CsPbX₃ (X = Cl, Br, I) inorganic perovskite nanocrystals (PNCs) not only maintain the excellent optical and electronic properties of bulk material but also possess the features of nano‐materials, such as tunable bandgap and easily processable colloidal ink, and enable them to be suitable for incorporation into various electronic devices and compatible with printing techniques. In contrast to the traditional II‐VI and III‐V semiconductor nanocrystals, the unique defect‐tolerance effect makes the CsPbX₃ PNCs promising materials for optoelectronic applications. The ligands around the PNCs play a critical role in the optoelectronic devices performance. Herein, through a facile hexane/ethyl acetate (MeOAc) solvent treatment method to control the ligand amount around CsPbBrI₂ PNCs, the impact of ligand amount on the performance of solar cell is systematically demonstrated and the ligand amount is quantified precisely via the nuclear magnetic resonance internal standard method. Through controlling the ligand amount, the film quality, charge transfer, and transport properties are largely improved. In addition, a simple annealing process is applied to improve the interface properties by partial crystal fusion. As a consequence, the photovoltaic power conversion efficiency of 12.2% is achieved, which is the highest performance reported for mixed‐halide CsPbX₃ PNCs solar cells.

中文翻译：

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高效CsPbBrI2钙钛矿型纳米晶体太阳能电池的表面配体管理

CsPbX ₃（X = Cl，Br，I）无机钙钛矿纳米晶体（PNCs）不仅保持了块状材料的优异光学和电子性能，而且还具有纳米材料的特性，例如可调谐带隙和易于加工的胶体油墨，以及使它们适合集成到各种电子设备中并与打印技术兼容。与传统的II-VI和III-V半导体纳米晶体相比，独特的缺陷容忍效应使CsPbX ₃ PNC有望成为光电子应用的材料。PNC周围的配体在光电器件性能中起关键作用。本文中，通过简便的己烷/乙酸乙酯（MeOAc）溶剂处理方法控制CsPbBrI ₂周围的配体量通过PNCs，系统地证明了配体数量对太阳能电池性能的影响，并通过核磁共振内标法精确定量了配体数量。通过控制配体的量，可以大大改善薄膜质量，电荷转移和传输性能。另外，采用简单的退火工艺以通过部分晶体熔融来改善界面性质。结果，实现了12.2％的光伏功率转换效率，这是混合卤化物CsPbX ₃ PNC太阳能电池所报告的最高性能。