Lai Yibin, Xu Xuehui, Li Pan, Peng Ran, Chen Huiyan, Yang Lurong, Yin Chunyang, Zhu Hanbo, Jia Ziyan, Hui Juan, Yan Buyi, Yao Jizhong, Bai Sai, She Xiaojian, Yang Yang Michael
State Key Laboratory of Extreme Photonics and Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China.
Jiaxing Key Laboratory of Photonic Sensing and Intelligent Imaging, Intelligent Optics and Photonics Research Center, Jiaxing Institute of Zhejiang University, Jiaxing, Zhejiang, 314041, China.
Small. 2025 Sep;21(36):e2506017. doi: 10.1002/smll.202506017. Epub 2025 Jul 11.
Tin-lead (Sn-Pb) mixed narrow band gap (NBG) perovskite solar cells (PSCs) hold promise for tandem photovoltaic applications due to their tunable bandgap (≈1.25 eV), but face challenges from rapid crystallization kinetics and operational instability. Conventional ammonium salt passivators improve efficiency but often compromise stability by introducing mobile ions. Herein, alkylammonium halide salts are systematically investigated with varying carbon chain lengths to reconcile this trade-off. As a result, it is found that the long-chain oleylammonium iodide (OAmI) achieves unprecedented synergy. It demonstrates superior defect passivation, enhanced crystallographic orientation, and suppressed ion migration. Transient ion current measurements reveal a fourfold reduction in mobile ion density for OAmI-treated devices. Electrostatic potential calculations and XPS analysis confirm stronger coordination between OAmI and undercoordinated Sn/Pb sites, while GIWAXS reveal improved (001)-oriented crystallization and reduced surface roughness. These synergies yield a champion power conversion efficiency (PCE) of 22.69% for gas-quenching produced Sn-Pb PSCs and 14.46% for 6 × 6 cm mini-modules, alongside a T80 lifetime nearly twofold increase compared to the control group.
锡铅（Sn-Pb）混合窄带隙（NBG）钙钛矿太阳能电池（PSC）因其可调节的带隙（约1.25 eV）在串联光伏应用中具有潜力，但面临着快速结晶动力学和运行不稳定性的挑战。传统的铵盐钝化剂提高了效率，但往往通过引入移动离子而损害稳定性。在此，系统地研究了不同碳链长度的烷基卤化铵盐，以协调这种权衡。结果发现，长链油基碘化铵（OAmI）实现了前所未有的协同效应。它表现出优异的缺陷钝化、增强的晶体取向和抑制的离子迁移。瞬态离子电流测量表明，经OAmI处理的器件中移动离子密度降低了四倍。静电势计算和XPS分析证实了OAmI与配位不足的Sn/Pb位点之间有更强的配位作用，而GIWAXS显示（001）取向的结晶得到改善，表面粗糙度降低。这些协同效应使气体淬火制备的Sn-Pb PSC的冠军功率转换效率（PCE）达到22.69%，6×6 cm的微型模块达到14.46%，同时T80寿命与对照组相比增加了近两倍。
