NO gas sensing properties of ZnO wire-like thin films synthesized by thermal oxidation of sputtered Zn metallic films in air

We investigated the NO gas sensing properties of the ZnO wire-like films synthesized by thermal oxidation of sputtered Zn metallic films in dry air. Morphological characterization revealed that we synthesized polycrystalline wurtzite ZnO films of a wire-like nanostructure with a width of 100-150 nm and a length of several microns. It was found from the gas sensing measurements that the ZnO wire-like films showed a significantly high sensitivity with a maximum sensitivity of 57.6 for 2 ppm NO at 200°C as well as a reversible fast response to NO with a very low detection limit of 50 ppb. These results suggest that the ZnO wire-like films can be used as the gas sensing materials for low-cost and high-performance NO gas sensors.