Implementation of a Multi-Functional-Group Strategy for Enhanced Performance of Perovskite Solar Cells through the...

Reducing the defect density of perovskite films during the crystallization process is critical in preparing high-performance perovskite solar cells (PSCs). Here, a multi-functional molecule, 3-phenyl-4-aminobutyric acid hydrochloride (APH), with three functional groups including a benzene ring, ─NH₃ ⁺ and ─COOH, is added into the perovskite precursor solution to improve perovskite crystallization and device performance. The benzene ring increases the hydrophobicity of perovskites, while ─NH₃ ⁺ and ─COOH passivate defects related to I^- and Pb²⁺, respectively. Consequently, the power conversion efficiency (PCE) of the optimal device increased to 24.65%. Additionally, an effective area of 1 cm² with a PCE of 22.45% is also prepared using APH as an additive. Furthermore, PSCs prepared with APH exhibit excellent stability by 87% initial PCE without encapsulation after exposure at room temperature under 25% humidity for 5000 h and retaining 70% of initial PCE after aging at 85 °C in an N₂ environment for 864 h.