1D single‐crystalline zinc oxide nanostructures are promising for nanoscale optoelectronic applications. Here a simple chemical vapor deposition method for the growth of well‐aligned ZnO nanorods (see Figure) at low temperature is demonstrated. The nanorods, which grow on fused silica and are preferentially oriented in the c‐axis direction, are strongly UV light emitting, peaking at around 386 nm at room temperature.

The heterostructures of Zn-ZnO coaxial nanocables and ZnO nanotubes with an average diameter of 30 nm have been synthesized by simple pyrolysis of zinc acetylacetonate. High-resolution transmission electron microscopy analyses reveal that the Zn core and the ZnO sheath of the nanocables have an epitaxial relationship with their longitudinal axis oriented along the ͗001͘ direction. ZnO nanotubes with a wall thickness of 4 nm possess a single-crystal structure and appear to be the extension of the ZnO sheath of the coaxial nanocables. It is suggested that the ZnO nanotubes are formed by partial evaporation of Zn core of the Zn-ZnO coaxial nanocables.

Diluted magnetic semiconductor Zn1−xCoxO nanorods with a Curie temperature higher than 350K have been synthesized by in situ doping of Co in ZnO nanorods using a simple thermal chemical vapor deposition method. Structural analyses indicated that the nanorod possesses the single-crystalline wurtzite structure and there is no segregated cluster of impurity phase appearing throughout the nanorod. The transparence of the Zn1−xCoxO nanorods in the visible region has been examined by UV-visible absorption. The fundamental absorptions of the Zn1−xCoxO nanorods estimated from the absorption spectra do not reveal pronounced difference from that of pure ZnO nanorods.

The formation of well‐aligned ZnO nanorods has been achieved via H2 treatment of as‐grown ZnO films. Structural analyses reveal that the ZnO nanorods on the ZnO films are preferentially oriented along the c‐axis direction and exhibit a single‐crystalline wurtzite structure. To investigate the mechanism of formation of ZnO nanorods on the film, further H2 treatment of the as‐grown ZnO nanorods was performed. Thinner and longer ZnO nanorods were obtained after certain periods of H2 treatment. It is proposed that both etching and re‐deposition processes are taking place during the process, resulting in the aspect‐ratio enhancement of the ZnO nanorods and the formation of ZnO nanorods on the ZnO films. It is suggested that an appropriate concentration of the etching products remaining from the initial rod‐forming H2 treatment allows subsequent re‐deposition of the ZnO nanorods with enhanced differentiation of the growth rates on the 〈001〉 and 〈100〉 crystal facets.

Highly-oriented ZnO nanorods were grown on the fused silica substrates by a thermal CVD technique using Zinc acetylacetonate (Zn(C5H70 2 ) 2 ). The substrate was heated to 500 0 C and the vaporization temperature of Zn(C 5 H 7 0 2 ) 2 was keep at around 135°C. X-ray diffraction and TEM analyses reveal that the nanorods are preferentially oriented toward the c-axis direction.Photoluminescence (PL) and absorption measurements show a strong emission at around 380nm which corresponds to the near band-edge emission of the bulk ZnO. Moreover, the negligible green emission band in PL spectrum and the absence of EI(LO) mode of the ZnO crystal inRaman spectrum indicate a low concentration of oxygen vacancy in the highly-oriented ZnO nanorods.