Amidino‐Based Molecular Ligand Induced Catalytic Crystallization and Stress Relaxation for High‐Efficiency Anti‐Solvent‐Free Perovskite Solar Cells

The development of anti-solvent-free techniques for fabricating high-quality perovskite films is crucial for advancing the scalable production of perovskite solar cells (PSCs). However, uncontrolled crystallization kinetics and residual lattice stress in the anti-solvent-free film preparation hinder the further improvement of device efficiency and stability. Herein, a molecular-ligand assisted crystallization method using N-(aminoiminomethyl)-4-Pyridinecarboxamide (AGPA) is developed to achieve high-performance inverted PSCs without anti-solvent. The multiple hydrogen bonds and coordination interactions of AGPA and the Pb-I framework effectively lower the energy barrier from δ- to α-phase perovskites, which is beneficial for regulating the crystallization kinetics and promote the directional crystallization of α-phase perovskites. Notably, the resultant perovskite films exhibit enlarged grain size, released residual stress, and passivated charge defects, leading to enhanced carrier extraction and reduced nonradiative recombination losses. Consequently, the anti-solvent-free inverted PSCs with AGPA achieve an impressive efficiency of 25.37%, and retain 91.4% after 1000 h of maximum power point (MPP) tracking at 65°C with ISOS-L-2I protocol. This work provides a reliable and effective strategy for optimizing solvent-free fabrication techniques, thereby promoting the large-scale industrial production of PSCs.