Colored selective absorber coating with excellent durability

Publication date: 1 December 2016
Source:Thin Solid Films, Volume 620
Author(s): Atasi Dan, Kamanio Chattopadhyay, Harish C. Barshilia, Bikramjit Basu
The colored solar-thermal collectors can provide advantages of architectural integration over energy performance. The colour appearance of the solar-thermal collectors can be achieved by increasing the number of layers. W/WAlN/WAlON/Al2O3 coating, fabricated by DC and RF magnetron sputtering showed a high solar absorptance of 0.948 and the low thermal emittance of 0.08 with a sky blue color appearance. The tandem absorber exhibited excellent long-term thermal stability at 500°C in air for 150h. The absorber deposited on SS substrates showed high solar selectivity (α/ε) of 0.918/0.11, even after heat treatment in air up to 500°C for 100h. The selective performance of the coating can be stable more than 25years. The humidity test confirms the significant moisture resistant of the coating. In summary, the new W/WAlN/WAlON/Al2O3 –based coating with its colourful appearance is appropriate to be used in solar thermal collectors.