Circumventing the polariton bottleneck via dark excitons in 2D semiconductors

Abstract

Efficient scattering into the exciton polariton ground state is a key prerequisite for generating Bose-Einstein condensates and low-threshold polariton lasing. However, this can be challenging to achieve at low densities due to the polariton bottleneck effect that impedes phonon-driven scattering into low-momentum polariton states. The rich exciton landscape of transition metal dichalcogenides (TMDs) provides potential intervalley scattering pathways via dark excitons to rapidly populate these polaritons. Here, we present a microscopic study exploring the time- and momentum-resolved relaxation of exciton polaritons supported by a \ce{MoSe2} monolayer integrated within a Fabry-Perot cavity. By exploiting phonon-assisted transitions between momentum-dark excitons and the lower polariton branch, we demonstrate that it is possible to circumvent the bottleneck region and efficiently populate the polariton ground state. Furthermore, this intervalley pathway is predicted to give rise to, yet unobserved, angle-resolved phonon sidebands in low-temperature photoluminescence spectra that are associated with momentum-dark excitons. This represents a distinctive experimental signature for efficient phonon-mediated polariton-dark-exciton interactions.

References in corpus (12)

• Intrinsic Transport Properties of Electrons and Holes in Monolayer Transition Metal Dichalcogenides
• Dark excitons in transition metal dichalcogenides
• Exciton optics, dynamics and transport in atomically thin semiconductors
• Intrinsic Lifetime of Higher Excitonic States in Tungsten Diselenide Monolayers
• Uncovering Temperature-Dependent Exciton-Polariton Relaxation Mechanisms in Perovskites
• Ultra-bright single photon source based on an atomically thin material
• Valley polarized relaxation and upconversion luminescence from Tamm-Plasmon Trion-Polaritons with a MoSe2 monolayer
• Brightening of a dark monolayer semiconductor via strong light-matter coupling in a cavity
• Microscopic modelling of exciton-polariton diffusion coefficients in atomically thin semiconductors
• Phonon signatures in spectra of exciton polaritons in transition metal dichalcogenides
• Signatures of dark excitons in exciton-polariton optics of transition metal dichalcogenides
• Interlayer exciton polaritons in homobilayers of transition metal dichalcogenides

Cited by in corpus (4)

• Photonics in Flatland: Challenges and Opportunities for Nanophotonics with 2D Semiconductors
• Magneto-Optics of Anisotropic Exciton Polaritons in Two-Dimensional Perovskites
• Two dimensional semiconductors: optical and electronic properties
• Polariton transport in 2D semiconductors: Phonon-mediated transitions between ballistic, superdiffusive and exciton-limited regimes