developing technologies that generate electricity from light and heat

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'Moth Eye' Graphene: New Breakthrough Increases Light Absorption Of Grap…

'Moth Eye' Graphene: New Breakthrough Increases Light Absorption Of Graphene

New material created at the University of Surrey in the U.K. can help develop technologies that generate electricity from light and heat.

By Tyler MacDonald | Feb 28, 2016 02:54 PM EST

Using a technique called nanotexturing, the team was able to increase the light absorption of graphene by localizing light into narrow spaces between the textured surface. (Photo : Twitter/SinaBahram)

In the continuously evolving field of graphene research, scientists from the University of Surrey have now created the most light-absorbent material ever seen for its weight, enabling researchers to create a host of new technologies, including "smart wallpaper" that can create electricity from excess light or heat.

The team made the discovery using a technique called nanotexturing, which is accomplished by growing graphene around a textured metallic surface, and combined this with nano-patterning in order to localize light into the narrow spaces between the textured surface. This was conducted in order to enhance the amount of light absorbed by the material, which is typically inefficient at light absorption.
"Nature has evolved simple yet powerful adaptations, from which we have taken inspiration in order to answer challenges of future technologies," Ravi Silva, who participated in the research, said in a press release.
"Moths' eyes have microscopic patterning that allows them to see in the dimmest conditions. 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. We have used the same technique to make an amazingly thin, efficient, light-absorbent material by patterning graphene in a similar fashion," he added.
Graphene has long been noted for its impressive electrical conductivity and mechanical strength, and while light absorption has never been its strong point, this is something that Silva and his team hope to change with their new research.
"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. It is now possible to observe strong light absorption from even nanometre-thin films," said José Anguita, lead author of the paper. "Typically a graphene sheet would have 2-3% light absorption. Using this method, our ultrathin coating of nanotextured few-layer graphene absorbs 95% of incident light across a broad spectrum, from the UV to the infrared."

Nanotextured graphene material possesses the ability to utilize very dim light and could be used to create "smart wallpaper" and "smart windows" that can generate electricity from light and heat, allowing them to act as power sources for numerous smart applications.
"We are looking for industry partners to exploit this technology and are keen to hear from innovative companies who we can explore the future applications of this technology with us," said Silva.
The findings were published in the Feb. 26 issue of Science Advances.