Environmental Instability and Degradation of Single- and Few-Layer WTe2 Nanosheets in Ambient Conditions

Abstract

Since the discovery of large, non-saturating magnetoresistance in bulk WTe2 which allows microexfoliation, single- and few-layer WTe2 crystals have attracted increasing interests. However, as it mentioned in existing studies, WTe2 flakes appear to degrade in ambient conditions. Here we report experimental observations of saturating degradation in few-layer WTe2 through Raman spectroscopy characterization and careful monitoring of the degradation of single-, bi- and tri-layer (1L, 2L & 3L) WTe2 over long time. Raman peak intensity decreases during WTe2 degradation and 1L flakes degrade faster than 2L and 3L flakes. The relatively faster degradation in 1L WTe2 could be attributed to low energy barrier of oxygen reaction with WTe2. We further investigate the degradation mechanisms of WTe2 using XPS and AES and find that oxidation of Te and W atoms is the main reason of WTe2 degradation. In addition, we observe oxidation occurs only in the depth of 0.5nm near the surface, and the oxidized WTe2 surface could help prevent inner layers from further degradation.

arXiv comment6 Figures, 11 Pages

References in corpus (10)

• Boron nitride substrates for high-quality graphene electronics
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• Titanic Magnetoresistance in WTe2
• Effective Passivation of Exfoliated Black Phosphorus Transistors against Ambient Degradation
• Superconductivity in Weyl Semimetal Candidate MoTe2
• Oxygen defects in phosphorene
• Tuning Magnetotransport in a Compensated Semimetal at the Atomic Scale
• Thermal Oxidation of WSe2 Nano-sheets Adhered on SiO2/Si Substrates
• Single- and Few-Layer WTe2 and Their Suspended Nanostructures: Raman Signatures and Nanomechanical Resonances
• Environmental, Thermal, and Electrical Susceptibility of Black Phosphorus Field Effect Transistors

Cited by in corpus (31)

• Observation of the Quantum Spin Hall Effect up to 100 Kelvin in a Monolayer Crystal
• Néel-type skyrmion in WTe2/Fe3GeTe2 van der Waals heterostructure
• Mechanical Properties of Atomically Thin Tungsten Dichalcogenides: WS${}_2$, WSe${}_2$ and WTe${}_2$
• Contact Engineering High Performance n-Type MoTe2 Transistors
• Two-Dimensional Gallium Sulfide Nanoflakes for UV-Selective Photoelectrochemical-type Photodetectors
• Enhancement of superconductivity in organic-inorganic hybrid topological materials
• Direct evidence for charge compensation induced large magnetoresistance in thin WTe2
• Magnetoresistance and Quantum Oscillations of an Electrostatically Tuned Semimetal-to-Metal Transition in Ultra-Thin WTe2
• In-situ exfoliation method of large-area 2D materials
• Thermopower and Unconventional Nernst in the Predicted Type-II Weyl Semi-metal WTe${}_2$
• Intrinsic Phonon Bands in High-Quality Monolayer T' Molybdenum Ditelluride
• Refractive uses of layered and two-dimensional materials for integrated photonics
• Low-temperature synthesis and electrocatalytic application of large-area PtTe2 thin films
• Thickness dependent electronic structure in WTe${}_2$ thin films
• Effect of aging-induced disorder on the quantum transport properties of atomically thin WTe${}_2$
• Exfoliation of 2D van der Waals crystals in ultrahigh vacuum for interface engineering
• Growth kinetics and atomistic mechanisms of native oxidation of ZrS${}_x$Se${}_{2-x}$ and MoS${}_2$ crystals
• Photo-induced anomalous Hall effect in the type-II Weyl-semimetal WTe2 at room-temperature
• Electron-phonon interaction and point contact enhanced superconductivity in trigonal PtBi2
• Air tightness of hBN encapsulation and its impact on Raman spectroscopy of van der Waals materials
• TaCo${}_2$Te${}_2$: An air-stable, magnetic van der Waals material with high mobility
• Switchable large-gap quantum spin Hall state in two-dimensional MSi${}_2$Z${}_4$ materials class
• Transparent Josephson Junctions in Higher-Order Topological Insulator WTe2 via Pd Diffusion
• Gate-defined Josephson weak-links in monolayer $\mathrm{WT}{\mathrm{e}}_2$
• Valley Phenomena in the Candidate Phase Change Material WSe${}_{2(1-x)}$Te${}_{2x}$
• Exploring Topological Transport in Pt${}_2$HgSe${}_3$ Nanoribbons: Insights for Spintronic Device Integration
• Substrate pre-sputtering for layer-by-layer van der Waals epitaxy of 2D materials
• Persistent spin texture preserved by local symmetry in graphene/WTe${}_2$ heterostructure
• Floquet engineering of spin-valley selective transport in jacutingaite
• Emergent One-Dimensional Helical Channel in Higher-Order Topological Insulators with Step Edges
• Liquid phase mass production of air-stable black phosphorus/phospholipids nanocomposite with ultralow tunneling barrier