Electrical engineers at Stanford University in the USA have identified two promising new semiconductor materials which "share or even exceed some of silicon's desirable traits". A report published by the Stanford News Service (via Engadget) says that hafnium diselenide and zirconium diselenide can enable circuits that are just three atoms (0.66nm) thick - beyond the realms of possibility with silicon.
Associate professor of electrical engineering, Eric Pop, and post-doctoral scholar Michal Mleczko published a paper in Science Advances about their work on the new materials. The pair start by talking about the importance of 'rust'. With Silicon electronics the 'rust' (silicon dioxide) is important as it is a native insulator. The new semiconductor materials championed by the scientists are said to rust in an even more desirable way than silicon.
Hafnium diselenide and zirconium diselenide oxides are both 'high-K' insulators, "which enable lower power operation than is possible with silicon and its silicon oxide insulator," explains the source article. Furthermore the band gap, the energy needed to switch transistors on, is in the same electronics sweet spot as silicon.
Last but not least the two newly identified semiconductor materials have the headlining physical property that enables them to be fashioned into circuits just three atoms thick (two thirds of a nanometre). That's not a possibility with silicon circuitry where a 5nm limit has been observed - before undesirable changes in the material properties occur.
Mleczko and Pop admit there is a long way to go for their ultrathin diselenide circuits to become commercialised. Manufacturers will still need silicon but combined with the new materials the scientists foresee a future path to thinner, smaller circuits, and greater energy-efficiency.
