Nanoscale antennae could make solar panels more efficient

Scientists at the University of Tel Aviv are creating nanoscale antennae that could be much more efficient than solar panels.

Radio waves are a type of electromagnetic wave, and when they are picked up by traditional metal antennas, the collision of the photon wave may for the photovoltaic effect, generate electrical current. Since the waves are also electromagnetic optics, and they are also carriers of energy, a team of scientists at the University of Tel Aviv wondered whether they could also be converted into electricity through an antenna. It turns out that they can - if the antenna is very, very short. They could replace the silicon semiconductors of solar panels, harvesting more energy from a wider spectrum of sunlight than is currently possible.

The nanoscale antennas are constructed from small amounts of aluminum and gold, and is less than one micron (a millionth of a meter) long - because the light has a wavelength short compared to radio waves, short antennae provide optimal absorption. Once created, the nanoscale antennae were exposed to light, to determine how well they can receive and transmit light energy. According to initial tests, 95% of the power is absorbed by the antennas.

The researchers believe that a panel containing a variety of lengths nanoscale antennas can collect energy from a solar spectrum much broader than is currently allowed by semiconductor technology.

Although silicon is not a particularly expensive material, scientists believe that the superior efficiency of their panels would allow them to be smaller than the photovoltaic panels, and therefore more profitable.