Scalable high performance radio frequency electronics based on large domain bilayer MoS₂.

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Atomically-thin layered molybdenum disulfide (MoS2) is a promising material for electronics.
• Bilayer MoS2 is predicted to offer superior electron mobility and density of states compared to single-layer MoS2.
• Flexible electronics demand high-performance semiconductor materials.

Purpose of the Study:

• To synthesize high-quality bilayer MoS2 with large domain sizes using chemical vapor deposition.
• To fabricate and characterize high-performance transistors and radio frequency devices based on bilayer MoS2.
• To evaluate the potential of bilayer MoS2 for flexible high-frequency electronics.

Main Methods:

• Chemical vapor deposition (CVD) on molten glass to grow bilayer MoS2.
• Fabrication of field-effect transistors (FETs) with optimized high-κ dielectrics.
• Electrical characterization of transistors at various temperatures (300 K and 4.3 K).
• Demonstration of radio frequency (RF) transistors and mixers.

Main Results:

• Achieved synthesis of high-quality bilayer MoS2 with domain sizes up to 200 μm.
• Demonstrated transistors with high ON-currents: 427 μA/μm at 300 K and 1.52 mA/μm at 4.3 K.
• Fabricated RF transistors with a high cut-off frequency of 7.2 GHz and maximum frequency of oscillation of 23 GHz.
• Developed gigahertz MoS2 mixers on flexible polyimide substrates.

Conclusions:

• High-quality bilayer MoS2 can be synthesized using CVD for advanced electronic applications.
• Bilayer MoS2 transistors exhibit excellent DC and RF performance, suitable for high-frequency electronics.
• The demonstrated flexible MoS2 devices highlight their potential for next-generation flexible electronic systems.