Xu Xiaodan, Wang Cong, Xiong Wenqi, Liu Yang, Yang Donghao, Zhang Xinzheng, Xu Jingjun
Key Laboratory for Microstructural Material Physics of Hebei Province, School of Science, Yanshan University, Qinhuangdao 066004, People's Republic of China.
The MOE Key Laboratory of Weak-Light Nonlinear Photonics, TEDA Institute of Applied Physics and School of Physics, Nankai University, Tianjin 300457, People's Republic of China.
Nanotechnology. 2021 Dec 3;33(8). doi: 10.1088/1361-6528/ac3a39.
Strain engineering can effectively modify the materials lattice parameters at atomic scale, hence it has become an efficient method for tuning the physical properties of two-dimensional (2D) materials. The study of the strain regulated interlayer coupling is deserved for different kinds of heterostructures. Here, we systematically studied the strain engineering of WSe/WSheterostructures as well as their constituent monolayers. The measured Raman and photoluminescence spectra demonstrate that the strain can evidently modulate the phonon energy and exciton emission of monolayer WSeand WSas well as the WSe/WSheterostructures. The tensile strain can tune the electronic band structure of WSe/WSheterostructure, as well as enhance the interlayer coupling. It is further revealed that the photoluminescence intensity ratio of WSto WSein our WSe/WSheterobilayer increases monotonically with tensile strain. These findings can broaden the understanding and practical application of strain engineering in 2D materials with nanometer-scale resolution.
应变工程可以在原子尺度上有效地改变材料的晶格参数，因此它已成为调节二维（2D）材料物理性质的一种有效方法。对于不同种类的异质结构，研究应变调控的层间耦合是值得的。在此，我们系统地研究了WSe/WS异质结构及其组成单层的应变工程。测量的拉曼光谱和光致发光光谱表明，应变可以明显地调制单层WSe和WS以及WSe/WS异质结构的声子能量和激子发射。拉伸应变可以调节WSe/WS异质结构的电子能带结构，并增强层间耦合。进一步发现，在我们的WSe/WS双层中，WS与WSe的光致发光强度比随拉伸应变单调增加。这些发现可以拓宽对应变工程在具有纳米级分辨率的二维材料中的理解和实际应用。
