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August 05, 2009

Graphene has Current Carrying Capability 100-1000 times Copper and Graphane For Easier Electronic Device Construction

1. Recent research into the properties of graphene nanoribbons provides two new reasons for using the material as interconnects in future computer chips. In widths as narrow as 16 nanometers, graphene has a current carrying capacity approximately a thousand times greater than copper—while providing improved thermal conductivity.

Georgia Tech is claiming 100MA/cm2 current densities for graphene interconnect. Our measurements show that graphene nanoribbons have a current carrying capacity of more than 10^8A/cm2, while a handful of them exceed 109," said researcher Raghunath Murali. Thermal conductivity is also high - more than 1kW/m.K for structures less than 20nm wide.

2. In August’s Physics World, Kostya Novoselov - a condensed-matter physicist from the Manchester University group that discovered graphene -- explains how their discovery of graphane, an insulating equivalent of graphene, may prove more versatile still

Graphane has the same honeycomb structure as graphene, except that it is "spray-painted" with hydrogen atoms that attach themselves to the carbon. The resulting bonds between the hydrogen and carbon atoms effectively tie down the electrons that make graphene so conducting. Yet graphane retains the thinness, super-strength, flexibility and density of its older chemical cousin.

One advantage of graphane is that it could actually become easier to make the tiny strips of graphene needed for electronic circuits




Physicists in Manchester have found that by gradually binding hydrogen to graphene they are able to drive the process of transforming a conducting material into an insulating one and watch what happens in between.

Perhaps most importantly of all, the discovery of graphane opens the flood gates to further chemical modifications of graphene. With metallic graphene at one end and insulating graphane at the other, can we fill in the divide between them with, say, graphene-based semiconductors or by, say, substituting hydrogen for fluorine?

As Professor Novoselov writes, "Being able to control the resistivity, optical transmittance and a material’s work function would all be important for photonic devices like solar cells and liquid-crystal displays, for example, and altering mechanical properties and surface potential is at the heart of designing composite materials. Chemical modification of graphene – with graphane as its first example – uncovers a whole new dimension of research. The capabilities are practically endless."



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