Weak interactions in mixed symmetric and asymmetric self-assembled monolayers for perovskite solar cells: a classical molecular dynamic view

Abstract

Self-assembled monolayers (SAMs) serve as critical hole-transporting components at the buried interfaces of high-performance inverted perovskite solar cells (PSCs). Herein, comprehensive classical molecular dynamics (MD) simulations were performed to elucidate the intricate non-covalent interactions governing the co-assembly of symmetric and asymmetric SAM configurations. Our molecular insights reveal that the asymmetric SAMs possess a pronounced dipole moment that promotes robust interfacial hydrogen bonding while simultaneously mitigating homo molecular π-π packing. Crucially, blending symmetric and asymmetric SAMs further decouples the π-π interactions, thereby synergistically boosting anchoring stability and maximizing surface coverage. Overall, these findings demonstrate that precise manipulation of weak non-covalent interactions within SAM networks represents a potent and generalizable paradigm for optimizing interfacial properties in advanced optoelectronics.