Nanoantennas Replacement for Solar Cells?
“Plastic sheets containing billions of nanoantennas that collect heat energy generated by the sun and other sources could dramatically improve the use of a type of energy we are all aware of, but have no use for so far,” believe Scientists from the U.S. Department of Energy’s Idaho National Laboratory. They further predict that under the right conditions, the simulated nanoantennas could harvest up to 92% of energy at infrared wavelengths.
The problem with traditional solar cells is that they only use up to 20% of the visible light they collect, and those that are more efficient are too expensive for mass production. Another drawback is that traditional solar cells can generate energy only when there is sunlight present.
While traditional solar cells only use visible light, the nanoantennas use mid-infrared rays and this quality enables them to collect energy even after dark. This happens because this latest approach does not focus on collecting sunlight, but capturing abundant solar energy mid-infrared rays radiated by the Earth as heat after absorbing energy from the sun during the day. This means the energy can be generated 24 hours nonstop. Another big advantage of using this source of energy is that it can be produced even by industrial processes such as coal-fired plants.
Of course there is a catch, as there always is; while the energy can be harvested, the scientists have found no solution yet to convert the energy into electricity. For that more technological advances are required.