Strong In-Plane Anisotropies of Optical and Electrical Response in Layered Dimetal Chalcogenide
Strong In-Plane Anisotropies of Optical and Electrical Response in Layered Dimetal Chalcogenide
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层状双金属硫属化物中光学和电学响应的强面内各向异性
DOI：
10.1021/acsnano.7b04860
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发表时间：
2017-10-01
期刊：
影响因子：
17.1
通讯作者：
Zhai, Tianyou
中科院分区：
文献类型：
--
作者：
Li, Liang;Gong, Penglai;Zhai, Tianyou
介绍了一种有趣的面内各向异性层状双金属硫属化物Ta2NiS5，并系统研究了其面内各向异性的光学和电学性质。拉曼振动模式已通过拉曼光谱测量结合声子相关特性的计算来确定。重要的是，Ta2NiS5 薄片在角分辨偏振拉曼光谱测量下表现出强烈的各向异性拉曼响应。我们发现Ag模式的拉曼强度不仅取决于旋转角度，还与样品厚度有关。相反，在偏振分辨红外光谱测量中，无论厚度如何，沿a轴方向偏振的光的红外吸收总是大于c轴方向的红外吸收。值得注意的是，第一原理计算与角度分辨电导测量相结合表明 Ta2NiS5 具有很强的各向异性电导率。我们的结果不仅证明 Ta2NiS5 是一种有前途的面内各向异性二维材料，而且还为未来的功能化电子设备提供了一个有趣的平台。
An interesting in-plane anisotropic layered dimetal chalcogenide Ta2NiS5 is introduced, and the optical and electrical properties with respect to its in-plane anisotropy are systematically studied. The Raman vibration modes have been identified by Raman spectra measurements combined with calculations of phonon-related properties. Importantly, the Ta2NiS5 flakes exhibit strong anisotropic Raman response under the angle-resolved polarized Raman spectroscopy measurements. We found that Raman intensities of the Ag mode not only depend on rotation angle but are also related to the sample thickness. In contrast, the infrared absorption with light polarized along the a axis direction is always larger than that in the c axis direction regardless of thickness under the polarization-resolved infrared spectroscopy measurements. Remarkably, the first-principles calculations combined with angle-resolved conductance measurements indicate strong anisotropic conductivity of Ta2NiS5. Our results not only prove Ta2NiS5 is a promising in-plane anisotropic 2D material but also provide an interesting platform for future functionalized electronic devices.