High-quality ZnOfilms grown by atmospheric pressure metal–organic chemical vapor deposition (AP-MOCVD)
are demonstrated in this paper. Surface morphology, structural quality and optical properties of the As-grown films
were investigated by AFM, double-crystal XRD and photoluminescence (PL) measurements. The effect of buffer layers
grown at different temperature on the film quality was studied. It was found that the low-temperature buffer layer was
effective to improve the surface morphology, but was not effective to improve the structural quality. On the other hand,
the high-temperature buffer layer can greatly improve the structural quality, but yields a relatively rougher surface.
Both the samples deposited using either a low-temperature or high-temperature buffer layer showed strong UV
luminescence at room-temperature. A fine structure of free excitons was observed at 11K in the sample with a hightemperature
buffer layer.