Electron-phonon interaction, excitations and ultrafast photoemission from doped monolayer MoS2

We analyze the effect of electron-phonon coupling on photoemission properties and ultrafast response of doped monolayer MoS2. The analysis is based on combined DFT and many-body (Eliashberg theory) approaches. In particular, we have calculated the electronic and phonon spectra, the electron-phonon coupling and the electronic spectral function of the system at different values of doping. We have also analyzed the emissive properties and the response of the system to femtosecond (fs) laser pulses. It is shown that position of the emission peak of undoped system is in agreement with the experimental data if one takes into account the excitonic effects. The results for the self-energy and spectral functions of the doped systems suggest that one can expect ultrafast processes to be important in the system response , which makes the system attractive from the point of view of modern technological applications. Similar to graphene, the doped system demonstrates ultrafast (fs) relaxation of the electronic subsystem when excited by fs pulses, and a high ultrafast phonon relaxation-induced spectral fluence of visible light emission. Together with high carrier mobility, these features of monolayer MoS2 might be used in modern optoelectronic technologies.