Inkjet-Printed MoS₂ Transistors with Predominantly Intraflake Transport.

Area of Science:

• Materials Science
• Nanotechnology
• Electronics Engineering

Background:

• 2D semiconductors like transition metal dichalcogenides (TMDs) offer unique properties for electronics, including suitable bandgaps and mechanical flexibility.
• Solution-processed TMD nanosheets are promising for low-temperature fabrication on diverse substrates.
• Poor inter-flake transport in conventional 2D-TMD networks limits device performance.

Purpose of the Study:

• To overcome inter-flake transport limitations in 2D-TMD transistors.
• To demonstrate high-performance, fully printed field-effect transistors (FETs) using molybdenum disulfide (MoS2) nanosheets.
• To explore subthermionic transport mechanisms and device feasibility for printed electronics.

Main Methods:

• Fabrication of narrow-channel MoS2 field-effect transistors (FETs) using electrolyte-gating.
• Implementation of a printing technique with an additional metal layer to shorten effective channel lengths.
• Characterization of device performance, including current saturation, on-off ratio, and subthreshold slope.

Main Results:

• Achieved high current saturation (>310 µA µm⁻¹) and on-off ratio (>10⁶) in printed MoS2 FETs.
• Demonstrated predominant intraflake transport by reducing effective channel lengths.
• Observed subthermionic transport with a low subthreshold slope (7.5 mV dec⁻¹).
• Presented thermionic MOSFETs and fully printed NMOS inverters.

Conclusions:

• The developed printing approach effectively overcomes transport limitations in 2D-TMD network transistors.
• The generic method using chemically exfoliated nanosheet inks enables fully printed 2D-TMD electronics with high yield.
• This work highlights the potential for large-scale, low-cost manufacturing of flexible electronic devices.