Phonon-assisted Photoluminescence from Dark Excitons in Monolayers of Transition Metal Dichalcogenides
Preprint, 2019

The photoluminescence (PL) spectrum of transition metal dichalcogenides (TMDs) shows a multitude of emission peaks below the bright exciton line and not all of them have been explained yet. Here, we study the emission traces of phonon-assisted recombinations of momentum-dark excitons. To this end, we develop a microscopic theory describing simultaneous exciton, phonon and photon interaction and including consistent many-particle dephasing. We explain the drastically different PL below the bright exciton in tungsten- and molybdenum-based materials as result of different configurations of bright and dark states. In good agreement with experiments, we show that WSe2 exhibits clearly visible low-temperature PL signals stemming from the phonon-assisted recombination of momentum-dark excitons.


Samuel Brem

Chalmers, Physics, Condensed Matter Theory

August Ekman

Dominik Christiansen

Florian Katsch

Malte Selig

Cedric Robert

Xavier Marie

Bernhard Urbaszek

Andreas Knorr

Ermin Malic

Chalmers, Physics, Condensed Matter Theory

Subject Categories

Subatomic Physics

Atom and Molecular Physics and Optics

Condensed Matter Physics

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