Tetrazole modulated perovskite films for efficient solar cells with improved moisture stability

The commercialization process of metal hybrid perovskite solar cells (PSCs) is hindered by the poor quality of perovskite films, imperfect carrier extraction, and inferior stability. Organic or inorganic molecules have been widely used to overcome these limitations. Herein, 5-(ethylthio)-1H-tetrazole (ETT) is applied for the deposition of perovskite films with high crystallinity and smooth surface. Due to the interaction between the lone pair electrons of tetrazole and Pb²⁺, the surface defects of perovskite films were passivated, thus leading to facilitated charge transport and inhibited carrier recombination. The improved crystallinity and defect passivation enabled a power conversion efficiency over 20% in the ETT-modified inverted MAPbI₃ PSC device, along with notably enhanced moisture stability. Our work provides a feasible strategy for the crystallization modulation and humidity stability enhancement of PSCs.