As transistors in ICs become smaller and smaller, they need higher and higher current densities to perform at the desired level. Most conventional electrical conductors, such as copper, tend to break due to overheating or other factors at high current densities, presenting a barrier to creating increasingly small components.
The electronics industry, therefore, needs alternatives to silicon and copper that can sustain extremely high current densities at sizes of just a few nanometres.
The advent of graphene resulted in a massive, worldwide effort directed at investigation of other 2D layered materials that would meet the need for nanoscale electronic components that can sustain a high current density. While 2D materials consist of a single layer of atoms, 1D materials consist of individual chains of atoms weakly bound to one another, but their potential for electronics has not been as widely studied.
UC discovered that ZrTe3 nanoribbons have an exceptionally high current density that far exceed that of any conventional metals like copper,pushing research from 2D to 1D materials.
"Conventional metals are polycrystalline. They have grain boundaries and surface roughness, which scatter electrons," professorAlexander A. Balandin of UC, said. "Quasi-1D materials, such as ZrTe3, comprise single-crystal atomic chains in one direction. They don’t have grain boundaries and often have atomically smooth surfaces after exfoliation. We attributed the high current density in ZrTe3 to the single-crystal nature of quasi-1D materials."
Such materials have the potential to be grown directly into nanowires with a cross-section that corresponds to an individual atomic thread or chain, explains UC.
In the present study, the level of the current sustained by the ZrTe3 quantum wires was higher than reported for any metals or other 1D materials. It almost reaches the current density in carbon nanotubes and graphene.
Electronic devices depend on special wiring to carry information between different parts of a circuit or system. As developers miniaturise devices, their internal parts also must become smaller, and the interconnects that carry information between parts must become smallest of all. Depending on how they are configured, the ZrTe3 nanoribbons could be made into either nanometre-scale local interconnects or device channels for components of the tiniest devices.
UC’s experiments were conducted with nanoribbons that had been sliced from a pre-made sheet of material. Industrial applications need to grow nanoribbon directly on the wafer. This manufacturing process is already under development, and Prof. Balandin believes 1D nanomaterials hold possibilities for applications in future electronics.
