SOLAR SELECTIVE COATING HAVING HIGH THERMAL STABILITY AND A PROCESS FOR THE PREPARATION THEREOF

摘要

The present invention describes an improved multilayer solar selective coating useful for solar thermal power generation. Solar selective coating of present invention essentially consists of Ti/Chrome interlayer, two absorber layers (AlTiN and AlTiON) an anti-reflection layer (AlTiO). Coating deposition process uses Ti and Al as the source materials, which are abundantly available and easy to manufacture as sputtering targets for industrial applications. The present invention allows deposition of all the layers in a single sputtering chamber on flat and tubular substrates with high absorptance and low emittance, thus making the process simpler and cost effective. The process of the present invention can be up-scaled easily for deposition on longer tubes with good uniformity and reproducibility. The coating of the present invention also displays improved adhesion, UV stability, corrosion resistance and stability under extreme environments.

主权项

1. An improved solar selective coating having high thermal, stability comprising tandem stack of layers consisting of an interlayer of titanium (Ti)/Chrome followed by a first absorber layer comprising aluminum-titanium nitride (AlTiN), a second absorber layer comprising aluminum-titanium oxy-nitride (AlTiON) and a third antireflection layer comprising aluminum-titanium oxide (AlTiO), said second absorber layer being deposited on the first absorber layer and said third antireflection layer being deposited on the second absorber layer at substrate temperature in the range 100-350° C. using a four-cathode reactive pulsed direct current unbalanced magnetron sputtering technique.