Stable field emission from rose-like zinc oxide nanostructures synthesized through a hydrothermal route

ZnO nanomaterial, which had rose-like structure, has been synthesized in a high yield through a hydrothermal route on a copper plate substrate. The rose-like structures were assembled by tens of uniform hexagonal ZnO nanosheets, with thicknesses raging from 150 to 250 nm. Field emission (FE) plots of the rose-like structures showed low turn-on fields of 1.60-2.78 V/μm and threshold fields of 5.38-7.42 V/μm at sample-anode distances of 200-400 μm. The field emission of the zinc oxide rose-like structures exhibited good stability. The fluctuation of FE current with density of 750 μA/cm² was less than 5% over 12 h. The low turn-on and threshold fields and the small fluctuation of current indicate this rose-like ZnO nanostructure can be employed as promising field emitters.