FiberCell, a company founded by Wake Forest University researchers, has been able to increase the efficiency of organic solar cells by adding what they call “light pipes” to their cells
. The light pipes do just what they sound like – they bring more sunlight to the solar cell. The light pipes, which are actually optical fibers sticking up from the surface of the cell, capture light from any angle – the photons entering the fiber bounces down the reflective surface of the pipe where they get delivered to the cell. The fibers themselves increase light absorption by about half – the other efficiency boost comes from the fact that the cells produce more electricity during the course of a day because they can take in light from different angles. As David Carroll, professor of physics at Wake Forest University says, “It’s the same thing as taking a flat device and pointing it directly at the sun all day long.”
Organic solar cells right now are much less efficient than silicon based solar cells – but they should be much cheaper to manufacture than silicon solar cells plus they can be made into flexible sheets. The most efficient organic solar cells right now have an efficiency rate of about 8%, although research is going on all the time to increase that. By increasing the amount of light hitting the cells, the FiberCell researchers are taking current organic cell design and doubling the output.
FiberCell is currently talking with investors – they want to produce roof tiles and other products that would benefit from being able to use light received from different angles.
FiberCell daily yield
via: Technology Review