Silicon puts on a nickel coat to pass as graphene

Researchers' creation of a silicon-based field-effect transistor that mimics the electrical properties of graphene shows the battle for the future of electronics is still on.
Written by Lucy Sherriff, Contributor

There is often a significant delay between astonishing discoveries in science and their exploitation in technology. That's often because although the physics works, getting the engineering to play ball in the real world is hard. Superconducting materials that work at liquid nitrogen temperatures are a good example of this phenomenon.

During that delay, existing technologies have a chance to play catch-up — and perhaps silicon is doing that to graphene as we speak. Researchers in Romania and Greece report creating a silicon-based field-effect-transistor (FET) that mimics the electrical properties of graphene.

Graphene is a two-dimensional form of carbon. It is, effectively, a single layer of graphite, and because it is just one atom thick, it has some amazing properties, which have prompted speculation that the days of silicon were numbered. However, those properties are easily disrupted by impurities, which in turn are easily introduced, especially when trying to grow graphene on a silicon substrate.

Now, researchers in Greece and Romania have designed and built a silicon FET that behaves as though it is made of graphene.

This breakthrough builds on work from researchers at Pohang University in Korea who wondered if they might manage to emulate graphene by reducing the mass of charge carriers in silicon. It turns out that if you cover silicon in a thin metallic film, the effective mass of charge carriers in silicon is very similar to those of graphene.

The Greek and Romanian researchers put this discovery to work. They created a sandwich of silicon and nickel, with a two-dimensional electron gas between the layers. In the abstract of their paper in the journal of Nanotechnology, they wrote: "We have demonstrated that the two-dimensional electron gas channel is modulated by the gate voltage. The dependence of the drain current on the drain voltage has no saturation region, similar to a field-effect transistor based on graphene."

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