Electron-phonon coupling contribution on the optical absorption and the dynamic of exciton-polaron in monolayer Transition Metal Dichalcogenides

摘要

In this paper, we theoretically investigate the effect of Electron-phonon coupling on the dynamic and optical absorption of exciton-polaron in Transition Metal Dichalcogenides (MoS2, WS2, MoSe2, and WSe2) under magnetic field using Huybrechts method. Both surface optical phonon mode and longitudinal phonon mode are taken into account. It is seen that the magnetic field strongly influence the dynamic parameter of exciton-polaron in the Transition Metal Dichalcogenides (TMDs). The absorption coefficient increases with the magnetic field and decreases with internal distance between TMDs monolayers and polar substrates. The latter did not affects the absorption coefficient for the low value of magnetic field. The absorption coefficient strongly depend to the choice of the polar substrates, it is highest for the substrate SiO2 and smallest for the substrate SiC. We observed that these caracteristics are similar in intermediate coupling and change for strong value of photon energy. It is seen that the absorption coefficient depends also with the type of TMDs. For weak and intermediate coupling, we observed that the absorption coefficient vanish for strong values of photon energy. The effective masse of exciton-polaron is highest in strong coupling than in intermediate coupling, whereas the exciton-polaron energy is highest in weak coupling than in strong coupling regime.