Defect Passivation through Cyclohexylethylamine Post-treatment for High-Performance and Stable Perovskite Solar Cells

Perovskite solar cells (PSCs) are one of the most prominent photovoltaic technologies, yet their stability, scalability, and engineering at the molecular level remain challenging. Herein, we report a facile strategy that can simultaneously enhance the stability and efficiency of perovskite optoelectronic devices. In particular, we introduce a passivation molecule, cyclohexylethylamine (CHEA), whose amine group can effectively reduce the number of defect sites and improve the crystallinity of the perovskite by forming Lewis adducts with undercoordinated Pb 2+ ions in the perovskite. Upon passivation by CHEA, the stability and performance of PSCs are correspondingly improved. By optimizing the concentration of CHEA, the power conversion efficiency of the device has been significantly improved from 18.05 to 21.53%.