论文标题
CVD种植分层MOS2中的Davydov分裂，共振效果和声子动力学
Davydov Splitting, Resonance Effect and Phonon Dynamics in CVD grown Layered MoS2
论文作者
论文摘要
我们为在共振条件下的温度范围为4至330 K的水平对齐的CVD分层MOS2提供了全面的依赖温度的拉曼测量值。我们对温度依赖性声子频移和线宽的分析表明，三个和四个声子Anharmonic效应的有限作用。我们观察到平面外（A1G）和面内（E12G）模式的Davydov分裂，归因于弱层间相互作用，并反映在3层和少量层系统中的其他模式下的其他模式。我们还观察到，与3L MOS2相比，Davydov分裂组件的数量更多，这表明它随着层数的增加而增加。拉曼光谱的温度评估表明，Davydov分裂，尤其是对于A1G模式，在低温下非常强大且能够很好地解决。我们注意到，A1G模式在低温下显示出分裂，而E12G模式甚至在室温下也被拆分，这暗示了A1G模式在层间相互作用中的重要作用。此外，通过在低温下声子模式的强度增加了几乎六十倍的共振效应的温度依赖性调整。
We present a comprehensive temperature dependent Raman measurements for horizontally aligned CVD grown layered MoS2 in a temperature range of 4 to 330 K under resonance condition. Our analysis of temperature dependent phonon frequency shift and linewidth suggest a finite role of three and four phonon anharmonic effect. We observed Davydov splitting of the out-of-plane (A1g ) and in-plane (E12g ) modes, attributed to the weak interlayer interaction, and reflected in the appearance of additional modes with decreasing temperature for both 3 layers and few layers system. We also observed that the number of Davydov splitting components are more in few layers as compared to 3L MoS2, suggesting it increases with increasing number of layers. Temperature evaluation of the Raman spectra shows that the Davydov splitting, especially for A1g mode, is very strong and well resolved at low temperature. We note that A1g mode shows splitting at low temperature, while E12g mode is splitted even at room temperature, and that suggests to prominent role of A1g mode to the interlayer interaction. Further, the temperature dependence tuning of resonance effect is observed, via almost sixty fold increase in the intensity of the phonon modes at low temperature.
