Smart wallpaper that traps light, heat to power homes
By growing graphene around
a textured metallic surface, researchers were able to create ultra-thin
graphene sheets that can more effectively capture light. This material could be
used in wallpapers, windows and smart electronics
Scientists have developed
new moth inspired, ultra-thin graphene sheets which can be used in a smart
wallpa per that could generate electricity from waste light or heat, and power
a host of applications at home.
Using a technique known as
nanotexturing, which involves growing graphene around a textured metallic
surface, researchers from the University of Surrey in the UK took inspiration
from nature to create ultrathin graphene sheets designed to more effectively
capture light.
Just one atom thick,
graphene is very strong but traditionally inefficient at light absorption.
To combat this, the team
used the nanopatterning to localise light into the narrow spaces between the
textured surface, enhancing the amount of light absorbed by the material by
about 90 per cent. “Moths' eyes have microscopic patterning that allows them to
see in the dimmest conditions,“ said Ravi Silva, Head of the University of
Surrey's Advanced Technology Institute.
“These work by channelling
light towards the middle of the eye, with the added benefit of eliminating
reflections, which would otherwise alert predators of their location,“ he said.
“We have used the same technique
to make an amazingly thin, efficient, light-absorbent material by patterning
graphene in a similar fashion,“ he said.
Graphene has already been
noted for its remarkable electrical conductivity and mechanical strength.
Researchers understood that
for graphene's potential to be realised as material for future applications, it
should also harness light and heat effectively.
“Solar cells coated with
this material would be able to harvest very dim light,“ Silva said.
“Installed indoors, as part
of future smart wallpaper or smart windows, this material could generate
electricity from waste light or heat, powering a numerous array of smart
applications,“ he said.
“New types of sensors and
energy harvesters connected through the Internet of Things would also benefit
from this type of coating,“ he said.
Graphene is only able to
absorb a small percentage of the light that falls on it making it unsuitable
for the kinds of optoelectronic technologies our `smart' future will demand,
said lead author Jose Anguita of the University of Surrey.
“Nanotexturing graphene has
the effect of channelling the light into the narrow spaces between
nanostructures, thereby enhancing the amount of light absorbed by the
material,“ said Anguita.
Graphene is traditionally
an excellent electronic material, but is inefficient for optical applications,
absorbs only 2.3 per cent of the light incident on it.
The new technique enhances
light absorption by 90 per cent across a broad spectrum, from the UV to the
infrared.
MM29FEB16
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