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DOE OSTI · 1894139

Monolayer-like lattice dynamics in bulk WSe 2

Cai, Qingan·Wei, Bin·Sun, Qiyang·Said, Ayman H.·Li, Chen
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Abstract

Understanding the microscopic lattice dynamics is essential for regulating the thermal properties in two-dimensional layered materials. In transition metal dichalcogenides, the layered structures result in different but closely related phonon dispersions between monolayer and bulk. Here, by combining inelastic X-ray scattering and first-principles calculations, the lattice dynamics of tungsten diselenide (WSe 2 ) was investigated comprehensively, and a monolayer-like lattice dynamics in the bulk WSe 2 was revealed. We performed the first temperature-dependent phonon dispersions measurement and obtained the mode Grüneisen parameters of bulk WSe 2 , which are found to be in better agreement with the calculations on the monolayer system than those of the bulk. This observation indicates that lattice dynamics in bulk WSe 2 hold the characteristic of monolayers. The result provides valuable insights into the thermal properties of WSe 2 -based devices.

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36 MATERIALS SCIENCEFirst-principal calculationsLattice dynamicsLayered materialPhonon dispersionThermal conductivityinelastic X-ray scattering

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Cai, Qingan, Wei, Bin, Sun, Qiyang, Said, Ayman H., Li, Chen. 2022-10-04. Monolayer-like lattice dynamics in bulk WSe 2. https://doi.org/10.1016/j.mtphys.2022.100856

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36 MATERIALS SCIENCE↗