Ultrathin graphene film offers new concept for solar energy

Researchers have developed a 2.5cm x 5cm working prototype of the graphene-based metamaterial absorber to demonstrate its photo-thermal performance.

Researchers at Swinburne, the University of Sydney and Australian National University have collaborated to develop a solar absorbing, ultrathin film with unique properties that has great potential for use in solar thermal energy harvesting.

The 90 nanometre material is 1000 times finer than a human hair and is able to rapidly heat up to 160°C under natural sunlight in an open environment.

This new graphene-based material also opens new avenues in:

  • thermophotovoltaics (the direct conversion of heat to electricity)
  • solar seawater desalination
  • infrared light source and heater
  • optical components: modulators and interconnects for communication devices
  • photodetectors
  • colourful display

It could even lead to the development of invisible cloaking technology through developing large-scale thin films enclosing the objects to be hidden.

The researchers have developed a 2.5cm x 5cm working prototype to demonstrate the photo-thermal performance of the graphene-based metamaterial absorber.

They have also proposed a scalable manufacture strategy to fabricate the proposed graphene-based absorber at low cost.

Swinburne’s Centre for Micro-Photonics nanophotonic solar technology research leader professor Baohua Jia said in this work, the reduced graphene oxide layer and grating structures were coated with a solution and fabricated by a laser nanofabrication method, respectively, which are both scalable and low cost.

Swinburne’s Centre for Micro-Photonics senior research fellow Dr Han Lin said the cost-effective and scalable graphene absorber is promising for integrated, large-scale applications that require polarisation-independent, angle insensitive and broad bandwidth absorption, such as energy-harvesting, thermal emitters, optical interconnects, photodetectors and optical modulators.

Director of the Institute of Photonics and Optical Science professor Martijn de Sterke said the result shows what can be achieved through collaboration between different universities, in this case with the University of Sydney and Swinburne.

“Each [are] bringing in their own expertise to discover new science and applications for our science.”

The research is published in Nature Photonics and has been funded by an Australian Research Council Discovery Project grant.