Researchers at Aalto University in Finland say they have created metallic graphene nanoribbons that are five carbon atoms wide. The results suggest the ribbons could be used as metallic interconnects in future microprocessors.

Graphene nanoribbons have been suggested as ideal wires for use in future nanoelectronics: when reduced to the atomic scale, graphene is expected to outperform copper in terms of conductance and resistance to electromigration. Until now, graphene nanoribbons have been semiconducting, which hampers their use as interconnects. But the researchers have shown that certain atomically precise graphene nanoribbon widths are nearly metallic, in accordance with earlier predictions based on theoretical calculations.

The team used scanning tunneling microscopy to probe the material’s structure and properties with atomic resolution. “We measured the properties of individual ribbons and showed that ribbons longer than 5nm exhibit metallic behaviour,” said Dr Amina Kimouche, the lead author of the paper published recently in Nature Communications.

The results are said to pave the way for using graphene in future electronic devices. The team will now work on devices combining both metallic and semiconducting graphene nanostructures. “While we are far from real applications, it is an extremely exciting concept to build useful devices from these tiny structures and to achieve graphene circuits with controlled junctions between GNRs,” said Professor Peter Liljeroth