Kai Zou

The fabrication and optical properties of highly crystalline ultra-long Cu-doped ZnO nanowires

We demonstrate the bulk synthesis of single crystalline Cu-doped ZnO nanowires using (CuI+ZnI2) powders at 600 °C. These mass nanowires are characterized through x-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction, and high-resolution TEM; they have uniform diameters of about 65 nm and are several tens of microns in length. The growth of ZnCuO nanowires is suggested for self-catalyzed vapour–liquid–solid. In particular, the PL spectra of these nanowires show emission peaks that strongly shift to long wavelength with increasing Cu, and the doping quantity is found to be responsible for the different characteristics; the PL mechanism is explained in detail.

Sb-induced bicrystal ZnO nanobelts

Zinc oxide bicrystal nanobelts of wurtzite structure were synthesized by simple thermal evaporation of a powder mixture of Zn and Sb2O3. The bicrystal nanobelts were found to have a growth direction of [2¯113], widths of 80–200 nm, and lengths up to several hundreds of micrometers. Energy dispersive x-ray spectroscopy and high angle annular dark field images showed that antimony was rich in the grain boundary of the bicrystal nanobelts. It was discovered that both sides of the bicrystal nanobelts were O-terminated toward the grain boundary. The mechanism of formation of the bicrystal nanobelts was also discussed.

Transmission electron microscopy investigation of self-assembly ZnO twinning nanostructures

Self-assembly ZnO twinning nanostructures are studied by transmission electron microscopy systematically. Selected area electron diffraction and high-resolution transmission electron microscopy observations indicate two types of twin boundaries (011¯1¯) and (011¯3) appeared in the same nanostructure and the twinning relationships are well defined. Convergent-beam electron diffraction techniques determine the polarities of the building blocks are all Zn terminated with the help of theoretical simulations, which is further confirmed by electron energy loss spectroscopy under (0002) and (0002¯) Bragg conditions.