Influence of seed layers on the reflectance of sputtered aluminum thin films

Abstract

The fabrication of highly reflective aluminum coatings is still an important part of current research due to their high intrinsic reflectivity in a broad spectral range. By using thin seed layers of Cu, CuOx, Cr, CrOx, Au, and Ag, the morphology of sputtered (unprotected) aluminum layers and, consequently, their reflectance can be influenced. In this long-term study, the reflectance behavior was measured continuously using spectrophotometry. Particular seed layer materials enhance the reflectance of aluminum coatings significantly and reduce their long-term degradation. Combining such seed layers with evaporation processes and suitable protective layers could further increase the reflectance of aluminum coatings.

In Situ Monitoring of Scale Effects on Phase Selection and Plasmonic Shifts during the Growth of AgCu Alloy Nanostructures for Anticounterfeiting Applications

“…The kinetics of the formation of single-component clusters on surfaces and their physical properties has extensively been investigated, both by theory and experiments. ,− Besides such single-component clusters, presently alloys or multicomponent-supported clusters receive increasing attention. Prominent supported cluster synthesis methods include chemical methods and vacuum deposition. − Hence, already much effort has been undertaken to synthesize such multicomponent and metallic clusters using different methods such as pyrolysis, sol–gel synthesis, templating, aggregation sources, , and sputter deposition. ,, The nucleation and growth of silver and copper clusters during magnetron sputtering was observed very successfully by X-ray scattering. , Applications of supported clusters range from heterogeneous catalysis and photocatalysis to information technology and solar cells as well as anticounterfeiting. − Here, nanoscale heterostructures and alloying allow for the facile tuning of chemical and optoelectronic properties. , Sputter deposition allows for alloying and high cluster density layers, enabling, for example, an organic shell-free cluster incorporated in layer-by-layer printing processes …”

Thermally stable metallic glass strain sensors with extended sensing range and sensitivity

“…After aging, a sharp decrease in the reflectance of the Al surface was observed, which suggests that the Al thin film underwent oxidation reactions with the GNPs, PVA, and PSS. 53,54 Conversely, the reflectance of AlY was not affected by the aging process, which should be due to the chemical inertness of the AlY thin film. The formation of insulating oxide layers at the interface between the metallic electrode and the graphene layer hinders the recovery of the conductive path as Fig.…”

Designing Optical Coatings with Incorporated Thin Metal Films

“…The effects of seed layers on the properties of the subsequently deposited metal films have been briefly addressed. Seed layers are of practical use for reducing the surface roughness of rather thick metal reflector coatings, and thus maximize their reflectance [45,46]. If the metal reflector film is sufficiently thick, no incident light will reach the seed layer, so that the optical constants of the seed layer are of no relevance for the measured reflectance.…”