An experimental transistor made of the semiconductor beta gallium oxide could usher in next-generation power electronics, the devices needed to control the flow of high-voltage electrical energy.

Purdue University researchers in Indiana demonstrated the high-performance potential of the semiconductor, which could be used in new ultra-efficient switches for power grids, aircraft and military ships.

Schematic for an experimental transistor made of the semiconductor beta gallium oxide. Credit: Peide Ye/Purdue University Such a technology could help to reduce global energy use and greenhouse gas emissions by replacing less efficient and bulky power electronics switches now in use, researchers say.

The transistor, called a gallium oxide on insulator field effect transistor, or GOOI, is especially promising because it possesses an “ultra-wide bandgap,” a trait needed for switches in high-voltage applications, says researcher Peide Ye, a Purdue University professor of electrical and computer engineering. Devices made from beta gallium oxide have a higher “breakdown voltage,” or the voltage at which the device fails, he says.

To help bring down the cost of producing transistors made from the material, Ye’s team developed an inexpensive method using adhesive tape to peel off layers of the semiconductor from a single crystal, representing a far less costly alternative to a laboratory technique called epitaxy.

The market price for a 1-centimeter-by-1.5-centimeter piece of beta gallium oxide produced using epitaxy is about $6,000, researchers say. In comparison, the “Scotch-tape” approach costs pennies and can be used to cut films of the beta gallium oxide material into belts or “nano-membranes,” which can then be transferred to a conventional silicon disc and manufactured into devices, Ye says.

The technique was found to yield extremely smooth films, having a surface roughness of 0.3 nanometers, which also bodes well for its use in electronic devices, Ye says.

Purdue researchers say they achieved electrical currents 10 to 100 times greater than other research groups working with the semiconductor.

One drawback to the material, however, is its poor thermal properties. To help solve the problem, additional research may involve attaching the material to a substrate that possesses those properties.