Prospects of zero Schottky barrier height in a graphene-inserted MoS2-metal interface

Chanana, Anuja and Mahapatra, Santanu (2016) Prospects of zero Schottky barrier height in a graphene-inserted MoS2-metal interface. In: JOURNAL OF APPLIED PHYSICS, 119 (1).

PDF Jou_App_Phy_119-1_014303_2016.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

A low Schottky barrier height (SBH) at source/drain contact is essential for achieving high drive current in atomic layer MoS(2-)channel-based field effect transistors. Approaches such as choosing metals with appropriate work functions and chemical doping are employed previously to improve the carrier injection from the contact electrodes to the channel and to mitigate the SBH between the MoS2 and metal. Recent experiments demonstrate significant SBH reduction when graphene layer is inserted between metal slab (Ti and Ni) and MoS2. However, the physical or chemical origin of this phenomenon is not yet clearly understood. In this work, density functional theory simulations are performed, employing pseudopotentials with very high basis sets to get insights of the charge transfer between metal and monolayer MoS2 through the inserted graphene layer. Our atomistic simulations on 16 different interfaces involving five different metals (Ti, Ag, Ru, Au, and Pt) reveal that (i) such a decrease in SBH is not consistent among various metals, rather an increase in SBH is observed in case of Au and Pt; (ii) unlike MoS2-metal interface, the projected dispersion of MoS2 remains preserved in any MoS2-graphene- metal system with shift in the bands on the energy axis. (iii) A proper choice of metal (e.g., Ru) may exhibit ohmic nature in a graphene-inserted MoS2-metal contact. These understandings would provide a direction in developing high-performance transistors involving heteroatomic layers as contact electrodes. (c) 2016 AIP Publishing LLC.

Item Type:	Journal Article
Publication:	JOURNAL OF APPLIED PHYSICS
Publisher:	AMER INST PHYSICS
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:	17 Feb 2016 05:16
Last Modified:	17 Feb 2016 05:16
URI:	http://eprints.iisc.ac.in/id/eprint/53229

Actions (login required)

View Item