Synthesis of In2O3Nanowires and Their Gas Sensing Properties

This paper presents the synthesis of In ₂ O ₃ nanowires (NWs) through the vapor-liquid-solid growth mechanism and the fabrication of an In ₂ O ₃ NW ethanol gas sensor. It was found that the 1-D In ₂ O ₃ NWs could only be grown at temperatures higher than 850 °C. It was also found that the average length increased while the average diameter decreased as the growth temperature increased. For the fabricated gas sensors, the response (R _a /R _g ) was 1.84, 3.78, and 13.97 for the samples thermally treated at 900 °C, 950 °C, and 1000 °C, respectively, at the operating temperatures of 300 °C with 100 ppm ethanol. Disregard the sensitivity, the In ₂ O ₃ nanowires could be measured at 25 °C to 300 °C. Furthermore, it was found that the fabricated device was much more sensitive to ethanol gas, compared with methanol and acetone gases.