Gradient silver nanoparticle layers in absorbing coatings--experimental study.

Metal island films show a characteristic absorption peak related to the surface plasmon resonance of free electrons. This kind of film can be used in absorbing coatings, together with dielectric layers. Such absorbing multilayer coatings, with and without the gradient of the silver mass thickness in metal island films throughout the coating, have been deposited by electron beam evaporation. It is shown experimentally that coatings with a gradient in the mass thickness of silver nanoparticles have higher absorption than equivalent nongradient coatings with the same total mass thickness of silver nanoparticles.