Jump to main content
Jump to site search


A new insight for ohmic contacts to MoS2: by tuning MoS2 affinity energies but not metal work-functions

Abstract

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have recently attracted tremendous interest in fundamental studies and applications. High contact resistances between the metal electrodes and the 2D TMDCs, usually composed of tunneling barrier (TB) and Schottky barrier (SB), are the key bottleneck to the realization of high performance devices based on such systems. Here, from van der Waals density functional theory calculations, we demonstrate that strain can provide a feasible means to reduce the contact resistances between, for example, 2D semiconductor MoS2 and metal surfaces, in both strong and weak coupling regimes. Both SB and TB are lowered significantly with the increasing tensile strain in both the coupling regimes. Especially, the SB can reduce to zero in all configurations considered, with increasing tensile strain to ~4% or above. The mechanism of SB reduction under tensile strain is attributed to the increase of the MoS2 affinity energy since the monolayer MoS2 conduction band minimum (CBm) is derived from anti-bonding states. Thus, the SB in other semiconducting TMDCs with anti-bonding CBm (for n-type contact) could also be reduced to zero by tensile strain. Our discoveries thus shed a new and general light toward minimizing the contact resistance of semiconducting TMDCs-metal based contacts and this can also prove applicable to other 2D semiconductors, e.g. phosphorene.

Back to tab navigation

Supplementary files

Publication details

The article was received on 28 Jul 2017, accepted on 05 Sep 2017 and first published on 05 Sep 2017


Article type: Paper
DOI: 10.1039/C7CP05109C
Citation: Phys. Chem. Chem. Phys., 2017, Accepted Manuscript
  •   Request permissions

    A new insight for ohmic contacts to MoS2: by tuning MoS2 affinity energies but not metal work-functions

    Q. Wang, B. Deng and X. SHI, Phys. Chem. Chem. Phys., 2017, Accepted Manuscript , DOI: 10.1039/C7CP05109C

Search articles by author

Spotlight

Advertisements