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

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 mu m(-1) at an emitter-anode gap of 525 mu m. 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.