A team of researchers in the Applied Electromagnetics Group led by electrical engineering professor Dan Sievenpiper at UC San Diego say they have fabricated the first semiconductor-free, optically-controlled microelectronic device.

Using metamaterials, the engineers were able to build a microscale device that shows a 1,000 percent increase in conductivity when activated by low voltage and a low power laser.

The vast majority of modern microelectronic devices rely on carriers within semiconductors due to their integrability. Therefore, the performance of these devices is limited due to natural semiconductor properties such as band gap and electron velocity.

Replacing the semiconductor channel in conventional microelectronic devices with a gas or vacuum channel may scale their speed, wavelength and power beyond what is available today, the engineers said.

The engineers demonstrated how the interaction between an engineered resonant surface and a low-power infrared laser can cause enough photoemission via electron tunneling to implement feasible microelectronic devices such as transistors, switches and modulators.

“This certainly won’t replace all semiconductor devices, but it may be the best approach for certain specialty applications, such as very high frequencies or high power devices,” Sievenpiper said.