title: Highly efficient and stable MoS2FETs with reversible n-doping using a dehydrated poly(vinyl-alcohol) coating.
abstract: Despite rapid progress in 2D molybdenum disulfide (MoS2) research in recent years, MoS2field-effect transistors (FETs) still suffer from a high metal-to-MoS2contact resistance and low intrinsic mobility, which are major hindrances to their future application. We report an efficient technique to dope thin-film MoS2FETs using a poly(vinyl-alcohol) (PVA) polymeric coating. This results in a reduction of the contact resistance by up to 30% as well as a reduction in the channel resistance to 20 kΩ sq-1. Using a dehydration process, we were able to effectively control the surface interactions between MoS2and the more electropositive hydroxyl groups (-OH) of PVA, which provided a controllable and yet reversible increase in the charge carrier density to a value of 8.0 × 1012cm-2. The non-covalent, thus non-destructive, PVA doping of MoS2increases the carrier concentration without degrading the mobility, which shows a monotonic increase while enhancing the doping effect. The PVA doping technique is then exploited to create heavily doped access regions to the intrinsic MoS2channel, which yields 200% increase of the ON-state source-drain current. This establishes PVA doping as an effective approach to enhance the transport properties of MoS2FETs for a variety of applications.
authors.affiliation: imec, Kapeldreef 75, B-3001 Leuven, Belgium. lockhart@imec.be.
authors.forename: César J
authors.initials: CJ
authors.lastname: Lockhart de la Rosa
authors.forename: Amirhasan
authors.initials: A
authors.lastname: Nourbakhsh
authors.forename: Markus
authors.initials: M
authors.lastname: Heyne
authors.forename: Inge
authors.initials: I
authors.lastname: Asselberghs
authors.forename: Cedric
authors.initials: C
authors.lastname: Huyghebaert
authors.forename: Iuliana
authors.initials: I
authors.lastname: Radu
authors.forename: Marc
authors.initials: M
authors.lastname: Heyns
authors.forename: Stefan
authors.initials: S
authors.lastname: De Gendt