The effect of ZnO buffer layers prepared at different temperatures on the structural, optical and morphological properties of the ZnO main layer is reported. ZnO thin films (comprising a buffer and a main layer) were deposited on (0 0 0 1) c-sapphire substrates by PEMOCVD. Two-step growth regimes were applied to realize a homoepitaxial growth on ZnO buffers: low-temperature ZnO buffer layer deposited at T-s = 300 degrees C and the main layer at T-s = 500 degrees C high-temperature ZnO buffer layer deposited at T-s = 500 degrees C and the main layer at T-s = 300 degrees C. For comparison, a sample grown at high -temperature T, = 500'C by one-step procedure was used. The lowtemperature buffer layer has shown the most beneficial effect on the structural and morphological properties, as expressed by the narrowing of the (0 0 2) diffraction peak (FWHM = 0.07 degrees) and crystallite size enlargement. However, the surface roughness of this sample is higher then that of the sample grown by one-step procedure and this needs further considerations. The photoluminescence results seem to support a conclusion that the application of a low-temperature buffer layer arriong the studied temperature regimes is the most advantageous. (C) 2007 Elsevier B.V. All rights reserved.