A team of European researchers claims to be the first to synthesize silicene, a new allotrope of element No. 14 that forms two-dimensional single-atom sheets rather than three-dimensional crystals. This could be good news for the semiconductor industry.
While graphene is the most conductive material in existence, its lack of a band gap can actually be a hindrance when you’re trying to build an effective transistor. IBM has shown it’s possible to build graphene transistors, but it may be a while before this type of research percolates from the lab to the factory. Silicene’s one-atom-thick structure could be even more effective in building faster transistors and computers, partly because of how its electrons are arranged.
A silicene sheet has a buckled honeycomb structure, seen below, in which a few atoms are arranged above and below the main sheet. Electrons in these locations have distinct energies, and when a voltage is applied, they can jump across the gap, allowing silicene to serve as an on-off transistor. Silicene sheets would thereby bring silicon’s superb on-off abilities to the smallest scales possible, while remaining compatible with existing fabrication processes and existing electronics. That’s something graphene can’t do, at least not yet.