Super-uniform ZnO nanohelices synthesized via thermal evaporation

Super-uniform single crystal ZnO nanohelices synthesized by Sb induced thermal evaporation is reported. The ZnO nanohelices as a whole have an axial direction of 〈0001〉, perfect hexagonal cross section and length of tens of micrometres. There are six blocks in each period of the helices, and they grow along six equivalent directions 〈01̄11〉. The typical pitch distance, mean diameter and thickness of the nanowire is about 600, 400 and 100 nm. Calculation according to a simple model shows that the helical structure is energetically favourable. It could be used as photonic crystals or construct blocks in nanoscale optoelectronic and electromechanical systems. In addition to ZnO nanohelices, zigzag ZnO nanostructures were also obtained.