Interface Passivation and Enhanced Charge Transport With a Triphenylamine Self‐Assembled Molecule in Inverted Perovskite Solar Cells

Perovskite solar cells are experiencing significant recent progress, yet their long‐term stability and interfacial losses remain serious drawbacks. Self‐assembled molecules (SAMs) have emerged as molecular gamechangers, offering ultrathin, ordered interfaces that can unlock record‐breaking efficiencies. In this work, we introduce SMA‐76 , a newly designed triphenylamine‐based SAM that delivers a power conversion efficiency of 22.4%, a fill factor of 82%, and nearly hysteresis‐free operation in inverted (p–i–n) perovskite devices, outperforming the widely used carbazole‐based benchmark EADR03. Through a combination of spectroscopy, microscopy, and advanced charge‐transport analyses, we reveal how SMA‐76 's nonplanar geometry and dipole moment drive defect passivation, uniform electrode coverage, and enhanced hole mobility. These molecular‐level advantages translate into superior charge extraction and reduced recombination losses at the ITO/perovskite interface. The result is a robust, scalable interfacial design that not only boosts efficiency but also strengthens device stability. Our findings highlight the power of molecular engineering in shaping next‐generation perovskite architectures.