A new discovery from a chemist at the University of Texas at Austin may allow photovoltaic solar cells to double their efficiency, thus providing loads more electrical power from regular sunlight.
Not only that, but it’s way cheap. Chemistry professor Xiaoyang Zhu and his team discovered that an organic plastic semiconductor could double the number of electrons harvested out of one photon of sunlight. Yep, plastic.
For the Record, 12:15 p.m. Dec. 19.: An earlier version of this online article incorrectly said Queen's University is in Toronto. It is in Kingston, Ontario.
An issue with regular photovoltaic panels is that much of the energy delivered by sunlight comes in the form of “hot” electrons, which are too high-energy to be converted to electricity in silicon and are instead lost as heat. For that reason, the max insolation-to-electricity efficiency of a silicon solar cell used today is considered to be about 31%. Capturing those hot electrons could boost it to 66%.
Zhu’s process involves absorbing the photon of sunlight in a plastic – in his experiments, pentacene – to produce a dark quantum “shadow state” from which two electrons can be retrieved, instead of just one.
Right now, his experiments use ordinary sunlight, and not focused sunlight, and he’s getting 44% efficiency. That’s a big boost in electricity, and it means it could be done with ordinary rooftop panels.