Analysis of Optical Properties of MoS2 Monolayer using Minimal-Basis Tight-Binding Models

N. Nouri, P. Potasz, S. Zia Borujeni, A. Wójs, G. Rashedi
2017 Acta Physica Polonica. A  
Optical properties of transition metal dichalcogenides monolayer of MoS2 are analyzed using multi-orbital tight-binding models with only Mo d-orbitals (three-band model) and with an inclusion of S p-orbitals (six-band model). We look at band structures, momentum matrix elements between valence and conduction band, and joint optical density of states. Good agreement between the two models is shown in a vicinity of K point of the Brillouin zone. On line connecting K and Γ points, a local
more » ... s, a local conduction band minimum at Q point is recovered only by six-band model in agreement with density functional theory and experimental results. We show that optical transitions at this point are active for both light polarizations. A peak in joint optical density of states is also seen at this point suggesting its potentially important role in a proper description of excitonic effects.
doi:10.12693/aphyspola.132.313 fatcat:whugjlbgjvcrtljfwlcfpd6zu4