(color online) High- and low-frequency Raman spectra of MoS₂ with various thickness. (a) Typical Raman spectra of 1L to bulk MoS₂ (left), and the positions of the E 2g 1 , A_1g, and 2 × LA ( M ) Raman modes as functions of NL. Reproduced with permission from Ref. [105]. Copyright 2012, American Chemical Society. (b) Stokes and anti-Stokes Raman spectra of MoS₂ with various thickness in a range from −60 to 60 cm⁻¹ (left), and the frequency and FWHM of the C and LB modes as functions of the number of layers (right). Reproduced with permission from Ref. [18]. Copyright 2013, American Physical Society.