Electron transport through metal/MoS2 interfaces: edge- or area-dependent process?

Authors: Mathieu Luisier1*, Aron Szabo1, Achint Jain2, Markus Parzefall2, Lukas Novotny2

  1. Integrated Systems Laboratory, ETH Zürich, 8092 Zürich, Switzerland
  2. Photonics Laboratory, ETH Zürich, 8093 Zürich, Switzerland
  • Corresponding author email: mluisier@iis.ee.ethz.ch

DOI10.24435/materialscloud:2019.0060/v1 (version v1, submitted on 14 October 2019)

How to cite this entry

Mathieu Luisier, Aron Szabo, Achint Jain, Markus Parzefall, Lukas Novotny, Electron transport through metal/MoS2 interfaces: edge- or area-dependent process?, Materials Cloud Archive (2019), doi: 10.24435/materialscloud:2019.0060/v1.

Description

In ultra-thin two-dimensional (2-D) materials, the formation of ohmic contacts with top metallic layers is a challenging task that involves different processes than in bulk-like structures. Besides the Schottky barrier height, the transfer length of electrons between metals and 2-D monolayers is a highly relevant parameter. For MoS2, both short (≤30 nm) and long (≥0.5 μm) values have been reported, corresponding to either an abrupt carrier injection at the contact edge or a more gradual transfer of electrons over a large contact area. Here we use ab initio quantum transport simulations to demonstrate that the presence of an oxide layer between a metallic contact and a MoS2 monolayer, for example TiO2 in case of titanium electrodes, favors an area-dependent process with a long transfer length, while a perfectly clean metal-semiconductor interface would lead to an edge process. These findings reconcile several theories that have been postulated about the physics of metal/MoS2 interfaces and provide a framework to design future devices with lower contact resistances.

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README.txt
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193 Bytes README File
MoS2-TiO2-Ti.tgz
MD5MD5: 76e6473389a1f8b4c66f61fb8dc84494
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Files and data are licensed under the terms of the following license: Creative Commons Attribution 4.0 International.

External references

Journal reference
A. Szabo, A. Jain, M. Parzefall, L. Novotny, and M. Luisier, Nano Letters 19, 3641-3647 (2019) doi:10.1021/acs.nanolett.9b00678

Keywords

MARVEL/DD3 2-D materials Metal-semiconductor interfaces Contact physics Transfer length Fermi level pinning Ab initio device simulations

Version history

14 October 2019 [This version]