SEM (Scaning Electron Microscope) image of GaAs nanowire crystal grown on a Silicon substrateIs it really possible to concentrate Sunlight upto 15 times of the normal sun light intensity? The Awnser is yes!
According to the new study released by Scientists from the Nano-Science Center at the Niels Bohr
Institut, Denmark and the Ecole Polytechnique Fédérale de Lausanne,
Switzerland, have shown that a single nanowire can concentrate the
sunlight up to 15 times of the normal sun light intensity. According to the researchers, this throws light into the development of a new breed of High efficiency Solar Cells.
The Researchers demonstrated, that the Nano wires have a unique yet intriguing light absorption property, which enables it to utilize more sunlight that can it absorbs. The results demonstrate by the scientists, draw light into the great potential of development of
nanowire-based solar cells. The research groups have during recent years studied how to develop and
improve the quality of the nanowire crystals, which is a cylindrical
structure with a diameter of about 10,000 part of a human hair.
The Creation of Resonance is the Key:
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. Thus, the resonances can give a
concentrated sunlight, where the energy is converted, which can be used
to give a higher conversion effeciency of the sun's energy, says Peter
Krogstrup, the postdoc in Center for Quantum Devices, Niels Bohr Institute., who with this discovery contributes to that the research in
solar cell technology based on nanowires get a real boost.
New Efficiency Level Created:
The typical efficiency limit - the so-called "Shockley-Queisser
Limit" - is a limit, which for many years has been a landmark for solar
cells efficiency among researchers, but now it seems that it may be
increased.
"It's exciting as a researcher to move the theoretical limits, as we
know. Although it does not sound like much, that the limit is moved by
only a few percent, it will have a major impact on the development of
solar cells, exploitation of nanowire solar rays and perhaps the
extraction of energy at international level. However, it will take some
years years before production of solar cells consisting of nanowires
becomes a reality," says Peter Krogstrup who just completed his PhD at
the Niels Bohr Institute, University of Copenhagen.
Article Written by Manu Krishnan
Article Written by Manu Krishnan
