Graphene is fairly often described as a potential replacement of silicon, but for one issue; the lack of a band gap. It turns out though that there are other issues preventing 300 GHz graphene transistors from being used. If such transistors were packed as densely as modern CPU transistors, the current leak would melt the chips in a fraction of a second. (No, the NH-D14 wouldn’t help with that.) Researchers at the University of Manchester have an idea for a solution though; build up instead of out.
The previous graphene transistors were built in a plane, which makes some sense since graphene is as close as one can get to an actual two dimensional object. The new design from Manchester has vertical graphene sheets and uses the material’s quantum mechanical properties. By placing the graphene on one side of a dielectric (resistant material) and a metal on the other, electrons can be made to tunnel through the dielectric. This will greatly reduce the energy and current needed for operation. Not only will the graphene encourage the electrons to tunnel, but it has the peculiar effect of allowing an external voltage to change the energy of the tunneling electrons.
Putting this all together makes the design the first vertical field-effect tunneling transistor. With further work, the researchers believe the transistor can be improved and scaled down in size to just nanometers. Ironically though, the transistor design itself may not be the most important aspect of this research. Instead it is how the researchers built the transistor one atomic layer at a time. Such control will allow for even more amazing structures to be made.