Edge-Passivated Monolayer WSe₂ Nanoribbon Transistors

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Physics

Background:

• Transistor scaling faces limitations from surface and edge states at the nanoscale.
• Two-dimensional (2D) semiconductors, such as transition metal dichalcogenides (TMDs), offer dangling-bond-free surfaces but suffer from edge state disorder.
• This disorder impedes the performance of width-scaled 2D transistors.

Purpose of the Study:

• To develop and demonstrate a facile edge passivation technique for monolayer WSe2 nanoribbons.
• To enhance the electrical properties and material quality of these nanoribbons.
• To assess the potential of this method for manufacturing beyond-silicon electronic devices.

Main Methods:

• Fabrication of monolayer WSe2 nanoribbons using nanolithography.
• Edge passivation using a controlled remote O2 plasma process to form amorphous WOxSey.
• Characterization through scanning transmission electron microscopy, optical spectroscopy, and field-effect transistor (FET) transport measurements.

Main Results:

• Passivation effectively minimized edge disorder in WSe2 nanoribbons.
• Passivated-edge nanoribbon FETs showed a 10 ± 6 times higher field-effect mobility compared to unpassivated ones.
• The amorphous WOxSey layer improved the overall material quality of the nanoribbons.

Conclusions:

• Edge passivation is a viable strategy to overcome performance limitations in 2D nanoribbon transistors.
• The demonstrated oxidation-based method is simple, effective, and suitable for scalable manufacturing.
• This technique holds promise for advancing TMD-based electronics and optoelectronics beyond current silicon technology.