Spontaneous formation of single crystal ZnO nanohelices

This paper reports a novel helix-like ZnO nanostructure with severaltens of nanometres in thickness synthesized on a gold-coated Sisubstrate by thermal evaporation of zinc sulfide powder at1020°C. Transmission electron microscope characterizationshows that as-synthesized ZnO nanohelices extend along [01bar 11]direction and the axial direction of the helix is along [0001]direction. A catalyst-intervened dislocation-induced growthmechanism has been suggested to explain the formation of thehelix-like ZnO nanostructures. This study opens a new route toconstruct helix-like ZnO nanostructures by different evaporationsources.