Building a cm²scale CVD graphene-based gas sensor: modelling the kinetic with a three-site adsorption/desorption...

Area of Science:

• Materials Science
• Chemical Engineering
• Nanoscience

Background:

• Graphene's unique electronic properties make it promising for gas sensing applications.
• Existing graphene gas sensors often suffer from slow response times and limited selectivity.
• Developing scalable fabrication methods for high-performance graphene sensors is crucial.

Purpose of the Study:

• To develop and characterize a sensitive and selective centimeter-squared scale graphene-based gas sensor.
• To investigate the sensor's performance for nitrogen dioxide (NO2) detection.
• To propose a novel modeling approach to understand and improve sensor kinetics.

Main Methods:

• Fabrication of sensors using monolayer chemical vapor deposition (CVD) graphene, photolithography, and layer transfer.
• Characterization of graphene ribbons using optical microscopy, Atomic Force Microscopy (AFM), micro-Raman spectroscopy, and electrical measurements.
• Gas sensing characterization with 200 ppm NO2 exposure and response modeling using a three-site adsorption/desorption Langmuir model.

Main Results:

• Successful fabrication and characterization of reproducible graphene ribbons.
• Demonstration of sensor response to NO2 exposure.
• Development of a novel Langmuir model to describe sensor response kinetics.

Conclusions:

• The developed fabrication process ensures good reproducibility for graphene-based sensors.
• The novel Langmuir model provides insights into sensor kinetics, potentially addressing slow response times.
• This work advances the development of high-performance graphene gas sensors for practical applications.