High sensitivity of a ZnO nanowire-based ammonia gas sensor with Pt nano-particles

We report the growth of high-density single crystalline ZnO nanowires on a patterned ZnO:Ga/SiO2/Si template, the adsorption of Pt nano-particles on the nanowire surface, and the fabrication of a ZnO nanowire-based NH3 gas sensor. It was found that the sensor responses were 22.5% and 36% for the nanowires without and with Pt adsorption when the chamber was injected with 1000 ppm of NH3 gas at 300 °C. With Pt adsorption, it was found that the measured sensitivities were around 16%, 22%, 26% and 36% when the concentration of the injected NH3 gas was 100, 200, 500 and 1000 ppm, respectively.