title: Hall and field-effect mobilities in few layered p-WSe₂ field-effect transistors.
abstract: Here, we present a temperature (T) dependent comparison between field-effect and Hall mobilities in field-effect transistors based on few-layered WSe2 exfoliated onto SiO2. Without dielectric engineering and beyond a T-dependent threshold gate-voltage, we observe maximum hole mobilities approaching 350 cm(2)/Vs at T = 300 K. The hole Hall mobility reaches a maximum value of 650 cm(2)/Vs as T is lowered below ~150 K, indicating that insofar WSe2-based field-effect transistors (FETs) display the largest Hall mobilities among the transition metal dichalcogenides. The gate capacitance, as extracted from the Hall-effect, reveals the presence of spurious charges in the channel, while the two-terminal sheet resistivity displays two-dimensional variable-range hopping behavior, indicating carrier localization induced by disorder at the interface between WSe2 and SiO2. We argue that improvements in the fabrication protocols as, for example, the use of a substrate free of dangling bonds are likely to produce WSe2-based FETs displaying higher room temperature mobilities, i.e. approaching those of p-doped Si, which would make it a suitable candidate for high performance opto-electronics.
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310, USA.
authors.forename: N R
authors.initials: NR
authors.lastname: Pradhan
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310, USA.
authors.forename: D
authors.initials: D
authors.lastname: Rhodes
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310, USA.
authors.forename: S
authors.initials: S
authors.lastname: Memaran
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Poumirol
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310, USA.
authors.forename: D
authors.initials: D
authors.lastname: Smirnov
authors.affiliation: Physics Department, Sourthern Illinois University, Carbondale-IL 62901-4401, USA.
authors.forename: S
authors.initials: S
authors.lastname: Talapatra
authors.affiliation: Department of Physics, Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: S
authors.initials: S
authors.lastname: Feng
authors.affiliation: Department of Physics, Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: N
authors.initials: N
authors.lastname: Perea-Lopez
authors.affiliation: Department of Physics, Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Elias
authors.affiliation: Department of Physics, Department of Materials Science and Engineering and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: M
authors.initials: M
authors.lastname: Terrones
authors.affiliation: Department of Mechanical Engineering and Materials Science, Rice University, Houston, TX 77005 USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Ajayan
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee-FL 32310, USA.
authors.forename: L
authors.initials: L
authors.lastname: Balicas