Strain is a powerful tool to modify the optical properties of semiconducting transition metal dichalcogenides like MoS₂, MoSe₂, WS₂ and WSe₂. In this work we provide a thorough description of the technical details to perform uniaxial strain measurements on these two-dimensional semiconductors and we provide a straightforward calibration method to determine the amount of applied strain with high accuracy. We then employ reflectance spectroscopy to analyze the strain tunability of the electronic properties of single-, bi- and tri-layer MoS₂, MoSe₂, WS₂ and WSe₂. Finally, we quantify the flake-to-flake variability by analyzing 15 different single-layer MoS₂ flakes.

应变是一种功能强大的工具，可改变半导体过渡金属_二卤化物如MoS ₂，MoSe ₂，WS ₂和WSe ₂的光学性质。在这项工作中，我们将对在这些二维半导体上执行单轴应变测量的技术细节进行全面描述，并提供一种直接的校准方法，以高精度确定施加的应变量。然后，我们使用反射光谱分析单层，双层和三层MoS ₂，MoSe ₂，WS ₂和WSe ₂的电子特性的应变可调性。。最后，我们通过分析15种不同的单层MoS ₂薄片来量化薄片到薄片的变异性。