Journal of the American Ceramic Society, Vol.93, No.11, 3531-3534, 2010
The Characterization of N Interstitials and Dangling Bond Point Defects on Ion-Implanted GaN Nanowires Studied by Photoluminescence and X-Ray Absorption Spectroscopy
Photoluminescence and X-ray absorption spectroscopy (XAS) measurement were used to characterize the near-band edge (NBE) emission intensity and electronic structure of asimplanted GaN nanowires (NWs) that had been implanted with Eu ions to different fluences. The N K- and Ga L-3-edge of total electron yield XAS spectra showed the formation of N interstitials (N-i) and dangling bond (N-db) point defects and the formation of metallic Ga layers on the surface of NWs. X-ray diffraction, Ga K-and L-3-edge of total fluorescence yield XAS spectra consistently revealed the wurtzite structure of the asimplanted NWs up to the highest fluence. The ratio of absorption intensity found in sp(3) and sp(2) environment and the NBE intensity were strongly affected by the implantation. It is suggested that the decrease of NBE intensity was closely related to the change from sp(3) to sp(2) environment. The absorption intensity ratio between the as-grown and as-implanted samples of N-db and N-i was directly proportional to the fluences indicating that these defects are preferentially formed during implantation.