Weakening Solvation via Dipole Interactions Enables Efficient and Stable Perovskite Solar Cells

Abstract

Perovskite solar cells (PSCs) have attracted extensive attention for their outstanding photovoltaic performance. However, fabricating high-quality perovskite films under ambient conditions remains challenging due to rapid nucleation and non-uniform crystallization caused by uncontrolled solvent evaporation. Here, we demonstrate that weakening solvent coordination through dipole interactions can effectively regulate perovskite crystallization during blade-coating. The introduction of low-polarity pentyl propionate interacts with DMF, reducing PbI₂ coordination and enabling slower crystallization and an extended processing window. Consequently, compact perovskite films with micrometer-scale grains and excellent uniformity are achieved. As a result, we achieved a power conversion efficiency (PCE) of 24.06% in small-area PSCs and 20.06% in a 5 × 5 cm2 large-area module, with the device retaining 80% of its initial PCE after 2880 h in a nitrogen atmosphere.