BREAKTHROUGH IN SOLAR CELLS

Most of today's solar cells are made from silicon and are heavy, rigid, and expensive to produce. Yet organic solar cells – which are made from materials and elements found in plants and animals – hold the promise of being lightweight, flexible, and cheap to make. However, organic solar cells have not yet reached the sunlight-to-electricity efficiencies of their silicon-based counterparts, preventing their commercialisation.

Now, researchers from the University of Cambridge, in a global collaboration with experts from Canada, Belgium, New Zealand, and China, have discovered a new fundamental way for energy to move in organic materials at a speed up to thousands of times faster than normal, getting steps closer to fully realising the promise of organic photovoltaics. This could enable the next generation of organic solar cells to convert sunlight into electrical power and aid the battle against climate change. This "transient exciton delocalisation" allows energy to move and transfer to the surrounding electrical wires much faster than normal.

"This new mechanism provides many opportunities to significantly improve the performance of traditional organic solar cells," said Professor Sir Richard Friend of the Cavendish Laboratory, who co-led the study. "It's also opening up prospects of whole new types of devices based on inexpensive and adaptable organic materials."