Air-Processed Perovskite Solar Cells with >25% Efficiency and High Stability Enabled by Crystallization Modulation and Holistic Passivation.

ABSTRACT

Organic semiconductors (e.g., PCBM and IDIC) frequently serve as interface passivants for perovskite solar cells (PSCs) due to their beneficial passivation effects on perovskite interfaces. However, their passivation to the interiors of perovskite films is greatly limited by their poor solubility in polar solvents and compatibility issues. Here the facile synthesis of organic semiconductor nanoparticle (NP) passivants that readily disperse in perovskite inks is reported. Adding these NPs into perovskite inks not only modulates perovskite crystallization, improves film quality and conductivity, but also achieves holistic bulk film passivation. Consequently, blade-coated p-i-n PSCs with ICBA NPs achieve an impressive efficiency of 25.1% (independently certified as 25.0%), the highest reported value for air-processed PSCs irrespective of fabrication methods or device structures. This work develops a novel approach for effective and holistic perovskite passivation by converting conventional passivants to perovskite-compatible NPs, paving the way for more efficient and stable perovskite solar devices.