1
Colored selective absorber coating with excellent durability
Atasi Dan,
a,
Kamanio Chattopadhyay,
b,c
Harish C. Barshilia,
d
Bikramjit Basu
a,b
Abstract
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/Al
2
O
3
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 100 hrs. 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 100 hrs. The selective performance of the coating can be stable more than 25
years. The humidity test confirms the significant moisture resistant of the coating. In
summary, the new W/WAlN/WAlON/Al
2
O
3
–based coating with its colourful appearance is
appropriate to be used in solar thermal collectors.
Key words: Solar-thermal collectors, colored coatings, spectral selectivity, optical
properties, thermal stability
1. Introduction
© 2016. This manuscript version is made available under the Elsevier user license
http://www.elsevier.com/open-access/userlicense/1.0/