A research team at the University of California, San Diego, USA, has developed a nanostructured optoelectronic device that does not rely on semiconductor conduction. Under the condition of low voltage and low power laser excitation, the conductivity of the device is nearly 10 times higher than that of the existing semiconductor devices. The results were published in the November 4 issue of nature communications.

Traditional semiconductor devices are limited by the material itself, and there are limits in frequency, power consumption and so on. The team has fabricated a mushroom shaped nanostructure (called "metamaterial" structure) from gold on silicon wafer. Under DC voltage below 10 V and low-power infrared laser excitation, free electrons can be released, thus greatly improving the conductivity of the device.

This device can not completely replace semiconductor devices, but it may be best used in special needs, such as UHF devices or high power devices. In the future, different surface structures of metamaterials may be suitable for different types of microelectronic devices, such as photochemistry, photocatalysis, photovoltaic conversion and so on.