Low-pressure chemical vapour deposition growth of high-quality ZnO films on epi-GaN/alpha-Al2O3

We present the first results on (0001) ZnO/(0001) epi-GaN/(0001) alpha -Al2 O3 heterostructure fabrication combining metal-organic vapour phase epitaxy and low-pressure chemical vapour deposition methods. The surface morpholog ies of the films were studied, and x-ray and reflection high-energy electro n diffraction measurements were made, which showed a high degree of structu ral perfection of the ZnO films, with crystallite misorientation as low as 21'. The measured photoluminescence spectra of the films featured prevailin gly emission within the excitonic region.