Microstructure and gas-sensing properties of thick film sensor using nanophase SnO2 powder

The object of the present work apply the nanophase SnO2 powder synthesized by inert gas condensation method (IGC) to thick film hydrogen sensor and to study the effect of microstructural changes of sensors on the sensing properties. SnO2 gas sensors were printed using nanophase SnO2 powder without any doping element by a silk screen printing method and subsequently sintered. Among the thick film sensors manufactured at various temperatures, the highest sensitivity was obtained in the sensor sintered at 600 °C, which exhibited its maximum sensitivity of 96% at 250 °C against the hydrogen concentration of 2500 ppm. The results were discussed in viewpoint of the pore structure and the crystallinity of the sensors.