@article{Taghavi2019, 
author = {Najme S. Taghavi and Patricia Gant and Peng Huang and Iris Niehues and Robert Schmidt and Steffen Michaelis de Vasconcellos and Rudolf Bratschitsch and Mar García-Hernández and Riccardo Frisenda and Andres Castellanos-Gomez},
title = {Thickness determination of MoS2, MoSe2, WS2 and WSe2 on transparent stamps used for deterministic transfer of 2D materials},
year = {2019},
journal = {Nano Research},
volume = {12},
number = {7},
pages = {1691-1695},
keywords = {transition metal dichalcogenides, optical identification, transparent substrate, trasmittance},
url = {https://www.sciopen.com/article/10.1007/s12274-019-2424-6},
doi = {10.1007/s12274-019-2424-6},
abstract = {Here, we propose a method to determine the thickness of the most common transition metal dichalcogenides (TMDCs) placed on the surface of transparent stamps, used for the deterministic placement of two-dimensional materials, by analyzing the red, green and blue channels of transmission-mode optical microscopy images of the samples. In particular, the blue channel transmittance shows a large and monotonic thickness dependence, making it a very convenient probe of the flake thickness. The method proves to be robust given the small flake-to-flake variation and the insensitivity to doping changes of MoS2. We also tested the method for MoSe2, WS2 and WSe2. These results provide a reference guide to identify the number of layers of this family of materials on transparent substrates only using optical microscopy.}
}