Two-dimensional transition metal dichalcogenides (TMDCs) have properties attractive for optoelectronic and quantum applications. A crucial element for devices is the metal-semiconductor interface. However, high contact resistances have hindered progress. Quantum transport studies are scant as low-quality contacts are intractable at cryogenic temperatures. Here, temperature-dependent transfer length measurements are performed on chemical vapour deposition grown single-layer and bilayer WS2 devices with indium alloy contacts. The devices exhibit low contact resistances and Schottky barrier heights (\sim10 kΩ\si{\micro\metre} at 3 K and 1.7 meV). Efficient carrier injection enables high carrier mobilities (∼190 cm2V−1s−1) and observation of resonant tunnelling. Density functional theory calculations provide insights into quantum transport and properties of the WS2-indium interface. Our results reveal significant advances towards high-performance WS2 devices using indium alloy contacts.
@article{arxiv.2102.02489,
title = {Quantum Transport in Two-Dimensional WS$_2$ with High-Efficiency Carrier Injection Through Indium Alloy Contacts},
author = {Chit Siong Lau and Jing Yee Chee and Yee Sin Ang and Shi Wun Tong and Liemao Cao and Zi-En Ooi and Tong Wang and Lay Kee Ang and Yan Wang and Manish Chhowalla and Kuan Eng Johnson Goh},
journal= {arXiv preprint arXiv:2102.02489},
year = {2021}
}