Abstract

The energy usage of the industrial countries is steadily rising whilst we try to decarbonise our energy consumption at the same time. This discrepancy requires affordable large-scale renewable energy sources. Solar panels have the potential to make up a large proportion of our future energy mix. The prices for conventional silicon-based solar cells have dropped by almost a factor of 100 over the last 20 years. However, no significant improvements have been made in the efficiency of those devices. Modern organic and hybrid organic-inorganic semiconductors have the ability to overcome the limitations of conventional solar cells. Not only are these electronics ultra-thin – one hundredth of a human hair – they are also easily manufactured via ink-jet printing. Their potential application goes beyond classical solar panels on the roof: They can act as energy source for off-grid villages in developing countries and as electricity-generating window tints in cars or office buildings. In the Cavendish Lab we use femtosecond (1 femtosecond = 0.000000000000001 s) laser spectroscopy to study these new fascinating materials. This allows us to investigate in ‘slow motion’ how light gets converted into electricity. In this talk, I will present new design approaches for next-generation solar cells and demonstrate how this will allow to overcome the efficiency limits of current photovoltaics. I will then present some of the laser spectroscopy work which helped us to boost the efficiency of these devices.