ZnO thin films have been grown on Si(I 0 0) substrate by plasma enhanced chemical vapor deposition (PECVD) using a zinc organic source (DEZ) and carbon dioxide (M) gas mixture at a low temperature. It is demonstrated that the radio frequency (RF) plasma power can dramatically effect the properties of ZnO thin films. The quality of ZnO thin films was studied by X-ray diffraction (XRD), atomic force microscopy (AFM), and photoluminescence spectra (PL). Under the optimized condition of RF power of 19 W, a c-axis-orientated wurtize structure ZnO thin film with the XRD full-width at half-maximum (FWHM) of 0.21degrees was prepared, and a strong free excitonic emission with a narrow PL FWHM of 90 meV at 3.286 eV was observed. The origin of the UV band is the free exciton recombination, as verified by temperature dependent PL spectra. (C) 2002 Elsevier Science B.V. All rights reserved.