June 21, 2010 European collaboration breakthrough in developing
research project has brought the world a step closer to
producing a new material on which future nanotechnology
could be based. Researchers across Europe, including NPL,
have demonstrated how an incredible material, graphene,
could hold the key to the future of high-speed electronics,
such as micro-chips and touchscreen technology.
has long shown potential, but has previously only been produced
on a very small scale, limiting how well it could be measured,
understood and developed. A paper published in Nature Nanotechnology
explains how researchers have, for the first time, produced graphene
to a size and quality where it can be practically developed and
successfully measured its electrical characteristics. These significant
breakthroughs overcome two of the biggest barriers to scaling
up the technology.
technology for the future
is a relatively new form of carbon made up of a single layer of
atoms arranged in a honeycomb shaped lattice. Despite being one
atom thick and chemically simple, graphene is extremely strong
and highly conductive, making it ideal for high-speed electronics,
photonics and beyond.
is a strong candidate to replace semiconductor chips. Moore's
Law observes that the density of transistors on an integrated
circuit doubles every two years, but silicon and other existing
transistor materials are thought to be close to the minimum size
where they can remain effective. Graphene transistors can potentially
run at faster speeds and cope with higher temperatures. Graphene
could be the solution to ensuring computing technology to continue
to grow in power whilst shrinking in size, extending the life
of Moore's law by many years.
microchip manufacturers, such as IBM and Intel, have openly expressed
interest in the potential of graphene as a material on which future
computing could be based.
also has potential for exciting new innovations such as touchscreen
technology, LCD displays and solar cells. Its unparalleled strength
and transparency make it perfect for these applications, and its
conductivity would offers a dramatic increase in efficiency on
to a usable size while maintaining quality
now, graphene of sufficient quality has only been produced in
the form of small flakes of tiny fractions of a millimeter, using
painstaking methods such as peeling layers off graphite crystals
with sticky tape. Producing useable electronics requires much
larger areas of material to be grown. This project saw researchers,
for the first time, produce and successfully operate a large number
of electronic devices from a sizable area of graphene layers (approximately
graphene sample, was produced epitaxially - a process of growing
one crystal layer on another - on silicon carbide. Having such
a significant sample not only proves that it can be done in a
practical, scalable way, but also allows the scientists to better
understand important properties.
second key breakthrough of the project was measuring graphene's
electrical characteristics with unprecedented precision, paving
the way for convenient and accurate standards to be established.
For products such as transistors in computers to work effectively
and be commercially viable, manufacturers must be able to make
such measurements with incredible accuracy against an agreed international
international standard for electrical resistance is provided by
the Quantum Hall Effect, a phenomenon whereby electrical properties
in 2D materials can be determined based only on fundamental constants
of nature. The effect has, until now, only been demonstrated with
sufficient precision in a small number of conventional semiconductors.
Furthermore, such measurements need temperatures close to absolute
zero, combined with very strong magnetic fields, and only a few
specialised laboratories in the world can achieve these conditions.
was long tipped to provide an even better standard, but samples
were inadequate to prove this. By producing samples of sufficient
size and quality, and accurately demonstrate Hall resistance,
the team proved that graphene has the potential to supersede conventional
semiconductors on a mass scale.
graphene shows the Quantum Hall Effect at much higher temperatures.
This means the graphene resistance standard could be used much
more widely as more labs can achieve the conditions required for
its use. In addition to its advantages of operating speed and
durability, this would also speed the production and reduce costs
of future electronics technology based on graphene. NPL's Professor
Alexander Tzalenchuk, and the lead author on the Nature Nanotechnology
paper, observes: "It is truly sensational that a large area of
epitaxial graphene demonstrated not only structural continuity,
but also the degree of perfection required for precise electrical
measurements on par with conventional semiconductors with a much
longer development history."
research team are hoping to go on to demonstrate even more precise
measurement, as well as accurate measurement at even higher temperatures.
They are currently seeking EU funding to drive this forward.
JT Janssen, an NPL Fellow who worked on the project, said: "We’ve
laid the groundwork for the future of graphene production, and
will strive in our ongoing research to provide greater understanding
of this exciting material. The challenge for industry in the coming
years will be to scale the material up in a practical way to meet
new technology demands. We have taken a huge step forward, and
once the manufacturing processes are in place, we hope graphene
will offer the world a faster and cheaper alternative to conventional
research was a joint project carried by the National Physical
Laboratory (UK), Chalmers University of Technology (Göteborg,
Sweden), Politecnico di Milano (Italy), Linköping University (Sweden)
and Lancaster University (UK).
for further information, please contact Alexander
out more about NPL's research into Quantum