title: High Current Density and Low Thermal Conductivity of Atomically Thin Semimetallic WTe2.
abstract: Two-dimensional (2D) semimetals beyond graphene have been relatively unexplored in the atomically thin limit. Here, we introduce a facile growth mechanism for semimetallic WTe2 crystals and then fabricate few-layer test structures while carefully avoiding degradation from exposure to air. Low-field electrical measurements of 80 nm to 2 μm long devices allow us to separate intrinsic and contact resistance, revealing metallic response in the thinnest encapsulated and stable WTe2 devices studied to date (3-20 layers thick). High-field electrical measurements and electrothermal modeling demonstrate that ultrathin WTe2 can carry remarkably high current density (approaching 50 MA/cm(2), higher than most common interconnect metals) despite a very low thermal conductivity (of the order ∼3 Wm(-1) K(-1)). These results suggest several pathways for air-stable technological viability of this layered semimetal.
authors.affiliation: Department of Electrical Engineering, ‡Department of Materials Science and Engineering, §Department of Applied Physics, and ∥Precourt Institute for Energy, Stanford University , Stanford, California 94305, United States.
authors.forename: Michal J
authors.initials: MJ
authors.lastname: Mleczko
authors.affiliation: Department of Electrical Engineering, ‡Department of Materials Science and Engineering, §Department of Applied Physics, and ∥Precourt Institute for Energy, Stanford University , Stanford, California 94305, United States.
authors.forename: Runjie Lily
authors.initials: RL
authors.lastname: Xu
authors.affiliation: Department of Electrical Engineering, ‡Department of Materials Science and Engineering, §Department of Applied Physics, and ∥Precourt Institute for Energy, Stanford University , Stanford, California 94305, United States.
authors.forename: Kye
authors.initials: K
authors.lastname: Okabe
authors.affiliation: Department of Electrical Engineering, ‡Department of Materials Science and Engineering, §Department of Applied Physics, and ∥Precourt Institute for Energy, Stanford University , Stanford, California 94305, United States.
authors.forename: Hsueh-Hui
authors.initials: HH
authors.lastname: Kuo
authors.affiliation: Department of Electrical Engineering, ‡Department of Materials Science and Engineering, §Department of Applied Physics, and ∥Precourt Institute for Energy, Stanford University , Stanford, California 94305, United States.
authors.forename: Ian R
authors.initials: IR
authors.lastname: Fisher
authors.affiliation: Department of Electrical Engineering, ‡Department of Materials Science and Engineering, §Department of Applied Physics, and ∥Precourt Institute for Energy, Stanford University , Stanford, California 94305, United States.
authors.forename: H-S Philip
authors.initials: HS
authors.lastname: Wong
authors.affiliation: Department of Electrical Engineering, ‡Department of Materials Science and Engineering, §Department of Applied Physics, and ∥Precourt Institute for Energy, Stanford University , Stanford, California 94305, United States.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Nishi
authors.affiliation: Department of Electrical Engineering, ‡Department of Materials Science and Engineering, §Department of Applied Physics, and ∥Precourt Institute for Energy, Stanford University , Stanford, California 94305, United States.
authors.forename: Eric
authors.initials: E
authors.lastname: Pop
keywords: current density; environmental stability; semimetals; thermal conductivity; transition metal dichalcogenides; two-dimensional atomic layers