Fabrication of ZnO:Ni nanowires and their Raman spectra

ZnO:Ni nanowires have been fabricated through high temperature vapor-solid deposition process. The morphology of the as-prepared samples was characterized by scanning electron microscopy. The room temperature Raman spectrum exhibited the presence of lattice defects in the system. The vibration modes of undoped ZnO and additional modes have been observed in the Raman spectra of Ni-doped ZnO nanowires. The strongest mode E2high at 437.2 cm−1 indicates that the ZnO:Ni nanowires still keep the hexagonal (wurtzite) structure. The mode at 656.6 cm−1 is ascribed as local vibrational mode due to the host defects. Ni-doped leads to an appearance of two additional modes at 254.1 and 540.6 cm−1. These modes can be attributed to the surface phonon mode and the Raman scattering peaks would be originated by Ni doping to form defects.