Novel horseshoe-shaped ZnO nanorods and their optical properties

Large areas of ZnO horseshoe-shaped nanorods have been fabricated vertically on MgO-coated Si (1 1 1) substrates by chemical vapor deposition method. The well-aligned nanorod arrays were characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscope (HRTEM), energy-dispersive X-ray spectroscopy (EDS), and photoluminescence spectroscopy (PL). The results show that the nanorods are perfect single crystals with hexagonal wurzite structure along the [0 0 0 1] growth direction. The nanorods have regular horseshoe shape, and the diameter of the rods rang 70–99 nm while the length is about 600 nm. The PL spectrum exhibits a strong peak at 500.8 nm and two relatively weak emission bands centered at 387.7 nm and 648.6 nm, which indicates that the ZnO arrays are of excellent optical quality.