ZnO films grown by low-pressure metal-organic chemical vapor deposition using diethylzinc (DEZn) and dimethylzinc (DMZn) as zinc precursors exhibited the different growth mechanisms and properties. The film grown with DMZn was covered by typical three-dimensional islands, while the film grown with DEZn shows a quasi-two-dimensional lateral growth features of large hexagonal grains and a smooth surface. Raman scattering measurements investigated the existence of high content of carbon and hydrogen in the DMZn grown films, due to which the photoluminescence properties are consequently degraded greatly with the distinct deep-level emissions. In contrast, ZnO grown with DEZn exhibits the superior structural and optical properties, as well as a lower carbon impurity concentration. (C) 2004 Elsevier B.V. All rights reserved.