Pressure-Dependent Optical and Vibrational Properties of Mono layer Molybdenum Disulfide

Nayak, Avinash P and Pandey, Tribhuwan and Voiry, Damien and Liu, Jin and Moran, Samuel T and Sharma, Ankit and Tan, Cheng and Chen, Chang-Hsiao and Li, Lain-Jong and Chhowalla, Manish and Lin, Jung-Fu and Singh, Abhishek K and Akinwande, Deji (2015) Pressure-Dependent Optical and Vibrational Properties of Mono layer Molybdenum Disulfide. In: NANO LETTERS, 15 (1). pp. 346-353.

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Abstract

Controlling the band gap by tuning the lattice structure through pressure engineering is a relatively new route for tailoring the optoelectronic properties of two-dimensional (2D) materials. Here, we investigate the electronic structure and lattice vibrational dynamics of the distorted monolayer 1T-MoS2 (1T') and the monolayer 2H-MoS2 via a diamond anvil cell (DAC) and density functional theory (DFT) calculations. The direct optical band gap of the monolayer 2H-MoS2 increases by 11.7% from 1.85 to 2.08 eV, which is the highest reported for a 2D transition metal dichalcogenide (TMD) material. DFT calculations reveal a subsequent decrease in the band gap with eventual metallization of the monolayer 2H-MoS2, an overall complex structureproperty relation due to the rich band structure of MoS2. Remarkably, the metastable 1T'-MoS2 metallic state remains invariant with pressure, with the J(2), A(1g), and E(2)g modes becoming dominant at high pressures. This substantial reversible tunability of the electronic and vibrational properties of the MoS2 family can be extended to other 2D TMDs. These results present an important advance toward controlling the band structure and optoelectronic properties of monolayer MoS2 via pressure, which has vital implications for enhanced device applications.

Item Type:	Journal Article
Publication:	NANO LETTERS
Publisher:	AMER CHEMICAL SOC
Additional Information:	Copy right for this article belongs to the AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Keywords:	2D Materials; Diamond Anvil Cell; Hydrostatic Pressure; MoS2; Photoluminescence; Pressure Engineering; Strain; Transition Metal Dichalcogenide
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	19 Mar 2015 12:10
Last Modified:	19 Mar 2015 12:10
URI:	http://eprints.iisc.ac.in/id/eprint/51056

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