Optical and structural properties of nanostructured copper oxide thin films as solar selective coating prepared by spray pyrolysis method

Copper (II) oxide thin films were prepared by spray pyrolysis method on soda-lime glass substrates using copper acetate precursor solution. Influence of substrate temperature on structural and optical properties was investigated. Structural analysis of these layers were carried out by X-ray diffraction (XRD). Single phase nature and high crystallinity of CuO nanostructures were observed on XRD patterns. The general appearance of the films was uniform and black in color. FT-IR transmittance spectra confirmed the results from the XRD study. Selective solar absorber coatings of copper oxide (CuO) on stainless steel substrates was prepared by spray pyrolysis method. Effect of deposition temperature on optical properties of thin films was investigated. Optical parameters, absorbance (α) and emittance (α) were evaluated from reflectance data. It can be deduced that the porous structure, such as a light traps, can greatly enhance absorbance, while the composition, thickness and roughness of thin films can greatly influence the emissivity. Single phase nature and high crystallinity of CuO nanostructures were observed by XRD patterns. Solar absorbance of thin films were in the range of 85 % to 92 %.