MoS2, MoSe2 and WSe2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO2/Si substrates were measured...MoS2, MoSe2 and WSe2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO2/Si substrates were measured by atomic force microscopy（AFM） and spectroscopic ellipsometer. A rapid and nondestructive method by using reflection spectra was proposed to identify the layer number of 2D layered transition metal dichalcogenides on SiO2（275 nm）/Si substrates. The contrast spectra of 2D nanosheets with different layer numbers are in agreement with theoretical calculations based on Fresnel＇s law, indicating that this method provides an unambiguous and nondestructive contrast spectra fingerprint for identifying single-and few-layered transition metal dichalcogenides. The results will greatly help in fundamental research and application.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.11304381 and 11174366)
文摘MoS2, MoSe2 and WSe2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO2/Si substrates were measured by atomic force microscopy（AFM） and spectroscopic ellipsometer. A rapid and nondestructive method by using reflection spectra was proposed to identify the layer number of 2D layered transition metal dichalcogenides on SiO2（275 nm）/Si substrates. The contrast spectra of 2D nanosheets with different layer numbers are in agreement with theoretical calculations based on Fresnel＇s law, indicating that this method provides an unambiguous and nondestructive contrast spectra fingerprint for identifying single-and few-layered transition metal dichalcogenides. The results will greatly help in fundamental research and application.
