Preparation And Properties Of TiOxNy/TiN Films By D.C. Magnetron Sputtering

In recent years, with the decreasing of traditional energy sources and the increasingly serious environmental problems brought by the energy utilization. Now people are paying more attention to solar resources because of it’s renewable and non-polluting characteristic. It is the key technology of the preparation of efficient solar energy selective absorption coating for the utilization of solar energy. Since the TiNxOy/TiN thin film has high solar absorption rate and low emissivity, it has been widely used as the absorbers for flat plate collector.In this work, selective absorbing coatings TiOxNy/TiN were deposited on the aluminium substrates by a DC reactive magnetron sputtering system under high vacuum. X-ray diffraction, Scanning Electron Microscope, precision colorimeter were used to analysis the phase composition, crystal structure, surface morphology and the colour of thin films. The corrosion resistance of thin films were measured by electrochemical workstation and salt spray test. Meanwhile the absorbance of films were characterized by ultraviolet and visible spectrophotometer. By changing the N2partial pressure,O2partial pressure, substrate initial morphology, the transition layer thickness and species, the best process parameters of the films were found out. The main results are as follows:Changing nitrogen partial pressure of surface layer, they all appeare (111) peak and (200) peak of TiN. Meanwhile the peak(111)at36.7°show that the diffraction intensity becomes stronger as nitrogen partial pressure decreases and grain size becomes small. The nitrogen partial pressure of0.09Pa has the best corrosion resistance. Corrosion current is2.284E-6A.Adjusting the oxygen partial pressure of intermediate layer, the surface morphology changes greatly. When the oxygen partial pressure is too high(0.22Pa),there are hole defects on the surface morphology. The oxygen partial pressure of0.13Pa has the better flatness. The oxygen partial pressure of0.13Pa has the best corrosion resistance. Corrosion current is2.284E-6A.Changing the partial pressure of oxygen and nitrogen, a series of optical interference coatings were prepared and they all showed blue. Light absorption rate are all higher than manufacturers standard samples. In the wavelength between700nm and800nm, their absorbance value is about1.5in this area. Film bluer, higher absorbance, by comparison of the absorbance and the color data. When the oxygen partial pressure is0.15Pa,the film has the best light absorbance and the date of L,a,b are33.93,-3.3,-35.84.The corrosion resistance of Ti transition layer is much better than that of Cu. With increasing the transition layer thickness within a certain range, films show stronger corrosion resistance and more smoothness surface. The highest corrosion resistance of film appears at the sputtering time of8min (about360nm). It’s corrosion current is1.263E-6and the corrosion potential is-0.598V.