5-Acetylsalicylamide as a multifunctional additive for synergistic defect passivation and crystallization control in inverted perovskite solar cells

Abstract

We introduce 5-acetylsalicylamide (5-ASA), a commercially available pharmaceutical intermediate, as a versatile additive into the FA0.95Cs0.05PbI3 precursor ink. Machine learning (ML) screening and density functional theory (DFT) calculations reveal that 5-ASA can synergistically passivate undercoordinated Pb2+ ions and iodide vacancies. This dual-passivation effect, combined with modulated crystallization, yields perovskite films with enlarged grains, improved crystallinity, and reduced defect density. Consequently, the 5-ASA-modified inverted perovskite solar cells achieve an improved power conversion efficiency (PCE) of 22.12%, with a high open-circuit voltage (VOC) of 1.085 V and a fill factor (FF) of 79.47%.