Conduction Mechanisms in CVD-Grown Monolayer MoS2 Transistors: From Variable-Range Hopping to Velocity Saturation

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Monolayer molybdenum disulfide (MoS2) is a promising 2D material for next-generation electronics.
• Understanding charge transport mechanisms in MoS2 is crucial for device optimization.

Purpose of the Study:

• To fabricate and characterize transistors using chemical vapor deposition (CVD)-grown monolayer MoS2.
• To investigate the electrical transport properties and identify limiting factors in MoS2 transistors.

Main Methods:

• Fabrication of transistors from CVD-grown monolayer MoS2 crystals.
• Electrical characterization of current-voltage (I-V) behavior at varying drain voltages (Vd).
• Analysis of low-field mobility and high-field transport phenomena.

Main Results:

• Demonstrated excellent current saturation at large drain voltages (Vd).
• Identified electron mobility limited by charged impurity scattering at low fields.
• Observed variable range hopping at low Vd and velocity saturation at higher Vd.

Conclusions:

• Monolayer MoS2 exhibits significant potential as a channel-replacement material in transistors.
• Multiple transport phenomena, including impurity scattering and hopping, govern MoS2 transistor performance.
• Further research can focus on mitigating scattering and optimizing MoS2 for enhanced electronic applications.