Enhanced optoelectronic properties of thermally evaporated Sb-doped ZnO nanowires via defect structures

Sb-doped ZnO nanowires were fabricated on Si (100) substrates by thermal evaporation via the vapor-liquid-solid mechanism at 850 °C, and their optoelectronic properties were examined. Two prominent emission regions at the near band-edge emission and deep-level emission of the pure ZnO nanowires were observed in the photoluminescence spectra. Doping with Sb reduced the intensities of near band edge emission and deep-level emission. Almost no near band-edge emission signal was obtained at Sb ≥ 2.2 at. % and almost no deep-level emission signal was obtained at Sb ≥ 5.46 at. %, owing to the formation of metallic Sb and the +5 oxidation state of the Sb2O5 phases. These results suggest that the Sb dopant content is the critical factor in improving the optoelectronic properties of Sb-doped ZnO nanowires, as revealed by their photoluminescence spectra.