Aniline Sulfonic Acid Induced Uniform Perovskite Film for Large-Scale Photovoltaics

Unreacted/excess lead iodide is considered to be the archcriminal for the rapid degradation of hybrid perovskite solar cells. Meanwhile, a high-quality perovskite film with uniform and large grain size is the basis for high-performance perovskite modules. Herein, a dual-site molecular additive 4-Aniline Sulfonic Acid (4A) is developed to regulate the unreacted/excess PbI2 and passivate defects through hydrogen bonding and intermolecular interactions between amino, and a sulfate groups and PbI2, respectively. Furthermore, the introduction of the 4A additive can induce perovskite seeds to grow uniformly on the substrate, yielding dense, uniform and defect-less perovskite films with large grain sizes. This enables the fabrication of perovskite photovoltaics with a maximum power conversion efficiency of 24.09% (0.09 cm(2)) and 20.87% (16 cm(2)), respectively. This work demonstrated a new strategy to deposit high-quality large-scale perovskite films for photovoltaic modules.