Resonant Raman scattering in MoS2—From bulk to monolayer

Resonant Raman scattering in molybdenum disulfide (MoS2) is studied as a function of the structure thickness. Optical emission from bulk, three-, two-, and one- monolayer MoS2 is studied both at room and at liquid helium temperature. The quenching of peaks due to second-order processes was observed and attributed to the effect of the substrate on the lattice dynamics in MoS2. The experimental results are discussed within the frames of the recently proposed model of electron–phonon coupling involving transverse acoustic phonons from the vicinity of the high-symmetry M point of the MoS2 Brillouin zone.