Self-catalytic synthesis, structure and properties of ultra-fine luminescent ZnO nanostructures for field emission applications.

A facile method to produce high-quality ZnO nanostructures; either tetrapod (TP), nanotetraneedle (NTN) or multipod (MP) with a high degree of homogeneity for advanced field emission (FE) applications is presented. Among these nanostructures, NTN has been successfully employed to demonstrate enhanced current densities (2.6 mA cm(-2)), turn-on field (1.5 V microm(-1)) and field-enhancement factors (6930) over conventional multiwalled carbon nanotubes (MWCNTs), TP, MP and ZnO-spheroids. A comparative study of FE from various ZnO nanostructures, morphologies and site densities has lead to the conclusion that diameter of the tip is one of the vital parameters in enhancing the overall FE properties.