Engineers create semiconductor-free microelectronics

Researchers at the University of California San Diego have developed what they say is the world’s first semiconductor-free, optically-controlled microelectronic device, which could lead to faster electronics and more efficient solar panels.

Semiconductors are at the heart of modern computing devices but are approaching the physical limits of what they can achieve using current materials. As a result, Moore’s Law - which predicts that computing power should double every two years - is no longer holding true.

To overcome this problem, the UC San Diego engineers replaced the electrons flowing through semiconductors with free electrons floating in space, similar to the vacuum tubes of early computing, but on a nanoscale. But liberating electrons from materials is difficult, requiring either high voltages, high temperatures or high powered lasers, none of which are practical for microelectronics.

However, the team was able to fabricate a device that releases electrons without the need for these extremes. Described in the journal Nature Communications, it consists of a gold metasurface with mushroom-shaped nanostructures on an array of parallel gold strips.This sits on top of a silicon wafer, with a layer of silicon dioxide in between.