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arXiv · 2102.02489

Quantum Transport in Two-Dimensional WS$_2$ with High-Efficiency Carrier Injection Through Indium Alloy Contacts

Chit Siong Lau·Jing Yee Chee·Yee Sin Ang·Shi Wun Tong·Liemao Cao·Zi-En Ooi·Tong Wang·Lay Kee Ang·Yan Wang·Manish Chhowalla·Kuan Eng Johnson Goh
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Abstract

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 WS$_2$ devices with indium alloy contacts. The devices exhibit low contact resistances and Schottky barrier heights (\sim10 k$\Omega$\si{\micro\metre} at 3 K and 1.7 meV). Efficient carrier injection enables high carrier mobilities ($\sim$190 cm$^2$V$^{-1}$s$^{-1}$) and observation of resonant tunnelling. Density functional theory calculations provide insights into quantum transport and properties of the WS$_2$-indium interface. Our results reveal significant advances towards high-performance WS$_2$ devices using indium alloy contacts.

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Chit Siong Lau, Jing Yee Chee, Yee Sin Ang, Shi Wun Tong, Liemao Cao, Zi-En Ooi, Tong Wang, Lay Kee Ang, Yan Wang, Manish Chhowalla, Kuan Eng Johnson Goh. 2021-02-04. Quantum Transport in Two-Dimensional WS$_2$ with High-Efficiency Carrier Injection Through Indium Alloy Contacts. https://doi.org/10.1021/acsnano.0c05915

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