Multifunctional anionic metal-organic frameworks enhancing stability of perovskite solar cells

Molecular design of multifunctional surface treatment materials that modulate the perovskite performance through simultaneous improvements in several factors is imperative for enhancing the stability of perovskite solar cells (PSCs). Herein, with amine-containing counterions in its pore, dense oxygen sites on the skeleton and the anionic porous framework, a metal-organic framework, ZnL, demonstrates its feasibility as multifunctional surface treatment materials on defects passivation, improving perovskite crystallization and blocking water/ metal electrode intrusion. Extensive theoretical calculations and experimental studies confirm the passivation ability of ZnL that amine-containing cations could effectively passivate negatively charged defects and the anionic framework with dense oxygen sites forms strong interaction with perovskite, anchoring the atoms of perovskite. As a result, ZnL-incorporated PSC device shows improved efficiency from 19.75% to 21.15% with enhanced stability during 3000 h. This work provides important insight into the design guidance of prospective multifunctional surface treatment reagents toward the higher performance of PSCs or other optoelectronic devices.