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Ohmic Contact Fabrication Using a Focused-ion Beam Technique and Electrical Characterization for Layer Semiconductor Nanostructures
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Spatial defects nanoengineering for bipolar conductivity in MoS2.
Xiaorui Zheng1, Annalisa Calò1,2, Tengfei Cao3,4
1Tandon School of Engineering, New York University, 6 MetroTech Center, New York, NY, 11201, USA.
Nature Communications
|July 12, 2020
Summary
Researchers precisely controlled defects in molybdenum disulfide (MoS2) using thermochemical scanning probe lithography (tc-SPL). This technique enables on-demand p- or n-type doping for advanced electronic devices.
Area of Science:
- Materials Science
- Nanotechnology
- Condensed Matter Physics
Background:
- Two-dimensional transition metal dichalcogenides are crucial for next-generation electronics.
- Controlling defects in these materials is key to tailoring their electronic properties.
Purpose of the Study:
- To demonstrate nanoscale control over defects in monolayer molybdenum disulfide (MoS2).
- To achieve on-demand p-type and n-type doping for fabricating electronic devices.
Main Methods:
- Integration of thermochemical scanning probe lithography (tc-SPL) with a flow-through reactive gas cell.
- Utilizing X-ray photoelectron spectroscopy, scanning transmission electron microscopy, and density functional theory for characterization.
Main Results:
- Achieved precise sub-micrometer spatial control of defects in MoS2.
- Demonstrated on-demand p-type doping (via HCl/H2O) and n-type doping (via N2).
- Fabricated field-effect transistors and p-n junctions with a rectification ratio exceeding 104.
Conclusions:
- Thermochemical scanning probe lithography offers precise defect engineering in 2D materials.
- Defect-induced doping in MoS2 can be controlled by reactive gas environments.
- Protruding covalent S-S bonds are linked to p-type doping, while N2 treatment leads to n-character.
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