title A Comparative Study of Lattice Dynamics of Three- and Two-Dimensional MoS sub2/sub/title

OpenAlex İngilizce

This paper presents a comparative study of the lattice dynamics of three-dimensional layered MoS 2 and two-dimensional single layer MoS 2 based on the density functional theory. A comprehensive analysis of energetics and optimized structure parameters is performed using different methods. It is found that the van der Waals attraction between layers of three-dimensional (3D) layered MoS 2 is weak but is essential to hold the layers together with the equilibrium interlayer spacing. Cohesive energy, phonon dispersion curves, and corresponding density of states and related properties, such as Born-effective charges, dielectric constants, Raman and infrared active modes are calculated for 3D layered as well as 2D single layer MoS 2 using their optimized structures. These calculated values are compared with the experimental data to reveal interesting dimensionality effects. The absence of a weak interlayer interaction in 2D single layer MoS 2 results in the softening of some of Raman active modes.