Xu Peng, Zhang Zhenhu, Zhang Jinping, Wang Jin, Wang Xin, Liu Tianjun, Zhang Wei, Sun Xiangnan, Zhao Xiaoming
Key Laboratory for Intelligent Nano Materials and Devices of Ministry of Education, State Key Laboratory of Mechanics and Control for Aerospace Structures, and Institute for Frontier Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
School of Chemistry, Chemical Engineering and Materials, Jining University, Qufu, 273155, China.
Small. 2025 Aug 25:e08224. doi: 10.1002/smll.202508224.
2D perovskites as interfacial modifiers have demonstrated potential for improving the stability of perovskite solar cells (PSCs); however, 2D structures based on flexible long-chain cations often lead to a high degree of octahedral distortions and larger interlayer spacing. These factors hinder efficient charge extraction between the perovskite and charge transport layers and affect the stability of 2D/3D devices. Here, imidazolyl spacers with rigid ring structures are employed as interfacial modifiers. The spacers of different molecular rigidity influence their anisotropic orientation with [PbI] octahedral, leading to reduced crystal distortion while maintaining compatible octahedral layer spacing, which facilitates efficient hole extraction from bulk perovskite to the surface layer, and increases structural stability of 2D perovskite. As a result, the optimized 2D/3D PSCs achieve power conversion efficiencies of 26% for unit cells (0.16 cm) and 22.4% for solar modules (38.9 cm). Moreover, these spacers enhance the phase stability of the 3D perovskite and effectively mitigate phase degradation, enabling the device to retain 98% of its initial efficiency after 2000 h of continuous operation under 1 sun illumination at 40 °C. These results suggest the potential of imidazolium-based interfacial modifiers in achieving efficient and stable 2D/3D PSCs.
二维钙钛矿作为界面修饰剂已展现出提高钙钛矿太阳能电池（PSC）稳定性的潜力；然而，基于柔性长链阳离子的二维结构往往会导致高度的八面体畸变和更大的层间距。这些因素阻碍了钙钛矿与电荷传输层之间的有效电荷提取，并影响二维/三维器件的稳定性。在此，具有刚性环结构的咪唑基间隔基团被用作界面修饰剂。不同分子刚性的间隔基团会影响它们与[PbI]八面体的各向异性取向，从而在保持兼容的八面体层间距的同时减少晶体畸变，这有利于从体相钙钛矿到表面层的有效空穴提取，并提高二维钙钛矿的结构稳定性。结果，优化后的二维/三维PSC在单位电池（0.16平方厘米）上实现了26%的功率转换效率，在太阳能模块（38.9平方厘米）上实现了22.4%的功率转换效率。此外，这些间隔基团增强了三维钙钛矿的相稳定性，并有效减轻了相降解，使器件在40℃的1个太阳光照下连续运行2000小时后仍能保持其初始效率的98%。这些结果表明基于咪唑鎓的界面修饰剂在实现高效稳定的二维/三维PSC方面具有潜力。
