and ingot machining to approximate the fabrication of crystal wafers ready for use in a device,” the report noted. “The assumptions used in the model included an ingot 1 meter long, a wafer 6 inches in diameter, and a manufacturing volume of 5,000 wafers a month.”

The report indicated that it would cost $283 to manufacture a gallium oxide wafer in the U.S., far less than the $919 to manufacture a SiC wafer. This means that a device made of gallium oxide would be twice as cheap.

It continued, “The potential exists to reduce the cost of gallium oxide wafers even further. More than half of the cost of a gallium oxide wafer comes from the use of iridium as the crucible in which the crystal ingot is grown. Using an alternative material, such as molybdenum or tungsten, could bring the price of gallium oxide semiconductors down further.”

The report was recently published in Joule. The full report can be read at https://www.cell.com/joule/fulltext/S2542-4351(19)30040-6.