High-performance ethanol sensing based on an aligned assembly of ZnO nanorods

We report fabrication and characterization of an ethanol sensor using aligned ZnO nanorods. The ZnO nanorods have an average diameter of 50 nm and an average length of 0.5 μm. The sensor response Ra/Rg, where Ra and Rg are the resistance in air and in ethanol vapor, respectively, is about 10 to 1 ppm ethanol, and increases to about 100 as the ethanol concentration is raised to 100 ppm. The mechanism of the highly sensitive ethanol detection is discussed.