Department of General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo, Komaba 3-8-1, Meguro-ku, Tokyo, 153-8902, Japan.
Research Center for Advanced Science and Technology, The University of Tokyo, Komaba 4-6-1, Meguro-ku, Tokyo, 153-8904, Japan.
Adv Mater. 2018 Feb;30(8). doi: 10.1002/adma.201705230. Epub 2018 Jan 10.
Organometal halide perovskites have attracted widespread attention as the most favorable prospective material for photovoltaic technology because of their high photoinduced charge separation and carrier transport performance. However, the microstructural aspects within the organometal halide perovskite are still unknown, even though it belongs to a crystal system. Here direct observation of the microstructure of the thin film organometal halide perovskite using transmission electron microscopy is reported. Unlike previous reports claiming each phase of the organometal halide perovskite solely exists at a given temperature range, it is identified that the tetragonal and cubic phases coexist at room temperature, and it is confirmed that superlattices composed of a mixture of tetragonal and cubic phases are self-organized without a compositional change. The organometal halide perovskite self-adjusts the configuration of phases and automatically organizes a buffer layer at boundaries by introducing a superlattice. This report shows the fundamental crystallographic information for the organometal halide perovskite and demonstrates new possibilities as promising materials for various applications.
金属有机卤化物钙钛矿由于其具有高光生电荷分离和载流子输运性能，因此作为最有前途的光伏技术材料而受到广泛关注。然而，尽管它属于晶体系统，但金属有机卤化物钙钛矿的微观结构仍不清楚。本文首次通过透射电子显微镜直接观察了薄膜金属有机卤化物钙钛矿的微观结构。与之前的报道不同，之前的报道声称金属有机卤化物钙钛矿的每个相仅在给定的温度范围内存在，本文确定了四方相和立方相在室温下共存，并且证实了由四方相和立方相混合物组成的超晶格是自组织的，没有组成变化。金属有机卤化物钙钛矿通过引入超晶格来自动调整相的配置并在边界处自动组织缓冲层。本报告展示了金属有机卤化物钙钛矿的基本晶体学信息，并为各种应用提供了作为有前途的材料的新可能性。
