Determining the thickness of a few-layer 2D material is a tough task that often involves complex and time consuming measurements. Here we discuss a rapid method for determining the number of layers of molybdenum disulfide, MoS\(_2\), flakes based on microscopic transmission imaging. By analyzing the contrast of the red, blue and green channels of the flake image against the background, we show that it is possible to unequivocally determine the number of layers. The presented method is based on the light absorption properties of MoS\(_2\) and its validity is confirmed by micro-Raman measurements. The main advantage of this method against traditional methods is to quickly determine the thickness of the material in the early stages of the experimental process with low cost apparatus.

确定几层2D材料的厚度是一项艰巨的任务，通常涉及复杂且耗时的测量。在这里，我们讨论一种基于显微透射成像确定二硫化钼薄片MoS \（_ 2 \）的快速方法。通过分析片状图像的红色，蓝色和绿色通道与背景的对比度，我们表明可以明确确定层数。所提出的方法是基于MoS \（_ 2 \）的光吸收特性，并通过微拉曼测量证实了其有效性。与传统方法相比，该方法的主要优点是可以在实验过程的早期阶段用低成本的设备快速确定材料的厚度。