Researchers at the Australian Research Council Centre of Excellence in Exciton Science have made a discovery that could lead to significantly boosted solar cell efficiency.
The research team, led by Professor Timothy Schmidt of the University of New South Wales, has been looking at ways of capturing the energy of visible light that is currently wasted due to the limitations of silicon.
Silicon, by itself, is only able to use about 25% of the solar spectrum. One of the ways to improve this is by coating the top of the silicon with materials that capture some of the energy of light that silicon cannot.
Professor Smith’s team have examined the role of an extremely short-lived (for about 8 billionths of a second), excited molecular complex called an excimer in singlet exciton fission, a process that generates two excitons from a single photon.
Their research suggests that what had previously been considered as an intermediate step in the process is, in fact, a source of loss. Using this discovery, the researchers believe that by incorporating singlet exciton fission silicon solar cell efficiencies can be boosted beyond 30%.