Fig. 5

Modeling of the electronic and optical properties of MoS₂. a Optimized atomic structure of trilayer MoS₂. The purple and the yellow balls are Mo and S atoms, respectively. b, c Band structure of trilayer MoS₂ without (b) and with (c) an electric field. In c, the different colors represent the bands projected onto the three correspondingly labeled layers in a. A separation of the valence and conduction bands as well as the energy difference between them at K are shown as a zoom-in inset in c. d Calculated absorption spectra with (green) and without (red) an electric field. Positions of the relevant intra- and inter-layer excitonic peaks are marked with vertical lines. e, f Excitonic wave functions of the first excitonic peak (intra-layer exciton) in the absorption spectrum without the electric field (e) and of the first excitonic peak (inter-layer exciton) in the presence of the electric field (f). The direction of the electric field is shown with a vertical black arrow. In e and f, the electron density is plotted for the case when the hole (marked by a small red arrow) is localized in layer 1 close to Mo atoms