A Chelating‐Agent‐Passivated Electron Transport Layer for Efficient Perovskite Solar Cells with Enhanced Reproducibility

Abstract Substandard printing quality of electron transport layers (ETLs) always leads to non‐ideal nucleation crystallization and bottom interface contact of the perovskite, followed by the formation of poor‐quality perovskite films with severe heterogeneity, which is the major source of non‐radiative recombination loss and environmental sensitivity of perovskite solar cells (PVSCs). These often result in serious photovoltaic performance loss, significant instability, and negative fabrication reproducibility. Herein, sodium phytate is proposed as a chelating agent for passivating the tin oxide (SnO 2 ) ETLs to enable the stabilization of SnO 2 nanoparticles and facilitate the printing of pinhole‐free films, thereby realizing the controlled nucleation crystallization in perovskite precursor. Thus, the printed PVSCs exhibit a champion power conversion efficiency up to 23.77% with negligible hysteresis effect. The unencapsulated devices demonstrate outstanding long‐term stability, which maintains over 80% of their initial efficiency under exposure to atmospheric environment (50% relative humidity) for 1500 hours, and a consistent and centralized distribution of efficiencies across all seasons, indicating their good reproducibility in diverse climatic atmospheres.