He Jiacheng, Sheng Wangping, Yang Jia, Zhong Yang, Cai Qianqian, Liu Yikun, Guo Zhao, Tan Licheng, Chen Yiwang
College of Chemistry and Chemical Engineering/Institute of Polymers and Energy Chemistry (IPEC), Nanchang University, 999 Xuefu Avenue, Nanchang, 330031, China.
National Engineering Research Center for Carbohydrate Synthesis/Key Laboratory of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of Education, Jiangxi Normal University, 99 Ziyang Avenue, Nanchang, 330022, China.
Angew Chem Int Ed Engl. 2024 Jan 2;63(1):e202315233. doi: 10.1002/anie.202315233. Epub 2023 Nov 30.
Eliminating the undesired photoinstability of excess lead iodide (PbI ) in the perovskite film and reducing the energy mismatch between the perovskite layer and heterogeneous interfaces are urgent issues to be addressed in the preparation of perovskite solar cells (PVSCs) by two-step sequential deposition method. Here, the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF ) is employed to convert superfluous PbI to more robust 1D EMIMPbI which can withstand lattice strain, while forming an interfacial dipole layer at the SnO /perovskite interface to reconfigure the interfacial energy band structure and accelerate the charge extraction. Consequently, the unencapsulated PVSCs device attains a champion efficiency of 24.28 % with one of the highest open-circuit voltage (1.19 V). Moreover, the unencapsulated devices showcase significantly improved thermal stability, enhanced environmental stability and remarkable operational stability accompanied by 85 % of primitive efficiency retained over 1500 h at maximum power point tracking under continuous illumination.
消除钙钛矿薄膜中过量碘化铅（PbI₂）不期望的光不稳定性以及减少钙钛矿层与异质界面之间的能量失配，是通过两步顺序沉积法制备钙钛矿太阳能电池（PVSCs）时亟待解决的问题。在此，采用1-乙基-3-甲基咪唑四氟硼酸盐（EMIMBF₄）将多余的PbI₂转化为更稳定的一维EMIMPbI₃，其能够承受晶格应变，同时在SnO₂/钙钛矿界面形成界面偶极层，以重新配置界面能带结构并加速电荷提取。因此，未封装的PVSCs器件实现了24.28%的最佳效率以及最高开路电压之一（1.19 V）。此外，未封装的器件展现出显著提高的热稳定性、增强的环境稳定性和卓越的运行稳定性，在连续光照下最大功率点跟踪时，1500 h内仍保留85%的初始效率。
