One of the major reasons that solar panels are facing such hurdles to replace conventional electricity sources is because they are very inefficient. The most efficient (and most expensive) panel is currently somewhere around 32 percent efficiency. However, scientists in Switzerland have figured out a way to utilize Graphene in solar panel design, raising its efficiency to an absolutely staggering 60% - a finally feasible amount.
Graphene based solar panels will have energy efficiency of 60 percent
The experiment was conducted by a team from École Polytechnique Fédérale de Lausanne (EPFL)
and no I cannot pronounce that and they were able to convert a single photon into electorns, producing an electric current. They did this by placing a thin layer of Graphene into an ultra high vacuum chamber. Electrons were subtracted and added chemically before the process (graphene doping). Then, it was blasted with a super fast pulse of laser light which excited the electrons in Graphene and put the whole material into a higher energy state. Since electric conduction is relative the new state was higher than before, resulting in current, and once again as it reverted back to its old state. This phenomenon can then be conducted as an electric current and used for power, and it all happens in a matter of femtoseconds, so a few quadrillionths of a second.
“a kind of stop-motion movie of the conversion process”, says Dexter Johnson at IEEE Spectrum.
“This indicates that a photovoltaic device using doped graphene could show significant efficiency in converting light to electricity,” one of the team, materials scientist Marco Grioni, said in a press release.
It is all the more exciting because Graphene is an insanely amazing conductor of heat and electricity but uptill now it wasnt very good at absorbing light. A very big problem currently with a graphene based solar panel design is the fact that the edges of the graphene sheet are highly reactive, so harvesting the current would prove to be much more of a challenge. Similarly in its natural state, Graphene doesn't really want to absorb sunlight, something they will have to figure out a way to solve. We know that Graphene is a very efficient photo voltaic material, the question is now how to make it react to light and harvest electricity without destroying its composition.
You can read the research paper over at Nano Letters.