ZnO films with <110> orientation were grown on R-Al 2O 3 substrates by LP-MOCVD, and the growth temperature was optimized. The quality of crystal, surface morphology and optical characteristic of the samples were investigated by XRD, AFM and PL method. The experimental results show that the FWHM of the optimized sample is only 0.50°. Compared with that of the sample grown on C-Al 2O 3 material under the same conditions, the surface morphology of the first sample is denser and smooth, while the PL spectra indicate that the exciton emitting intensity of <110> oriented ZnO film in the ultraviolet range is lower. However, the deep-level emission related to the intrinsic defects disappears in the spectrum. All above indicate that the <110> oriented ZnO film is more suitable for fabrication of the film SAWF with a low loss and a high frequency than for fabrication of the emitting device in ultraviolet range.
