Greatly enhanced solar absorption via high entropy ceramic AlCrTaTiZrN based solar selective absorber coatings

High entropy alloys (HEAs), which is at the expense of high cost compared to traditional alloy, should not be confined to the mechanical properties, but should be employed to devise a novel combination with unique functional and mechanical performances. In this work, high entropy alloy nitride (HEAN) is utilized as a novel double absorption layer to improve solar absorption in the high temperature solar selective absorbing coatings (SSACs). Our primary motivation is to lower thermal emittance (epsilon) and enhance solar absorptance (alpha). In order to realize this goal, coating design (CODE) software is employed to design and optimize the proposed HEAN based SSACs using appropriate dielectric function model. The ultimate as-deposited coating shows good optical properties with a high alpha value of 0.965 and a low epsilon value of 0.086 (at 82 degrees C). The estimate of thermal stability tests indicates that HEAN based SSACs has the ability to resist instability in high working temperature, which keeps good optical properties (alpha = 0.925, epsilon = 0.070) after annealing at 600 degrees C for 10 h. (C) 2020 The Chinese Ceramic Society. Production and hosting by Elsevier B.V.

Automated summary

This study utilized high entropy alloy nitride (HEAN) as a novel double absorption layer to improve solar absorption in high temperature solar selective absorbing coatings (SSACs). The as-deposited coating exhibited good optical properties with high solar absorptance and low thermal emittance. Thermal stability tests showed that HEAN-based SSACs have the ability to resist instability in high working temperatures.