title: Novel near-infrared emission from crystal defects in MoS2multilayer flakes.
abstract: The structural defects in two-dimensional transition metal dichalcogenides, including point defects, dislocations and grain boundaries, are scarcely considered regarding their potential to manipulate the electrical and optical properties of this class of materials, notwithstanding the significant advances already made. Indeed, impurities and vacancies may influence the exciton population, create disorder-induced localization, as well as modify the electrical behaviour of the material. Here we report on the experimental evidence, confirmed by ab initio calculations, that sulfur vacancies give rise to a novel near-infrared emission peak around 0.75 eV in exfoliated MoS2flakes. In addition, we demonstrate an excess of sulfur vacancies at the flake's edges by means of cathodoluminescence mapping, aberration-corrected transmission electron microscopy imaging and electron energy loss analyses. Moreover, we show that ripplocations, extended line defects peculiar to this material, broaden and redshift the MoS2indirect bandgap emission.
authors.affiliation: IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124 Parma, Italy.|KET Lab, c/o Italian Space Agency via del Politecnico, 00133 Roma, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Fabbri
authors.affiliation: IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Rotunno
authors.affiliation: Laboratorio MDM, IMM-CNR, via C. Olivetti 2, I-20864 Agrate Brianza, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Cinquanta
authors.affiliation: Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via R. Cozzi 55, 20126 Milano, Italy.
authors.forename: D
authors.initials: D
authors.lastname: Campi
authors.affiliation: IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Bonnini
authors.affiliation: U.S. Army RDECOM-ARDEC, Fuze Precision Armaments and Technology Directorate, Picatinny Arsenal, New Jersey 07806-5000, USA.
authors.forename: D
authors.initials: D
authors.lastname: Kaplan
authors.affiliation: IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Lazzarini
authors.affiliation: Dipartimento di Scienza dei Materiali, Università di Milano-Bicocca, Via R. Cozzi 55, 20126 Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Bernasconi
authors.affiliation: IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Ferrari
authors.affiliation: Laboratorio MDM, IMM-CNR, via C. Olivetti 2, I-20864 Agrate Brianza, Italy.
authors.forename: M
authors.identifier: 0000-0002-6364-8184
authors.initials: M
authors.lastname: Longo
authors.affiliation: IMM-CNR Institute, Strada VIII, 5, 95121 Catania, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Nicotra
authors.affiliation: Laboratorio MDM, IMM-CNR, via C. Olivetti 2, I-20864 Agrate Brianza, Italy.
authors.forename: A
authors.identifier: 0000-0002-3860-4120
authors.initials: A
authors.lastname: Molle
authors.affiliation: U.S. Army RDECOM-ARDEC, Fuze Precision Armaments and Technology Directorate, Picatinny Arsenal, New Jersey 07806-5000, USA.
authors.forename: V
authors.initials: V
authors.lastname: Swaminathan
authors.affiliation: IMEM-CNR Institute, Parco Area delle Scienze 37/A, 43124 Parma, Italy.
authors.forename: G
authors.identifier: 0000-0002-9828-6371
authors.initials: G
authors.lastname: Salviati