title: Observation of Ultrafast Free Carrier Dynamics in Single Layer MoS2.
abstract: The dynamics of excited electrons and holes in single layer (SL) MoS2 have so far been difficult to disentangle from the excitons that dominate the optical response of this material. Here, we use time- and angle-resolved photoemission spectroscopy for a SL of MoS2 on a metallic substrate to directly measure the excited free carriers. This allows us to ascertain a direct quasiparticle band gap of 1.95 eV and determine an ultrafast (50 fs) extraction of excited free carriers via the metal in contact with the SL MoS2. This process is of key importance for optoelectronic applications that rely on separated free carriers rather than excitons.
authors: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University , 8000 Aarhus C, Denmark.
authors: Antonija
authors: A
authors: Grubišić Čabo
authors: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University , 8000 Aarhus C, Denmark.
authors: Jill A
authors: JA
authors: Miwa
authors: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University , 8000 Aarhus C, Denmark.
authors: Signe S
authors: SS
authors: Grønborg
authors: SUPA, School of Physics and Astronomy, University of St. Andrews , St. Andrews, Fife KY16 9SS, United Kingdom.
authors: Jonathon M
authors: JM
authors: Riley
authors: Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne, Switzerland.
authors: Jens C
authors: JC
authors: Johannsen
authors: Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, United Kingdom.
authors: Cephise
authors: C
authors: Cacho
authors: Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, United Kingdom.
authors: Oliver
authors: O
authors: Alexander
authors: Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, United Kingdom.
authors: Richard T
authors: RT
authors: Chapman
authors: Central Laser Facility, STFC Rutherford Appleton Laboratory, Harwell, Didcot OX11 0QX, United Kingdom.
authors: Emma
authors: E
authors: Springate
authors: Institute of Condensed Matter Physics, École Polytechnique Fédérale de Lausanne (EPFL) , 1015 Lausanne, Switzerland.
authors: Marco
authors: M
authors: Grioni
authors: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University , 8000 Aarhus C, Denmark.
authors: Jeppe V
authors: JV
authors: Lauritsen
authors: SUPA, School of Physics and Astronomy, University of St. Andrews , St. Andrews, Fife KY16 9SS, United Kingdom.
authors: Phil D C
authors: PD
authors: King
authors: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University , 8000 Aarhus C, Denmark.
authors: Philip
authors: P
authors: Hofmann
authors: Department of Physics and Astronomy, Interdisciplinary Nanoscience Center, Aarhus University , 8000 Aarhus C, Denmark.
authors: Søren
authors: S
authors: Ulstrup
keywords: MoS2; Transition metal dichalcogenides; excitons; free carriers; time- and angle-resolved photoemission spectroscopy