Field-emission properties of individual ZnO nanowires studied in situ by transmission electron microscopy

The field-emission properties of individual zinc oxide (ZnO) nanowires, grown by a solid-vapour phase thermal evaporation process, were studied in situ by transmission electron microscopy ( TEM) using a home- made piezo-manipulator. The results indicate that ZnO nanowires present an outstanding field-emission property with low turn-on voltage and high emission current; the proper linearity of 1/V-1n(I/V-2) curves basically accords with the Fowler Nordheim model, and the dependence of the field-enhancement factor beta on the distance d between the nanowire tip and its counter anode fits a linear relationship. The investigations show that ZnO nanowires show promise for potential applications as field emitters.