Enhanced thermal stability and spectral selectivity of SS/TiC-Y/Al2O3 spectrally selective solar absorber by thermal annealing

Exploring a high performance spectrally selective solar absorber is one of the great challenges in the development of Concentrating Solar Power (CSP). Herein, a porous structure of SS/TiC-Y/Al2O3 solar absorber is developed by a facile and scalable method combined with a simple vacuum annealing process. The tandem SS/TiC-Y/Al2O3 solar absorber exhibits a high absorptance of 0.90 and a low emittance of 0.11 after vacuum annealed at 800 °C for 5 h. Long term thermal annealing result indicates that the SS/TiC-Y/Al2O3 solar absorber coating has a good thermal stability at 800 °C in vacuum for 100 h. Due to the addition of rare earth yttrium (Y) and post-annealing, the porous structure is formed, which makes contribution to the spectral selectivity. Benefiting from these advantageous features, the post-annealed SS/TiC-Y/Al2O3 coating can be good candidate for the Concentrating Solar Power application.