Nanotechnology set to ramp up photovoltaics efficiency
Solar cells may be at the threshold of becoming dramatically more effective thanks to nanotechnology.
Scientists from the Nano-Science Centre at the Niels Bohr Institut, Denmark and the Ecole Polytechnique Fédérale de Lausanne, Switzerland, have shown that a single nano-wire can concentrate sunlight up to 15 times of the normal sun light intensity.
The results are definitely surprising and the potential for developing a new type of highly-efficient solar cells is great.
Due to some unique physical light absorption properties of nanowires, the limit of how much energy we can utilise from the sun’s rays is higher than previous believed.
These results demonstrate the great potential of development of nanowire-based solar cells, according to the Niels Bohr Institut’s Dr Peter Krogstrup on the surprising discovery that is described in the journal Nature Photonics.
Research groups at both institutes have been trying to work out how to develop and improve the quality of the nanowire crystals, which is a cylindrical structure with a diameter of about 10,000th of a human hair.
The nanowires are predicted to have great potential in the development not only of solar cells, but also of future quantum computers and other electronic products.
It turns out that the nanowires naturally concentrate the sun’s rays into a very small area in the crystal by up to a factor 15.
Because the diameter of a nanowire crystal is smaller than the wavelength of the light coming from the sun it can cause resonances in the intensity of light in and around nanowires.
In turn, the resonances can give a concentrated sunlight, where the energy is converted and can be used to achieve a higher conversion efficiency of the sun’s energy than hitherto possible, according to Krogstrup.
It seems that this latest research will lead to a rewrite of the rules regarding photovoltaics efficiency . . . the so-called “Shockley-Queisser Limit”.
The research is conducted in collaboration with the Laboratory des Matériaux Semiconducteurs, Ecole Polytechnique Fédérale de Lausanne and the Danish firm SunFlake.