Aggregation of ZnO Nanorods into Films by Oriented Attachment

Highly oriented and densely packed ZnO films of nanorod arrays are formed free of substrate via a chemical vapor deposition (CVD) route. The resulting films are composed of single-crystal ZnO nanorods, which grow along their c -axis paralleling each other. The ZnO nanoclusters form first in the highly saturated vapor environment, followed by preferential growth along their [0001] directions to produce nanorods via a vapor−solid (VS) growth process. During transferring, the nanorods aggregate into films by oriented attachment with assistance of ZnCO 3 . Raman scattering studies confirm that the ZnO nanorods are c -axis oriented and well-aligned as well as being of high-crystal quality. Room-temperature photoluminescence spectrum of such ZnO films exhibit a strong and narrow ultraviolet emission, which facilitates their potential applications in the future photoelectric nanodevices.