Field emission microscopy study of zinc oxide nanowires on tungsten tip

This article focuses on the field emission froth a small number of zinc oxide (ZnO) nanowires. ZnO nanowires were grown directly oil W tips and their field emission was studied in a traditional field emission microscope (FEM). The FEM pattern of a single ZnO nanowire was ring shaped, indicating that most of the emission front the (0001) facets of the ZnO nanowires came from their circumferences. Scanning electron microscopy observation, measurement of dependence of the emission current oil the applied cathode voltage (I-V behavior), and acquirement of FEM patterns were performed before and after heat treatment of the samples, respectively. The heat treatment was found to play either a favorable or an unfavorable role. It Could lead to a stable emission or damage of the emitters, depending oil the heating conditions. (C) 2009 American Vacuum Society. [DOI: 10.1116/1.3079650]