One does not expect to see such effects in organic molecules - which [...] tend to resemble a plate of cooked spaghetti
- Simon Gélinas
By using an ultrafast camera, scientists say they have observed the very first instants following the absorption of light into artificial yet organic nanostructures and found that charges not only formed rapidly but also separated very quickly over long distances - phenomena that occur due to the wavelike nature of electrons which are governed by fundamental laws of quantum mechanics.
This result surprised scientists as such phenomena were believed to be limited to "perfect" - and expensive - inorganic structures; rather than the soft, flexible organic material believed by many to be the key to cheap, 'roll-to-roll' solar cells that could be printed at room temperatures - a very different world from the traditional but costly processing of current silicon technologies.
The study, published in the journal Science, sheds new light on the mystery mechanism that allows positive and negative charges to be separated efficiently - a critical question that continues to puzzle scientists - and takes researchers a step closer to effectively mimicking the highly efficient ability to harvest sunlight and convert into energy, namely photosynthesis, which the natural world evolved over the course of millennia.
"This is a very surprising result. Such quantum phenomena are usually confined to perfect crystals of inorganic semiconductors, and one does not expect to see such effects in organic molecules - which are very disordered and tend to resemble a plate of cooked spaghetti rather than a crystal," said Dr Simon Gélinas, from Cambridge's Cavendish Laboratory, who led the research with colleagues from Cambridge as well as the University of California in Santa Barbara.
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Image: This is the experimental setup used to generate femtosecond laser pulses which serve as an ultrafast "flash " for the camera so that very rapid phenomenon can be filmed
Credit: Simon Gélinas
Reproduced courtesy of the University of Cambridge
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