Gas-sensing properties of ITO materials with different morphologies prepared by sputtering

Indium tin oxide (ITO) materials with different morphologies have been fabricated via sputtering technology by adjusting the oxygen flow rate and RF-power. The repeatable and controllable growth conditions of different ITO materials have been achieved. The gas sensors with different ITO materials were fabricated on ceramic tube directly, which have the characteristics of low cost and simple preparation process. Through our analysis, the nanowires have larger specific surface area, more oxygen vacancies and an oriented electron transport channel. The sensor made by nanowires was the best one, and the value of sensitivity run up to 235.6 at the ethanol gas concentration of 400 ppm under 250 °C.The gas sensing properties of the whole ITO material system to ethanol gas were studied. The difference of gas sensing properties is explained by calculating the surface adsorption energy of ITO materials with different morphologies based on first-principle calculation method. These results provide guidance for the application of ITO materials in the field of gas sensors.