Synthesis of In2O3 Nanowires 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.