Interference Crystallization Rebalances Facet Competition for Efficient and Stable Perovskite Solar Cells

Crystallographic orientation governs lattice strain, defect formation, and stability in perovskite solar cells, yet precise control remains challenging in sequential deposition due to the intrinsic growth dominance of low‐surface‐energy (100) facets. Here, we report an interference crystallization strategy that reshapes facet competition by modulating A‐site intercalation kinetics. Incorporation of a sulfonate‐based additive into the PbI 2 precursor imposes facet‐dependent kinetic perturbation during FA + insertion. Preferential adsorption of this additive on the (100) surface restricts A‐site accessibility and selectively retards its growth, whereas weaker interaction with the (111) surface preserves intercalation kinetics and enables its competitive development. This asymmetric interference establishes a balanced (100)/(111) orientation distribution, alleviating residual lattice strain associated with single‐facet dominance. The coexistence of both facets integrates their complementary merits, combining the superior optoelectronic quality of (100) with the enhanced moisture tolerance of (111). Meanwhile, strong surface adsorption of this additive on both facets provides additional defect passivation, suppressing non‐radiative recombination. Devices fabricated via this strategy achieve a power conversion efficiency of 26.41% and exhibit negligible degradation after 1300 h maximum power point tracking, demonstrating interference‐mediated crystallization as a viable pathway for orientation regulation in sequentially deposited perovskites.