Growth of Zinc Oxide Thornballs by a Novel Method

Thornballs of zinc oxide (ZnO) is firstly synthesized by a simple solid vapour deposition process under lead oxide (PbO) atmosphere. The micro-thornballs were constituted by numerous needles, which extend outwards in all directions symmetrically. The balls have the dimensions of 120μm in diameter, while the average diameter of the needles was about 100--200nm. The needles on the balls grow along the <0001> orientation and have gradient cross-sectional radii. Control experiments proved that PbO plays an important role in the growth. The excitation-emission measurement exhibits that the synthesized ZnO thornballs possess intensive photoluminescence property, which provides the evidence that PbO does not deteriorate the optical properties of ZnO thornballs.