Intermolecular Interaction Induced Synergistic Uniform Passivation of Grain Boundary Multiple Defects Enables High‐Performance Inverted Perovskite Solar Cells

Abstract Inverted perovskite solar cells (PSCs) have received significant attention due to prominent advancements in power conversion efficiency (PCE) and long‐term stability. However, the further improvement of PCE and stability is still impeded by inefficient grain boundary (GB) and interface synergistic passivation method mainly induced by the uneven distribution of passivators. Herein, a simple and effective intermolecular interaction‐induced synergistic uniform defect passivation strategy is reported through functional group functionalization. (S)‐2‐amino‐3‐guanidinopropanoic acid dihydrochloride (AGAD) and 2‐aminoethanesulphonamide monohydrochloride (AESM) are used as additive and surface modifiers, respectively. AGAD and AESM can synergistically passivate the multiple defects at GBs and the surface of perovskite films. Moreover, hydrogen bond interaction between AGAD and AESM results in uniform distribution of AESM at GBs, which facilitates uniform and efficient defect passivation. The remarkably suppressed nonradiative recombination losses enable efficient inverted devices with a PCE of 26.14%, which is one of the highest PCEs reported for the PSCs using the vacuum flash evaporation technique. The synergistically passivated inverted devices retain 90% of their initial PCE after 1200 h of continuous maximum power point tracking. This work proposes an efficient avenue to minimize bulk and interfacial nonradiative recombination by rationally controlling the uniform distribution of passivators at GBs via modulating intermolecular interaction.