{
  "id": "1908.10690",
  "version": "v1",
  "published": "2019-08-28T12:44:16.000Z",
  "updated": "2019-08-28T12:44:16.000Z",
  "title": "Filtering the photoluminescence spectra of atomically thin semiconductors with graphene",
  "authors": [
    "Etienne Lorchat",
    "Luis E. Parra López",
    "Cédric Robert",
    "Delphine Lagarde",
    "Guillaume Froehlicher",
    "Takashi Taniguchi",
    "Kenji Watanabe",
    "Xavier Marie",
    "Stéphane Berciaud"
  ],
  "categories": [
    "cond-mat.mes-hall",
    "cond-mat.mtrl-sci",
    "physics.optics"
  ],
  "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 typical photoluminescence spectra of TMD monolayers display a large number of intrinsic and extrinsic features that are particularly challenging to decipher. On a practical level, monochromatic TMD-based emitters would be beneficial for low-dimensional devices but no solution has yet been found to meet this challenge. Here, using a counter-intuitive strategy that consists in interfacing TMD monolayers with graphene, a system known as an efficient luminescence quencher, we demonstrate bright, single and narrow-line photoluminescence arising solely from TMD neutral excitons. This observation stems from two effects: (i) complete neutralization of the TMD by the adjacent graphene leading to the absence of optical features from charged excitons (ii) selective non-radiative transfer of TMD excitons to graphene, that is sufficiently rapid to quench radiative recombination of long-lived excitonic species without significantly affecting bright excitons, which display much shorter, picosecond radiative lifetimes at low temperatures. Our approach is systematically applied to four tungsten and molybdenum-based TMDs and establishes TMD/graphene heterostructures as a unique set of opto-electronic building blocks. Graphene not only endows TMDs monolayers with superior optical performance and enhanced photostability but also provides an excellent electrical contact, suitable for TMD-based electroluminescent systems emitting visible and near-infrared photons at near THz rate with linewidths approaching the lifetime limit.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-08-28T12:44:16.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "atomically thin semiconductors",
      "photoluminescence spectra",
      "electroluminescent systems emitting visible",
      "tmd monolayers display",
      "strong light-matter interactions"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}