Three-Dimensional ZnO Nanostructure Based Gas and Humidity Sensors.

The ZnO nanostructure environmental sensors were prepared via the three-dimensional through silicon via (3D-TSV) technique. For 3D-TSV, the diameter and length of the Si via were about 200 and 400 μm, respectively. For nitrogen oxide (NO), the measured responses were around ~12, ~16, and ~20% when the concentrations of the injected NO gas were 20, 40 and 60 ppm, respectively. For humidity and temperature sensing, the measured nanowire current increased logarithmically with increasing chamber temperature. The response to relative humidity increased with increasing temperature.