Patent ID: 9222703
Filing Date: 2015-12-29
Classification: B23K,F24S,F28F,Y02E

Abstract:
1. Composite material for use as a selective solar absorber, comprising a carrier layer consisting of aluminum, an aluminum alloy, copper or stainless steel, wherein at least the following layers are present on a side (B) of the carrier layer: a reflection layer consisting of a metal or a metal alloy with an integral reflection greater than 80% in the wavelength range between 2.5 μm and 50 μm, an absorber layer consisting of a substoichiometric metal compound of oxygen and/or nitrogen and/or carbon concerning the sum of the anions, wherein the metal is selected from among the metals of subgroup IV, chromium, a combination of a metal of subgroup IV with aluminum, or a combination of chromium with aluminum, wherein the aluminum is present in a percentage of at most 95 at. % relative to the total quantity of metal, wherein the absorber layer is located above reflection layer, a dielectric and/or oxidic antireflection layer with a stoichiometric or non-stoichiometric composition with a refractive index between 1.3 and 2.4, which is located above the absorber layer, characterized in that a layer consisting of a nitride, a carbide or a carbonitride of a metal or of a mixture of two or more metals from subgroup IV, V or VI is located between absorber layer and reflection layer, and an optically active layer consisting of a metal compound with stoichiometric composition is located between absorber layer and the dielectric antireflection layer.