Resonance Raman Scattering Spectroscopy of Four-Monolayer Thick MoS2 Films

Abstract

We studied the Raman scattering in bulk and four-monolayer thick MoS₂ films under the resonance laser excitation of A, B, and C excitons. We demonstrate the fine structure agility of a phonon mode associated with out-of-plane vibration of sulfur atoms (A_1g) when passing from bulk to atomically thin film. The C exciton resonance excitation allows us to register the line corresponding to optical-phonon (E_1g) scattering and the set of peaks with a 660 – 740 cm⁻¹ Stokes shift associated with resonance scattering by two optical (E_u) phonons.