The distance that energy can be moved in these materials comes as a big surprise.
- Richard Friend
The researchers, whose work appears in the journal Science, say their findings could be a “game changer” by allowing the energy from sunlight absorbed in these materials to be captured and used more efficiently.
Lightweight semiconducting plastics are now widely used in mass market electronic displays such as those found in phones, tablets and flat-screen televisions. However, using these materials to convert sunlight into electricity to make solar cells is far more complex.
The photo-excited states – when photons of light are absorbed by the semiconducting material – need to move so that they can be “harvested” before they lose their energy. These excitations typically only travel about 10 nanometres in plastic (or polymeric) semiconductors, so researchers need to build tiny structures patterned at the nanoscale to maximise the “harvest”.
Dr Xu-Hui Jin and colleagues at the University of Bristol developed a new way to make highly ordered crystalline semiconducting structures using polymers.
Dr Michael Price of Cambridge's Cavendish Laboratory measured the distance that the photo-exited states travelled, which reached distances of 200 nanometres – 20 times further than was previously possible.
Image: shows light emission from the polymeric nanostructures and schematic of a single nanostructure
Credit: University of Bristol
Reproduced courtesy of the University of Cambridge