High Current Gain MoS₂ Bipolar Junction Transistor Based on Metal-Semiconductor Schottky Contacts

Area of Science:

• Materials Science
• Condensed Matter Physics
• Electrical Engineering

Background:

• Two-dimensional (2D) semiconductors show promise for electronics but are underexplored in bipolar junction transistors (BJTs).
• Field-effect transistors based on 2D materials are widely studied, but BJT applications lag behind.
• High-power electronics rely heavily on BJTs, creating a need for advanced materials.

Purpose of the Study:

• To demonstrate high-gain BJTs utilizing 2D semiconductors.
• To explore the application of molybdenum disulfide (MoS2) in BJT devices.
• To investigate Schottky contacts for BJT functionality in 2D materials.

Main Methods:

• Fabrication of MoS2-based BJTs using metal-semiconductor Schottky contacts.
• Utilizing thermal ionization at the emitter-base Schottky junction for electron emission.
• Employing the collector-base Schottky barrier for electron collection.
• Analyzing device performance through current gain measurements.

Main Results:

• Achieved a common-base current gain of 0.99.
• Demonstrated a high common-emitter current gain of 1967.
• Reported the highest performance for BJTs based on 2D semiconductors to date.
• Showcased performance comparable to traditional silicon-based BJTs.

Conclusions:

• MoS2 BJTs based on Schottky contacts offer a viable pathway for high-performance 2D electronic devices.
• The demonstrated device performance rivals that of established silicon BJTs.
• This work opens new avenues for 2D materials in high-power electronic applications.