Gao Mengyu, Park Yoonjae, Jin Jianbo, Chen Peng-Cheng, Devyldere Hannah, Yang Yao, Song Chengyu, Lin Zhenni, Zhao Qiuchen, Siron Martin, Scott Mary C, Limmer David T, Yang Peidong
Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States.
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
J Am Chem Soc. 2023 Mar 1;145(8):4800-4807. doi: 10.1021/jacs.2c13711. Epub 2023 Feb 16.
Halide perovskite is a unique dynamical system, whose structural and chemical processes happening across different timescales have significant impact on its physical properties and device-level performance. However, due to its intrinsic instability, real-time investigation of the structure dynamics of halide perovskite is challenging, which hinders the systematic understanding of the chemical processes in the synthesis, phase transition, and degradation of halide perovskite. Here, we show that atomically thin carbon materials can stabilize ultrathin halide perovskite nanostructures against otherwise detrimental conditions. Moreover, the protective carbon shells enable atomic-level visualization of the vibrational, rotational, and translational movement of halide perovskite unit cells. Albeit atomically thin, protected halide perovskite nanostructures can maintain their structural integrity up to an electron dose rate of 10,000 e/Å·s while exhibiting unusual dynamical behaviors pertaining to the lattice anharmonicity and nanoscale confinement. Our work demonstrates an effective method to protect beam-sensitive materials during observation, unlocking new solutions to study new modes of structure dynamics of nanomaterials.
卤化物钙钛矿是一种独特的动力学系统，其在不同时间尺度上发生的结构和化学过程对其物理性质和器件级性能有重大影响。然而，由于其固有的不稳定性，对卤化物钙钛矿结构动力学进行实时研究具有挑战性，这阻碍了对卤化物钙钛矿合成、相变和降解过程中化学过程的系统理解。在此，我们表明原子级薄的碳材料可以稳定超薄卤化物钙钛矿纳米结构，使其免受其他不利条件的影响。此外，保护性碳壳能够对卤化物钙钛矿晶胞的振动、旋转和平移运动进行原子级可视化。尽管是原子级薄的，但受保护的卤化物钙钛矿纳米结构在电子剂量率高达10,000 e/Å·s时仍能保持其结构完整性，同时展现出与晶格非谐性和纳米尺度限制相关的异常动力学行为。我们的工作展示了一种在观察过程中保护对束敏感材料的有效方法，为研究纳米材料结构动力学的新模式开辟了新的解决方案。
