Solar spectrum selective absorption coating and its manufacturing method

Abstract

A solar spectrum selective absorption coating is disclosed. The coating includes, from the substrate to the air interface: substrate 1, infrared reflective layer 2, semiconductor absorption layer 3 (Ge), and antireflection layer 4 formed by a higher refractive-index dielectric layer 41 and a lower refractive-index dielectric layer 42. The solar spectrum selective absorption coating has superior spectrum selectivity, with a steep transition zone between solar absorption and infrared reflection zones. It has a relatively high absorptance α in the solar spectrum range (0.3-2 μm), and a very low absorptance/emissivity ε in the infrared thermal radiation spectrum range (2-50 μm); its a/c ratio is significantly higher than current commercially available products, making it suitable for medium-temperature solar heat collectors using low-power optical concentration. The manufacturing process is simple and does not require complex deposition equipment, so it is suitable for low-cost large-scale production.

Dependencies are inferred from the claim text.