Preparation and photoluminescence of ZnO complex structures with controlled morphology

ZnO complex structures including spheres, ellipsoids, flowers and propellers have been successfully and controllably achieved on a large scale by a low-temperature (60 °C) solution phase process with continuous stirring. These structures of single-crystal hexagonal phase could be easily obtained respectively using different amounts of ammonia (NH3·H2O) and different concentrations of the reaction solution. The formation mechanisms have been systematically discussed based on the experimental results and the function of organic molecules. A very strong UV emission at ∼390 nm with a negligible green emission observed in the room-temperature photoluminescence (PL) spectra of the four kinds of ZnO microcrystals indicated that they are of high crystal quality.