A more efficient transistor

Cornell University grad student Junxia Shi has developed a super-effcient transistor which could form the basis for the circuitry in products from laptops to hybrid vehicles. Research on the gallium nitride device was published July 28 in the journal Applied Physics Letters.

The new transistor's on-resistance, or measure of resistance to electric current, is 10 to 20 times lower than today's silicon-based power devices. It also has a high breakdown voltage, which is a measure of how much voltage can be applied across a material before it fails. The key to the device lies in gallium nitride's low electrical resistance, causing less power loss to heat, and its ability to handle up to 3 million volts per square centimeter without electrical failure. Silicon, a competing material, can handle only about 250,000 volts per square centimeter.

"Before now, there were no electronic devices that could handle both high current and the high voltage, but our device can do it," explains Cornell engineering professor Lester Eastman, in whose lab Shi did his work.

Shi and Eastman have a provisional patent on their device. The New Jersey-based company Velox and Motorola spinoff Freescale have also helped fund the research, with the hope of producing the devices at an industrial scale.

The Cornell news release on the device can be found here:

http://www.news.cornell.edu/stories/Dec09/GaNtransistor.html