Li Botong, Liu Xuepeng, Wei Yijin, Lin Zedong, Han Mingyuan, Du Weilun, Zhang Xianfu, Chen Haibin, Lin Changqing, Shao Zhipeng, Ding Yong, Dai Songyuan
Beijing Key Laboratory of Novel Thin-Film Solar Cells, School of New Energy, North China Electric Power University, Beijing, 102206, P. R. China.
Key Laboratory of Photoelectric Conversion and Utilization of Solar Energy, Qingdao New Energy Shandong Laboratory, Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Science, Qingdao, 266101, P. R. China.
Adv Mater. 2025 Aug 5:e00732. doi: 10.1002/adma.202500732.
In inverted perovskite solar cells (PSCs), the arrangement of self-assembled hole-transporting monolayers (SAMs) on substrates and their interaction with perovskite layer are critical for device efficiency and stability. Herein, two spiro SAMs are developed by introducing O and S atoms into the structure, named Spiro-O and Spiro-S, respectively. On one hand, the unique orthogonal molecular configuration of the spiro structure weakens intermolecular π-π interactions, thereby inhibiting molecular aggregation. This ensures uniform coverage on the substrate and a homogeneous surface potential distribution. On the other hand, the lone pair electrons of the introduced heteroatoms can interact with the Pb ions, enhancing the quality of the perovskite film and effectively passivating the defects at the perovskite/SAM interface. The experimental and theoretical results show that the S in Spiro-S strongly interacts with perovskite, resulting in the formation of a more uniform and higher-quality crystalline perovskite layer. Compared to PSCs based on Spiro-O, the device with Spiro-S shows decreased defects at the buried interface, ultimately achieving an impressive power conversion efficiency of 25.75% (certified 25.19%). Furthermore, the PSCs based on Spiro-S also exhibit better long stability; the unencapsulated champion devices retain 92% of the initial efficiency after being stored at 25 °C for 1200 h.
在倒置钙钛矿太阳能电池（PSC）中，自组装空穴传输单分子层（SAM）在基底上的排列及其与钙钛矿层的相互作用对于器件效率和稳定性至关重要。在此，通过将O和S原子引入结构中开发了两种螺环SAM，分别命名为Spiro-O和Spiro-S。一方面，螺环结构独特的正交分子构型减弱了分子间的π-π相互作用，从而抑制了分子聚集。这确保了在基底上的均匀覆盖和均匀的表面电势分布。另一方面，引入的杂原子的孤对电子可以与Pb离子相互作用，提高钙钛矿薄膜的质量并有效钝化钙钛矿/SAM界面处的缺陷。实验和理论结果表明，Spiro-S中的S与钙钛矿强烈相互作用，导致形成更均匀、更高质量的结晶钙钛矿层。与基于Spiro-O的PSC相比，基于Spiro-S的器件在掩埋界面处的缺陷减少，最终实现了令人印象深刻的25.75%的功率转换效率（认证效率为25.19%）。此外，基于Spiro-S的PSC还表现出更好的长期稳定性；未封装的冠军器件在25°C下储存1200小时后仍保留初始效率的92%。
