Abstract: ZnO films were deposited on Si（100） substrates at 300℃ by metal-organic chemical vapor deposition（MOCVD）.The effect of different ratios of DEZn to N₂O on crystal quality was analyzed.It is found that the optimum ratio of DEZn to N₂O is 2:1.And in this optimum growth condition,X-ray diffraction（XRD） and scanning probe morphology（SPM） images indicate that the films grow along the c-axis orientation.ZnO film exhibits a strong UV optical absorption near 388 nm.And the optical absorbance is close to zero,that indicates nearly 100% optical transparence.Photoluminescence（PL） spectrum shows only strong near-band-edge emissions with little or no deep-level emission related to defects.The full-width at half-maximum（FWHM） of the ultraviolet emission peak is 80meV.The results indicate that better crystal quality can be obtained.