Self-assembled hole-selective contact for efficient Sn-Pb perovskite solar cells and all-perovskite tandems

• Published in: Nature communications Vol. 16; no. 1; pp. 240 - 11
• Main Authors: Zhu, Jingwei, Huang, Xiaozhen, Luo, Yi, Jiao, Wenbo, Xu, Yuliang, Wang, Juncheng, Gao, Zhiyu, Wei, Kun, Ma, Tianshu, You, Jiayu, Jin, Jialun, Wu, Shenghan, Zhang, Zhihao, Liang, Wenqing, Wang, Yang, Ren, Shengqiang, Wang, Changlei, Chen, Cong, Zhang, Jinbao, Zhao, Dewei
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 02.01.2025; Nature Publishing Group; Nature Portfolio
• Subjects: 142/136; 639/301/299/946; 639/4077/4072/4062; Abbreviations; Crystal defects; Crystal growth; Efficiency; Humanities and Social Sciences; Lead; Monolayers; multidisciplinary; Perovskites; Photovoltaic cells; Radiative recombination; Science; Science (multidisciplinary); Self-assembled monolayers; Self-assembly; Solar cells; Surface defects; Tin
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-55492-4

Self-assembled monolayers (SAMs) have displayed unpredictable potential in efficient perovskite solar cells (PSCs). Yet most of SAMs are largely suitable for pure Pb-based devices, precisely developing promising hole-selective contacts (HSCs) for Sn-based PSCs and exploring the underlying general mechanism are fundamentally desired. Here, based on the prototypical donor-acceptor SAM MPA-BT-BA (BT), oligoether side chains with different length (i.e., methoxy, 2-methoxyethoxy, 2-(2-methoxyethoxy)ethoxy group) were custom-introduced on the benzothiadiazole unit to produce the target SAMs with acronyms MPA-MBT-BA (MBT), MPA-EBT-BA (EBT), and MPA-MEBT-BA (MEBT), respectively, and acting as HSCs for efficient Sn-Pb PSCs and all-perovskite tandems. The introduction of oligoether side chains enables HSCs effectively accelerate hole extraction, regulate the crystal growth and passivate surface defects of Sn-Pb perovskites. In particular, benefiting from the enhanced Sn-Pb perovskite film quality and the suppressed interfacial non-radiative recombination losses, EBT-tailored LBG devices yield a champion efficiency of 23.54%, enabling 28.61% efficient monolithic all-perovskite tandems with an impressive V OC of 2.155 V and excellent operational stability as well as 28.22%-efficiency 4-T tandems. The development of hole-selective contacts for Sn-based perovskite solar cells is highly desirable. Here, the authors report self-assembled monolayers with oligoether side chains on the benzothiadiazole unit and achieve an efficiency of 28.61% for operationally stable all-perovskite tandems.