Periodic zinc oxide rod arrays were fabricated on patterned templates by electrochemical deposition and were employed as field emitters. The morphology and crystal structure of the zinc oxide array were examined by scanning electron microscopy and x-ray diffraction, respectively. The dependence of the field emission current density J and the applied electric field E presented a two-stage slope behavior in ln(J∕E2)−1∕E plot according to Fowler-Nordheim equation. The mechanism of the electron emission is attributed to the defects in the electrochemically deposited zinc oxide rods.

Field emission properties of screen-printed ZnO nanotetrapods on a carbon nanofiber buffered Ag electrode were studied. The turn-on electric field (at a current of 0.1 μA/cm2) and maximum emission current are 0.6 V/μm and 2.8 mA/cm2 (at a field of 2.2 V/μm), which were significantly improved compared to the control device made of ZnO nanotetrapods on Ag directly without a carbon nanofiber buffer. The improved field emission is due to the better contact (both mechanical and electrical) formed with a carbon nanofiber buffer.

We report a surface-conducted field emitter made of a ZnO nanotetrapod and MgO nanoparticle composites with a high emission efficiency (∼100%) and current (3.77 mA at a gate voltage of 100 V and anode voltage of 1800 V). The fabrications of the triode structure with a 10×10pixel array and corresponding driving method have been proposed. The electron trajectories are simulated according to the structure. Individual pixel addressing can be achieved by a sequential scanning mode. Display of moving images employing this triode structure was demonstrated. The results are of significance to the development of ZnO based triode field emitters.

This article describes a study on field emission properties of ZnO tetrapods, which were synthesized by rapid heating metal zinc pellets at 900°C in air. A diode configuration with a screen-printed cathode was used to measure the field emission properties of the ZnO emitters. A low turn-on field of 1.86 V / m at a current density of 1 A / cm 2 was obtained, while the emission current density reached 1 mA/ cm 2 at an applied field of 4.15 V / m and showed no saturation. The field emission of the ZnO-tetrapod sample was recorded for 20 h: no degradation of the emission current was observed in this period, while the fluctuations of the emission current were less than 3%. These experimental results indicate that ZnO tetrapods are a promising cold cathode for low cost field emission displays using screen printing.

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