title: Auger Recombination in Chemical Vapor Deposition-Grown Monolayer WS2.
abstract: Reduced dimensionality and strong Coulombic interactions in monolayer semiconductors lead to enhanced many-body interactions. Here, we report Auger recombination, i.e., exciton-exciton annihilation, in large-area chemical vapor deposition-grown monolayer WS2. Using ultrafast spectroscopy, we experimentally determine the Auger rate to be 0.089 ± 0.001 cm2/s at room temperature, which is an order of magnitude greater than the bulk value. This nonradiative recombination pathway dominates, regardless of excitation energy, for exciton densities greater than 8.0 ± 0.6 × 1010cm-2and below the Mott density. Higher-energy excitation above the A exciton resonance may initially produce a hot electron-hole gas that precedes exciton formation. Therefore, we use resonant excitation of the A exciton to ensure accuracy and avoid artifacts associated with other photogenerated species.
authors.affiliation: U.S. Naval Research Laboratory , Washington, D.C. 20375, United States.
authors.forename: Paul D
authors.identifier: http://orcid.org/0000-0002-3602-1503
authors.initials: PD
authors.lastname: Cunningham
authors.affiliation: U.S. Naval Research Laboratory , Washington, D.C. 20375, United States.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: McCreary
authors.affiliation: U.S. Naval Research Laboratory , Washington, D.C. 20375, United States.
authors.forename: Berend T
authors.identifier: http://orcid.org/0000-0001-8816-7857
authors.initials: BT
authors.lastname: Jonker