Tailoring interface-anchoring molecules for efficient and stable perovskite solar cells

Interfacial dipolar molecules play a crucial role in achieving high-performance perovskite solar cells (PSCs). However, the random distribution at the interface often limits their ability to effectively regulate interfacial energy levels and carrier extraction. Here, we report a bifunctional antisymmetric molecule, N-(1-carboxyethyl)iminodiacetic acid trisodium salt (MGDA·3Na), which enables both directional alignment and stable anchoring on SnO₂ and perovskite interfaces. The methyl side chain in the MGDA^- anion induces intramolecular electronic polarization and dipole reorientation, facilitating selective adsorption on the SnO₂ surface and perovskite buried interface. This significantly improves interface uniformity, enabling efficient passivation of SnO₂ surface defects and precise regulation of perovskite crystal growth. The dual anchoring effect not only aligns energy levels to minimize charge extraction barriers but also templates vertical perovskite growth, reducing buried interface defects and enhancing crystallization quality. As a result, we achieved a power conversion efficiency of 26.43% in small-area PSCs and 23.27% in a 5 × 5 cm² large-area module, highlighting the potential for industrial-scale application. The device maintains 96% of its initial efficiency for 2000 h under nitrogen-filled glove box, 96% after 800 h at 55 °C/55% RH, and 99% after 800 h of continuous illumination at the maximum power point.