Mapping of Low-Frequency Raman Modes in CVD-Grown Transition Metal Dichalcogenides: Layer Number, Stacking Orientation and Resonant Effects.
Mapping of Low-Frequency Raman Modes in CVD-Grown Transition Metal Dichalcogenides: Layer Number, Stacking Orientation and Resonant Effects.
复制标题
DOI：
10.1038/srep19476
复制
发表时间：
2016-01-14
影响因子：
4.6
通讯作者：
Duesberg GS
中科院分区：
文献类型：
--
作者：
O'Brien M;McEvoy N;Hanlon D;Hallam T;Coleman JN;Duesberg GS
层状无机材料，如过渡金属二卤化物(TMDs)，因其特殊的电学和光学性质而备受关注。如果要开发这些性能，就必须开发这些材料的可靠合成和表征。本文对化学气相沉积(CVD)生长的MoS_2、MoSe_2、WSe_2和WS_2进行了低频拉曼分析。拉曼光谱是在大范围内获得的，允许在地图上可视化剪切和层呼吸模式的位置和强度的变化。这使得可以对单层和少层TMD进行详细的表征，这是对成熟的(高频)拉曼光谱和光致发光光谱的补充。这项研究为基本理解层状材料提供了一个重要的垫脚石，因为映射低频模式可以在大范围内探测2D材料的质量、对称性、堆叠结构和层数。此外，我们还报道了WS2拉曼光谱低频区的反常共振效应。
Layered inorganic materials, such as the transition metal dichalcogenides (TMDs), have attracted much attention due to their exceptional electronic and optical properties. Reliable synthesis and characterization of these materials must be developed if these properties are to be exploited. Herein, we present low-frequency Raman analysis of MoS2, MoSe2, WSe2 and WS2 grown by chemical vapour deposition (CVD). Raman spectra are acquired over large areas allowing changes in the position and intensity of the shear and layer-breathing modes to be visualized in maps. This allows detailed characterization of mono- and few-layered TMDs which is complementary to well-established (high-frequency) Raman and photoluminescence spectroscopy. This study presents a major stepping stone in fundamental understanding of layered materials as mapping the low-frequency modes allows the quality, symmetry, stacking configuration and layer number of 2D materials to be probed over large areas. In addition, we report on anomalous resonance effects in the low-frequency region of the WS2 Raman spectrum.