New research could help enhance solar thermal energy harvesting

A unique solar absorbing material can rapidly heat up under natural sunlight.

Researchers in Australia have made advancement in solar thermal energy technology. The researchers at the University of Sydney, Swinburne University of Technology and the Australian National University collaborated to develop a solar absorbing film with unique properties that can quickly heat up to 160 degrees under natural sunlight in an open environment.

The novel graphene-based material is 1,000 times finer than a single human hair.

This ultrathin 90-nanometere material has great potential for use in solar thermal energy harvesting. More specifically, the material is believed to be potentially beneficial for thermophotovoltaics. This is a direct conversion of heat to electricity.

It may also be beneficial for solar seawater desalination, photodetectors, infrared light source and heater and optical components, such as modulators and interconnects for communication devices.

“We have developed a new class of optical material, the properties of which can be tuned for multiple uses,” says Professor Martijn De Sterke from the University of Sydney Nano Institute and School of Physics and the Director of the Institute for Photonics and Optical Science, reports R&D Mag.

The researchers developed a prototype to demonstrate the material’s solar thermal energy harvesting capabilities.

The 2.5cm x 5cm working prototype is capable of demonstrating the photo-thermal performance of the graphene-based metamaterial absorber.

The researchers have also come up with a scalable manufacture strategy to manufacture their proposed graphene-based absorber at low cost.

“In this work, the reduced graphene oxide layer and grating structures were coated with a solution and fabricated by a laser nanofabrication method, which are both scalable and low cost,” says Professor Baohua Jia, Researcher Leader, Nanophotonic Solar Technology, in Swinburne’s Centre for Micro-Photonics.

According to Dr. Han Lin – Senior Research Fellow and Swinburne’s Centre for Micro-Photonics and first author of the research paper published in the journal Nature Photonics – the researchers’ cost-effect and scalable graphene absorber show’s a lot of promise for integrated and large-scale applications, such as thermal emitters, energy-harvesting, optical modulators, optical interconnects, and photodetectors.

An Australian Research Council Discovery Project grant funded the solar thermal energy research.