Solar Energy, Vol.202, 115-122, 2020
Toward versatile applications via tuning transition wavelength of the WTa-SiO2 based spectrally selective absorber
Controlling solar spectra via the careful design could realize the optimized utilization of energy. Especially for spectrally selective solar absorbers, achieving the appropriate transition wavelength can boom conversion efficiency for a certain application under the consideration of cost. Here, we experimentally demonstrated a kind of WTa-SiO2 cermet based absorbers with transition wavelength of around 1500 nm, 2000 nm, and 2500 nm, which can meet the versatile applications under the conditions of different operating temperatures and different optical concentrations. All the absorbers possess a promising solar absorptance of above 95% and photothermal efficiency of above 91% at 82 degrees C with 1 sun, as well as the superior thermal stability at 600 degrees C due to the formation of tantalum oxide in WTa-SiO2 cermet in the annealing process.