Effect of air-pressure on room temperature hydrogen sensing characteristics of nanocrystalline doped tin oxide MEMS-based sensor.

Nanocrystalline indium oxide (In2O3)-doped tin oxide (SnO2) thin film sensor has been sol-gel dip-coated on a microelectrochemical system (MEMS) device using a sol-gel dip-coating technique. Hydrogen (H2) at ppm-level has been successfully detected at room temperature using the present MEMS-based sensor. The room temperature H2 sensing characteristics (sensitivity, response and recovery time, and recovery rate) of the present MEMS-based sensor has been investigated as a function of air-pressure (50-600 Torr) with and without the ultraviolet (UV) radiation exposure.