On-chip fabrication of SnO2-nanowire gas sensor: The effect of growth time on sensor performance

In this works, we report on the on-chip fabrication of SnO2-nanowire gas sensors by selective growth of the nanowires on Pt interdigitated at different grown time lengths. The gas-sensing properties of the on-chip fabricated sensors were characterized using liquefied petroleum gas (LPG) and NH3 gas at different operating temperatures. The effect of growth time on sensor performances was systematically investigated and reported. In addition, the influence of nanowire diameter and nanowire film thickness on gas sensor performance was also studied for thick film nanowire sensors fabricated by a screen-printing method to elucidate the sensing mechanisms of nanowire-based sensors. The results reveal that the diameter of SnO2 nanowires and their film thickness increased with increasing growth time. The response of the on-chip fabricated SnO2-nanowire sensors varied from 1.4 to 21.8 with respect to the growth time, which was varied from 15 to 60 min. The increase of the sensor response with increasing growth time was attributed to the enhancement of wire–wire contact densities.