Diffraction imaging of nanocrystalline structures in organic semiconductor molecular thin films
Diffraction imaging of nanocrystalline structures in organic semiconductor molecular thin films
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DOI：
10.1038/s41563-019-0387-3
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发表时间：
2019-08-01
期刊：
影响因子：
41.2
通讯作者：
Minor, Andrew M.
中科院分区：
文献类型：
--
作者：
Panova, Ouliana;Ophus, Colin;Minor, Andrew M.
有机固体的性质取决于它们的结构和形态，然而使用常规电子显微镜方法的直接成像受到这些材料的复杂内部结构和它们对电子束的敏感性的阻碍。在这里，我们设法观察纳米晶体结构的两个有机分子薄膜系统，使用透射电子显微镜，通过采用扫描纳米衍射方法，允许完全访问倒易空间的大小的空间定位探针（类似于2纳米）。通过这种技术揭示的形态从具有明显的结构分割的晶粒变化-其特征在于尖锐的晶界和重叠域-到具有在所有可能的旋转中平滑变化的晶体取向的液晶结构，所述旋转包含表示在指向矢场中的奇点的向错。结果显示了如何使用以前仅适用于金属和陶瓷等硬质材料的技术在有机系统中可视化结构-性能关系。
The properties of organic solids depend on their structure and morphology, yet direct imaging using conventional electron microscopy methods is hampered by the complex internal structure of these materials and their sensitivity to electron beams. Here, we manage to observe the nanocrystalline structure of two organic molecular thin-film systems using transmission electron microscopy by employing a scanning nanodiffraction method that allows for full access to reciprocal space over the size of a spatially localized probe (similar to 2 nm). The morphologies revealed by this technique vary from grains with pronounced segmentation of the structure-characterized by sharp grain boundaries and overlapping domains-to liquid-crystal structures with crystalline orientations varying smoothly over all possible rotations that contain disclinations representing singularities in the director field. The results show how structure-property relationships can be visualized in organic systems using techniques previously only available for hard materials such as metals and ceramics.