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Understanding Interlayer Coupling in TMD-hBN Heterostructure by Raman Spectroscopy
- Source :
- other univ website
- Publication Year :
- 2018
- Publisher :
- Institute of Electrical and Electronics Engineers (IEEE), 2018.
-
Abstract
- © 2018 IEEE. In 2-D van der Waals heterostructures, interactions between atomic layers dramatically change the vibrational properties of the hybrid system and demonstrate several interesting phenomena that are absent in individual materials. In this paper, we have investigated the vibrational properties of the heterostructure between transition metal dichalcogenide (TMD) and hexagonal boron nitride (hBN) on gold film at low- and high-frequency ranges by Raman spectroscopy. Nineteen Raman modes have been observed from the sample, including a new interlayer coupling mode at 28.8 cm-1. Compared to reported experimental results of tungsten disulfide (WS2) on SiO2/Si substrates, the Raman spectrum for WS2 on hBN/Au emerges a blue shift of about 8 cm-1. Furthermore, a remarkable enhancement of Raman intensity can be obtained when tuning hBN thickness in the heterostructure. Through systematic first-principles calculations, numerical simulations, and analytical calculations, we find that the 28.8 cm-1 mode originates from the shearing motion between monolayer TMD and hBN layers. In addition, the gold substrate and hBN layers form an optical cavity and the cavity interference effects enhance the obtained Raman intensity. This paper demonstrates the novel vibrational modes of 2-D van der Waals heterostructure as an effective tool to characterize a variety of such heterostructures and reveals a new method to enhance the Raman response of 2-D materials.
- Subjects :
- Materials science
Heterojunction
02 engineering and technology
Substrate (electronics)
021001 nanoscience & nanotechnology
01 natural sciences
Molecular physics
Electronic, Optical and Magnetic Materials
Blueshift
law.invention
Condensed Matter::Materials Science
symbols.namesake
law
Optical cavity
Molecular vibration
0103 physical sciences
Monolayer
symbols
Electrical and Electronic Engineering
van der Waals force
010306 general physics
0210 nano-technology
Raman spectroscopy
Subjects
Details
- ISSN :
- 15579646 and 00189383
- Volume :
- 65
- Database :
- OpenAIRE
- Journal :
- IEEE Transactions on Electron Devices
- Accession number :
- edsair.doi.dedup.....ed85dd75b7592d4f760a16090a5e4335