A design of selective solar absorber for high temperature applications. (15th September 2018) - AL-Rjoub, A.
Highlights: Solar selective absorber design for high temperature applications. High stability and good oxidation resistance of the optical stack. Selective thermal absorber based on W/CrAlSiNx /CrAlSiOy Nx /SiAlOx . Abstract: This study presents a design of multilayer solar selective absorber for high temperature applications. The optical stack is composed of four layers deposited by magnetron sputtering on stainless steel substrates. The first is a back-reflector tungsten layer, which is followed by two absorption layers based on CrAlSiNx /CrAlSiOy Nx structure for phase interference. The final layer is an antireflection layer of SiAlOx . The design was theoretically modelled with SCOUT software using transmittance and reflectance curves of individual thin layers, which were deposited on glass substrates. The final design shows simultaneously high solar absorbance α = 95.2% and low emissivity ε = 9.8% (calculated for 400 °C) together with high thermal stability at 400 °C, in air, and 600 °C in vacuum for 650 h.