Fig. 1. (a) Top view and (b) side view of the atomic structures of a MoX₂ (X = S, Te) monolayer. Calculated electronic band structures of (c) MoS₂ and (d) MoTe₂ monolayers from PBE and HSE functionals. Phonon spectrum of (e) MoS₂ and (f) MoTe₂ monolayers.