Halide perovskites are a class of next generation photovoltaic (PV) materials which have achieved Power Conversion Efficiencies (PCEs) above 25%. This is comparable to the performance of single-crystal silicon PVs, the current market leader. However, the precise mechanisms responsible for the high PCEs of halide perovskites remain unknown. Additionally, many of the best performing devices are highly unstable under a range of real-world conditions. Thus, further research is needed to allow halide perovskite-based PVs to be designed which maintain high efficiencies while also achieving a lifetime suitable for commercial applications.
My PhD will investigate the effect of trap states on the charge dynamics of halide perovskite solar cells. Halide perovskites are observed to contain a high density of trap sites compared to other inorganic PV materials. However, questions remain about where these traps are located within the perovskite and whether or not the traps lie near the centre of the band gap or close to the band edges. Understanding the answers to these questions will be crucial in order to realise further gains in device PCE. Furthermore, knowledge of how the trap distribution evolves over time may elucidate the causes of device instability. I will investigate these questions using a combination of optoelectronic measurements and computational modelling.