Electronic Homogenization Regulation via Nicotinamide Derivative Ligands for Efficient Blade‐Coated Wide‐Bandgap Perovskite Solar Cells

Abstract The spatial heterogeneity of electronic properties mediated by surface terminal disorder is a major limitation to achieving high‐efficiency metal‐halide perovskite photovoltaics. An in‐depth understanding of how molecular configurations affect electronic heterogeneity is still lacking, posing a challenge to interface optimization design. This work presents an effective interface control strategy aimed at achieving spatial homogenization of electronic properties. Using two isomeric D‐π‐A molecules, namely 2‐amino‐nicotinamide and 6‐amino‐nicotinamide, the spatial conformations of the nicotinamide molecules are modulated to achieve different adsorption orientations. Via synergistic intermolecular interactions, facilitating flexible multi‐site adsorption strengthened interactions with the perovskite, promoting uniform redistribution of surface charges, thereby reducing spatial electronic heterogeneity, facilitating energy level alignment, and suppressing nonradiative recombination at the perovskite surface. As a result, blade‐coated perovskite solar cells with a bandgap of 1.67 eV achieved a power conversion efficiency of 22.0%. This strategy is expected to play a pivotal role in overcoming existing performance bottlenecks and pushing perovskite solar cells closer to their theoretical efficiency limits.