Plasmonic SolarMonday 15th September 2014
The shape of a centuries-old Buddhist singing bowl has inspired a Canberra,Australia, scientist to re-think the way that solar cells are designed to maximize their efficiency.
Dr Niraj Lal, of the Australian National University (ANU), found during his PhD at the University of Cambridge, that small nano-sized versions of Buddhist singing bowls resonate with light in the same way as they do with sound, and he’s applied this shape to solar cells to increase their ability to capture more light and convert it into electricity.
Normally used in meditation, music, and relaxation, Buddhist singing bowls make a continuous harmonic ringing sound when the rim of the metal bowl is vibrated with a wooden or other utensil.
During his PhD, Niraj discovered that his ‘nanobowls’ manipulated light by creating a ‘plasmonic’ resonance, which quadrupled the laboratory solar cell’s efficiency compared to a similarly made flat solar cell.
Now, Niraj and his team aim to change all that by applying his singing-bowl discovery to tandem solar cells: a technology that has previously been limited to aerospace applications.
In research, published in the IEEE Journal of Photonics, Niraj and his colleagues have shown that by layering two different types of solar panels on top of each other in tandem, the efficiency of flat rooftop solar panels can achieve 30%—currently, laboratory silicon solar panels convert only 25% of light into electricity, while commercial varieties convert closer to 20%.
The tandem cell design works by absorbing sunlight more effectively —each cell is made from a different material so that it can ‘see’ a different light wavelength.
Niraj and a team at ANU reckon that can super-charge the tandem cell design by applying the Buddhist singing bowl shape, further increasing efficiency.
Source: Science In Public.
Monday 15th September 2014