Strain Relaxation of Monolayer WS2 on Plastic Substrate
Strain Relaxation of Monolayer WS2 on Plastic Substrate
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DOI：
10.1002/adfm.201603064
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发表时间：
2016-12
影响因子：
19
通讯作者：
Qianhui Zhang;Zhenyue Chang;Guanzhong Xu;Ziyu Wang;Yupeng Zhang;Zai‐Quan Xu;Shujian Chen;Q. Bao-Q.
中科院分区：
文献类型：
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作者：
Qianhui Zhang;Zhenyue Chang;Guanzhong Xu;Ziyu Wang;Yupeng Zhang;Zai‐Quan Xu;Shujian Chen;Q. Bao-Q.
原子级薄的过渡金属二硫属化物的应变相关电学和光学性质可用于感测应用。然而，在原子级薄的材料中应变如何松弛的问题仍然没有得到很好的理解。本文研究了沉积在聚二甲基硅氧烷衬底上的三角形WS 2的应变弛豫。当衬底拉伸应变从0增加到0.16时，三电子（X-）和激子（X 0）的光致发光发生了约20 meV的线性红移。然而，当衬底应变从0.16进一步增加到0.32时，由于WS 2中的应变弛豫，红移停止。通过在WS 2晶体中形成褶皱而发生应变弛豫。褶皱的图案被发现是依赖于三角形WS 2晶体的边缘和拉伸应变方向之间的相对角度。WS 2晶体内部应变分布的有限元模拟解释了实验观察结果。
Strain‐dependent electrical and optical properties of atomically thin transition metal dichalcogenides may be useful in sensing applications. However, the question of how strain relaxes in atomically thin materials remains not well understood. Herein, the strain relaxation of triangular WS2 deposited on polydimethylsiloxane substrate is investigated. The photoluminescence of trions (X–) and excitons (X0) undergoes linear redshifts of ≈20 meV when the substrate tensile strain increases from 0 to 0.16. However, when the substrate strain further increases from 0.16 to 0.32, the redshifts cease due to strain relaxation in WS2. The strain relaxation occurs through formation of wrinkles in the WS2 crystal. The pattern of wrinkles is found to be dependent on the relative angle between an edge of the triangular WS2 crystal and tensile strain direction. Finite element simulations of the strain distribution inside the WS2 crystals explain the experimental observations.