Theoretical Study of Electron-Surface Optical Phonon Interaction in Monolayer Transition Metal Dichalcogenides Deposited on SiC and Hexagonal BN Dielectric Substrates in the Vicinity of the Points K+ K- of the Brillouin Zone

We investigated theoretically the electron-surface optical phonon interaction across the long-range Fröhlich coupling in monolayer transition metal dichalcogenides such as WS2, WSe2, MoS2, and MoSe2 monolayers on SiC and hexagonal BN dielectric substrates. We employed the effective Hamiltonian in the 〖K_(+ ) (K〗_-) valley of the hexagonal Brillouin zone, to assess electronic energy shifts induced by the interaction between electronic states and surface polar optical phonons. Our results indicate that the interaction between electron and surface optical phonon depends upon the polar nature of the substrate. We have also calculated the polaronic oscillator strength as well as the polaronic scattering rate of the lower polaron state in monolayer WS2, WSe2, MoS2, and MoSe2 on SiC and hexagonal BN dielectric substrates. As a result, we have proved theoretically; firstly, the enhancement of polaronic scattering rate with temperature, and secondly, the notable influence of the careful selection of surrounding dielectrics on both Polaronic oscillator strength and polaronic scattering rate. Thus, the optimal dielectrics would be those exhibiting both elevated optical phonon energy and a high static dielectric constant.