Kinetically Stabilized Perovskites via Selective Iodoplumbate Cold Casting for High-Efficiency Bilayer 3D:2D Photovoltaic Module

Traditional perovskite research has largely focused on thermodynamically stable structures, which has limited the exploration of new architectures. In 3D perovskites, compositional changes typically lead to minor structural alterations or impurities. Thermodynamically stabilized 2D perovskites have faced significant charge transport problems due to poor energy alignment and horizontal orientation. This study introduces a groundbreaking Selective Iodoplumbate Cold Casting (SICC) process, enabling the formation of kinetic products that correspond to local minima in the reaction energy landscape. Previously, there wasn't a controlled method for synthesizing kinetically stabilized perovskites. SICC, by combining simplified precursors with room-temperature crystallization, can replicate reactant compositional changes, allowing for the creation of diverse structures that were unattainable with conventional methods. The research presents a novel corrugated 2D structure using a cation known for forming 3D perovskite structures. Additionally, kinetically stabilized n=1 2D perovskite films show grain sizes equivalent to their correlation length and a mixed orientation with over 21% out-of-plane alignment. These features enhance vertical charge transport and provide a beneficial band alignment for 3D:2D heterostructures. To prove SICC's scalability, a 50 cm² 3D:2D perovskite mini-module was fabricated. This SICC-based mini-module achieved an impressive efficiency of 22.15% and a geometric fill factor of 94.36%. It also demonstrated outstanding stability, maintaining T90 for 1200 hours under MPPT conditions at 50 °C.