论文部分内容阅读
MoS_2, MoSe_2 and WSe_2 thin flakes were fabricated by the standard micromechanical cleavage procedures. The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO_2/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 SiO_2(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.
The thickness and the optical contrast of the atomic thin dichalcogenide flakes on SiO 2 / 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 SiO 2 (275 nm) / Si substrates. The contrast spectra of 2D nanosheets with different layer numbers are in agreement with the 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.