High-Efficiency and Stable Perovskite Solar Cells via DL-Methionine-Enhanced Crystallization and Defect Passivation

Abstract

As an emerging photovoltaic technology, perovskite solar cells (PSCs) have become a research hotspot due to their excellent photoelectric conversion efficiency (PCE) and low-cost manufacturing process. Enhancing the crystallization quality of perovskite films and mitigating defects through material engineering is crucial for improving the performance of PSCs. In this study, a naturally occurring amino acid, DL-Methionine, is incorporated as an additive to enhance the crystallization quality and passivate defects in perovskite films. The results show that the appropriate concentration of DL-Methionine additive can not only improve the crystallization kinetics of perovskite but also reduce the defects of perovskite films through its coordination with perovskite ions, thereby reducing defect-assisted recombination. Finally, the optimized PSCs based on the DL-Methionine additive obtained the highest power conversion efficiency of 24.72%, significantly higher than those without the DL-Methionine additive (21.83%). Moreover, the stability of PSCs is significantly improved with the DL-Methionine additive. This work demonstrates the potential of DL-Methionine as an effective passivation agent for high-efficiency and stable PSCs.