Raman scattering in a MoS2 monolayer on quartz from DFT calculations: Effect of the substrate

The effect of a quartz substrate on Raman scattering in a molybdenum disulfide monolayer is analyzed within the DFT framework. The Raman spectra were studied for several types of the MoS2/SiO2 interface, corresponding to the case of a "dense" SiO2 surface, a surface with defects, roughness and an interface with S-O chemical bonds. Calculations show that for the vdW type of MoS2/SiO2 interaction, the substrate weakly affects Raman scattering in MoS2, except some extreme configurations of the SiO2 surface. In contrast, for interface with S-O chemical bonds the influence of the substrate becomes much stronger, leading to a noticeable splitting and shift of the E1 and A1g Raman peaks in the MoS2 monolayer. 2g