Monoammonium Porphyrin for Blade-Coating Stable Large-Area Perovskite Solar Cells with >18% Efficiency

Efficient control of crystallization and defects of perovskite films are the key factors toward the performance and stability of perovskite solar cells (PSCs), especially for the preparation of large-area PSCs devices. Herein, we directly embedded surfactant-like monoammonium zinc porphyrin (ZnP) compound into the methylammonium (MA⁺) lead iodide perovskite film to blade-coat large-area uniform perovskite films as large as 16 cm². Efficiency as high as 18.3% for blade-coating large-area (1.96 cm²) PSCs with ZnP was unprecedentedly achieved, while the best efficiency of fabricated small-area (0.1 cm²) device was up to 20.5%. The detailed analyses demonstrated the functions of ZnP in crystallization control and defects passivation of perovskite surfaces and grain boundaries. As a consequence, the ZnP-encapsulated devices retained over 90% of its initial efficiency after 1000 h with a humidity of about 45% at 85 °C. This research presents a facile way to achieve the synergistic effect of large-area coating, morphology tailoring, and defect suppression based on the molecular encapsulation strategy for perovskite films, further improving the photovoltaic performance and stability of PSCs.