Proton-beam engineered surface-point defects for highly sensitive and reliable NO₂ sensing under humid environments

Area of Science:

• Materials Science
• Chemical Sensing
• Surface Science

Background:

• Humidity interference significantly limits the accuracy of semiconductor metal-oxide gas sensors.
• Water molecules deactivate active sites on metal oxide surfaces, hindering gas adsorption and detection.

Purpose of the Study:

• To develop a novel method for engineering surface-point defects to improve gas sensor performance.
• To simultaneously enhance target gas response and humidity tolerance in metal-oxide gas sensors.

Main Methods:

• Facile surface-point defect engineering using proton-beam irradiation.
• Surface analysis techniques and Density Functional Theory (DFT) calculations to investigate defect mechanisms.
• Fabrication and testing of proton-beam irradiated metal-oxide gas sensors.

Main Results:

• Proton-beam irradiation successfully engineered surface-point defects on ZnO surfaces.
• The irradiated sensor exhibited an enhanced response to nitrogen dioxide (NO2).
• The sensor demonstrated significant tolerance to humidity interference during NO2 detection.

Conclusions:

• Proton-beam induced point defects promote preferential adsorption of NO2 over H2O molecules.
• This approach enables improved NO2 detection with reduced humidity interference, paving the way for practical gas sensors.