Synthesis and microstructural characterization of cupric oxide and cobalt oxide nanostructures for their application as selective solar coatings

In the present work, cupric oxide and cobalt oxide thin films were synthesized as selective absorbent coatings by aerosol-assisted chemical vapor deposition, a simple, relatively inexpensive technique, it can represent an attractive development alternative for the industrial sector. Here it is reported, the synthesis and microstructural characterization of thin films of a single layer or multilayer onto different substrates, the microstructural, optical and morphological properties are presented using X-ray diffraction, UV-Vis-Infrared spectrophotometry and field emission scanning electron microscopy. To complete the work, thermal emittance measurements at different temperatures were acquired from the materials obtained. As a complement, the Tauc method and variations of the Kubelka-Munk method were employed to estimate the band gap of each material. Finally, the influence of the metal oxides synthesized in single layer or multilayers, the thickness obtained from them, their morphological structure and the substrate composition in the spectral selectivity are discussed. The optical properties of the selective materials obtained in the present work clearly indicated the dependence of the thickness and the morphology generated. In general, optimal selectivity values were acquired in the materials obtained. Maximum solar absorptance of 92% and thermal emittance of 0.08 were determined.