| NiO thin films is an important wide bandgap semiconductor functional materials, it exhibits excellent physical, chemical stability, as well as optical, electrical and magnetic features. As it has the significant value and wide application, so it has recently drawn considerable attention for research. The NiO and GaN/NiO heterojunction have the advantage of low cost, which cause the attention of peaple.First, we successfully prepare NiO films on glass through RF magnetron sputtering technique and deeply investigate the effects of deposition pressureã€02/Ar and sputtering power on the properties. The samples were studyed by 3D surface profiler, ultraviolet and visible spectrophotometer, X-ray diffraction (XRD), scanning electron microscope (SEM) to analyze the thickness, crystal structure, optical performance, crystal structures and elemental contents and surface morphological structures, with the purpose of providing some reference and inspiration for the research and development of NiO thin films.The experimental results show that the range of optimized growth conditions are obtained as follows:the deposited pressure is at 4.5 Pa, O2 flues are 10sccm, Ar flues are 20sccm and sputtering power is 160 W, which could prepare better quality NiO thin films with (200) preferred orientation.On the basis of growth of NiO films, then we prepare high quality GaN films on the NiO films by ECR-PEMOCVD at low temperature. And the influence of TMGa flues on the properties of GaN were intensively studyed. Results reveal TMGa flues have significant affects on the growth of GaN films and indicate that optimum TMGa flow at 0.8 sccm, GaN films exhibit good crystal structure with highly c-axis oriented, good optical properties, the surface morphology is uniform. Due to adopt the GaN buffer layer, the background electron concentration is high which will cause interface tunneling effect of the heterojunction, so the GaN/NiO heterojunction present ohmic contact property. |
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