Interface Engineering for High‐Performance Perovskite Solar Cells

Perovskite solar cells (PSCs), which represent a new generation of photovoltaic technologies, have demonstrated great commercialization potential due to their high PCE, good stability, and low‐cost processing capability. However, defects, energy level mismatch, ion migration, and environmental instability at the interfaces of functional layers severely limit device performance and stability. This article systematically reviews recent advances in interface engineering for high‐performance PSCs, which focus on key regulation strategies at the hole transport layer (HTL)/perovskite, electron transport layer (ETL)/perovskite, and electrode interfaces. These strategies include energy level alignment optimization, defect passivation, suppression of ion migration, improvement of interfacial wettability, and construction of multifunctional composite interfaces. In addition, the roles of advanced characterization techniques, such as GIWAXS, time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS), and TRPL, and theoretical simulation methods are summarized. Finally, future development directions of interface engineering for promoting high efficiency, high stability, and commercial PSCs are discussed.