Nonlinear electronic devices on single-layer CVD graphene for thermistors

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Graphene's unique electronic properties are highly sought after for novel electronic devices.
• Developing cost-effective and efficient electronic components remains a key challenge in materials science.

Purpose of the Study:

• To create simple, cost-effective, passive electronic devices utilizing single-layer chemical vapor deposited (CVD) graphene.
• To demonstrate nonlinear and asymmetric current-voltage characteristics (CVCs) in graphene-based devices for sensing applications.

Main Methods:

• Fabrication of devices using single-layer (SL) CVD graphene with Al2O3-Ti-Au contacts.
• Characterization of current-voltage characteristics (CVCs) at ambient temperatures.
• Evaluation of thermoelectric and thermoresistive sensing capabilities across a range of temperatures (4 K - 300 K) and voltages (±200 mV to ±4 V).

Main Results:

• Achieved nonlinear and asymmetric CVCs due to nonlinear resistance from specific contacts.
• Demonstrated high graphene mobility (6200 cm2V-1S-1) on polyethylene terephthalate.
• Observed thermoelectric and thermoresistive effects, showing voltage and temperature changes correlated with electronic power and resistance.

Conclusions:

• Developed stable, flexible, and cost-effective graphene-based devices suitable for thermoelectric and thermoresistive sensing.
• Highlighted the potential for integration into complementary metal-oxide semiconductor (CMOS) interfaces and wearable electronics.
• Demonstrated a strong negative temperature coefficient of resistance for NTC thermistor applications.