The researchers, led by the University of Cambridge, identified a loss pathway in organic solar cells which makes them less efficient than silicon-based cells at converting sunlight into electricity. In addition, they identified a way to suppress this pathway by manipulating molecules inside the solar cell to prevent the loss of electrical current through an undesirable state, known as a triplet exciton.
Their results, reported in the journal Nature, suggest that it could be possible for organic solar cells to compete more closely with silicon-based cells for efficiency.
Organic solar cells, which are flexible, semi-transparent, and cheap, can greatly expand the range of applications for solar technology. They could be wrapped around the exteriors of buildings and can be used for the efficient recycling of the energy used for indoor lighting, neither of which are possible with conventional silicon panels. They are also far more environmentally friendly to produce.
“Organic solar cells can do lots of things that inorganic solar cells can’t, but their commercial development has plateaued in recent years, in part due to their inferior efficiency,” said Dr Alexander Gillett from Cambridge’s Cavendish Laboratory, the paper’s first author. “A typical silicon-based solar cell can reach efficiencies as high as 20 to 25%, while organic solar cells can reach efficiencies of around 19% under laboratory conditions, and real-world efficiencies of about 10 to 12%.”
Image: Lasers in the Optoelectronics Lab
Credit: Akshay Rao
Reproduced courtesy of the University of Cambridge