Light to direct current (dc) : an antenna's flights of fancy

Recently, the United States at Georgia tech engineers developed a optical rectifying antenna, can convert light directly into direct current. The researchers believe that this outcome is expected to provide a new optical detection without refrigeration technology, can also collect waste heat into electricity, and eventually become a new way of utilizing solar energy.

The optical rectifying antenna can work at 5 ℃ to 77 ℃ temperature, based on carbon nanotubes as an antenna, capture the sun or other light source. When light waves hit the nanotubes, the oscillation will charge through the rectifier, rectifier in thousands MHZ frequency switch, small dc. Although the equipment efficiency is only 1%, but billions of rectifying antenna arranged in array, can produce strong currents.

Rectifying antenna development in the sixties and seventies of the last century, about 10 microns in general the wavelength range of work, and the new rectifying antenna into the visible light range, require the antenna and rectifier diode is small enough to capture the electromagnetic oscillation and can very quickly. George woodruff school of mechanical engineering, associate professor at barak figure DE cora explained: "the essence of rectifying antenna ?

Physicists network reported, the researchers first on a conductive substrate grow vertically aligned carbon nanotube bundle, then use a variety of nano manufacturing technology made of metal, insulation, metal multilayer structure of the rectifier. At work, oscillation waves of light through the calcium - aluminum electrodes and interact with nanotubes, the rectifier can be at the top of the nanotubes with femtosecond speed switch, let the antenna of electrons from one direction only into the electrode.

Cora said, now create a rectifying antenna still need to improve efficiency, carbon nanotubes to achieve more open, to reduce the resistance of conductive channels will eventually produce efficiency is two times, cheaper solar cells.

The researchers also hope that through optimization technology to improve the output power, they may believe that commercial rectifying antenna