Development of Indium Titanium Zinc Oxide Thin Films Used as Sensing Layer in Gas Sensor Applications

Abstract

InTiZnO gas sensors with different oxygen ratios were fabricated by RF sputtering at room temperature. The sensing responses for five different gases, including ethanol, isopropanol (IPA), acetone (ACE), CO, and SO2, were reported. The InTiZnO gas sensor with the MSM (metal–semiconductor–metal) structure generated a higher sensing response when the O2/Ar ratio was increased to 10%. It also revealed high selectivity among these gases and good repeatability. Moreover, the UV light-activated InTiZnO gas sensors were also studied, which could reduce the operating temperature from 300 °C to 150 °C and did not seem to damage the sensing film, demonstrating long-term stability. The high response and selectivity revealed that InTiZnO thin films possess high potential to be applied in gas sensing technology.