Benzoyl Sulfonyl Molecules for Bilateral Passivation and Crystalline Regulation at Buried Interfaces toward High‐Performance Perovskite Solar Cells

Abstract

Well‐engineered buried interfaces play a pivotal role in achieving high‐performance perovskite solar cells (PSCs). A superior buried interface involves controlled perovskite crystallization, efficient charge transfer across interfaces, and robust interfacial bonding. Here, a class of innovative additives, benzoyl sulfonyl molecules including 4‐sulfobenzoic acid monopotassium salt (K‐SBA), and 4‐sulfamoylbenzoic acid (SBA) is introduced to tailer the SnO2/perovskite buried interface, aiming to meet these essential criteria. Among them, K‐SBA performed better. The findings reveal that the functional groups of K‐SBA establish interactions with both SnO2 and perovskite, leading to effective bilateral passivation and mitigation of interface stress. This results in the formation of a pore‐free buried interface and high‐quality perovskite films with substantial crystal sizes. Consequently, PSCs incorporating K‐SBA exhibited a notable increase in efficiency, achieving 24.56% efficiency compared to the control device's 22.27%. Furthermore, these K‐SBA‐enhanced PSCs maintain 90% of their original efficiency even after 500 h of maximum power point tracking. This work provides valuable insights for further refinement and advancement of buried interfaces in PSCs.