Solvent-Engineered PEACl Passivation: A Pathway to 24.27% Efficiency and Industrially Scalable Perovskite Solar Cells.

Addressing the critical challenges of interfacial defects and insufficient stability in perovskite solar cells, this work introduces a co-solvent engineering strategy to dynamically regulate the phenethylammonium chloride (PEACl) passivation layer. The effect of isopropyl alcohol (IPA) and a DMSO: IPA (1:100) mixture as solvent for forming the PEACl 2D passivation layer is systematically explored, and the synergistic interplay between solvent coordination strength and crystallization kinetics is systematically investigated. The DMSO: IPA (1:100) blend balances Pb-O coordination (via DMSO) and rapid phase separation (via IPA), enabling the oriented growth of a dense, ultrathin 2D perovskite overlayer. This suppresses defect density (electron traps reduced to 1.68 × 10 cm) and extends carrier lifetime, yielding a champion power conversion efficiency (PCE) of 24.27%-a significant improvement over the control (22.73%). For the first time, we establish a dual-parameter "solvent coordination-crystallization kinetics" model, providing a universal framework for designing environmentally benign solvent systems and advancing the industrial scalability of high-performance perovskite solar cells (PSCs).