Research Paper: Self-assembled hole-selective contact for efficient Sn-Pb perovskite solar cells and all-perovskite tandems
Scientific Summary
This study addresses the critical need for efficient hole-selective contacts (HSCs) in mixed tin-lead (Sn-Pb) perovskite solar cells (PSCs) and all-perovskite tandem solar cells (TSCs), which typically face challenges with existing hole-transporting materials. The main goal was to design and evaluate novel donor-acceptor (D-A) self-assembled monolayers (SAMs) featuring oligoether side chains (specifically EBT) to improve device performance and stability.
Key findings reveal that EBT, by introducing oligoether side chains, effectively accelerates hole extraction, regulates Sn-Pb perovskite crystal growth, and passivates surface defects, thereby significantly suppressing interfacial non-radiative recombination losses. This optimized interface led to champion power conversion efficiencies (PCEs) of 23.54% for low-bandgap (LBG) PSCs. More impressively, EBT-tailored devices enabled high-performance monolithic 2-terminal (2-T) all-perovskite tandems with a record PCE of 28.61% and an open-circuit voltage (VOC) of 2.155 V, along with excellent operational stability (retaining over 92% efficiency after 400 hours). This work provides a crucial molecular design strategy for developing high-efficiency, stable, and cost-effective perovskite photovoltaics, pushing beyond the theoretical limits of single-junction cells for sustainable energy applications.
Publication Details
Jingwei Zhu, Xiaozhen Huang, Yi Luo, Wenbo Jiao, Yuliang Xu, Juncheng Wang, Zhiyu Gao, Kun Wei, Tianshu Ma, Jiayu You, Jialun Jin, Shenghan Wu, Zhihao Zhang, Wenqing Liang, Yang Wang, Shengqiang Ren, Changlei Wang, Cong Chen, Jinbao Zhang and Dewei Zhao (2024), Self-assembled hole-selective contact for efficient Sn-Pb perovskite solar cells and all-perovskite tandems. Nature Communications. [Volume and page numbers not available in the provided sources]. https://doi.org/10.1038/s41467-024-55492-4
Fluxim Tools Used
The PAIOS all-in-one characterization system from Fluxim AG was employed to perform Mott-Schottky plots and Electrochemical Impedance Spectroscopy (EIS) measurements. These measurements were crucial for quantifying electronic properties like built-in potential and recombination resistance, thereby validating the enhanced device performance and reduced non-radiative recombination observed with the new SAMs. The benefit of using PAIOSTM lies in its ability to provide comprehensive electrical characterization, offering precise insights into the underlying device physics that contributed to the optimized performance.