Every day more energy falls on the Earth in the form of sunlight than humanity uses, so it makes sense that we are trying to tap that power source. The means to best harvest the energy though is still being developed. Now researchers at the University of Pennsylvania have developed a new method to convert the energy of light to an electrical current that could be far more efficient than modern techniques.
Plasmons are quasiparticles created when photons and electrons couple on a metallic surface, which can allow the energy of the photon to be carried across the metal. That current though can be controlled by special patterns of gold nanoparticles and external electrical fields. When the Penn researchers have determined is that with the proper design, they can create a system to form a current of the hot electrons in plasmons, which can then be used to power a circuit. This discovery actually dates back to 2010, but it was only this recent experiment that confirmed it was the plasmonic nanostructure allowing the optical energy to be captured, and not something else.
According to the researchers' measurements, their process was achieving efficiencies three to ten times that of conventional photoexcitation methods. This is extremely promising for the new technique as they have not yet started to optimize it.
Source: University of Pennsylvania