Synthesis and field emission of four kinds of ZnO nanostructures: nanosleeve-fishes, radial nanowire arrays, nanocombs and nanoflowers

Four different hierarchical ZnO nanostructures, including nanosleeve-fishes, radial nanowire arrays, nanocombs and nanoflowers, have been successfully fabricated through thermal chemical vapour deposition by adjusting the source temperature and the gas flow rate. Field emission measurements of these nanostructures showed a high emission current density and a low turn-on field of 1.3, 1.9, 2.5 and 3.4 V μm −1 in sequence, which is comparable to that of one-dimensional ZnO nanostructures and carbon nanotubes. The good performance for field emission makes the hierarchical ZnO nanostructures promising candidates for further applications in field emission microelectronic devices.