The rapid adoption of perovskite materials in the construction of solar cells delivering astounding efficiencies close to the Shockley-Queisser limit has given rise to a new generation of solar cells. From 2009 to 2020, perovskite-based solar cells power conversion efficiency has risen from 4% to 26%.[1,2]  Their electronic properties differ from those observed in the past for silicon-based solar cells or dye-sensitized solar cells, and thus, the efforts to quantize its underlying mechanisms continue. An elusive understanding of the working mechanisms is required to build upon a better efficiency than the present. Electrochemical impedance spectroscopy (EIS) analysis has proven to be a hassle-free technique for parameterizing physical processes in terms of resistors, capacitors, and inductors. Previously, EIS along with complementary approaches (IMPS, IMVS) for solar cells such as Silicon, DSSC, QDSSC and CZTS have found to be an effective way to know the core working electronic mechanisms taking place inside which govern the performance altering parameters like Jsc, Voc or fill factor.

There has been considerable research on PSC by EIS analysis. Over the years, multiple circuital and mathematical models have been proposed for different architectures such as mesoporous electron transport layer, planar thin film, crystal-based, and mixed cation.[3-5]  EIS analysis and interpretation for Perovskite solar cells (PSCs) are not yet established as its implicit processes continue to be a topic of debate in the literature. The discrepancy in the EIS analysis of PSCs lies due to the ionic nature of the perovskite material.  It has been clear that a generic model for all device architectures is not possible owing to their widely different electronic properties and dependence on hysteretic behaviour, construction, age of the device, and interfacial contacts. However, EIS has aided our understanding of probable origins of voltage loss, ionic conductivity in dark, dielectric behaviour, electronic and ionic recombination dynamics, kinetic properties, and interfacial phenomena.[4,6-9]  There is a lack of a centralized source of EIS analysis and progress details, making it tougher to account for the advancements made. The review will be focused on compiling the research done on various PSC device architectures via EIS to construct a brief yet comprehensive foundation of information on equivalent circuits and associated processes.