UV-illumination and Au-nanoparticles enhanced gas sensing of p-type Na-doped ZnO nanowires operating at room temperature

High density p-type Na-doped ZnO nanowires were uniformly grown on glass substrate via the hydrothermal method, and then examined by SEM, XRD, PL, XPS, and TEM analysis. The p-type characteristic of the nanowires was verified through Hall and humidity measurements. 2∼6 nm Au nanoparticles were sputtered on the nanowires to fabricate a room temperature sensor and strengthen its p-type property, which was enhanced by the Schottky barrier at Au NPs/ZnO interface. The p-type gas sensor has a high response, sensitivity and selectivity under UV illumination at room temperature.