ZnO films were grown on Si substrates by using plasma-assisted metal-organic chemical vapor deposition (MOCVD) method. Low-temperature ZnO buffer layers deposited on Si substrates were used as intermediate layers for the growth. The samples were investigated by X-ray diffraction

Scanning electron microscope and photoluminescence (PL) spectra. It is discovered that the low-temperature buffer layer can reduce the lattice distortion caused by lattice misfit and difference of the thermal expansion coefficients. With a low-temperature grown ZnO buffer layer

the X-ray diffraction (XRD) of the ZnO film results a strong (002) diffraction peak. The full-width at half-maximum (FWHM) of the (002) ZnO peak becomes narrower and the value of it declines from 0.21° to 0.18°. Meanwhile

the PL spectra peak value of the sample at room temperature increases obviously. The crystal quality and optical properties of the ZnO films which are deposited at 610℃ on low-temperature buffer layer are improved significantly.