Raman spectroscopy study of lattice vibration and crystallographic orientation of monolayer MoS2 under uniaxial strain.

The false-color (3D type) image of the intensity of the Raman spectra of monolayer MoS2 versus both peak positions and polar angles is plotted. It shows that the strongest E2g (1+) and E2g (1-) peaks appear at different angles, reflected as the alternation of the maxima of the intensity within the frequency range of the E2g (1) mode, which is the consequence of the crystallographic orientation relevant to the strain direction as predicted by theoretical analysis.