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

We demonstrate the bulk synthesis of single crystalline Cu-doped ZnCi nanowires using (CuI + ZnI2) powders at 600degreesC. 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.