Size and Substrate effect on excitation dynamics of 2D materials

Excitation dynamics of 2D materials has been extensively studied by different theoretical and experimental methods. However, effect of substrate and size effect on the excitation dynamics of 2D materials has not been well delineated due to large number of atoms. We perform quantum molecular dynamics simulations at high electron temperatures within the density functional theory framework to understand the effect of substrate and size. We computed the intralayer mean square displacement and Debye-waller factor of top and bottom layer of WSe₂. The simulation results show that interaction between substrate and transition metal dichalcogenide layers create distinct anisotropy in electronic excitation-induced lattice dynamics that may be experimentally observable.