Raman spectroscopic mapping and atomic force microscopy statistical analyses for the determination of WS2 flake thickness

This database contains the statistical analyses carried out in order to evaluate the thickness of the WS₂ nanoflakes. In order to have a reliable comparison we determine the methodology of comparing Raman spectroscopic mapping and atomic force microscopy (AFM).

In case of Raman spectroscopy, the thickness is evaluated by employing the separation of the two vibrational mode, namely E_2g and A_1g. This method is well-established and the number of layers has been previously tabulated in different articles.   

Each spectrum of the Raman analysis, is performed with a 100X objective in a confocal microscope, with a 473 nm laser excitation, a laser power of 0.5 mW and an acquisition time of 1 s.

The AFM analysis are carried out in tapping mode with a 512-pixel x 512-pixel resolution and and a scan rate of 1Hz per line.