Researchers at the University of Manchester have found a way to predictably switch graphene out of its highly-conductive mode - the highlight of a month that has seen graphene announcements worldwide.
The material, discovered at Manchester in 2004, is a mono-layer of carbon atoms that resembles nano-chicken wire.
Effectively un-rolled carbon nanotube, the two-dimensional substance has a carrier mobility far above that of silicon and is a candidate for combining fast nano-carbon semiconductors with the planar process favoured by industry.
Until now, predictable grown and useful band-gap manipulation have been impossible.
Revealed in the journal Science, Manchester converted metallic conducting graphene to an insulating form dubbed graphane in a process that can be reversed by heating.
"We have placed hydrogen on graphene, and it bonds, very nicely," Manchester scientist Dr Kostya Novoselov told Electronics Weekly.
Something similar was done previously by other researchers with hydroxide ions to form graphene oxide, said Novoselov, but the lattice was badly damaged in the process.
The work proves atoms can be attached to graphene to modify its electronic properties, and suggests the lattice could support local modification to form conductor/insulator patterns.
Two weeks ago, in an unrelated programme, researchers at the US Rensselaer Polytechnic Institute revealed they had also modified the band gap of graphene - this time in a computer using large-scale quantum mechanical simulations.
Published in Applied Physics Letters, Rensselaer's results predict that modification of an underlying SiO2 substrate would have a similar effect.
"When deposited on a surface treated with oxygen, graphene exhibits semiconductor properties," said the Institute, "When deposited on a material treated with hydrogen, however, graphene exhibits metallic properties."
In this case, according to Manchester's Novoselov, hydrogen's bonds are used up on the substrate, stopping it bonding to the graphene, whereas oxygen can still bond with the graphene, changing its structure and electron behaviour.
It is unclear whether this theoretical structure could be turned into a real structure.
Good quality graphene is literally flaked from samples of graphite - the black rock that used to be used in pencils. The flakes are deposited on a substrate and then manipulated.
It can be grown, but the resultant material was almost useless - until earlier in January when Korean scientist revealed a technique so good that they used to prepare transparent electrodes on a flexible substrate.
From Sungkyunkwan University and Samsung Advanced Institute of Technology, the researchers used chemical vapour deposition on nickel layers to make the graphene, then not only patterned it, but found a way to transfer it to a plastic substrate.
According to a letter published in Nature, the transferred films have a sheet resistance around 280Ω/square, with approximately 80% optical transparency.
On SiO2, electron mobility in the Korean material is over 3,700cm2/Vs. This and measured quantum effects suggest the film is as good at flaked graphene.
"Half a year ago, if anyone had asked me if we would ever have wafers of graphene, I would have said no. Now I would say yes," said Manchester's Novoselov. "Over this month, graphene has become exciting."
While January had materials revelations, December had a significant graphene device announcement when IBM Researchers demonstrated a 26GHz FET - the highest frequency claimed for a graphene device yet.
Published in NanoLetters, the top gate device, with a 150nm long gate, was built on a graphene flake laying on an SiO2 surface using Al2O3 gate oxide.
"The researchers expect that by improving the gate dielectric materials, the performance of these graphene transistors could be further enhanced," said IBM. "They expect that THz graphene transistors could be achieved in an optimised device with a gate length of 50nm."