Material and structural optimization of metal nanowire/AAO composites for high-temperature solar thermal application

In this paper, we study the solar selective absorbing properties of metal nanowire array (NWA) / anodic aluminum oxide (AAO) composites at 1000 K via numerical simulation. The materials and structural parameters which influence the wavelength absorption between 0.28 and 10 microns are simulated and optimized. The results reveal that W NWA / AAO composites with nanowire length of 7.3 microns, fill factor of 0.03, and AAO template thickness of 0.1 microns exhibits the best selective absorption. This composite has 0.90 solar absorptivity and 0.045 thermal emissivity in 1000 K, and shows a photothermal conversion efficiency of 71.5 %.