Properties of cupric oxide coatings prepared by cathodic arc deposition

A systematic study of CuO coatings produced with a dc cathodic arc is presented. During the deposition process, the substrates were exposed in three different conditions: grounded, biased (−300 V) or heated (300 °C). The morphology, structure and adhesion of the coatings obtained under these conditions were compared. The film surface was observed with an optical microscope and a scanning electron microscope. X-ray diffraction (XRD) was used to identify the compounds present in the coating and to study the film texture. The adhesion was evaluated with scotch and scratch tests. Results show that the morphology and composition in the three conditions are similar, while the film adhesion is much better for the heated substrates than in the other cases. Optical properties of the coating on heated substrates were characterized by measuring the surface reflectance in the UV–visible–IR range. The film presents a good performance as a selective solar absorber coating.