Enhancing Charge Collection of Tin-Based Perovskite Solar Cells by Optimizing the Buried Interface with a Multifunctional Self-Assembled Monolayer

作者：Junyu Qu, Xiaoxue Wang, Chuan Ning Luo, Chenwu Zeng, Hangyu Zhou, Zihao Yang, Zhihao Zhang, Jialun Jin, Yongbo Huang, Chao Ding, Cong Chen, Shengqiang Ren, Dewei Zhao · 发表于：ACS Applied Materials & Interfaces · 年份：2025 · DOI：10.1021/acsami.5c01653 · 被引用次数：13 · 研究领域：Perovskite Materials and Applications、Conducting polymers and applications、Chalcogenide Semiconductor Thin Films

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is a widely used hole transport material in inverted tin-based perovskite solar cells (Sn–PSCs). However, the efficiency and stability of these Sn–PSCs that utilize PEDOT:PSS are unsatisfactory, partly due to concerns about their mismatched work functions, hydrophobicity, and chemical interactions. Here, we introduce a self-assembled monolayer (SAM), (2-(7 H -dibenzo[c,g]carbazol-7-yl)ethyl) phosphonic acid (2PADCB) as a multifunctional buffer molecule at the buried PEDOT:PSS/Sn perovskite interface. The phosphate group in the 2PADCB molecule reacts with the sulfur atom on the thiophene ring in PEDOT:PSS. This reaction process effectively anchors the SAM molecule firmly to the surface of PEDOT:PSS. Additionally, it reduces the binding sites between PEDOT and PSS, alleviating the acidification of the PEDOT:PSS surface and the poor conductivity caused by excessive PSS. Furthermore, the presence of two additional benzene rings in the 2PADCB molecule terminal group increases the electron density around Sn 2+, thereby inhibiting its oxidation. Additionally, the hydrophobic characteristics of the 2PADCB molecule mitigate moisture infiltration from PEDOT:PSS, thereby protecting the degradation of Sn perovskite. Consequently, the Sn–PSCs based on the PEDOT:PSS/2PADCB film achieve a champion efficiency of 14.7%, higher than that of their pristine counterpart (12.5%). Moreover, the 2PADCB molecule improves the stabilit...