Crystal Growth Nucleation Induced by CsPb₂Br₅ 2D for Efficient and Stable Perovskite Solar Cells

Crystallization is a crucial step in obtaining high‐quality perovskite films. A 2D seed‐induced method is proposed for fabricating perovskite solar cells (PSCs). CsPb₂Br₅ significantly reduces the formation energy of perovskite according to the density functional theory calculations. The creation of perovskites is facilitated by CsPb₂Br₅, which also helps to improve the conditions for perovskite formation. The creation of large perovskite particles is accelerated by using a 2D seed‐precursor solution, which also improves the performance of PbI₂ thin films. However, excessive doping can cause dopants to precipitate on the smooth surface of PbI₂ thin films, resulting in the formation of perovskite thin films with numerous cracks, ultimately reducing device efficiency. Through meticulous optimization, the perovskite thin film obtained from a precursor solution with 30% concentration identifies the longest charge lifetime. With a remarkable power conversion efficiency of 24.06% under one solar illumination, the champion gadget demonstrates extraordinary photovoltaic performance. These results offer important insights for the logical design and manufacture of perovskite materials and have the potential to significantly advance PSC technology.