NOx gas response characteristics of thin film mixed oxide semiconductor

Many metal oxide gas sensors have been developed for improving stability during last several decades. In this paper, we proposed the hot-wire type micro-gas sensor with single electrode for improving sensitivity and stability. This type sensor has only a single electrode by forming a sensing material onto Pt heater so the resistance of the single electrode is very low for parallel values of Pt heater resistor and sensing materials of mixed oxide semiconductor. Mixed oxide (Sn–In)O + Pt with various composition Sn–In = 1:1, 2:1, 5:1 and 10:1 for sensing materials were prepared. The fabricated sensor showed high sensitivity for NOx at low gas concentration and good selectivity for CO and HC gases.