Stable electron field emission from triangular-shaped ZnO nanoplate arrays with low local heating effects

Abstract

We show here successful large-area growth of triangular-shaped ZnO nanoplate arrays on silicon substrates and the investigation of their electron field emission properties. The special geometric-shaped nanoplate emitters have a very large surface area for heat dissipation and large field enhancement factors. These lead to very stable and low-threshold field emission. The fluctuations of the macroscopic current density are less than 1.5%. The threshold macroscopic field is about 4.3 V µm−1 at an emitter–anode gap of 525 µm. The stable electron field emission is ascribed to low local heating effects, originating from the superior heat dissipation ability and the low Joule heating of the sheet-like emitters. Plotting Fowler–Nordheim curves yields straight lines with small deviations at low and high macroscopic fields. The origins of these deviations are discussed. Our experiments demonstrate a promising design for stable and efficient emitters.

Al doped ZnO nanoplate arrays and microbox structures grown by thermal deposition

“…Also ZnO triangular nanoplates with ͓0110͔ growth direction have been grown on a Si substrate with Au catalyst. 27 The triangles observed in this work only grow in the samples with higher Al content in the precursor, which suggests that their formation is associated to the presence of Al. No triangles were found in undoped 20 or Sn doped 11 ZnO microstructures grown by the same procedure used here.…”

“…Figure 3 shows the XRD pattern of the structures showing preferred ͑103͒ orientation, different to the ͑002͒ orientation reported for aligned Al doped microrods 16 or the ͑201͒ orientation of triangular undoped nanoplates. 27 Selected area diffraction patterns and TEM images of the nanostructures reveal their single-crystalline nature. Figure 4͑a͒ shows the TEM image of a nanotriangle and the corresponding diffraction pattern.…”

“…27 The geometry of the structures obtained in this work, forming arrays of empty boxes, would also favors heat dissipation.…”

Fluorescence Invigoration in Carbon-Incorporated Zinc Oxide Nanowires from Passage of Field Emission Electrons

“…Joule heating has been observed in field emission by carbon nanotubes 29,30 , resulting in temperature of ~2000K and is an important consideration in field emission stability of ZnO nanomaterials 31 . ZnO has a low heat conduction coefficient and this gives rise to a rapid local annealing process.…”

Three dimensional ZnO nanostructures realized through a polymer mediated aqueous chemical route: candidate for transparent flexible electronics

“…Much higher electron emission stability can be attributed to the greater heat dissipation ability of the hierarchical assembly of nanosheets owing to its larger radiation area. 43…”