Rugometric and Microtopographic Inspection of Cr–Cr2O3Cermet Solar Absorbers

The development of new efficient and cost effective solar energy collectors andconverters either quantum or thermal attracts great attention and effort in a number ofresearch laboratories all over the world. Cr–Cr2O3 cermet PVD coatings can be successfully employed in thermal converters. Their energy conversion efficiency depends on their chemical and physical structural characteristics and related optical properties like reflectance, emittance, solar light absorption, or absorptance and transmittance. Parameters such as roughness and topographic characteristics of the produced coatings will greatly influence their relevant optical properties. A careful evaluation of the coatings' roughness and their microtopographic inspection is fundamental. The Cr–Cr2O3 cermet coatings sputter deposited on cooper and aluminium shows similar absorption (92%) but the first ones present a better emittance and higher waviness (over 30%) with similar roughness. In comparison with commercially available solar panels with a slightly betterabsorption but worse emittance our coatings have a much lower waviness (∼150%) and roughly 50% higher roughness