Dynamic Passivation of Perovskite Films via Gradual Additive Release for Enhanced Solar Cell Efficiency

Modifying perovskites with functional additives has proven effective in refining the crystallization process and passivating the defects of perovskite films, thereby ensuring high photovoltaic efficiencies. However, conventional methods that involve pre-mixing additives into the precursor solution often face challenges due to discrepancies in the spatial distribution of slow-diffused additives relative to dynamically formed defect sites, resulting in limited passivation effectiveness. To address this issue, this study innovatively proposes a dynamic passivation strategy that utilizes a pre-passivator to gradually release active additives during the thermal crystallization process of perovskite films. By leveraging the principle of energy minimization, these timely-released additives can interact precisely and selectively with the high-energy defect sites generated during crystallization, thus facilitating efficient additive utilization and in situ real-time defect passivation. Through analysis of crystallization kinetics and carrier dynamic, it is demonstrated that this dynamic passivation approach significantly improves film quality and prolongs carrier lifetime, outperforming traditional pre-mixing tactics. Consequently, the final perovskite solar cell achieves an impressive solar conversion efficiency of 25.33 %, along with exceptional stability. This work provides strong support of tailored additive strategies aimed at further enhancing the efficiency of perovskite solar cells and their subsequent commercial applications.