Phonon Sidebands in Transition Metal Dichalcogenides

Abstract

Excitons dominate the optical properties of monolayer transition metal dichalcogenides (TMDs). Besides optically accessible bright exciton states, TMDs exhibit also a multitude of optically forbidden dark excitons. Here, we show that efficient exciton-phonon scattering couples bright and dark states and gives rise to an asymmetric excitonic line shape. The observed asymmetry can be traced back to phonon-induced sidebands that are accompanied by a polaron redshift. We present a joint theory-experiment study investigating the microscopic origin of these sidebands in different TMD materials taking into account intra- and intervalley scattering channels opened by optical and acoustic phonons. The gained insights contribute to a better understanding of the optical fingerprint of these technologically promising nanomaterials.

References in corpus (4)

• Tightly bound excitons in monolayer WSe2
• k.p theory for two-dimensional transition metal dichalcogenide semiconductors
• Intrinsic Transport Properties of Electrons and Holes in Monolayer Transition Metal Dichalcogenides
• Exciton band structure of monolayer MoS2

Cited by in corpus (5)

• Dark excitons in transition metal dichalcogenides
• Intrinsic Lifetime of Higher Excitonic States in Tungsten Diselenide Monolayers
• Non-Markovian features in semiconductor quantum optics: Quantifying the role of phonons in experiment and theory
• Intervalley Polaron in Atomically Thin Transition Metal Dichalcogenides
• Molecule signatures in photoluminescence spectra of transition metal dichalcogenides