First principle calculation of thermal conversion properties of W-Al2O3 based solar selective absorbing coating

Al2O3 based solar selective absorbing coatings have been considered as a promising candidate for solar thermal conversions, but their properties are expected to be improved urgently. Herein, inspired by the composite materials design, an optimization method for optical performance and thermal stability of Al2O3 was explored by us, the W-Al2O3 based composite structures used for solar was developed, and its electronic structure and optical performance were investigated by the first-principles calculations. It was found that the band gap of the proposed composite structure can be successfully regulated and it decreases significantly with the increase of the mass fraction of W doped in Al2O3, which leads to the improvement of the thermal stability. The optical properties and solar thermal conversion properties of W-Al2O3 based selective absorption coating are accurately predicted. The results show that W-Al2O3 based solar selective absorption coating also has good absorption and reflection properties. The addition of W atom leads to the reduction of solar thermal efficiency. When the W mass fraction doped in W-Al2O3 is 23.92% at the temperature of 273 K, compared with pure Al2O3, the solar thermal conversion efficiency is reduced by 6.56%, and the corresponding absorption rate and thermal radiation was reduced by 6.54% and 1.99%, respectively.