Wu Xing, Cai Yongqing, Bian Jihong, Su Guohui, Luo Chen, Yang Yaodong, Zhang Gang
Shanghai Key Laboratory of Multidimensional Information Processing, School of Communication and Electronic Engineering 500 Dongchuan Road Shanghai 200241 China
Institute of High Performance Computing (IHPC), ASTAR 138632 Singapore
RSC Adv. 2020 Apr 28;10(28):16718-16726. doi: 10.1039/d0ra02499f. eCollection 2020 Apr 23.
Beside the extraordinary structural, mechanical and physical properties of two-dimensional (2D) materials, the capability to tune properties strain engineering has shown great potential for nano-electromechanical systems. External strain, in a controlled manner, can manipulate the optical and electronic properties of the 2D materials. We observed the lattice vibration modulation in strained mono- and few-layer tantalum sulfide (TaS). Two Raman modes, E and E , exhibit sensitive strain dependence, with the frequency of the former intensity increasing and the latter decreasing under a compressive strain. The opposite direction of the intensity shifts, which cannot be explained solely by van der Waals interlayer coupling, is attributed to strain-induced competition between the electron-phonon interlayer coupling and possible stacking-induced changes of the intralayer transport. Our results enrich the understanding of the lattice vibration of TaS and point to strain engineering as a powerful tool for tuning the electron-phonon coupling of 2D materials.
除了二维（2D）材料具有非凡的结构、机械和物理特性外，通过应变工程调节特性的能力在纳米机电系统中显示出巨大潜力。以可控方式施加的外部应变能够操控二维材料的光学和电子特性。我们观察到了应变的单层和少层硫化钽（TaS）中的晶格振动调制。两种拉曼模式，E和E，表现出敏感的应变依赖性，在压缩应变下，前者的频率强度增加，后者降低。强度位移的相反方向不能仅由范德华层间耦合来解释，这归因于应变诱导的电子 - 声子层间耦合竞争以及层内传输可能因堆叠引起的变化。我们的结果丰富了对TaS晶格振动的理解，并指出应变工程是调节二维材料电子 - 声子耦合的有力工具。
