Atomistic modeling of the metallic-to-semiconducting phase boundaries in monolayer MoS2

Saha, Dipankar and Mahapatra, Santanu (2016) Atomistic modeling of the metallic-to-semiconducting phase boundaries in monolayer MoS2. In: APPLIED PHYSICS LETTERS, 108 (25).

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Abstract

Recent experimental demonstration on the coexistence of metallic and semiconducting phases in the same monolayer MoS2 crystal has attracted much attention for its use in ultra-low contact resistance-MoS2 transistors. However, the electronic structures of the metallic-to-semiconducting phase boundaries, which appear to dictate the carrier injection in such transistors, are not yet well understood. In this letter, interfacing the 2H and 1T' polytypes appropriately, we first model the ``beta'' (beta) and the ``gamma'' (gamma) phase boundaries, and demonstrate good agreement with experiential results. We then apply first-principles based density functional theory to calculate the electronic structures for those optimized geometries. We further employ non equilibrium Green's function formalism to evaluate the transmission spectra and the local density of states (LDOS) in order to assess the Schottky barrier nature of the phase boundaries. Our study reveals that while the gamma boundary yields p-type Schottky barrier, the beta boundary leads to the distinct symmetric Schottky barrier with an atomically sharp transition region. This understanding could be useful for designing high performance transistors using phase-engineered MoS2 crystals. Published by AIP Publishing.

Item Type:	Journal Article
Publication:	APPLIED PHYSICS LETTERS
Publisher:	AMER INST PHYSICS, USA
Additional Information:	Copy right for this article belongs to the AMER INST PHYSICS, 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA
Department/Centre:	Division of Electrical Sciences > Electronic Systems Engineering (Formerly Centre for Electronic Design & Technology)
Date Deposited:	19 Aug 2016 09:16
Last Modified:	19 Aug 2016 09:16
URI:	http://eprints.iisc.ac.in/id/eprint/54367

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