Study on thermal stability of solar selective absorbing surfaces with new material

The DC reactive sputtering with aluminum alloy (LY13) in air and argon was taken, and the solar selective absorbing surfaces with the graded and multilayer structure were obtained. When the ratio of the flux of air and argon was above 0.14-0.16, the refractive index and extinction coefficient of the AlxOy-AINx coating are 1.65-1.88 and 0.002-0.005 respectively, The AlxOy-AlNx and AlN coatings used as antireflection coatings with proper thickness were deposited on the same absorbing coatings. After heating at 450°C for 30 minutes in 4.5 × 10-3 Pa vacuum, the AlxOy-AlNx coating has higher stability than the AlN coating. The AlxOy-AlNx antireflection coatings with a thickness of 60 nm and the AlxOy-AlNx-Al absorbing coatings with a thickness of about 250 nm were deposited on the boron-silicon glass and stainless steel respectively to get solar selective absorbing surfaces.