Department of Chemistry, University of Wisconsin-Madison , 1101 University Avenue, Madison, Wisconsin 53706, United States.
International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University , Shaanxi 710049, P. R. China.
Nano Lett. 2017 Jan 11;17(1):460-466. doi: 10.1021/acs.nanolett.6b04450. Epub 2016 Dec 27.
With the intense interest in inorganic cesium lead halide perovskites and their nanostructures for optoelectronic applications, high-quality crystalline nanomaterials with controllable morphologies and growth directions are desirable. Here, we report a vapor-phase epitaxial growth of horizontal single-crystal CsPbX (X = Cl, Br, I) nanowires (NWs) and microwires (MWs) with controlled crystallographic orientations on the (001) plane of phlogopite and muscovite mica. Moreover, single NWs, Y-shaped branches, interconnected NW or MW networks with 6-fold symmetry, and, eventually, highly dense epitaxial network of CsPbBr with nearly continuous coverage were controllably obtained by varying the growth time. Detailed structural study revealed that the CsPbBr wires grow along the [001] directions and have the (100) facets exposed. The incommensurate heteroepitaxial lattice match between the CsPbBr and mica crystal structures and the growth mechanism of these horizontal wires due to asymmetric lattice mismatch were proposed. Furthermore, the photoluminescence waveguiding and good performance from the photodetector device fabricated with these CsPbBr networks demonstrated that these well-connected CsPbBr NWs could serve as straightforward platforms for fundamental studies and optoelectronic applications.
由于人们对无机铯铅卤钙钛矿及其纳米结构在光电子学应用方面的浓厚兴趣，因此需要具有可控形貌和生长方向的高质量晶体纳米材料。在这里，我们报告了在金云母和白云母的（001）面上通过气相外延生长具有受控晶体取向的水平单晶 CsPbX（X = Cl、Br、I）纳米线（NWs）和微丝（MWs）。此外，通过改变生长时间，可以可控地获得单根 NWs、Y 型分支、相互连接的 NW 或 MW 网络以及具有近连续覆盖度的高度密集的 CsPbBr 外延网络。详细的结构研究表明，CsPbBr 线沿[001]方向生长，并具有暴露的（100）面。提出了 CsPbBr 和云母晶体结构之间的非共格异质外延晶格匹配以及由于不对称晶格失配导致这些水平线生长的机制。此外，由这些 CsPbBr 网络制成的光电探测器器件的光致发光波导和良好性能表明，这些良好连接的 CsPbBr NWs 可以作为基础研究和光电子学应用的直接平台。
