Semiconductor-Free Microelectronic Devices Now Possible Thanks to Metamaterials

University of California San Diego engineers have fabricated the first-ever semiconductor-free, optically-controlled microelectronic device. Their discovery paves the way for microelectronic devices that are faster and capable of handling more power, and could also lead to more efficient solar panels. Using metamaterials, the engineers built a microscale device that exhibits a 1,000 percent increase in conductivity when activated by low voltage and a low-power laser. The capabilities of existing microelectronic devices, such as transistors, are limited by the properties of their constituent materials, such as their semiconductors. Semiconductors can impose limits on a device's conductivity, or electron flow. Semiconductors have a band gap and require a boost of external energy to get electrons to flow through them. Electron velocity is limited, since electrons are constantly colliding with atoms as they flow through the semiconductor.

Transcript

00:00:00 [Music] micro electronic devices such as transistors continue to improve each year making new innovations possible however the ultimate capabilities of these devices are limited by the natural properties of their comprising materials conventional micro electronics rely on semiconductors in the applied electromagnetics screen we are replacing

00:00:26 semiconductors with free electrons in air or vacuum similar to vintage vacuum tubes but in nanoscale dimensions this replacement may scale the speed wavelength and power handling of micro electronics to beyond what is available today by restoring some of the benefits of vacuum electronics however liberating electrons from materials is quite challenging it either

00:00:53 requires applying high DC voltages or short wavelength lasers both of which are not practical in a micro scale device to address this challenge we used a specifically patterned service called the meta surface to liberate electrons from gold nano structures the new devices can be activated by low DC voltages along with a low-power infrared laser at the applied electromagnetics

00:01:19 group at UC San Diego we implemented this concept and fabricated the first nano scale photo emission based device test results show a conductivity change of 1000% after activation by laser this may enable semiconductor free switches transistors photo detectors and even solar cells in the future [Music]