Degradation Analysis of Triple-Cation Perovskite Solar Cells by Electrochemical Impedance Spectroscopy

In this work, the electrical properties of different triple-cation compositions with the formula Cs0.05FA1–X MA X Pb­(I1–X Br X )3 have been analyzed using electrochemical impedance spectroscopy. The perovskite solar cells were subjected to ambient conditions to compare their results in terms of ambient degradation. Their morphology, optical properties, and photovoltaic performance were characterized. We analyzed the causes and effects of ambient degradation mechanisms on the devices. Electrochemical processes such as ion movement, a combination of radiative recombination and nonradiative recombination, and charge transport were detected. The MA percentage decrease in the composition of triple-cation perovskites, APbX3 produces an improvement in the stability and durability of perovskite solar cells. This enhancement is due to the reduction of the amount of ion vacancies helping to reduce the degradation in the device by avoiding the accumulation of defects.