Field Emission and Emission-Stimulated Desorption of ZnO Nanomaterials

Compared with other field-emission nanomaterials, 1D ZnO nanomaterials have some unique properties-such as high melting point, high thermal and chemical stability, and ambient insensitivity-which means they have promising potential applications as field emitters in harsh environments. This work proposed a water-assisted physical vapor deposition method to prepare various ZnO nanostructures simultaneously on a silicon substrate with one experimental run. Field emission characteristics of the as-grown ZnO nanomaterials were measured and analyzed. Emission-stimulated desorption was proposed and investigated. The gas released under the emission-stimulated desorption effect was measured in the way of monitoring the variation of the pressure. The results show that the slight variation of the pressure has almost no effects on the field-emissions, and field emission properties can be improved with the gases released from the surface of ZnO under the emission-stimulated-desorption effect. Finally, a low turn-on voltage in the range of 0.5-0.9 V/mu m was achieved and a stable emission current was obtained. The ambient insensitivity of ZnO nanomaterials make them possible to be used as field emission cathodes in harsh environments with fluctuating pressure.