Graphene-based film may one day soon dramatically improve the efficiency of solar energy harvesting according to researchers at Swinburne University.
“At just 90-nanometres thick – 1000 times finer than the width of a human hair – this ultra-thin, graphene-based film may one day soon dramatically improve the efficiency of solar energy harvesting.
The film was developed by researchers led by Han Lin from Australia’s Swinburne University, and is detailed in a paper in the journal Nature Photonics.
It is capable of heating up rapidly to 160 degrees Celsius in natural sunlight in an unshaded environment, and promises to open new research avenues in fields as diverse as thermo-photovoltaics, solar seawater desalination and communications technology.”
Graphene Film – Abstract
“Broadband strong light absorption of unpolarized light over a wide range of angles in a large-area ultrathin film is critical for applications such as photovoltaics, photodetectors, thermal emitters and optical modulators.
Despite long-standing efforts in design and fabrication, it has been challenging to achieve all these desired properties simultaneously. We experimentally demonstrate a 12.5 cm2, 90-nm-thick graphene metamaterial with approximately 85% absorptivity of unpolarised, visible and near-infrared light covering almost the entire solar spectrum (300–2,500 nm).
The metamaterial consists of alternating graphene and dielectric layers; a grating couples the light into waveguide modes to achieve broadband absorption over incident angles up to 60°.
The very broad spectral and angular responses of the absorber are ideal for solar thermal applications, as we illustrate by showing heating to 160 °C in natural sunlight.
These devices open a novel approach to applications of strongly absorbing large-area photonic devices based on two-dimensional materials.”
Read More Thin and powerful
The research paper is called “A 90-nm-thick graphene metamaterial for strong and extremely broadband absorption of unpolarized light“. Image shows: A small piece of the newly designed ultra-thin film.
Source: Cosmos Magazine