Raman spectroscopy characterization of two-dimensional materials

Liang Fang^{, #,}, Xu Hejun^{, #,}, Wu Xing^{, †}, Wang Chaolun^,, Luo Chen^,, Zhang Jian^,

(color online) Symmetry and normal displacements of optical vibration modes for the 2H-, 3R-, and 1T polytypes of monolayer, bilayer, and bulk MX₂.