Synthesis and field-emission properties of aligned MoO3 nanowires

Aligned MoO3 nanowires have been grown on silicon substrates without using any catalyst. They were prepared in a two-step process: first by thermal evaporation and then further processed by oxidation. The MoO3 nanowires are of crystalline and have an orthorhombic structure. They also have high purity. Field-emission measurement showed that, typically, their turn-on field and threshold field were about 3.5 and 7.65 MV/m, respectively. Furthermore, the spatial distribution of emission sites was studied using transparent anode technique and the emission current of the sites was relatively uniform. These may be attributed to very good uniformity in the height and diameter of the nanowires, and to the separation between nanowires. Finally, the stability of the emission current over time was found to be within 10%. These findings indicate that MoO3 nanowires as a cold cathode have a potential future. (C) 2003 American Institute of Physics.