A highly thermally stable Mn-Cu-Fe composite oxide based solar selective absorber layer with low thermal loss at high temperature

A highly thermally stable Mn-Cu-Fe composite oxide based solar selective absorber layer for high temperature applications has been developed on a special variety of alloy substrate (SS-J4) using an economical process of controlled thermal oxidation. This novel type of composite oxide layer exhibits a high thermal stability and low emissive property even in an open air atmospheric condition. It is very contrary from previously known selective solar absorber coatings exhibited strong thermal stability along with low emissive property only in the vacuum environment. A solar absorptance of 91.5% (alpha(AM1.5); 300-2400 nm) and a spectral emittance of 0.14(3-25 mu m) have been achieved for an absorber layer developed by the best optimised conditions. An open air high temperature cyclic test of the optimised composite layer was also investigated at 500 degrees C and the stability of the coatings with respect to optical properties was established. Moreover, a constant value of thermal emissivity, 0.19 at 500 degrees C, was measured repeatedly by the thermal emittance measurement as well as a low value of performance criterion (PC), <0.01, was calculated after thermal cycle test, indicating a high thermal stability and long durability of the absorber layer. (C) 2015 Elsevier B.V. All rights reserved.