Optical characterization of TiAlON-based film used for solar energy

Optical characterization of TiAlON film applied in solar energy is presented in this paper. TiAlON-based films with different thicknesses have been deposited by magnetron sputtering. The spectrophotometer and spectroscopic ellipsometry (GES5) have been used to study the samples. Surface morphology and component of the films were investigated using scanning electron microscope (SEM), X-ray diffraction (XRD), atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). The optical constants and film thicknesses of TiAlON films with different thicknesses have been obtained by theoretical modeling analysis fitting (Cauchy model) and point-to-point analysis fitting. Results show that the refraction coefficient and extinction coefficient change with the film thickness increased. Those optical properties are useful for selecting the layers with adequate optical constants and thickness to design a solar selective absorber.