title: Sub-bandgap Voltage Electroluminescence and Magneto-oscillations in a WSe2Light-Emitting van der Waals Heterostructure.
abstract: We report on experimental investigations of an electrically driven WSe2based light-emitting van der Waals heterostructure. We observe a threshold voltage for electroluminescence significantly lower than the corresponding single particle band gap of monolayer WSe2. This observation can be interpreted by considering the Coulomb interaction and a tunneling process involving excitons, well beyond the picture of independent charge carriers. An applied magnetic field reveals pronounced magneto-oscillations in the electroluminescence of the free exciton emission intensity with a 1/B periodicity. This effect is ascribed to a modulation of the tunneling probability resulting from the Landau quantization in the graphene electrodes. A sharp feature in the differential conductance indicates that the Fermi level is pinned and allows for an estimation of the acceptor binding energy.
authors.affiliation: Laboratoire National des Champs Magnetiques Intenses, CNRS-UGA-UPS-INSA-EMFL , 25 Rue des Martyrs, 38042 Grenoble, France.|Faculty of Physics, University of Warsaw , Pasteura 5, 02-093 Warsaw, Poland.
authors.forename: Johannes
authors.identifier: 0000-0002-0461-7716
authors.initials: J
authors.lastname: Binder
authors.affiliation: School of Physics and Astronomy, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.|National Graphene Institute, University of Manchester , Oxford Road, Manchester, M13 9PL, United Kingdom.
authors.forename: Freddie
authors.initials: F
authors.lastname: Withers
authors.affiliation: Laboratoire National des Champs Magnetiques Intenses, CNRS-UGA-UPS-INSA-EMFL , 25 Rue des Martyrs, 38042 Grenoble, France.
authors.forename: Maciej R
authors.initials: MR
authors.lastname: Molas
authors.affiliation: Laboratoire National des Champs Magnetiques Intenses, CNRS-UGA-UPS-INSA-EMFL , 25 Rue des Martyrs, 38042 Grenoble, France.
authors.forename: Clement
authors.initials: C
authors.lastname: Faugeras
authors.affiliation: Laboratoire National des Champs Magnetiques Intenses, CNRS-UGA-UPS-INSA-EMFL , 25 Rue des Martyrs, 38042 Grenoble, France.
authors.forename: Karol
authors.initials: K
authors.lastname: Nogajewski
authors.affiliation: National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Kenji
authors.identifier: 0000-0003-3701-8119
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: National Institute for Materials Science , 1-1 Namiki, Tsukuba 305-0044, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Taniguchi
authors.affiliation: School of Physics and Astronomy, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.|National Graphene Institute, University of Manchester , Oxford Road, Manchester, M13 9PL, United Kingdom.
authors.forename: Aleksey
authors.initials: A
authors.lastname: Kozikov
authors.affiliation: National Graphene Institute, University of Manchester , Oxford Road, Manchester, M13 9PL, United Kingdom.|Manchester Centre for Mesoscience and Nanotechnology, University of Manchester , Oxford Road, Manchester, M13 9PL, United Kingdom.
authors.forename: Andre K
authors.initials: AK
authors.lastname: Geim
authors.affiliation: School of Physics and Astronomy, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.|National Graphene Institute, University of Manchester , Oxford Road, Manchester, M13 9PL, United Kingdom.
authors.forename: Kostya S
authors.initials: KS
authors.lastname: Novoselov
authors.affiliation: Laboratoire National des Champs Magnetiques Intenses, CNRS-UGA-UPS-INSA-EMFL , 25 Rue des Martyrs, 38042 Grenoble, France.
authors.forename: Marek
authors.initials: M
authors.lastname: Potemski
keywords: Electroluminescence; acceptor; hexagonal boron nitride; magneto-oscillations; tungsten diselenide; van der Waals heterostructures