Efficient Trap Passivation of MAPbI3 via Multifunctional Anchoring for High-Performance and Stable Perovskite Solar Cells

y Chemical passivation of ionic defects in perovskite materials is an effective strategy to reduce charge recombination in perovskite solar cells (PSCs). Although several additives have been used for this purpose, the passivation mechanisms of different functional groups have remained unclear. Herein, the effect of molecules possessing multiple functional anchoring is systematically investigated. Three different multifunctional molecules namely 5-aminoisophthalic acid (AIA), 5-hydroxyisophthalic acid (HIA), and chelidamic acid (CA) are strategically chosen. These molecules not only take part in the crystallization process but also passivate the trap states effectively. CA shows superior passivation capacity among all with a better dipolar electron density distribution. The passivated films have considerably improved morphology with fewer pin holes, larger grains, and lower trap states in comparison to the pristine film. CA-passivated p-i-n structured photovoltaic devices demonstrate the best power conversion efficiency (PCE) of 19.06% with an impressive open circuit voltage (V-OC) of 1.097 V, whereas pristine devices show a PCE of 13.60% and V-OC of 0.972 V. Moreover, the modified device reveals notable thermal and ambient stability in comparison to the pristine device due to lower defect states and reduced ion migration.