We have analysed the growth, morphological and structural characterization of Cd1-xZnxO thin films grown on rsapphire substrates by atmospheric pressure metal organic chemical vapour deposition, mainly focusing on the Cd-rich rock-salt phase for its promising optical and technological applications. The evolution of the surface morphology and crystalline properties as a function of Zn content has been studied by means of high resolution x-ray diffraction and electron microscopy techniques. Monocrystalline (002) single-phase cubic films were obtained with Zn contents up to 10.4%, and with a low density of dislocations as a consequence of the optimized crystal growth process. Particular attention has been paid to the alloy characterization for compositions when cubic and wurtzite phases coexist.