Synthesis of indium oxide nanowires on quartz substrate for gas sensor

Abstract

ABSTRACT In this paper, Indium oxide nanowires (In2O3 NWs) were successfully synthesized on quartz substrate pre-coated with gold nanoparticles (Au NPs) using chemical vapor deposition (CVD). The nanowires were characterized via x-ray diffraction (XRD), scanning electron microscope (SEM), Ultraviolet-Visible (UV-VIS) spectrophotometer. The sputtered of Au NPs on quartz were analyzed by atomic force microscopy (AFM). The structural, morphological, and optical properties were investigated. The XRD structure reviled a single crystal, with cubic crystal, with preferred orientation along (222). The SEM revealed nanowires growth. The obtained band gap value of 3.6 eV confirmed the formation of In2O3 nanostructures. Regarding to the characteristics of In2O3 NWs, it was fabricated as an ethanol gas sensor at 10-1500 ppm and an optimized temperature of 210 oC. The minimum ethanol gas response of Ra/Rg = 1.6 was obtained at a concentration of 10 ppm. The corresponding response and recovery time were achieved at the lowest concentration of 10 ppm is 10 s and 10 s respectively. So, the In2O3 NWs film synthesized via CVD can be considered as a good ethanol gas sensor device at low concentration. In2O3 NWs growth and gas sensing mechanism were also explained.