Morphology and field emission from ZnO nanowire arrays synthesized at different temperature

Three kinds of ZnO nanowire arrays were fabricated on Au coated (1 1 0)silicon wafer by using of heating the mixture of zinc oxide (ZnO) and graphite powders at various depositing temperature. The synthesized samples were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analytic technology, respectively. Structural analyses revealed that the morphologies and crystal microstructures of ZnO nanoarrays were related with the substrate temperature. And control to the growth morphologies can be achieved by carefully tuning the depositing temperature. The testing results to different nanowire arrays showed that the properties of field emission follow the Fowler–Nordheim law. The quais-aligned ZnO nanowire array sample synthesized at 750 °C had the lowest turn-on field of 7.4 V/μm, highest β of 1028. This largest emission efficiency is attributed to the clear tip and appropriate coverage density. As well as the nanowires are straight with long length and parallel to each other with good crystal quality. The experimental results could be very useful for field emission materials and other nanoelectronics device applications.