Semiconductor Free Microelectronics
A research department at the University of California San Diego has developed the first semiconductor-free microelectronic device, which is controlled optics and could increase the speed of electronics and increase the efficiency of solar panels.
Although semiconductors are the bases of modern devices they are reaching the limits of what is possible using materials available today. Moore’s law, which suggests that every two years computing power will double, is not true at present.
To change these physical limits, the engineers have changed the present electrons with free electrons that are floating in space on a nanoscale, which is not unlike the vacuum tubes used in early computing. Freeing these electrons is not easy and needs high voltages, high temperatures, or high powered lasers. None of these are particularly practical for micro-electrics.
The device they have created which frees these electrons without the above-mentioned extremes has been described in the journal, ‘Nature Communications’. The meta-surface is made of gold and has nanostructures in a mushroom-shape, sitting on parallel gold strips. This is on top of a silicon wafer, which is divided by a later of silicon dioxide. The energy used to pull the electrons from the metal and ‘free’ them comes from less than 10 volts DC and a low power infrared laser. This creates “hot spots” with a high-intensity electric field on the meta-surface. Tests showed a 1000% increase in conductivity on the device, when it was activated.
Dan Stevenpiper, an electrical engineering professor from the university, said that although this won’t replace all semiconductor devices, it may be best for some speciality application, particularly very high frequency or high power devices.
He also said they would need to learn more about the limits of these devices. The researcher added that different types of meta-surfaces may need to be created for different devices.
Image Source: www.jacobsschool.ucsd.edu