arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2004.12262physics.app-ph
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有机-无机杂化钙钛矿的透射电子显微镜:神话与真相

Transmission electron microscopy of organic-inorganic hybrid perovskites: myths and truths

Shulin Chen, Ying Zhang, Jinjin Zhao, Zhou Mi, Jingmin Zhang, Jian Cao, Jicai Feng, Guanglei Zhang, Junlei Qi, Jiangyu Li, Peng Gao

摘要:

有机-无机杂化钙钛矿(OIHP)作为高效且廉价的太阳能电池的有希望的候选者吸引了广泛的研究兴趣。透射电子显微镜表征,可以受益于基本的理解和降解机制被广泛用于这些材料。然而,它们对电子束照射的敏感性和因此的结构不稳定性通常阻止我们获得内在信息,甚至导致显著的伪影。在这里,我们系统地研究了不同实验因素下的结构退化行为,以揭示OIHP的TEM表征的优化条件,通过使用低剂量电子衍射和成像技术。我们发现,低温并没有减缓束损伤,而是诱导了快速非晶化的OIHP。此外,在较高的加速电压下观察到不太严重的损伤。发现MAPbI_3的电子束灵敏度与面有关,(100)面比(001)面更稳定。在这些指导下,我们成功地获得了原始MAPbI 3的原子结构,并确定了非常窄的表征窗口。这些发现有助于指导这些束敏感材料的未来电子显微镜表征,这也有助于找到改善钙钛矿太阳能电池稳定性和性能的策略。

英文摘要:

Organic-inorganic hybrid perovskites (OIHPs) have attracted extensive research interest as a promising candidate for efficient and inexpensive solar cells. Transmission electron microscopy characterizations that can benefit the fundamental understanding and the degradation mechanism are widely used for these materials. However, their sensitivity to the electron beam illumination and hence structural instabilities usually prevent us from obtaining the intrinsic information or even lead to significant artifacts. Here, we systematacially investigate the structural degradation behaviors under different experimental factors to reveal the optimized conditions for TEM characterizations of OIHPs by using low-dose electron diffraction and imaging techniques. We find that a low temperature does not slow down the beam damage but instead induces a rapid amorphization for OIHPs. Moreover, a less severe damage is observed at a higher accelerating voltage. The beam-sensitivity is found to be facet-dependent that a (100) exposed MAPbI3 surface is more stable than (001) surface. With these guidance, we successfully acquire the atomic structure of pristine MAPbI3 and identify the characterization window that is very narrow. These findings are helpful to guide future electron microscopy characterization of these beam-sensitive materials, which are also useful for finding strategies to improve the stability and the performance of the perovskite solar cells.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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