Time-Evolving Electroluminescence Imaging in Perovskite Solar Cells

We present an approach to evaluate perovskite solar cell reliability and metastability during 100-hour stress/rest cycling under electrical bias with in-situ electroluminescence (EL) imaging. We show an example of time-evolving EL and associated voltage transients under constant current bias for triple-cation mixed-halide devices with defects of lead-iodide-rich wrinkles. We observe the greatest degradation in the regions of the wrinkles. Our results demonstrate how time-evolving luminescence imaging can be applied to better understand impacts of spatial imperfections on perovskite photovoltaic device stability.