title: Nanopatterning and Electrical Tuning of MoS2 Layers with a Subnanometer Helium Ion Beam.
abstract: We report subnanometer modification enabled by an ultrafine helium ion beam. By adjusting ion dose and the beam profile, structural defects were controllably introduced in a few-layer molybdenum disulfide (MoS2) sample and its stoichiometry was modified by preferential sputtering of sulfur at a few-nanometer scale. Localized tuning of the resistivity of MoS2 was demonstrated and semiconducting, metallic-like, or insulating material was obtained by irradiation with different doses of He(+). Amorphous MoSx with metallic behavior has been demonstrated for the first time. Fabrication of MoS2 nanostructures with 7 nm dimensions and pristine crystal structure was also achieved. The damage at the edges of these nanostructures was typically confined to within 1 nm. Nanoribbons with widths as small as 1 nm were reproducibly fabricated. This nanoscale modification technique is a generalized approach that can be applied to various two-dimensional (2D) materials to produce a new range of 2D metamaterials.
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Fox
authors.forename: Yangbo
authors.initials: Y
authors.lastname: Zhou
authors.forename: Pierce
authors.initials: P
authors.lastname: Maguire
authors.forename: Arlene
authors.initials: A
authors.lastname: O'Neill
authors.forename: Cormac
authors.initials: C
authors.lastname: Ó'Coileáin
authors.forename: Riley
authors.initials: R
authors.lastname: Gatensby
authors.affiliation: §Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC 3216, Australia.|∥Melbourne Centre for Nanofabrication, 151 Wellington Rd, Clayton, VIC 3168, Australia.
authors.forename: Alexey M
authors.initials: AM
authors.lastname: Glushenkov
authors.affiliation: §Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC 3216, Australia.
authors.forename: Tao
authors.initials: T
authors.lastname: Tao
authors.forename: Georg S
authors.initials: GS
authors.lastname: Duesberg
authors.forename: Igor V
authors.initials: IV
authors.lastname: Shvets
authors.affiliation: ⊥KSU-Aramco Center, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abid
authors.affiliation: ⊥KSU-Aramco Center, King Saud University, Riyadh 11451, Saudi Arabia.
authors.forename: Mourad
authors.initials: M
authors.lastname: Abid
authors.affiliation: #School of Physics, Beijing Institute of Technology, Beijing, 100081, People's Republic of China.
authors.forename: Han-Chun
authors.initials: HC
authors.lastname: Wu
authors.affiliation: §Institute for Frontier Materials, Deakin University, Waurn Ponds, VIC 3216, Australia.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Coleman
authors.forename: John F
authors.initials: JF
authors.lastname: Donegan
authors.forename: Hongzhou
authors.initials: H
authors.lastname: Zhang
keywords: Helium ion beam; MoS2; electrical tuning; nanopatterning; nanoribbon; stoichiometry