Strong Effect of Interelectrode Distance on the Performance of a Novel ZnO Nanorod Lateral Field Emission Device Fabricated by a Single-Step Hydrothermal Approach

Novel lateral field emission devices composed of ZnO nanorods have been fabricated by a single-step hydrothermal approach on glass substrate. With the combined effect from a ZnO seed layer and a passivation layer for nanorod growth, ZnO nanorods could grow laterally and aligned between two electrodes. In this way, the conventional “pick and place” method and pattern grown on single crystal of nanorod integration are avoided. All the Fowler−Nordheim (FN) curves are straight lines and in excellent agreement with FN theory, which indicates that the electron emission of the as-grown samples is a tunneling and cold electron emission process. Measurement results also show that the samples with larger separation distance exhibit better field emission characteristics. By calculating the electrostatic field distribution, it was found that the electric field near the surface of the emitter is strongly dependent on the vacuum separation distance.