Ion implantation is an interesting method to dope semiconducting materialssuch as zinc oxide provided that the implantation-induced defects can besubsequently removed. Nitrogen implantation followed by anneals under O2 werecarried out on zinc oxide nanowires in the same conditions as in a previousstudy on bulk ZnO [J. Appl.Phys. 109, 023513 (2011)], allowing a directcomparison of the defect recovery mechanisms. Transmission electron microscopyand cathodoluminescence were carried out to assess the effects of nitrogenimplantation and of subsequent anneals on the structural and optical propertiesof ZnO nanowires. Defect recovery is shown to be more effective in nanowirescompared with bulk material due to the proximity of free surfaces.Nevertheless, the optical emission of implanted and annealed nanowiresdeteriorated compared to as-grown nanowires, as also observed for unimplantedand annealed nanowires. This is tentatively attributed to the dissociation ofexcitons in the space charge region induced by O2 adsorption on the nanowiresurface.
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