Effects of substrate temperatures on the thermal stability of AlxOy/Pt/AlxOy multilayered selective solar absorber coatings

Abstract

a b s t r a c tWe report the effects of substrate temperatures on the thermal stability of Al x O y /Pt/Al x O y multilayered selective solar absorber coating (MSSAC). The samples were deposited at different substrate temperatures (from room temperature up to 250 C), and then annealed at various temperatures (300e600 C) in air for 2 h. Characterizations are made via X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), Atomic Force Microscopy (AFM), Raman Spectroscopy, UV eVis and emissometeric measurements. These coatings were found to be thermally stable up to 500 C with good spectral selectivity of 0.930/0.11. Furthermore, the observed decrease in the spectral selectivity 0.883/0.13 at 600 C is attributed to the diffusion of Cu and the formation of CuO phase. Such phase formation was confirmed using XRD and Raman spectral analysis. The insensitiveness of the thermal stability of such coatings on the substrate temperature is demonstrated.

Thermal Stability and Weather Resistance of a Bionic Lotus Multiscale Micro–Nanostructure TiC/TiN–Ni/Mo Spectral Selective Absorber Based on Laser Cladding-Induced Melt Foaming

“…The technology of generating electricity for thermal energy shows great application prospects. , Selective absorption coating is the core material of solar collectors. The coating needs to have a high absorptivity (α) in the solar spectral range of 0.3–2.5 μm, a low thermal emissivity (ε) in the infrared region of 2.5–25 μm, and excellent optical stability and corrosion resistance at high temperatures. − The types of solar absorption coatings include intrinsic absorption coatings, optical interference coatings, dielectric-metal composite coatings, and optical trap coatings. − Recently, the optical interference coatings with multilayer cermet structures, such as Co-WC-Al 2 O 3 , TiC-Al 2 O 3 , WNi-Al 2 O 3 , and WTi-Al 2 O 3 , have become the research focus because of excellent optical properties. − However, the atomic diffusion between the layers of the traditional multilayer solar absorption coating destroys the multilayer structure at high temperatures, resulting in a significant reduction in the light interference absorption efficiency, making it less stable at high temperatures . In addition, due to the weather environment such as rain and snow, the corrosion resistance is crucial for the long-term application of the coating, which directly affects the service life of the coating …”