Researchers learn how to tame 'wild' electrons in graphene

Graphene breakthrough paves way for nano-transistors

Scientists working at Rutgers University in New Brunswick have discovered a way to manage "unruly" electrons that move through graphene, potentially paving the way for nano-transistors and radically smaller electronic devices.

Graphene is a better electrical conductor than copper and could be used in electronics, except that specialists have struggled to work out a way to stop the electrons that freely flow through the material.

However, this advancement in graphene research, according to the scientists, could pave the way for the ultra-fast transportation of low-loss-energy electrons in novel systems.

Published in the journal Nature Nanotechnology, the study was led by Rutgers postdoctoral fellows Yuhang Jiang and Jinhai Mao, along with a graduate student at the University of Antwerp in Belgium.

Eva Y. Andrei, board of governors professor in Rutgers' department of physics and astronomy and the study's senior author, said: "This shows we can electrically control the electrons in graphene.

"In the past, we couldn't do it. This is the reason people thought that one could not make devices like transistors that require switching with graphene, because their electrons run wild."

Andrei added that her team's research means it should now be possible to generate graphene nano-scale transistors. Up until now, graphene electronics have consisted of ultra-fast amplifiers, supercapacitors and ultra-low resistivity wires.

With the addition of this transistor, specialists can work towards developing all-graphene electronics platforms. This technology is being used in ultra-sensitive chemical and biological sensors, filters for desalination and water purification, as well as flat flexible screens and electronic circuits.

Graphene is a bi-directional crystal structure found in the nano-thin layer of carbon-based graphite in pencils. It is both stronger than steel and also an effective conductor - indeed, too effective for many uses.

But as a result of electrons moving through it, there are straight lines and high velocity, Andrei explained. "If they hit a barrier, they can't turn back, so they have to go through it, People have been looking at how to control or tame these electrons."

To tame the wild electrons, the researchers sent a voltage through a high-tech microscope. They came up with a result similar to an optical system.

Andrei added: "You can trap electrons without making holes in the graphene," she said. "If you change the voltage, you can release the electrons. So you can catch them and let them go at will."