Conjugated linker-boosted self-assembled monolayer molecule for inverted perovskite solar cells

This study builds upon the success achieved from commercial self-assembled monolayers (SAMs), such as Me-4PACz, by replacing its flexible butyl linker with a conjugated phenylene ring to form a SAM molecule, Me-PhpPACz, for inverted perovskite solar cells (PSCs). The Me-PhpPACz-derived PSCs exhibited an unprecedented power conversion efficiency of 26.17% with an extremely high fill factor of 86.79% and exceptional long-term stability. The result from ultrafast spectroscopy shows that phenylene-linked SAMs not only modulate the work function of indium tin oxide electrode but also facilitate charge carrier extraction and transport. Our detailed study helps deepen our understanding of the delicate relationship between SAM molecular design and PSC performance, paving the way for further enhancing the efficiency and stability of PSCs.