Ionic-Liquid Free and Flexible Transistors Made of 2D Material Inks

Area of Science:

• Materials Science
• Nanotechnology
• Electronics Engineering

Background:

• Thin-film transistors (TFTs) using 2D materials are key for advanced electronics.
• Current high-performance 2D TFTs rely on ionic-liquid gating (ILG), which has practical limitations.
• Existing fabrication methods often use harsh conditions unsuitable for flexible electronics.

Purpose of the Study:

• To demonstrate the first ionic-liquid gating-free, all-2D-material TFT on a flexible substrate.
• To establish a scalable, low-cost, solution-processable platform for flexible electronics.
• To overcome the limitations of ILG and harsh fabrication conditions.

Main Methods:

• Utilized water-based inks of graphene and hexagonal boron nitride (h-BN) for printing electrodes and dielectrics.
• Employed supramolecular interfacial self-assembly for creating uniform MoS2 channel films.
• Fabricated TFTs on flexible substrates using a low-temperature, solution-based process.

Main Results:

• Achieved operating voltages below 3 V with negligible leakage current.
• Demonstrated field-effect mobilities up to 0.46 cm² V⁻¹ s⁻¹ (2.47 cm² V⁻¹ s⁻¹ with silver electrodes) under ambient conditions.
• Confirmed excellent mechanical flexibility and transferability of 2D material films.

Conclusions:

• This work presents a viable, scalable platform for practical flexible electronics using 2D materials.
• The developed method avoids ILG and harsh fabrication conditions, enabling wider applications.
• The all-2D-material TFTs meet practical requirements for low-cost, flexible electronic devices.