The scientists have developed a new method for adding an extended defect to graphene, a one-atom-thick planar sheet of carbon atoms that many believe could replace silicon as the material for building virtually all electronics.

To be useful in electronic applications like integrated circuits, small defects must be introduced to the material. Previous attempts at making the necessary defects have either proved inconsistent or produced samples in which only the edges of thin strips of graphene or graphene nanoribbons possessed a useful defect structure. Atomically-sharp edges are difficult to create due to natural roughness and the uncontrolled chemistry of dangling bonds at the edge of the samples.

The USF team has now found a way to create a well-defined, extended defect several atoms across, containing octagonal and pentagonal carbon rings embedded in a perfect graphene sheet. This defect acts as a quasi-one-dimensional metallic wire that easily conducts electric current. Such defects could be used as metallic interconnects or elements of device structures of all-carbon, atomic-scale electronics.

The scientists synthesized two graphene half-sheets translated relative to each other with atomic precision. When the two halves merged at the boundary, they naturally formed an extended line defect. Both scanning tunneling microscopy and electronic structure calculations were used to confirm that this novel one-dimensional carbon defect possessed a well-defined, periodic atomic structure, as well as metallic properties within the narrow strip along the defect.

This tiny wire could have a big impact on the future of computer chips and the myriad of devices that use them, they may provide a crucial step in the development of smaller, yet more powerful, electronic devices in the not-too-distant future.