Comparison of structure and solar-selective absorbance properties of Al2O3 thin films with Al and Ni reflector interlayers

Abstract This work aims at evaluating the selective solar absorbance (SSA) of Al 2 O 3 thin films deposited by physical vapor deposition (PVD) with two different metallic reflector interlayers. are on same substrate stainless steel (SS) 304L, interlayers between film and substrate, namely, nickel (Ni) aluminum (Al) used as interlayer SS304L/Al/Al SS304L/Ni/Al . A scanning electron microscope (SEM) was utilized to characterize chemical composition energy dispersive X-ray analysis (EDX) surface morphology films. The phases were analyzed identified diffraction (XRD) detect present phases. topography thickness investigated using an atomic force (AFM). optical properties (absorbance & emittance) in conditions Fourier transform infrared spectroscopy (FTIR) spectrophotometer. obtained results demonstrate that both show good performance, such high low thermal emittance. However, Al/Al provides selectivity (absorbance/emittance ( α/ε )) 0.916/0.05, compared 0.913/0.15 for Ni/Al coating. effect microstructure efficiency showed has higher (92%) visible ultraviolet (UV) regions; lower emittance (5%) than shows intermediate IR layer a more pronounced rather layer.