PROPERTIES OF ZnO NANOTETRAPODS

ZnO nanotetrapods were synthesized by microwave plasma. The nanotetrapod structures were imaged to be straight with diameters in the range of 10 to 25 nm and lengths up to 160 nm by transmission electron microscopes (TEM). The dark field images and lattice fringes of high resolution TEM show that the crystal orientation or structure of the core is different from that of the legs. The Auger electron peak of Zn shifts more distinctly to lower energy in the legs, which indicates the degree difference of bond ionicity between the core and leg. Cathodoluminescence spectrum of a single ZnO nanotetrapod is characterized by a stronger ultraviolet emission without broad emission bands in its lower energy side. This result further suggests that ZnO nanotetrapods are free from defects.