Effect of additives on the properties of printed ITO sensors

The effects of additives on the methane gas sensing performance of printed indium tin oxide (ITO) sensor have been investigated. Room temperature gas sensing of ITO sensor has been achieved under the methane flow of 100 ppm. To improve the sensor performance, Ag and carbon nanotube (CNT) were chosen as an additive, and simply incorporated into the printing paste in the form of mixture. Increase of sensitivity (40-times) was dominant for the ITO+Ag sensor, while improved response performance (50%) was achieved from the ITO+CNT sensor. The most advanced performance has achieved from the ITO+(Ag, CNT) sensor. Ag and CNT co-incorporation results in 652-times large sensitivity and 88% fast response time in compare to the pure ITO sensor under the same test conditions.