Catalyst-free synthesis of vertically aligned screw-shape InZnO nanorods array

Vertically aligned “screw-shape” indium-doped zinc oxide (InZnO) nanorods were grown by a catalyst-free thermal evaporation method on zinc oxide (ZnO) film. A strong ultraviolet emission and almost absence of green emission observed in room temperature photoluminescence, together with the high-resolution transmission electron microscopy analysis, indicate that the obtained InZnO nanorods are of good crystalline quality. The morphology of single InZnO nanorod reveals a “screw-shape” feature, which is induced by the incorporation of indium. The possible mechanism of forming these “screw-shape” nanorods was proposed tentatively as a result of segregation of indium. Moreover, the source of UV emission of InZnO nanorods array was investigated via temperature-dependent photoluminescence.