Amino-Linked Conjugated Tetrazole Ring Passivation Strategy for Air-Processed Perovskite Cells with Predominant Stability and Efficiency

Perovskite solar cells (PSCs) develop rapidly with certified efficiency over 25.5 %, but there are remaining problems such as defects-induced recombination and degradation throughout the whole device. Functional organic small molecule passivation strategies are diverse and efficient, enhancing the efficiency and stability of PSCs. Here, 5-aminotetrazole (5ATZ) was introduced for the first time as an effective passivator, where -NH2 and -NH as active sites interacted with the Pb and I related to vacancy defects in perovskites, anchoring defects and preventing further unavoidable ion migration and device degradation. Furthermore, the extensive pi-electron delocalization around the tetrazole conjugated ring significantly promoted the charge transfer. Therefore, the 5ATZ-processed PSCs provided enhanced voltage and current, showed superior 19.75 % power conversion efficiency with excellent performance and improved stability, and demonstrated one of the best performances in all-air preparation to date. The simultaneous multi-effect passivation strategy of vacancy defects in perovskites will contribute to eliminate obstacles on the road to commercialization of PSCs.