A collaboration between researchers in the UK and China recently led to the publication of the 8000th research article describing cutting edge science carried out at Diamond Light Source. Professor David Lidzey from the University of Sheffield and his collaborator Professor Tao Wang from Wuhan University of Technology published their findings in Nano Energy with implications for the future of solar cells.
Fullerene molecules known as “Bucky balls” have been used as charge acceptors in solar cells for a long time. Researchers used Diamond Light Source to investigate new acceptor molecules that would be cheaper to manufacture. They discovered that depending on the molecule and the way that it was blended with polymers, they were able to see a significant efficiency increase over traditional compositions. The added efficiency came from the fact that the new compositions could absorb light over a broader wavelength range. This means that if used in solar cells, they will be able to use more of the sun’s light than is possible using current materials.
The added efficiency comes from the molecules themselves as well as the way they are blended and cast. Using the GWAXS technique at Diamond, the researchers found that flat acceptor molecules were able to stack very efficiently and that the production method allowed them to self-organise on nanometre length scales allowing aggregates to form that extend the wavelengths that can be absorbed.
Image: A representation of a “bucky ball” or fullerene molecule, commonly used as charge acceptors in solar panels.