ZnO nanorods based ultra sensitive and selective explosive sensor

A small scale (20 μm), ultra sensitive (50 ppb) and highly selective sensor based on ZnO nanostructures using Micro-electro-mechanical system (MEMS) platform has been reported here for the detection of explosive and Volatile Organic Compound (VOC) vapors. Flower and rod like architectures of nanorods were used as a sensing layer. The nanorods prepared via chemical synthesis were uniform with diameters of 50-80 nm and lengths about 3-4 μm. X-ray diffraction (XRD) and Scanning electron microscopy (SEM) reveal that the nanostructures are well oriented with the c-axis, perpendicular to the substrate. A relatively higher selectivity for 2, 4, 6-Trinitrotoluene (TNT) vapors compared to other VOCs at room temperature were observed. The intensity of deep level green emission peak associated with point defects decreases after exposure as revealed from Photoluminescence (PL) spectra.