Fig. 3.

Raman and PL studies of the bilayer MoS₂ crystals. a Raman and b PL spectra of the as-grown AA and AB stacking bilayer MoS₂, CVD-grown monolayer MoS₂ and mechanically exfoliated bilayer MoS₂, where the PL signal of all bilayer samples were enlarged by 100 times in order to compare with that of monolayer one. Optical image (c) the Raman peak intensity mappings of E¹_2g (d) and A_1g (e) as well as the PL intensity mapping of peak A (f) of the as-grown complete AA stacking bilayer MoS₂. g Optical image, the Raman peak intensity mappings of E¹_2g h and A_1g i as well as the PL intensity mapping of peak A j of the as-grown AB stacking bilayer MoS₂. The scale bar is 50 μm