Growth and Characterization of ZnO Nanowires

Single crystal ZnO nanowires were grown by chemical vapor deposition using monodisperse 5 nm or 20 nm diameter gold nanoparticle catalysts to control the nanowire diameter and location. The nanowires reach several microns in length and grow only from the gold nanoparticles. The nanowires have narrowly dispersed diameters, albeit significantly larger than the diameter of the gold particles used for catalyzing the growth. The nanowires grow in the [101̄0] or [101̄1] directions normal to the lowest energy planes in ZnO. ZnO nanowires emit in the near ultraviolet region of the electromagnetic spectrum upon excitation with high-energy photons or electrons. Electron diffraction and absence of luminescence associated with oxygen vacancies indicate high quality crystalline ZnO nanowires. Cathodoluminescence emission along the entire length of the wire is consistent with a lack of non-radiative recombination sites associated with defects, lending further support for the high quality of these nanowires.