Semiconductor-free Microelectronics Are Now Possible, Thanks to Metamaterials

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Engineers during a University of California San Diego have built a initial semiconductor-free, optically-controlled microelectronic device. Using metamaterials, engineers were means to build a microscale device that shows a 1,000 percent boost in conductivity when activated by low voltage and a low appetite laser.

The find paves a proceed for microelectronic inclination that are faster and able of doing some-more power, and could also lead to some-more fit solar panels. The work was published in Nature Communications.

The capabilities of existent microelectronic devices, such as transistors, are eventually singular by a properties of their basic materials, such as their semiconductors, researchers said.

Scanning nucleus micrograph images of a semiconductor-free microelectronic device (top left) and a bullion metasurface (top right, bottom). Image pleasantness of UC San Diego Applied Electromagnetics Group.

Scanning nucleus micrograph images of a semiconductor-free microelectronic device (top left) and a bullion metasurface (top right, bottom). Image pleasantness of UC San Diego Applied Electromagnetics Group.

For example, semiconductors can levy boundary on a device’s conductivity, or nucleus flow. Semiconductors have what’s called a rope gap, definition they need a boost of outmost appetite to get electrons to upsurge by them. And nucleus quickness is limited, given electrons are constantly colliding with atoms as they upsurge by a semiconductor.

A group of researchers in a Applied Electromagnetics Group led by electrical engineering highbrow Dan Sievenpiper during UC San Diego sought to mislay these roadblocks to conductivity by replacing semiconductors with giveaway electrons in space. “And we wanted to do this during a microscale,” pronounced Ebrahim Forati, a former postdoctoral researcher in Sievenpiper’s lab and initial author of a study.

However, liberating electrons from materials is challenging. It possibly requires requesting high voltages (at slightest 100 Volts), high appetite lasers or intensely high temperatures (more than 1,000 degrees Fahrenheit), that aren’t unsentimental in micro- and nanoscale electronic devices.

To residence this challenge, Sievenpiper’s group built a microscale device that can recover electrons from a element though such impassioned requirements. The device consists of an engineered surface, called a metasurface, on tip of a silicon wafer, with a covering of silicon dioxide in between. The metasurface consists of an array of bullion mushroom-like nanostructures on an array of together bullion strips.

The bullion metasurface is designed such that when a low DC voltage (under 10 Volts) and a low appetite infrared laser are both applied, a metasurface generates “hot spots”—spots with a high energy electric field—that yield adequate appetite to lift electrons out from a steel and acquit them into space.

Tests on a device showed a 1,000 percent change in conductivity. “That means some-more accessible electrons for manipulation,” Ebrahim said.

“This positively won’t reinstate all semiconductor devices, though it might be a best proceed for certain specialty applications, such as really high frequencies or high appetite devices,” Sievenpiper said.

According to researchers, this sold metasurface was designed as a proof-of-concept. Different metasurfaces will need to be designed and optimized for opposite forms of microelectronic devices.

“Next we need to know how distant these inclination can be scaled and a boundary of their performance,” Sievenpiper said. The group is also exploring other applications for this record besides electronics, such as photochemistry, photocatalysis, enabling new kinds of photovoltaic inclination or environmental applications.

Source: UC San Diego