Graphene, a wonder material that has been theorised for decades but which was only synthesised in 2004, is up to 200 times stronger than the strongest steel, and is just one atom thick.
The research suggests that indoor solar cells that capture energy from indirect sunlight, as well as ambient energy from household devices could become a reality, possibly in the form of smart wallpaper.
The Advanced Technology Institute examined the ways that a moth’s eye efficiently traps electromagnetic waves, and was then able to mimic the surface of a moth’s eye and create a thin, efficient, light-absorbent material made of graphene, which is more conductive than copper and as flexible as rubber.
The work suggests that the new technology could capture light from the visible and invisible spectrum, something that was previously thought impossible.
In the paper published in Science Advances, the researchers said the ability to engineer a thin two-dimensional surface for light trapping across an ultra-broad spectral range is central for an increasing number of applications including energy, optoelectronics, and spectroscopy.
By combining the broadband light–coupling effect from nanometer-scale absorbers in the disordered nanotextures, and taking into account the natural thinness and remarkably high and wavelength-independent absorption of graphene results in an ultrathin yet ultra-broadband blackbody absorber, with 99% absorption of the spectrum spanning from the mid-infrared to the ultraviolet.
The next step would be the development of rectennas – rectifying antennas – a concept first conceived in 1964 that can convert electromagnetic energy into direct current electricity.
Rectennas would be able to efficiently capture and convert energy from ambient microwave and radio frequencies from household devices, such as smartphones, computers and lightbulbs.
This scavenged energy could then be used to power smart sensors and Internet of Things devices in the home without the need for batteries or wired connectivity.
However, development of the next generation solar cells could be at least a decade away.
