ZnS nanowires were synthesized in order to investigate NO 2 gas sensing properties. They were grown on the sapphire substrate using ZnS powders. SEM (scanning electron microscopy) showed the diameter and length of the ZnS nanowires were approximately in the range of 50 -100 nm and a few 10s µm, respectively. They were also found to be composed of Wurtzite-structured single crystals from TEM (transmission electron microscopy) analysis. NO 2 gas sensing performance of the ZnS nanowire was

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... with electrical resistance changes caused by NO 2 gas with a concentration of 1-5ppm. The sensor was UV treated with an intensity of 1.2 mW/cm 2 to facilitate charge carrier transfer. The responses of the ZnS nanowires to the NO 2 gas at room temperature, treated with UV of two different wavelengths of 365 nm and 254 nm, are measured to be 124. 53 -206.87 % and 233.97 -554.83%, respectively. In the current work, the effect of UV treatment on the gas sensing performance of the ZnS nanowires was studied. And the underlying mechanism for the electrical resistance changes of the ZnS nanowires by NO 2 gas was also discussed.