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(Invited) An Investigation into the Local Optical and Electrical Response of Hybrid Perovskites for Solar Cell Applications

Monday, 29 May 2017: 11:20
Churchill C1 (Hilton New Orleans Riverside)
S. Draguta (University of Notre Dame) and M. Kuno (university of notre dame)
Hybrid perovskite (MAPbI3, MA=CH3NH3) based solar cells have attracted great interest recently due their fast growing power conversion efficiencies. Over the last 5 years solar conversion efficiencies have risen from 3.8 to 22 %. To further increase these power conversion efficiencies, a better understanding of underlying charge recombination mechanisms in hybrid perovskite thin films is needed. The solution-based fabrication of hybrid perovskite-based solar cells additionally means that there can be significant spatial heterogeneities in the dominant charge recombination mechanism across films. This can translate into spatially-varying photovoltaic performance. To address these issues, we have therefore conducted spatially-resolved measurements of carrier recombination in MAPbI3 thin films. This has led to the observation of large variations in local carrier trap densities. These variations, in turn, directly impact local photoluminescence quantum yields as well as photovoltaic performance. We have also conducted work to better understand the optical response of mixed halide perovskite thin films, which undergo phase separation upon illumination.