Surface texturing of copper by sputter etching with applications for solar selective absorbing surfaces

Abstract

Solar selective absorbing surfaces have been produced by texturing copper specimens in a novel magnetron cosputtering system which allows high rate sputter etching of a moving metal plate seeded with low sputter rate material. Unusual topographical features have been produced on copper in this apparatus using titanium seed. The variation of optical properties and surface morphology of the copper as a function of sputter etching conditions has been studied. Typical selective surfaces produced have absorptances α∠0.90 and emittances ε∠0.10 at 300 K.