Direct observation of intrinsic twin domains in tetragonal CH(3)NH(3)PbI(3).
Direct observation of intrinsic twin domains in tetragonal CH(3)NH(3)PbI(3).
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DOI：
10.1038/ncomms14547
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发表时间：
2017-02-23
影响因子：
16.6
通讯作者：
Cheng YB
中科院分区：
文献类型：
--
作者：
Rothmann MU;Li W;Zhu Y;Bach U;Spiccia L;Etheridge J;Cheng YB
有机-无机杂化钙钛矿是下一代太阳能电池的令人兴奋的候选者，其中CH 3 NH3 PbI 3是研究最广泛的候选者之一。虽然已经进行了大量的努力来制造和优化使用CH 3 NH3 PbI 3的光伏器件，但关于控制混合钙钛矿材料的独特性质的晶体结构仍然存在关键问题。在这里，我们报告明确的证据，晶体学的双晶域在tetraphylacCH 3 NH3 PbI 3，观察到使用低剂量透射电子显微镜和选区电子衍射。畴宽约100-300 nm，在四方到立方相变温度（约57 °C）以上/以下消失/再现，这是一个可逆过程，通常会“记忆”畴的尺度和取向。由于这些区域存在于太阳能电池的操作温度范围内，并且具有与太阳能电池中典型的CH 3 NH3 PbI 3膜的厚度相当的尺寸，因此理解孪晶几何形状和取向对于进一步改进钙钛矿太阳能电池是必不可少的。Rothmann、Li、Zhu等人使用低剂量透射电子显微镜报告了四方CH 3 NH3 PbI 3钙钛矿中双晶畴的直接证据。这些孪晶畴的相关尺度和转变温度可能对钙钛矿太阳能电池有影响。
Organic–inorganic hybrid perovskites are exciting candidates for next-generation solar cells, with CH3NH3PbI3 being one of the most widely studied. While there have been intense efforts to fabricate and optimize photovoltaic devices using CH3NH3PbI3, critical questions remain regarding the crystal structure that governs its unique properties of the hybrid perovskite material. Here we report unambiguous evidence for crystallographic twin domains in tetragonal CH3NH3PbI3, observed using low-dose transmission electron microscopy and selected area electron diffraction. The domains are around 100–300 nm wide, which disappear/reappear above/below the tetragonal-to-cubic phase transition temperature (approximate 57 °C) in a reversible process that often ‘memorizes' the scale and orientation of the domains. Since these domains exist within the operational temperature range of solar cells, and have dimensions comparable to the thickness of typical CH3NH3PbI3 films in the solar cells, understanding the twin geometry and orientation is essential for further improving perovskite solar cells. Using low dose transmission electron microscopy, Rothmann, Li, Zhu et al. report direct evidence for twin domains in tetragonal CH3NH3PbI3 perovskite. The relevant scale and transition temperature of these twin domains could have implications for perovskite solar cells.