Suppressing the Precursor Aging for Efficient Formamidinium-Based Dion–Jacobson Two-Dimensional Perovskite Solar Cells

作者：Xianglan Tang, Yun Lin, Fang Wan, Wen Deng, Lei Wang, Ting Hu, Xiaotian Hu, Lin Zhang, Fangping Ouyang, Biao Liu, Junliang Yang, Zhihui Chen, Bin Yang, Liming Ding, Xiao Wang, Shuping Pang, Jun He, Yiwang Chen, Yongbo Yuan · 发表于：ACS Nano · 年份：2025 · DOI：10.1021/acsnano.5c03211 · 被引用次数：8 · 研究领域：Perovskite Materials and Applications、Conducting polymers and applications、Organic Electronics and Photovoltaics

For the quasi-two-dimensional (Q-2D) perovskites containing formamidinium cations (FA + ), the chemical reaction between FA + and amine-based organic spacers deteriorates the phase purity and repeatability of perovskite solar cells (PSCs), but it has attracted little attention so far. In this work, the aging process of the 1,3-propanediamine- (PDA-) and FA + -based Dion–Jacobson (DJ) type Q-2D perovskite precursor has been investigated. The deprotonated PDA interacts with the FA + via its two terminal amines successively to form a ring molecule, giving rise to a highly insoluble complex with lead iodide and causing reversible precursor aging. Adding a small amount of acid is demonstrated as a general route to eliminate the FA + -related reactions in the precursor. In our study, the used methanesulfonic acid (MSA) effectively eliminates the precursor aging in both PDA- and butylamine (BA)-containing Q-2D perovskite films and meanwhile passivates the undercoordinated Pb 2+ with its S═O group, leading to both improved power conversion efficiency (PCE) of solar cells and precursor stability. FA-based Q-2D PSCs have been enhanced from 14.60% to 18.26%.