Local Crystal Misorientation Influences Non-radiative Recombination in Halide Perovskites
Local Crystal Misorientation Influences Non-radiative Recombination in Halide Perovskites
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DOI：
10.1016/j.joule.2019.09.001
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发表时间：
2019-12-18
期刊：
影响因子：
39.8
通讯作者：
Ginger, David S.
中科院分区：
文献类型：
--
作者：
Jariwala, Sarthak;Sun, Hongyu;Ginger, David S.
利用超灵敏电子背散射衍射(EBSD)研究了CH3NH3PbI3(MAPI)钙钛矿薄膜的晶向、晶界和晶界。尽管真实的颗粒结构与扫描电子显微镜(SEM)中可见的形态大体一致，但EBSD拍摄的反极图揭示了颗粒结构和否则被隐藏的内部取向错误。局部晶体取向不良与局部应变的存在是一致的，局部应变随颗粒的不同而不同。我们在用于EBSD的相同MAPI样品上获得了共聚焦光学光致发光(PL)显微图像。我们对光学和EBSD数据进行了关联，表明PL与晶体的局域取向扩散是反相关的，这表明晶体取向不均匀程度越高(局域应变)的晶体表现出更多的非辐射复合。我们发现，较大的颗粒倾向于具有较大的晶粒取向分布，这与较高的应变程度和非辐射复合相一致。
We use ultrasensitive electron backscatter diffraction (EBSD) to map the local crystal orientations, grains, and grain boundaries in CH3NH3PbI3 (MAPI) perovskite thin films. Although the true grain structure is broadly consistent with the morphology visible in scanning electron microscopy (SEM), the inverse pole figure maps taken with EBSD reveal grain structure and internal misorientation that is otherwise hidden. Local crystal misorientation is consistent with the presence of local strain, which varies from one grain to the next. We acquire co-aligned confocal optical photoluminescence (PL) microscopy images on the same MAPI samples used for EBSD. We correlate optical and EBSD data, showing that PL is anticorrelated with the local grain orientation spread, suggesting that grains with higher degrees of crystalline orientational heterogeneity (local strain) exhibit more non-radiative recombination. We find that larger grains tend to have larger grain orientation spread, consistent with higher degrees of strain and non-radiative recombination.