Preparation Of AlCrN-based Solar Selective Absorbing Coatings By CAIP And Optical Property

With the continuous progress of science and technology,there is more and more huge demand for energy in our human society.However,the consumption of traditional fossil energy is vast and its reserves are decreasing.Therefore,the development and utilization of new energy clean and efficient are significant methods for the future development of society.Recently,concentrating solar power?CSP?system,as an important method for the utilization of solar energy,has gradually become a hotspot research all around the world.Solar spectrum selective absorbing coatings are the core components of the system,which has attracted increasing academic attention.A series of metals and their nitrides,nitrogen oxides are popular candidates,including Al,Ti,CrN,AlCr NO,Ti NO and wide researches have been launched on preparation technologies and selective absorbing properties.In this paper,SS/AlCrN-based solar selective absorbing coatings were prepared on stainless steels?SS?by cathodic arc ion plating?CAIP?.Deposition current,deposition time and flow rate of N₂ were investigated on its optical absorbing property and thermal emitting property followed an orthogonal experiment of L₂₅?5⁶?to obtain optimized parameters.And optimized SS/AlCrN-based solar selective absorbing coatings were prepared followed the optimized parameters.Scanningelectronmicroscope?SEM?,EnergyDisperse Spectroscopy?EDS?,X-raydiffractometer?XRD?,x-rayphotoelectron spectrometer?XPS?were used to investigated microstructure,element composition,Phase and element state respectively.The results show that the surface was relatively smooth and exists bits of metallic particles.And the main phases were metal?Al,Cr?and ceramic phases?AlN and Cr₂N?.the optimized SS/AlCrN solar selective absorbing coatings present better optical selective absorbing properties and the absorbance was 0.733,emittance was 0.148.In order to further optimize optical selective absorbing properties of the coatings,Al₂O₃ anti-reflection coatings were deposited on the SS/Al CrN coatings.By changing the deposition time,three kinds of thickness of the coatings were prepared.It is found that with the increasing of deposition time,the sizes of the particle were linear increased.Surface phases were amorphous Al₂O₃.And after measuring the optical selective absorbing properties,we find that when the deposition time was 1 min,the thickness was 91.7 nm and the coatings present the best selective absorbing properties of the SS/Al CrN/Al₂O₃,the absorbance was 0.832,emittance was 0.159.