Effect of N2 flow rate on morphology and structure of ZnO nanocrystals synthesized via vapor deposition

ZnO nanotetrapods, ZnO nanowires and Zn nanowires were fabricated by the vapor deposition process at the different flow rates of the carrier gas (N2). Further oxidation of the Zn nanowires led to the formation of ultra-fine ZnO nanoneedles. Photoluminescence (PL) spectra of ZnO nanocrystals exhibited a deep-level emission in the visible region and a near-band-edge emission in the ultraviolet (UV) region. The PL spectra reflected the variation of the stoichiometry and the structure of ZnO nanocrystals.