One step solution synthesis towards ultra-thin and uniform single-crystalline ZnO nanowires

Bundles of high-aspect-ratio single-crystalline ZnO nanowires were fabricated by a single-step mild hydrothermal condition without the use of a seeding layer, thus eliminating an annealing step. The growth yields nanowires of high aspect ratio (> 200). No significant lateral growth takes place with prolonged reaction time. The morphology and aspect ratio of the final products depend on the concentration of the precursors; a highly water-soluble tetradentate cyclic tertiary amine and zinc nitrate system. The nanowires grow along the [0001] direction and have an average width of < 10 nm and a narrow distribution of +/- 5 nm. Photoluminescence measurements of the ultra-thin nanowires exhibit a strong band-edge emission at room temperature. The highly crystalline sub tens of nanometer scale diameter nanowires can, in combination, be a good one-dimensional candidate to study optical and electronic properties.