Double‐Side Passivation of Perovskite Solar Cells for High Performance and Stability

Abstract Perovskite solar cells (PSCs) are in the spotlight as promising renewable energy devices by their appealing properties. However, they face challenges both in power conversion efficiency (PCE) and long‐term stability. The presence of surface defects in the PSCs is a significant obstacle to achieving both high efficiency and stability, as these defects cause nonradiative recombination and degradation. Herein, a novel double‐side surface passivation method using phenyltrimethylammonium iodide (PTMAI) salt is applied to remove electronic defects effectively. Furthermore, double‐side passivation with PTMAI contributes to the enhancement of the perovskite crystallinity with the relaxed non‐uniform distribution of local strains. Finally, the efficiency of PSC is significantly improved by double‐side passivation with PTMAI, achieving a PCE of 21.87%. Furthermore, the passivated cell exhibited enhanced long‐term stability, maintaining over 80% of initial PCE after 1860 and 1030 h under 60 °C and 1 sun illumination, respectively.