Researchers at Samsung’s Advance Institute of Technology have developed a new transistor structure using everyone’s favourite two-dimensional material, Graphene.
Despite its wonderful conductivity, electron mobility and so on that make it such an alluring prospect for chip designers bumping into the physical limits of silicon, it has no band gap. This means it has no way of switching off current flow, which makes it all but useless for logic transistors which need both logic state 1 and 0.
Samsung’s researchers have taken a new approach to this stumbling block, and report achieving an on/off ration of 100,000 without spoiling graphene’s stunning electron mobility.
The Schottky barrier is a potential energy barrier formed at the interface between a metal (graphene in this case, as it is semi-metallic) and a semiconductor. It prevents an electric charge flow from metal to silicon, Samsung explains in the announcement: “Generally, metal-semiconductor junction would have fixed work function and Schottky barrier height, but for graphene, Schottky barrier height can be controlled through the work function, [the amount of energy required to remove an electron from the material].”
The work was published in the online version of the journal Science on May 17.