Optical and electrical properites of ZnO nanorods synthesized by nanoparticle assisted pulsed laser deposition

This paper describes the characterization of nano-structured ZnO crystals synthesized by laser ablation deposition method. The influence of the synthesis conditions on the morphologies of the ZnO crystals was investigated in detail. ZnO nanorods with a hexagonal- and pyramidal top surface were obtained under limited growth conditions. The most critical process parameter for the growth of ZnO nanorods was gas pressure, whose process window was in the range from 1.0 to 5 Torr. In a high temperature background gas, on the other hand, unique nano-structured ZnO crystals were obtained, including a nano-wire pig-tailed ZnO nano-rod which has a nano-wire of less than 100 nm in diameter at the hexagonal top of nano-rods, a ZnO nano-cone with a bottom diameter of 500 nm and a height of 2 μm and so on. The unique geometrical shapes have a great potential in the application to the field emission devices and nano-optics.