Filtering the photoluminescence spectra of atomically thin semiconductors with graphene

Etienne Lorchat; Luis E. Parra López; Cédric Robert; Delphine Lagarde; Guillaume Froehlicher; Takashi Taniguchi; Kenji Watanabe; Xavier Marie; Stéphane Berciaud

doi:10.1038/s41565-020-0644-2

arXiv · 1908.10690

Filtering the photoluminescence spectra of atomically thin semiconductors with graphene

Etienne Lorchat·Luis E. Parra López·Cédric Robert·Delphine Lagarde·Guillaume Froehlicher·Takashi Taniguchi·Kenji Watanabe·Xavier Marie·Stéphane Berciaud

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Abstract

Atomically thin semiconductors made from transition metal dichalcogenides (TMDs) are model systems for investigations of strong light-matter interactions and applications in nanophotonics, opto-electronics and valley-tronics. However, the photoluminescence spectra of TMD monolayers display a large number of features that are particularly challenging to decipher. On a practical level, monochromatic TMD-based emitters would be beneficial for low-dimensional devices but this challenge is yet to be resolved. Here, we show that graphene, directly stacked onto TMD monolayers enables single and narrow-line photoluminescence arising solely from TMD neutral excitons. This filtering effect stems from complete neutralization of the TMD by graphene combined with selective non-radiative transfer of long-lived excitonic species to graphene. Our approach is applied to four tungsten and molybdenum-based TMDs and establishes TMD/graphene heterostructures as a unique set of opto-electronic building blocks, suitable for electroluminescent systems emitting visible and near-infrared photons at near THz rate with linewidths approaching the lifetime limit.

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Etienne Lorchat, Luis E. Parra López, Cédric Robert, Delphine Lagarde, Guillaume Froehlicher, Takashi Taniguchi, Kenji Watanabe, Xavier Marie, Stéphane Berciaud. 2019-08-28. Filtering the photoluminescence spectra of atomically thin semiconductors with graphene. https://doi.org/10.1038/s41565-020-0644-2

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