title: Monolayer Single-Crystal 1T'-MoTe2 Grown by Chemical Vapor Deposition Exhibits Weak Antilocalization Effect.
abstract: Growth of transition metal dichalcogenide (TMD) monolayers is of interest due to their unique electrical and optical properties. Films in the 2H and 1T phases have been widely studied but monolayers of some 1T'-TMDs are predicted to be large-gap quantum spin Hall insulators, suitable for innovative transistor structures that can be switched via a topological phase transition rather than conventional carrier depletion [ Qian et al. Science 2014 , 346 , 1344 - 1347 ]. Here we detail a reproducible method for chemical vapor deposition of monolayer, single-crystal flakes of 1T'-MoTe2. Atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy confirm the composition and structure of MoTe2 flakes. Variable temperature magnetotransport shows weak antilocalization at low temperatures, an effect seen in topological insulators and evidence of strong spin-orbit coupling. Our approach provides a pathway to systematic investigation of monolayer, single-crystal 1T'-MoTe2 and implementation in next-generation nanoelectronic devices.
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Carl H
authors.initials: CH
authors.lastname: Naylor
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: William M
authors.initials: WM
authors.lastname: Parkin
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Jinglei
authors.initials: J
authors.lastname: Ping
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Zhaoli
authors.initials: Z
authors.lastname: Gao
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Yu Ren
authors.initials: YR
authors.lastname: Zhou
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Youngkuk
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Frank
authors.initials: F
authors.lastname: Streller
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Carpick
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Rappe
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: Marija
authors.initials: M
authors.lastname: Drndić
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: James M
authors.initials: JM
authors.lastname: Kikkawa
authors.affiliation: Department of Physics and Astronomy, ‡Department of Chemistry, §Department of Materials Science and Engineering, and ∥Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
authors.forename: A T Charlie
authors.initials: AT
authors.lastname: Johnson
mesh_terms: D003080:Cold Temperature; D005740:Gases / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D013059:Spectrum Analysis, Raman; D013696:Temperature
chemical_list: D005740:Gases
keywords: 1T′-MoTe2; CVD; Transition metal dichalcogenide; monolayer growth; weak antilocalization