Characterization of low-frequency excess noise in perovskite-based photovoltaic cells

We present experimental results on low-frequency noise characterizations of high-efficiency perovskite solar cells (PSCs). It is shown that annealing the device in dry oxygen results in significant enhancement in the power conversion efficiency of the device. Systematic investigations on the photothermal deflection spectroscopy and the low-frequency excess noise of the devices a indicate that oxygen annealing of the device resulted in the passivation of traps located at the grain boundaries of the perovskite films as well as the perovskite-spiro-MeOTAD interface.