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

Abstract

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.

Semi-circular shaped ZnO nanowhiskers assemblies deposited using an aqueous solution

“…ZnO is being explored for application as a transparent conductive oxide for gas sensors [1], varistors [2], piezoelectric devices [3], transistors [4], light-emitting diodes [5], field emission flat panel displays [6] and photodiodes [7]. Techniques such as spray pyrolysis [8], chemical vapor deposition (CVD) [9], sol-gel process [10][11][12][13], sputtering techniques [14,15], chemical deposition [16], electrodeposition [17] and pulse laser deposition (PLD) [18], are used to deposit ZnO.…”

Enhanced field emission of graphene–ZnO quantum dots hybrid structure

“…E is the applied electric field, b is the field enhancement factor, and / is the work function of 5 eV and 5.3 eV for graphene [2] and ZnO [16], respectively. The enhancement factor b of pristine graphene and ZnO QDsdecorated graphene emitters can be calculated from the slope of the F-N plots.…”

Sixfold self-assembled hierarchical structures synthesized by direct annealing of Zn microtips

“…The turn-on electric field for the microtip arrays of Zn is about 33.9 V/mm at a current density of 10 mm/cm 2 , and is enhanced to 8.5 V/mm for hierarchical structures. The obtained field-emission property after annealing treatment is not significantly improved compared with ZnO 1D nanostructures (3.9 V/mm) and hierarchical structures (3 V/mm) obtained by thermal oxidation of brass (CuZn alloy) foil [8,21]. The linear Fowler-Nordheim (FN) behavior (shown in Fig.…”