Physical vapor deposition-free scalable high-efficiency electrical contacts to MoS2

Anusha Shanmugam; Muhammad Arshad Thekke Purayil; Sai Abhishikth Dhurjati; Madhu Thalakulam

doi:10.1088/1361-6528/ad12e4

Physical vapor deposition-free scalable high-efficiency electrical contacts to MoS₂

Nanotechnology. 2023 Dec 27;35(11). doi: 10.1088/1361-6528/ad12e4.

Authors

Anusha Shanmugam¹, Muhammad Arshad Thekke Purayil¹, Sai Abhishikth Dhurjati¹, Madhu Thalakulam¹

Affiliation

¹ Indian Institute of Science Education & Research Thiruvananthapuram, Kerala 695551, India.

PMID: 38055966
DOI: 10.1088/1361-6528/ad12e4

Abstract

Fermi-level pinning caused by the kinetic damage during metallization has been recognized as one of the major reasons for the non-ideal behavior of electrical contacts, forbidding reaching the Schottky-Mott limit. In this manuscript, we present a scalable technique wherein Indium, a low-work-function metal, is diffused to contact a few-layered MoS₂flake. The technique exploits a smooth outflow of Indium over gold electrodes to make edge contacts to pre-transferred MoS₂flakes. We compare the performance of three pairs of contacts made onto the same MoS₂flake, the bottom-gold, top-gold, and Indium contacts, and find that the Indium contacts are superior to other contacts. The Indium contacts maintain linearI-Vcharacteristics down to cryogenic temperatures with an extracted Schottky barrier height of ∼2.1 meV. First-principle calculations show the induced in-gap states close to the Fermi level, and the damage-free contact interface could be the reason for the nearly Ohmic behavior of the Indium/MoS₂interface.

Keywords: MoS2; contact engineering; indium contacts; low Schottky barrier.