Li Yuheng, Li Lin, Zeng Haipeng, Lan Chunxiang, Yang Shaomin, Zheng Ziwei, Zeng Miaomiao, Shi Yingying, Gao Kai, Cui Lianmeng, Guo Rui, Guo Jing, Hu Bin, Rong Yaoguang, Xie Haibing, Li Xiong
Michael Grätzel Center for Mesoscopic Solar Cells, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology (HUST), Wuhan, 430074, China.
Institute of New Materials and Advanced Manufacturing, Beijing Academy of Science and Technology (BJAST), Beijing, 100089, China.
Nat Commun. 2025 Jul 1;16(1):6038. doi: 10.1038/s41467-025-61294-z.
Addressing the stability challenges induced by the chemical interactions between metal electrodes and perovskite components is essential for high-performance perovskite solar cells (PSCs). Herein, we design a bilayer multifunctional polymer buffer composed of polyethyleneimine (PEI) and 2-((2-methyl-3-(2-((2-methylbutanoyl)oxy)ethoxy)-3-oxopropyl)thio)-3-(methylthio)succinic acid (PDMEA), inserting into the interface of metal electrode/transporting layer. This buffer mitigates metal atom diffusion by forming thioether-metal-carboxyl chelation rings between the metal layer and PDMEA. Additionally, it facilitates efficient electron transport and suppresses interfacial recombination through an in-situ cross-linking between the carboxyl groups of PDMEA and the amine groups of PEI based on Lewis acid-base reaction. Consequently, this design effectively reduces undesirable metal/ion interdiffusion during device fabrication and operation. The resulting PSCs with the PEI/PDMEA buffer achieve certified power conversion efficiencies (PCEs) of 26.46% (0.1 cm) and 24.70% (1.01 cm), demonstrating enhanced thermal and operational stability. We anticipate that this buffer design strategy, which forms bilayer polymer buffers via cross-linking of polymers with distinct functionalities, will inspire the rational design of robust buffers for highly efficient and stable PSCs and other electronic devices.
解决金属电极与钙钛矿组件之间化学相互作用引发的稳定性挑战对于高性能钙钛矿太阳能电池（PSC）至关重要。在此，我们设计了一种由聚乙烯亚胺（PEI）和2-((2-甲基-3-(2-((2-甲基丁酰基)氧基)乙氧基)-3-氧代丙基)硫代)-3-(甲硫基)琥珀酸（PDMEA）组成的双层多功能聚合物缓冲层，插入到金属电极/传输层的界面。该缓冲层通过在金属层和PDMEA之间形成硫醚-金属-羧基螯合环来减轻金属原子扩散。此外，它基于路易斯酸碱反应通过PDMEA的羧基与PEI的胺基之间的原位交联促进高效电子传输并抑制界面复合。因此，这种设计有效地减少了器件制造和运行过程中不期望的金属/离子相互扩散。所得具有PEI/PDMEA缓冲层的PSC实现了26.46%（0.1平方厘米）和24.70%（1.01平方厘米）的认证功率转换效率（PCE），展示出增强的热稳定性和运行稳定性。我们预计这种通过具有不同功能的聚合物交联形成双层聚合物缓冲层的缓冲层设计策略，将激发用于高效稳定PSC和其他电子器件的稳健缓冲层的合理设计。
