Intel's doing a bang-up job and shrinking transistors and packing them in tighter than ever before, but let's face it: it's going to be hard to scale silicon down much further. That eventual wall is why engineers are pumped about the potential of graphene, a substance with more than 200 times the electron mobility of silicon. (Read: better potential performance.) Coaxing graphene transistors into switching off current to create the 1 and 0 signals we know and love has been tricky, however. Now Samsung says it's developed a solution that does just that, without limiting graphene's electron mobility.
That last part is key: most of the previous solutions to graphene's electric current woes involved transforming the material into a semi-conductor, but doing so reduced its electron mobility -- thereby eliminating much of its performance gain over silicon.
Samsung Electronics' R&D arm, the Samsung Advanced Institute of Technology, created a special three-terminal Schottky barrier (dubbed the "Barristor" by Samsung) that can be raised or lowered in order to allow or impede the flow of electrical. The three-terminal device is basically a gate.
So how does Barristor stop current without mucking up electron mobility? From the abstract:
The key is an atomically sharp interface between graphene and hydrogenated silicon. Large modulation on the device current (on/off ratio of 10^5) is achieved by adjusting the gate voltage to control the graphene-silicon Schottky barrier.
Subscribers to the Science journal can check out the full text for an even more in-depth and jargon-filled explanation. It was published on the website yesterday.