title: Single- and few-layer WTe2 and their suspended nanostructures: Raman signatures and nanomechanical resonances.
abstract: Single crystal tungsten ditelluride (WTe2) has recently been discovered to exhibit non-saturating extreme magnetoresistance in bulk; it has also emerged as a new layered material from which atomic layer crystals can be extracted. While atomically thin WTe2 is attractive for its unique properties, little research has been conducted on single- and few-layer WTe2. Here we report the isolation of single- and few-layer WTe2, as well as the fabrication and characterization of the first WTe2 suspended nanostructures. We have observed new Raman signatures of single- and few-layer WTe2 that have been theoretically predicted but have not been reported to date, in both on-substrate and suspended WTe2 flakes. We have further probed the nanomechanical properties of suspended WTe2 structures by measuring their flexural resonances, and obtain a Young's modulus of E(Y) ≈ 80 GPa for the suspended WTe2 flakes. This study paves the way for future investigations and utilizations of the multiple new Raman fingerprints of single- and few-layer WTe2, and for explorations of mechanical control of WTe2 atomic layers.
authors.affiliation: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. philip.feng@case.edu.
authors.forename: Jaesung
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. philip.feng@case.edu.
authors.forename: Fan
authors.initials: F
authors.lastname: Ye
authors.affiliation: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. philip.feng@case.edu.
authors.forename: Zenghui
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. philip.feng@case.edu.
authors.forename: Rui
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: Hu
authors.affiliation: Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Mao
authors.affiliation: Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA.
authors.forename: Jiang
authors.initials: J
authors.lastname: Wei
authors.affiliation: Department of Electrical Engineering & Computer Science, Case School of Engineering, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, OH 44106, USA. philip.feng@case.edu.
authors.forename: Philip X-L
authors.initials: PX
authors.lastname: Feng