Ultraviolet-emitting ZnO nanowires synthesized by a physical vapor deposition approach

ZnO nanowires were mass produced using a physical vapor deposition approach. The ZnO nanowire monocrystallites have an average diameter around 60 nm and length up to a few micrometers. The unidirectional growth of the ZnO nanowires was controlled by the conventional vapor-liquid-solid mechanism. Intensive UV light emission peaked around 3.27 eV was observed at room temperature, which was assigned to emission from free exciton under low excitation intensity. The observed room temperature UV emission was ascribed to the decrease in structure defects as compared to bulk ZnO materials, and in particularly to the size effect in the ZnO wires. (C) 2001 American Institute of Physics.