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

Abstract

In the present investigation, electron beam-influenced modifications on the CO gas sensing properties of indium doped ZnO (IZO) thin films were reported. Dose rates of 5, 10, and 15 kGy were irradiated to the IZO nano films while maintaining the In doping concentration to be 15 wt%. The wurtzite structure of IZO films is observed from XRD studies post electron beam irradiation, confirming structural stability, even in the intense radiation environment. The surface morphological studies by SEM confirms the granular structure with distinct and sharp grain boundaries for 5 kGy and 10 kGy irradiated films whereas the IZO film irradiated at 15 kGy shows the deterioration of defined grains. The presence of defects viz oxygen vacancies, interstitials are recorded from room temperature photoluminescence (RTPL) studies. The CO gas sensing estimations were executed at an optimized operating temperature of 300 °C for 1 ppm, 2 ppm, 3 ppm, 4 ppm, and 5 ppm. The 10 kGy treated IZO film displayed an enhanced sensor response of 2.61 towards low concentrations of 1 ppm and 4.35 towards 5 ppm. The enhancement in sensor response after irradiation is assigned to the growth in oxygen vacancies and well-defined grain boundaries since the former and latter act as vital adsorption locations for the CO gas.

Preparation of Antimony Tin Oxide Thin Film Using Green Synthesized Nanoparticles by E-Beam Technique for NO2 Gas Sensing

“…Further, the summary of NO 2 gas sensor performance parameters developed by various researchers is listed in Table 1. As mentioned in Table 1, the response of the WO 3 nanomaterial-based gas sensor prepared by [13] using the thermal evaporation method exhibited a response of four at an operating temperature of 250 • C. A SrTi 0.85 Fe0 0.15 O 3 nanomaterial-based gas sensor prepared by [14] using an E-beam evaporation method exhibited a response of four with a response/recovery time of 15 s/35 s at an operating temperature of 260 • C. A Pd:MoO 3 nanomaterial-based gas sensor prepared by [15] using the chemical spray pyrolysis method exhibited a response of 5.5% with a response/recovery time of 11 s/76 s at an operating temperature of 200 • C towards 5 ppm of NO 2 gas. However, this work utilized green synthesized ATO nanoparticles, and their thin films were prepared by the E-beam evaporation method for the development of a NO 2 gas sensor which exhibited a response of 16.20 with a response/recovery time of 285 s/510 s at an operating temperature of 200 • C towards 4.8 ppm of NO 2 gas.…”