Achieving Large, Tunable Strain in Monolayer Transition-Metal Dichalcogenides

Abstract

We describe a facile technique based on polymer encapsulation to apply several percent controllable strains to monolayer and few-layer Transition Metal Dichalcogenides (TMDs). We use this technique to study the lattice response to strain via polarized Raman spectroscopy in monolayer WSe2 and WS2. The application of strain causes mode-dependent redshifts, with larger shift rates observed for in-plane modes. We observe a splitting of the degeneracy of the in-plane E' modes in both materials and measure the Gruneisen parameters. At large strain, we observe that the reduction of crystal symmetry can lead to a change in the polarization response of the A' mode in WS2. While both WSe2 and WS2 exhibit similar qualitative changes in the phonon structure with strain, we observe much larger changes in mode positions and intensities with strain in WS2. These differences can be explained simply by the degree of iconicity of the metal-chalcogen bond.

22 pages total, 4 figures in main text, 6 figures in Supporting Information

References in corpus (17)

• Bandgap Engineering of Strained Monolayer and Bilayer MoS2
• Quantum Spin Hall Effect and Topological Field Effect Transistor in Two-Dimensional Transition Metal Dichalcogenides
• Uniaxial Strain in Graphene by Raman Spectroscopy: G peak splitting, Gruneisen Parameters and Sample Orientation
• Phonons in single and few-layer MoS2 and WS2
• Local strain engineering in atomically thin MoS2
• Phonon and Raman scattering of two-dimensional transition metal dichalcogenides from monolayer, multilayer to bulk material
• Strain engineering in semiconducting two-dimensional crystals
• Anomalous Raman Spectra and Thickness Dependent Electronic properties of WSe2
• Strain tuning of optical emission energy and polarization in monolayer and bilayer MoS2
• Novel effects of strains in graphene and other two dimensional materials
• Thermal conductivity of monolayer MoS2, MoSe2, and WS2: Interplay of mass effect, interatomic bonding and anharmonicity
• Strain-dependent modulation of conductivity in single layer transition-metal dichalcogenides
• Raman Signature and Phonon Dispersion of Atomically Thin Boron Nitride
• Quantum Spin Hall Effect in Two-dimensional Crystals of Transition Metal Dichalcogenides
• Mapping of Low-Frequency Raman Modes in CVD-Grown Transition Metal Dichalcogenides: Layer Number, Stacking Orientation and Resonant Effects
• Role of Strain on Electronic and Mechanical Response of Semiconducting Transition-Metal Dichalcogenide Monolayers: an ab-initio study
• Synthesis and optical properties of large-scale single-crystalline two-dimensional semiconductor WS2 monolayer from chemical vapor deposition

Cited by in corpus (16)

• Variation of the fundamental band gap nature in curved two-dimensional WS2
• Possible strain induced Mott gap collapse in 1T-TaS${}_2$
• WS2 Monolayers Coupled to Hyperbolic Metamaterial Nanoantennas: Broad Implications for Light-Matter-Interaction Applications
• Strain-dependent exciton diffusion in transition metal dichalcogenides
• Strain control of exciton and trion spin-valley dynamics in monolayer transition metal dichalcogenides
• Toward Mass-Production of Transition Metal Dichalcogenide Solar Cells: Scalable Growth of Photovoltaic-Grade Multilayer WSe2 by Tungsten Selenization
• Local tuning of WS2 photoluminescence using polymeric micro-actuators in a monolithic van der Waals heterostructure
• Curvature-enhanced localised emission from dark states in wrinkled monolayer WSe2 at room temperature
• Nano-Raman Spectroscopy Analysis of Nanoprotuberances in MoSe2
• Two dimensional semiconductors: optical and electronic properties
• Mesoscopic Stacking Reconfigurations in Stacked van der Waals Film
• Anomalous phonon Grüneisen parameters in semiconductor Ta${}_2$NiS${}_5$
• Raman Digital Twin of Monolayer Janus Transition Metal Dichalcogenides
• Mechanical Detuning of Exciton-Phonon Resonance in WS2
• Tuning Terahertz Optomechanics of MoS2 Bilayers with Homogeneous In-plane Strain
• Angular Emission Properties of Strained Transition-Metal Dichalcogenides