Self-assembled conformal SnO2 electron transport layer via targeted chelating enables efficient, scalable, and stable perovskite solar cells

Balance between coverage and performance in the electron transport layer (ETL) is crucial for maximizing the efficiency, scalability, and stability of large-area perovskite solar cells (PSCs). Here, a solution-based targeted chelating strategy is designed to construct a self-assembled conformal SnO 2 ETL on a textured transparent conductive oxide surface with submicron roughness. By fine-tuning the molecular architecture, the targeted chelating molecule with two-electron-donating group and conjugated structure, capable of electron redistribution, can bridge the targeted V O of SnO 2 nanoparticles and F O of transparent conductive oxide, respectively, which balances the interface charge dynamics. The use of a self-assembled conformal SnO 2 ETL modified with targeted chelating molecules enabled PSCs with efficiencies of 25.32% and 24.57% on aperture areas of 0.09 and 1.00 cm 2 , respectively, and 1,600-h operational stability based on the ISOS-L-3 protocol (maximum power point, continuous 1 sun illumination, 65°C, and ca. 50% relative humidity).