Improved environmental stability of perovskite films enabled by a one-pot synthesized eco-friendly additive

The long-term instability of metal halide perovskites, such as MAPbI 3 and FAPbI 3 , remains a major obstacle to their commercialization. This study introduces a multifunctional-organic-additive (agent 1), synthesized via a one-pot reaction using ethanol as a green solvent, offering an environmentally benign approach. Agent 1 was incorporated into MAPbI 3 films through antisolvent treatment and surface passivation, enhancing both shelf and operational stability. Under moderate humidity (35–45%), antisolvent-treated films showed only 23% degradation after ∼36 days, compared to 60% in untreated samples. At higher humidity (55–65%), passivated films retained 67% of the original material, while reference films degraded by 97%. On the other hand, solar cells treated with agent 1 maintained 91% of their initial efficiency after 60 minutes of continuous operation. Long-term storage tests (168 h) revealed a 41% efficiency drop in reference devices, versus 13% and 29% in antisolvent- and passivated-treated devices, respectively. Agent 1 also exhibited excellent thermal/chemical stability, with negligible decomposition above 200 °C and only 0.35% weight loss after 24 hours at 95 °C. Its molecular integrity was confirmed via 1 H NMR after one year. Combining ease of synthesis, environmental safety, and multifunctionality, agent 1 is a promising candidate for industrial-scale stabilization of perovskite solar cells.