High-yield synthesis of single-crystal nanosprings of ZnO

A technique for successful manipulation of growth kinetics to synthesize single crystal ZnO nanorings at a high yield of more than 50%. A systematic characterization of the these nanostructures at different deposition areas of different local growth temperature was conducted by scanning electron microscopy (SEM) to examine the morphology and chemical composition. It was found that in a region of 500-500°C, high yield of nanosprings was successfully achieved on a polycrystalline alumina substrate. It was also observed that doping is not necessary for forming polar-surface-dominated nanosprings and nanoloops, but a pre-growth low pressure is very important for this synthesis. The simple control of the pre-growth conditions can result in a greatly improved yield of nanosprings.