Mitra, S and Srivastava, D and Singha, SS and Dutta, S and Satpati, B and Karppinen, M and Ghosh, A and Singha, A (2020) Tailoring phonon modes of few-layered MoS2 by in-plane electric field. In: npj 2D Materials and Applications, 4 (1).
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Abstract
We discuss the effect of the in-plane electric field on the Raman spectroscopy for few-layered MoS2. The characteristic Raman modes of MoS2 show gradual red shift, while the intensity increases by 45�50 as the electric field is increased, showing a large electro-optical effect. Structural analysis suggests that our few-layered MoS2 belongs to P6/m2 space group with broken inversion symmetry. We attribute this gradual red shift to this broken symmetry-driven piezoelectricity in MoS2, which generates tensile strain along the perpendicular direction when the electric field is applied. The enhancement of the effect upon reversing the electric field direction adds credence to our interpretation. Our first principal density-functional theory calculation further substantiates the claim. This optical probing of the electromechanical coupling may lead to applications as a nonextensive technique for electric field/strain sensors in the nanoelectronics devices.
| Item Type: | Journal Article |
|---|---|
| Publication: | npj 2D Materials and Applications |
| Publisher: | Nature Research |
| Additional Information: | Copy right for this article belongs to Nature Research |
| Keywords: | Crystallography; Density functional theory; Doppler effect; Electric fields; Electromechanical coupling; Electromechanical devices; Layered semiconductors; Molybdenum compounds; Phosphorus compounds; Red Shift; Tensile strain, Broken symmetry; Electric-field directions; In-plane electric fields; Inversion symmetry; Optical probing; Phonon mode; Raman modes; Space Groups, Sulfur compounds |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 14 Oct 2020 10:14 |
| Last Modified: | 14 Oct 2020 10:14 |
| URI: | http://eprints.iisc.ac.in/id/eprint/65415 |
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