High conductivity is one of the major issues of graphene and this restricts it to be used as a base material for producing computer chips.
Researchers have been seeking for a solution for this problem ever since the discovery of the wonder material by Professor Konstantin Novoselov and Professor Andre Geim from the University of Manchester in 2004. Now, a University of Manchester team, headed by Geim and Novoselov, has demonstrated a transistor, which paves the way to use graphene as a replacement for silicon in computer chips.
Most of the existing high-frequency transistors made of graphene are not suitable to be packed closely in a computer chip, as they seep out more current, even in the nanomaterial’s high insulating state. Computer chips will melt due to this electric current leakage. The university team’s suggestion is to use graphene in the vertical direction rather than laterally. It developed a tunneling diode in which graphene was used as an electrode that transfers electrons into another metal through a dielectric.
The team then used a novel feature of graphene by which the energy of the tunneling electrons is strongly changed by an external voltage, creating a novel device called a vertical field-effect tunneling transistor. It fabricated the transistors by coupling graphene with atomic planes of molybdenum disulfide and boron nitride. The transistors were arranged in a layer-by-layer manner in a preferred sequence on an atomic scale.
The atomic-scale layer-cake superstructure offers a high level of functionality. According to Novoselov, several devices other than the tunneling transistor can be fabricated by using such atomic-scale assembly like photovoltaic devices, light emission diodes and much more.
Source: http://www.manchester.ac.uk