Strong connection between PVK and ETL induced by an anti-allergic agent interface for high-quality PSCs

It is crucial to promote crystallinity of active layer to improve stability and restrain non-radiative carrier recombination for high-quality perovskite solar cells (PSCs). Here, Chlorpheniramine Maleate (CM) interface layer is introduced between SnO 2 electron transport layer (ETL) and perovskite (PVK) film. The esterification between carboxyl group in CM and hydroxyl group on the surface of SnO 2 greatly enhances the surface evenness of SnO 2 , leading to enhanced smoothness of ETL; thus, the crystallinity of perovskite (PVK) film is validly improved. Meanwhile, the lone pair electrons of nitrogen element in pyridine group in CM coordinate with vacant orbit of Pb 2+ in perovskite that validly decreases the defects of active layer. Thus, the CM interface results into strong connection between PVK and ETL, which greatly enhances the performance and stability of PSCs. After CM modification, the PCE of the PSCs is increased from 19.29 to 21.12%. In addition, unencapsulated CM-modified devices demonstrate much better humidity stability than unmodified one due to high quality of the perovskite film. After 100 h under RH = 70 ± 5% in air condition, the SnO 2 -CM based device still remains 60% of its initial PCE, while the PCE of unmodified device totally breaks down after 72 h.