Fu Dongying, Zhang Yue, Chen Zhuo, Pan Lin, He Yueyue, Luo Junhua
Institute of Crystalline Materials, Shanxi University, Taiyuan, Shanxi, 030006, P. R. China.
State Key Laboratory of Quantum Optics and Quantum Optics Devices, Shanxi University, Taiyuan, Shanxi, 030006, P. R. China.
Small. 2024 Sep;20(37):e2403198. doi: 10.1002/smll.202403198. Epub 2024 May 13.
Hydrogen bonding as a multifunctional tool has always influenced the structure of hybrid perovskites. Compared with the research on hydrogen bonding, the study of halogen-halogen interactions on the structure and properties of hybrid perovskites is still in its early stages. Herein, a polar bilayered hybrid perovskite (IEA)FAPbI (IEA is 2-iodoethyl-1-ammonium, FA is formamidinium) with iodine-substituted spacer is successfully constructed by changing the configuration of interlayer cations and regulating non-covalent interactions at the organic-inorganic interface, which shows a shorter interlayer spacing and higher density (ρ = 3.862 g cm). The generation of structure polarity in (IEA)FAPbI is caused by the synergistic effect of hydrogen bonding and halogen-halogen interactions. Especially, as the length of the carbon chain in organic cations decreases, the I---I interaction in the system gradually strengthens, which may be the main reason for the symmetry-breaking. Polarity-induced bulk photovoltaics (V = 1.0 V) and higher density endow the device based on (I-EA)FAPbI exhibit a high sensitivity of 175.6 µC Gy cm and an ultralow detection limit of 60.4 nGy s at 0 V bias under X-ray irradiation. The results present a facile approach for designing polar multifunctional hybrid perovskites, also providing useful assistance for future research on halogen-halogen interactions.
氢键作为一种多功能工具，一直影响着杂化钙钛矿的结构。与氢键研究相比，关于卤-卤相互作用对杂化钙钛矿结构和性能影响的研究仍处于早期阶段。在此，通过改变层间阳离子的构型并调节有机-无机界面处的非共价相互作用，成功构建了一种带有碘取代间隔基的极性双层杂化钙钛矿(IEA)FAPbI（IEA为2-碘乙基-1-铵，FA为甲脒），其层间距较短且密度较高(ρ = 3.862 g cm)。(IEA)FAPbI中结构极性的产生是由氢键和卤-卤相互作用的协同效应引起的。特别是，随着有机阳离子中碳链长度的减小，体系中的I---I相互作用逐渐增强，这可能是对称性破缺的主要原因。极性诱导的体光伏效应(V = 1.0 V)和更高的密度使基于(I-EA)FAPbI的器件在X射线照射下，在0 V偏压下表现出175.6 µC Gy cm的高灵敏度和60.4 nGy s的超低检测限。这些结果提出了一种设计极性多功能杂化钙钛矿的简便方法，也为未来卤-卤相互作用的研究提供了有益的帮助。
