Graphene – often touted as the ‘wonder material’ – can transmit extremely high currents, making it a potential building block for next-generation ultra-fast electronics, scientists say.
Researchers from Technische Universitat Wien (TU Wien) in Austria showed that the electrons in graphene are extremely mobile and react very quickly.
Impacting xenon ions with a particularly high electric charge on a graphene film causes a large number of electrons to be torn away from the graphene in a very precise spot.
However, the material was able to replace the electrons within some femtoseconds. This resulted in extremely high currents, which would not be maintained under normal circumstances.
Its extraordinary electronic properties make graphene a very promising candidate for future applications in the field of electronics.
“We work with extremely highly-charged xenon ions. Up to 35 electrons are removed from the xenon atoms, meaning the atoms have a high positive electric charge,” said Elisabeth Gruber from TU Wien.
These ions are then fired at a free-standing single layer of graphene, which is clamped between microscopically small brackets.
“The xenon ion penetrates the graphene film, thereby knocking a carbon atom out of the graphene – but that has very little effect, as the gap that has opened up in the graphene is then refilled with another carbon atom,” said Gruber.
“For us, what is much more interesting is how the electrical field of the highly charged ion affects the electrons in the graphene film,” she said.
This happens even before the highly charged xenon ion collides with the graphene film. As the highly charged ion is approaching it starts tearing electrons away from the graphene due to its extremely strong electric field.
By the time the ion has fully passed through the graphene layer, it has a positive charge of less than ten, compared to over 30 when it started out.
The ion is able to extract more than 20 electrons from a tiny area of the graphene film.
This means that electrons are now missing from the graphene layer, so the carbon atoms surrounding the point of impact of the xenon ions are positively charged.
This extremely high electron mobility in graphene is of great significance for a number of potential applications.
“The hope is that for this very reason, it will be possible to use graphene to build ultra-fast electronics,” said researchers.
“Graphene also appears to be excellently suited for use in optics, for example in connecting optical and electronic components,” they added.
The study was published in the journal Nature Communications.—PTI