Temperature-dependent excitonic effects in the optical properties of single-layer MoS2

peer reviewedThe electron-phonon interaction alters substantially the conventional picture of the band structure. It also changes the properties of excitonic states, which are very pronounced in many 2D materials. Using many-body perturbation theory, the authors describe how the inclusion of temperature modifies the electronic bands of single-layer MoS2. Different bands and different regions in the Brillouin zone are affected in different ways by electron-phonon coupling. Using the temperature-broadened bands as input for the Bethe-Salpeter equation, the authors explain why, for the bound A and B excitons, the electron-phonon coupling changes mainly the position, and for the C exciton, only the width is affected by temperature, while the energy is rather constant