WS2 Transistors with Sulfur Atoms Being Replaced at the Interface: First-Principles Quantum-Transport Study
Chih-Hung Chung1, Hong-Ren Chen1, Meng-Ju Ho1
1Department of Electronics and Electrical Engineering and Institute of Electronics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan.
ACS Omega
|March 27, 2023
Summary
Researchers developed novel sulfur-replaced edge contacts for two-dimensional transistors. This method significantly lowers contact resistance in WS2 transistors, paving the way for improved electronic devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Reducing contact resistance is crucial for advancing two-dimensional (2D) material-based transistors.
- High Schottky barriers at metal-semiconductor interfaces impede device performance.
Purpose of the Study:
- To investigate novel partially sulfur-replaced edge contacts (metal/WSX/WS2) for lowering Schottky barrier height.
- To reduce contact resistance in 2D material transistors.
Main Methods:
- First-principles quantum-transport calculations.
- Ab initio molecular dynamics simulations.
- Analysis of interface metallization and bonding in WSX/WS2 systems.
Main Results:
- Partially sulfur-replaced WSX (X = P, As, F, Cl) segments were created by substituting sulfur atoms with group V or halogen elements.
- Achieved low contact resistances of 142 Ω·μm for p-type Pt/WSP/WS2 and 173 Ω·μm for n-type Ti/WSCl/WS2 edge contacts.
- Demonstrated the stability of standalone WSX monolayers at room temperature via molecular dynamics.
Conclusions:
- Partially sulfur-replaced edge contacts effectively reduce Schottky barriers and contact resistance in WS2 transistors.
- The WSX buffer layer offers a promising strategy for high-performance 2D electronic devices.
- Stable WSX monolayers open possibilities for novel material applications.
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