High‐Efficiency Large‐Area Perovskite Solar Cells via a Multifunctional Crystallization Regulating Passivation Additive

Abstract Film morphology and surface/interface defect density play a critical role in determining the efficiency and stability of perovskite solar cells (PSCs). Here, a chlorine‐substituted aromatic polycyclic derivative (BNCl) is reported, which shows strong interaction with both lead iodide and dimethyl sulfoxide, to regulate the crystallization of perovskite, along with effective passivation of grain boundaries and surface. In addition, the extruded BNCl molecule at the hole transport layer (HTL)/perovskite interface can facilitate the hole transport, leading to better charge transfer. As a result, certified power conversion efficiencies (PCEs) of 25.04% and 22.81% are achieved for PSCs and minimodules with aperture areas of 1 cm 2 and 12 cm 2 respectively. In addition, the device maintained 80% of its initial efficiency after 2500 h of maximum power point (MPP) tracking under ISOS‐L‐1 standard.