Silicene discovered: Single-layer silicon that could beat graphene to market

http://www.extremetech.com/computing/127887-silicene-discovered-single-layer-silicon-that-could-beat-graphene-to-market

Numerous research groups around the world are reporting that they have created silicene, a one-atom-thick hexagonal mesh of silicon atoms — the silicon equivalent of graphene.

Since its discovery a few years ago, you will have heard a lot about graphene, especially with regard to its truly wondrous electrical properties. Graphene is the most conductive material in the known universe, and IBM has shown that graphene transistors could be become the basis of transistors (and computers) that operate in the hundreds-of-gigahertz or terahertz (THz) range. There’s only one problem: Graphene isn’t really a semiconductor in the silicon/computer chip sense of the word. Unlike silicon (or germanium), graphene doesn’t have a bandgap, which makes it very hard to actually build a switching device — such as a transistor — out of it. Researchers have had some luck in introducing a bandgap, but graphene is still a long way away from being used in current silicon processes.

Silicene (pictured right) is more exciting than graphene because, technically, it should be compatible with silicon-based electronics and the huge, existing semiconductor fabrication processes.

In this case, each of the research groups created a silicene sheet by condensing vaporized silicon on a silver substrate. It’s theorized that silicene should have very desirable electrical characteristics, similar to graphene, but for now we simply have evidence that silicene exists (it has been observed with a scanning tunneling electron microscope).

For further investigation of its properties, we need to grow silicene on an insulator. No less than four research groups have recently grown silicene on silver, though, so it’s fairly safe to assume that they’re now working on an insulating substrate that’s amenable to silicon vapor deposition. Considering no other semiconductor has really raised its head above silicon — a material which willprobably reach its physical limits in the next 5-10 years — it really would be handy if silicene turns out to be as miraculous as graphene.

Read more at Physical Review Letters (paywalled)