Suppressing Non‐Radiative Recombination in Perovskite Solar Cells Through Integrated Tuning of Out‐of‐Plane Lattice Texture and Strain

Crystallographic orientation and lattice strain directly govern performance and stability; however, they are often treated as independent structural parameters, and therefore their combined influence on non‐radiative recombination remains poorly understood. Here, we reveal the interplay between these parameters and establish their correlation with non‐radiative recombination in perovskite solar cells (PSCs). The coupled control of structural parameters is achieved through novel bimolecular cooperative interactions between sodium hydroxyquinoline sulfonate and sodium aminonaphthalene sulfonate. These interactions regulate crystallization at molecular level by destabilizing solvent–PbI 2 adducts. As a result, they promote out‐of‐plane growth of corner‐sharing [PbI 6 ] 4─ networks along [100] direction and shift the lattice strain from a tensile to a compressive state. This leads to an open‐circuit voltage of 1.22 V (only 49 mV behind the theoretical limit), achieving a power conversion efficiency (PCE) up to 26.21% and a reverse‐bias breakdown voltage of −16.5 V in PSCs. Furthermore, the device retains 90% of its initial PCE after 3300 h at >85% relative humidity. Control experiments further confirm that this integrated structural tuning is the dominant factor governing suppressed non‐radiative recombination and enhanced breakdown voltage.