Marking a revolution in the chip industry for electronics, American scientists have designed the world's first semiconductor-free, optically controlled microelectronic device. Without semiconductors, the newly designed device can transmit electricity 1,000 times better than other electronic devices.

The rare feat was achieved by the engineers at the University of California San Diego who came up with the first ever semiconductor-free microelectronic device that is optically controlled. The details of the study were published in Nature Communications on Nov. 4, with the paper analyzing the limitations of transistors, as they are hamstrung by constraints of semiconductors.

A Chip Like No Other

The chip can be triggered by a low-voltage electric source or low-power laser source, unlike semiconductors that require a huge external trigger to start the flow of electrons. Expected to act as a fillip for designing microelectronic devices, the semiconductor-free chip will be faster and capable enough to handle more power such as in superefficient solar panels.

Among the demerits of semiconductors included "band gap" that mandates trigger by a huge external energy to expedite the flow of electrons. It is further compounded by the slow pace in electron velocity by the constant collision with atoms while passing through a semiconductor.

Electrical engineering professor Dan Sievenpiper, as the team leader, wanted the removal of all barriers in conductivity as a high priority. By replacing semiconductors with free-flowing electrons in space, the newly designed chip makes no requirement of high voltage power (100 volts), high power lasers or high temperatures in triggering electrons as required in semiconductors.

Ideal For Special Applications

The metamaterial-made chip has an engineered surface known as metasurface, which is affixed on top of a silicon wafer with a silicon dioxide layer acting as the buffer. The parallel gold strips in the metasurface can absorb low DC voltage (under 10 volts) and low power infrared lasers to trigger hot spot electric fields of huge intensity.

Elated by the results that proved 1,000 percent more conductivity, researcher Ebrahim Forati said that the device leaves more electrons for manipulation.

Sievenpiper also noted that the achievement is modest given that the material device may not replace all semiconductor devices. However, there is a bright scope in trying them for specialty applications, including high frequencies or high power devices.

It may be noted that metasurfaces will vary depending on the application and needs to be optimized differently. Besides electronics, the team is also looking to widen the technology into photochemistry, photocatalysis and photovoltaic devices for use in environmental applications. This must be good news for the chip sector's future growth.

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