Identification of individual and few layers of WS2 using Raman Spectroscopy
By A. Berkdemir, H. Gutiérrez, A. Botello-Méndez, N. Peréa-López, A. Elías, Cheng-Ing Chia, Bei Wang, V. Crespi, F. López‐Urías, Jean-Christophe Charlier and 2 more. Scientific Reports, 2013
1,444 citations recorded by the source corpus.
The Raman scattering of single- and few-layered WS2 is studied as a function of the number of S-W-S layers and the excitation wavelength in the visible range (488, 514 and 647 nm). For the three excitation wavelengths used in this study, the frequency of the A1g(Γ) phonon mode monotonically decreases with the number of layers. For single-layer WS2, the 514.5 nm laser excitation generates a second-order Raman resonance involving the longitudinal acoustic mode (LA(M)). This resonance results from a coupling between the electronic band structure and lattice vibrations. First-principles calculations were used to determine the electronic and phonon band structures of single-layer and bulk WS2. The reduced intensity of the 2LA mode was then computed, as a function of the laser wavelength, from the fourth-order Fermi golden rule. Our observations establish an unambiguous and nondestructive Raman fingerprint for identifying single- and few-layered WS2 films.
Subfields: Electrical and Electronic Engineering, Materials Chemistry
View Paper: https://www.semanticscholar.org/paper/f442aa9ba3951dc89dc65051c01636c4287a2dc0
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In Electrical and Electronic Engineering
- R. Lv
- T. Yu
- Ya Cheng
- Di Xiao
- Michael S. Strano
- Steven G. Louie
- Jonathan N. Coleman
- Mauricio Terrones
In Materials Chemistry
- Jonathan N. Coleman
- Mauricio Terrones
- Steven G. Louie
- H. Terrones
- Jun Wang
- W. Blau
- R. Lv
- Vincent Meunier
Citations in the corpus
- Recent Advances in Two-Dimensional Materials beyond Graphene. (2015, methodology): “theoretical approach based on first-principles calculations agrees with the experiment.(241) Moreover, DFPT”
- Tunable nonlinear refractive index of two-dimensional MoS 2 , WS 2 , and MoSe 2 nanosheet dispersions [Invited] (2015, background): “This indicates that the layer number of WS2 nanoflakes in our experiment is less than ∼5monolayers [15,16].”