Blade‐Coated Perovskite‐Organic Tandem Solar Cells in Ambient Conditions

Abstract Perovskite‐organic tandem solar cells have emerged as a promising alternative to air‐instable all‐perovskite tandem architectures by eliminating tin‐based perovskites prone to oxidative degradation. However, the practical realization of efficient air‐processed perovskite‐organic tandem devices remains unexplored. This study reveals critical ambient‐induced challenges in blade‐coated ultra‐wide bandgap (UWBG) perovskite films, including compromised crystallization kinetics and elevated trap densities under ambient conditions. To address these issues, a thiocyanate pseudohalide modulator is introduced to synergistically regulate crystal growth dynamics and defect passivation. Specifically, thiocyanate incorporation not only enhances nucleation density through extended crystallization windows but also mitigates moisture‐triggered defect formation. This dual functionality enables high‐quality blade‐coated UWBG perovskite films under ambient conditions, achieving a remarkable power conversion efficiency (PCE) of 17.2% with exceptional operational stability. By integrating this optimized photoactive layer into monolithic perovskite‐organic tandem architectures, the first air‐processed tandem devices with a PCE of 24.4% are demonstrated.