Slashdot Mirror
Graphene Conducts Electricity Ten Times Better Than Expected
ananyo writes "Physicists have produced nanoribbons of graphene — the single-atom-thick carbon — that conduct electrons better than theory predicted even for the most idealized form of the material (abstract). The finding could help graphene realize its promise in high-end electronics, where researchers have long hoped it could outperform traditional materials such as silicon. In graphene, electrons can move faster than in any other material at room temperature. But techniques that cut sheets of graphene into the narrow ribbons needed to form wires of a nano-scale circuit leave ragged edges, which disrupt the electron flow. Now a team led by physicist Walt de Heer at the Georgia Institute of Technology in Atlanta has made ribbons that conduct electric charges for more than 10 micrometres without meeting resistance — 1,000 times farther than in typical graphene nanoribbons. The ribbons made by de Heer's team in fact conduct electrons ten times better than standard theories of electron transport they should, say the authors."
Graphene has very high conductivity for what it is: a monoatomic layer. This is important in ICs where certain material thicknesses are in the nanometres. Also graphene has a very specific and uniform thickness, which solves uniformity problem when trying to deposit 1 nm material uniformly across 300 mm wafers. But when you can afford to increase the thickness (in macroscopic systems), metals become much more conductive than "macroscopic grahene," which is just regular graphite and is not so conductive. Actually graphite is used as electronic resistors and in certain heater elements (as it is conductive enough to pass large currents, but resistive enough to heat a lot by Joule effect and finally stands very well high temperatures).
You are correct that using graphene or carbon nanotubes (which are close cousins) only for the wiring wouldn't gain you much; especially since large resistances can arise from the junctions between two conductors/materials.
People are certainly investigating how to turn graphene and nanotubes into transistors. There have been demonstrations of using an applied voltage to mechanically 'kink' a nanotube so that its resistance changes. Thus it can be used as a non-volatile memory element. (The kinking is reversible and fast.) Others have looked into ways to 'dope' graphene by controlling what material it is sitting on top of (which changes its electrical properties, similar to doping atoms into silicon). Things like this can be used to make transistors out of these carbon nanomaterials; and in principle to do it in a way where the conducting carbon network is unbroken.
Of course, the devil is in the details. We've seen demonstrations of many pieces of the puzzle, but turning it all into a technology (where you can build it all easily on a single substrate, in a scalable way, etc.) is still a ways off. But there is at least a chance these materials will pan out.
P.S.: Don't let this comment distract from the legitimate outcry against Slashdot Beta.