Simultaneous Photocurrent and Photoluminescence of Perovskite Solar Cells

Organic-inorganic metal halide perovskite solar cells show great promise in the photovoltaic industry due to their low cost and intriguing photophysical properties which include high power conversion efficiencies, large diffusion lengths and slow hot carrier cooling. Perovskite solar cells have reached power conversion efficiencies as high as 25.5% but unfortunately, the material degrades when it is exposed to air, water or light. Degradation is a huge obstacle to the commercialization of this material. In order to understand the photophysical processes t hat cause degradation, the experiment simultaneously measures photocurrent, spatial, and spectral photoluminescence at the microscopic level. The experimental apparatus can be used to take measurements over time, space or both. The photocurrent reveals cell power conversion efficiency and can be compared to spectral photoluminescence to determine the correlation while the spatial photoluminescence can be used to extract the diffusion length. While this research is still ongoing, it is expected that photoluminescence will decay over time when exposed to air or light and that the photocurrent and photoluminescence will exhibit a strong negative correlation. Once the photocurrent, spatial and spectral photoluminescence are determined for each point on the perovskite solar cells, our collaborators can be informed and together we hope to determine how to improve the stability of perovskite solar cells,