Designed Lewis Acid–Base Passivation for High Performance Perovskite Solar Cells

ABSTRACT Silicon's high cost and long energy payback time remain major barriers to the global expansion of solar power. In contrast, metal–halide perovskites offer abundant, solution‐processable absorbers, and have achieved efficiencies of 25%–30%, positioning them as strong competitors to silicon. However, commercialization of is hindered by instability and performance fluctuations arising from defects such as uncoordinated Pb 2 + , halide vacancies, and grain‐boundary traps within the perovskite and adjacent layers. This review provides information on the current advances in Lewis acid/base chemistry for the perovskite layer, the electron transport layer, and the hole transport layer; it includes multiple examples of how the ability to modify molecular pairs helps to passivate grain boundaries, reduce recombination, and create interfacial layers that repel moisture and block ion movement. The review closes with a roadmap for researchers seeking to advance the efficiency and stability limits of perovskite photovoltaics by bridging the gap between fundamental chemistry and device engineering.