Revolutionary Transistor Invented at Rensselaer

A new invention that could replace the silicon transistor for high-power and high-temperature applications has recently captured the attention of American and Japanese automobile companies. A transistor based on a gallium nitride material, which can reduce power consumption and improve the efficiency of power electronics systems in devices ranging from house appliances all the way to defense equipment, has been created by Weixiao Huang, a Chinese student, for his doctorate at the Rensselaer Polytechnic Institute.

"Silicon has been the workhorse in the semiconductor industry for the last two decades. But as power electronics get more sophisticated and require higher performing transistors, engineers have been seeking an alternative like gallium nitride-based transistors that can perform better than silicon and in extreme conditions", says Huang.

There are multiple types of transistors, but the most important of them are the bipolar and MOS-FET transistors. The MOS-FET transistors are today the most used type of transistors in the world. A single computer processor, for example, can hold several tens of millions of MOS-FET transistors. MOS-FET basically means metal/oxide semiconductor field-effect transistor. As many other electronic devices nowadays, they are generally silicon based, although this doesn't necessarily mean transistors can't be made of other semiconductor materials.

Huang chose gallium nitride to demonstrate that this particular semiconductor has better electrical properties than those of silicon. Several attempts have been previously made to build gallium nitride MOS-FET transistors but remained unsuccessful until now. Huang's innovation could provide the possibility to integrate several electronic functions on a single chip, as well as creating high performance high-voltage MOS-gated FETs.

"This will significantly simplify entire electronic systems", Huang said. "If these new GaN transistors replaced many existing silicon MOS-FETs in power electronics systems, there would be global reduction in fossil fuel consumption and pollution."

The new device can be operated in high temperature and high-power environments and even in highly radioactive mediums. "Because it is so resilient, the device could open up the field of electronic engineering in ways that were not previously possible due to the limitations imposed by less tolerant silicon transistors", Huang said.