On the origin of metallicity and stability of the metastable phase in chemically exfoliated MoS2

Pariari, D and Varma, RM and Nair, MN and Zeller, P and Amati, M and Gregoratti, L and Nanda, KK and Sarma, DD (2020) On the origin of metallicity and stability of the metastable phase in chemically exfoliated MoS2. In: Applied Materials Today, 19 .

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Abstract

Chemical exfoliation of MoS2 via Li-intercalation route has led to many desirable properties and spectacular applications due to the presence of a metastable state in addition to the stable H phase. However, the nature of the specific metastable phase formed, and its basic charge conduction properties have remained controversial. Using spatially resolved Raman spectroscopy (�1 μm resolution) and photoelectron spectroscopy (�130 nm resolution), we probe such chemically exfoliated MoS2 samples in comparison to a mechanically exfoliated H phase sample and confirm that the dominant metastable state formed by this approach is a distorted T� state with a small semiconducting gap. Investigating two such samples with different extents of Li residues present, we establish that Li+ ions, not only help to exfoliate MoS2 into few layer samples, but also contribute to enhancing the relative stability of the metastable state as well as dope the system with electrons, giving rise to a lightly doped small bandgap system with the T� structure, responsible for its spectacular properties.

Item Type:	Journal Article
Publication:	Applied Materials Today
Publisher:	Elsevier Ltd
Additional Information:	Copyright of this article belongs to Elsevier Ltd
Keywords:	Astrophysics; Chemical stability; Energy gap; Exfoliation (materials science); Intercalation; Layered semiconductors; Lithium compounds; Metastable phases; Molybdenum compounds; Photoelectron spectroscopy, 2D MoS2; Chemical exfoliations; Meta-stable state; Metallicities; Small bandgap, Sulfur compounds
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	13 Feb 2020 09:52
Last Modified:	13 Feb 2020 09:52
URI:	http://eprints.iisc.ac.in/id/eprint/64497

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