forest fires, and melting glaciers: it is evident that global over-reliance on fossil fuels must shift in favor of carbonfree energy sources to mitigate climate change. [1][2][3] Global energy consumption in 2020 was 162 Petawatt hours (PWh), out of which the electricity consumption was ≈30 PWh. [2,4] It is predicted that by 2050, an additional 30 TW will be required to meet mankind's increasing power demands. [5][6][7] The sun is an inexhaustible clean energy source transmitting nearly 120 000 TW to the earth's surface, far greater in magnitude than all other renewable energy sources combined. [8,9] While this power is abundantly available, harnessing it on terawatt scales with reliable and cost-efficient methods poses a tremendous challenge. [9] Photovoltaics (PVs) harvest the sun's energy by directly converting photons into electricity without the release of greenhouse gases (GHGs). PV systems are reliable, silent (no moving parts), and operate on a zero-cost energy source. These advantages coupled with the falling prices of energy storage systems suggest that PV systems can provide a continuous supply of electricity for residential and commercial applications. [8,9] The levelized cost of energy (LCOE) can be used to evaluate the cost-effectiveness of different energy sources. [10,11] For PV systems, LCOE denotes the discounted lifetime costs associated with the PV system installation divided by the discounted lifetime energy production of the system (typically ≈ 25 years). In sunny regions, the LCOE for utility-scale PV (29 $/MWh) now competes with electricity generated from conventional sources

Impedance spectroscopy (IS) is an effective characterization technique used to probe and distinguish charge dynamics occurring at different timescales in optoelectronic and electric devices. With the rapid rise of research being conducted on perovskite solar cells (PSCs), IS has significantly contributed to the understanding of their device performance and degradation mechanisms, including metastable effects such as current–voltage hysteresis. The ionic–electronic behavior of PSCs and the presence of a wide variety of perovskite compositions and cell architectures add complexity to the accurate interpretation of the physical processes occurring in these devices. In this review, the most common IS protocols are explained to help perform accurate impedance measurements on PSC devices. It critically reviews the most commonly used equivalent circuits alongside drift‐diffusion modeling as a complementary technique to analyze the impedance response of PSCs. As an emerging method for characterizing the interfacial recombination between the perovskite layer and selective contacts, light intensity modulated impedance spectroscopy technique is further discussed. Lastly, important works on the application of IS measurement protocols for PSCs are summarized followed by a detailed discussion, providing a critical perspective and outlook on the growing topic of IS on PSCs.