Catalyst effect on ZnO nanostructure shape

ZnO nanostructures are synthesized by a simple physical vapor phase transport technique using metallic clusters as the catalyst. Two kinds of catalyst are used: gold and platinum. The shape and growth direction were investigated by scanning electron microscopy, transmission electron microscopy and using X-ray diffraction. Depending on the metal used, we have shown that various kinds of nanostructures can be obtained. With gold catalyst, a homogeneous distribution of nanorods is observed. On the other hand, with platinum catalyst, two nanoribbon families are observed in addition to nanorods. A vapor-solid (VS) process with or without catalyst assistance is proposed to explain the nanoribbon growth and some photoluminescence measurements are presented.