According to reports, engineers have produced the first light-controlled microelectronic device that does not require semiconductors. The microdevice uses a new superconducting material, which can increase the conductivity by 10 times when activated by a low-voltage and low-power laser pointer. This discovery paved the way for the development of faster and more powerful semiconductor-free microelectronics and more efficient solar panels.
According to reports, the performance of existing microelectronic devices such as transistors will be limited by the material composition. Semiconductors have a band gap, which means they need external energy to make electrons flow. The speed of electrons is limited, because electrons will continue to collide with atoms when flowing through the semiconductor, so the semiconductor will limit the conductivity or current of the device.
Releasing electrons from materials is a very challenging task, requiring high-voltage, high-energy lasers above 100 volts, or ultra-high temperatures above 540°C, which cannot be applied to micro and nano-level electronic devices. A research team led by Dan Sevenpiper, a professor in the Department of Electronic Engineering at the University of California, San Diego, has found a new way to break the conductivity barrier and verified it on a microscopic scale.
The micro-devices they made can release electrons from the material without the extreme conditions mentioned above. The device contains an engineered "metasurface" composed of mushroom-shaped gold nanostructures on top of an array of parallel gold strips. This design enables the metasurface to generate "hot spots" with high-intensity electric fields when low voltages below 10 volts and low-energy infrared light are applied, so as to provide enough energy to pull electrons out of the metal and release them. Experiments show that the conductivity of the device has increased by more than 10 times.
The researchers said that although this cannot completely replace all semiconductor devices, it is the best way green laser pointer for some very high frequency or power devices. At present, the research team is exploring other applications of this technology besides electronics, so as to make it possible to produce new photovoltaic devices.