Size control of ZnO nanostructures formed in different temperature zones by varying Ar flow rate with tunable optical properties

ZnO nanostructures were synthesized by the vapor transport method. ZnO nanocombs, nanowires and nanorods were formed in a single experiment, in high-, intermediate- and low-temperature zones, respectively. A systematic increase in diameters is observed for all the nanostructures when Ar flow is gradually increased. The diameters of these nanostructures were controlled from few 10's of nanometers to few micrometers. Photoluminescence (PL) properties of as-synthesized nanostructures and effect of heat treatment on optical properties and morphology were investigated.