Light Absorption Of Graphene Enhanced By New 'Moth Eye' Graphene
The continuously developing field of graphene research shows scientists from the University of Surrey building up the most light-absorbent material ever seen for its weight. Hence, experts have built up a number of new technologies, including "smart wallpaper", in order to generate electricity from excess light or heat.
The study was published in the Feb. 26 issue of Science Advances.
The technique used for its creation was nanotexturing, which was achieved by growing graphene on a textured metallic surface. It was combined with nano-patterning so that light could be confined into narrow spaces between the textured surfaces. It was undertaken so that it could enhance the amount of light absorbed. The material is usually not too effective in absorbing light.
"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's impressive electrical conductivity and mechanical strength has always been well-known. At present, its light absorption is hoped to be improved by the team headed by Silva.
"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 can use dim light to create "smart wallpaper" and "smart windows" that can generate electricity from light and heat. Hence, they would be power sources for a number of 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.