Subthreshold Current Suppression in ReS₂ Nanosheet-Based Field-Effect Transistors at High Temperatures

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Two-dimensional rhenium disulfide (ReS2) is a transition-metal dichalcogenide with promising applications in electronics.
• Field-effect transistors (FETs) based on ReS2 are being explored for devices like photodetectors and memory.

Purpose of the Study:

• Investigate the suppression of subthreshold current in ReS2 FETs.
• Analyze the resulting inversion of hysteresis in transfer characteristics.
• Determine the influence of temperature, sweeping gate voltage, and pressure on this phenomenon.

Main Methods:

• Fabrication and characterization of ReS2 nanosheet-based FETs.
• Electrical measurements of transfer characteristics under varying conditions (temperature, gate sweep, pressure).
• Analysis of gate current behavior in conjunction with drain current suppression.

Main Results:

• Forward voltage gate sweep suppresses subthreshold current in ReS2 FETs.
• This suppression leads to an anticlockwise hysteresis, inverting the typical clockwise behavior.
• Current suppression correlates with a gate current peak, dependent on temperature but not pressure.
• Thermal-assisted tunneling through gate oxide traps is identified as the mechanism.

Conclusions:

• The charge/discharge of gate oxide traps via thermal-assisted tunneling explains the observed current suppression and hysteresis inversion.
• High-temperature operation of ReS2 FETs can reduce power consumption.
• This study extends the potential operational temperature range for ReS2 nanosheet-based FETs.