Dynamic screening of quasiparticles in WS${}_2$ monolayers

Abstract

We unravel the influence of quasiparticle screening in the non-equilibrium exciton dynamics of monolayer WS${}_2$. We report pump photon energy-dependent exciton blue and red-shifts from time-resolved-reflectance contrast measurements. Based on a phenomenological model, we isolate the effective impact of excitons and free carriers on the renormalization of the quasi-free particle band gap, exciton binding energy and linewidth broadening. By this, our work does not only provide a comprehensive picture of the competing phenomena governing the exciton dynamics in WS${}_2$ upon photoexcitation, but also demonstrates that exciton and carrier contributions to dynamic screening of the Coulomb interaction differ significantly.

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Cited by in corpus (2)

• Momentum-Resolved Signatures of Carrier Screening Effects on Electron-Phonon Coupling in MoS${}_2$
• Effect of photoinduced screening on the spectroscopic signature of exciton-phonon coupling