title: p-Type transition-metal doping of large-area MoS2thin films grown by chemical vapor deposition.
abstract: Two-dimensional transition metal dichalcogenides (e.g. MoS2) have recently emerged as a promising material system for electronic and optoelectronic applications. A major challenge for these materials, however, is to realize bipolar electrical transport properties (i.e. both p-type and n-type conduction), which is critical for enhancing device performance and functionalities. Here, we demonstrate the transition metal zinc as a p-type dopant in the otherwise n-type MoS2, through systematic characterizations of large area Zn-doped MoS2thin films grown by a one-step chemical vapor deposition (CVD) approach. Raman characterization and X-ray photoelectron spectroscopy studies identified millimeter-scale, monolayer films with 1-2% Zn as dopants. Zinc doping suppresses n-type conductivity in MoS2and shifts its Fermi level downwards. The stability and p-type nature of Zn dopants were further confirmed by density-functional-theory calculations of formation energies and electronic band structures. The electrical transport properties of Zn-MoS2films can be influenced by stoichiometry, and p-type gate transfer characteristics were realized by thermal treatment under a sulfur atmosphere. Our work highlights transition-metal doping followed by sulfur vacancy elimination in CVD grown films as a promising route for achieving large area p-type transition metal dichalcogenide films that are essential for practical applications in electronics and optoelectronics.
authors.affiliation: Department of Physics, Indiana University, Bloomington, IN 47405, USA. sxzhang@indiana.edu.
authors.forename: E Z
authors.initials: EZ
authors.lastname: Xu
authors.affiliation: Department of Physics, Indiana University, Bloomington, IN 47405, USA. sxzhang@indiana.edu.
authors.forename: H M
authors.initials: HM
authors.lastname: Liu
authors.affiliation: Department of Physics, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: K
authors.initials: K
authors.lastname: Park
authors.affiliation: Department of Physics, Indiana University, Bloomington, IN 47405, USA. sxzhang@indiana.edu.
authors.forename: Z
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Chemistry, Indiana University, Bloomington, IN 47405, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Losovyj
authors.affiliation: Department of Physics, Indiana University, Bloomington, IN 47405, USA. sxzhang@indiana.edu.
authors.forename: M
authors.initials: M
authors.lastname: Starr
authors.affiliation: Department of Physics, Indiana University, Bloomington, IN 47405, USA. sxzhang@indiana.edu.
authors.forename: M
authors.initials: M
authors.lastname: Werbianskyj
authors.affiliation: Department of Physics, Indiana University, Bloomington, IN 47405, USA. sxzhang@indiana.edu.
authors.forename: H A
authors.initials: HA
authors.lastname: Fertig
authors.affiliation: Department of Physics, Indiana University, Bloomington, IN 47405, USA. sxzhang@indiana.edu.
authors.forename: S X
authors.identifier: http://orcid.org/0000-0002-1004-0597
authors.initials: SX
authors.lastname: Zhang