Low Frequency Raman Scattering Of Two-Dimensional Materials Beyond Graphene

Two-dimensional (2D) materials beyond graphene are undergoing intense study owing to their remarkable electronic and optical properties. This chapter is mainly devoted to Raman scattering measurements of 2D transition metal dichalcogenides (TMD). The similarities and differences in terms of phonon structure of monolayer and bulk MX2 are discussed. Layer-dependent Raman characteristics of monolayer and few-layer MoS2 could be obtained with both high and low frequency detection. The effect of uniaxial strain on the Raman spectrum of monolayer MoS2 is demonstrated. The stacking order and interlayer van der Waals (vdWs) interaction in few-layer TMD materials could be identified by low frequency (LF) Raman spectrum and imaging (similar to 10 rel. cm(-1)).