An 8 MeV Electron Beam Modified In:ZnO Thin Films for CO Gas Sensing towards Low Concentration

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Sensing

Background:

• Indium-doped zinc oxide (IZO) is a promising material for gas sensors.
• Electron beam irradiation is explored as a method to modify material properties.

Purpose of the Study:

• To investigate the effect of electron beam irradiation on the CO gas sensing properties of IZO thin films.
• To determine the optimal irradiation dose for enhanced sensor performance.

Main Methods:

• IZO thin films with 15 wt% In doping were prepared.
• Films were irradiated with electron beams at doses of 5, 10, and 15 kGy.
• X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Room Temperature Photoluminescence (RTPL) were used for characterization.
• CO gas sensing was evaluated at 300 °C for concentrations ranging from 1 to 5 ppm.

Main Results:

• Electron beam irradiation maintained the wurtzite structure of IZO films.
• SEM revealed distinct grain boundaries for 5 and 10 kGy irradiation, with deterioration at 15 kGy.
• RTPL indicated an increase in oxygen vacancies and interstitials post-irradiation.
• The 10 kGy irradiated IZO film showed enhanced sensor response (2.61 at 1 ppm, 4.35 at 5 ppm).

Conclusions:

• Electron beam irradiation, particularly at 10 kGy, effectively enhances CO gas sensing in IZO films.
• Increased oxygen vacancies and improved grain boundary definition are key factors for the enhanced sensor response.
• IZO films are robust in radiation environments and show potential for improved gas sensing applications.