Mapping of Low-Frequency Raman Modes in CVD-Grown Transition Metal Dichalcogenides: Layer Number, Stacking Orientation and Resonant Effects

Abstract

Layered inorganic materials, such as the transition metal dichalcogenides (TMDs), have attracted much attention due to their exceptional electronic and optical properties. Reliable synthesis and characterization of these materials must be developed if these properties are to be exploited. Herein, we present low-frequency Raman analysis of MoS2, MoSe2, WSe2 and WS2 grown by chemical vapour deposition (CVD). Raman spectra are acquired over large areas allowing changes in the position and intensity of the shear and layer-breathing modes to be visualized in maps. This allows detailed characterization of mono- and few-layered TMDs which is complementary to well-established (high-frequency) Raman and photoluminescence spectroscopy. This study presents a major stepping stone in fundamental understanding of layered materials as mapping the low-frequency modes allows the quality, symmetry, stacking configuration and layer number of 2D materials to be probed over large areas. In addition, we report on anomalous resonance effects in the low-frequency region of the WS2 Raman spectrum.

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Cited by in corpus (20)

• Achieving Large, Tunable Strain in Monolayer Transition-Metal Dichalcogenides
• A WSe2 vertical field emission transistor
• Electronic band structure of Two-Dimensional WS2/Graphene van der Waals Heterostructures
• Environmental effects on the electrical characteristics of back-gated WSe2 field effect transistors
• Stacking-Dependent Interlayer Phonons in 3R and 2H MoS${}_2$
• Interlayer bond polarizability model for stacking-dependent low-frequency Raman scattering in layered materials
• Effect of different precursors on CVD growth of molybdenum disulfide
• Determination of the thickness and orientation of few-layer tungsten ditelluride using polarized Raman spectroscopy
• Stacking-Dependent Optical Properties in Bilayer WSe2
• Interlayer Charge Transfer and Defect Creation in Type I van der Waals Heterostructures
• Monolayer WS${}_2$ electro- and photo-luminescence enhancement by TFSI treatment
• Raman Scattering with infrared excitation resonant with MoSe${}_2$ indirect band gap
• Rapid multiplex ultrafast nonlinear microscopy for material characterization
• Growth and Properties of Dislocated Two-dimensional Layered Materials
• Suppression of the Shear Raman Mode in Defective Bilayer MoS2
• A Facile Method for Precise Layer Number Identification of Two-Dimensional Materials through Optical Images
• Long wavelength interdomain phonons and instability of dislocations in small-angle twisted bilayers
• Analysis of Side-band Inequivalence
• Wafer-scale epitaxial growth of single orientation WS2 monolayers on sapphire
• Kolmogorov-Crespi Potential For Multilayer Transition Metal Dichalcogenides: Capturing Structural Transformations In Moiré Superlattices