Metal nanolayer deposited highly stable Ag thin films and their optical properties

Abstract

We have reported that deposition of several-nm-thick Al surface layer on Ag thin films improved thermal stability remarkably. In the present study, we investigated the influence of the deposition of Al nanolayer on the reflectance of the Al/Ag multilayer. 100-nm-thick Ag film and 1–5-nm-thick Al surface layer were deposited successively by vacuum evaporation, and their optical properties were measured. The reflectance of the samples on which a 1- or 3-nm-thick Al layer was deposited on the Ag film was almost the same as that of the Ag single-layer film. However, the samples on which a 5-nm-thick Al layer was deposited on the Ag film showed decreased reflectance. It was considered that the deposited Al nanolayer was fully oxidized in the former samples, but metallic Al and oxidized Al coexisted in the latter sample, which coincided with the simulated reflectance data. As a result, we revealed that thermally stable Ag films formed by 1- or 3-nm-thick Al nanolayer deposition have also high optical reflectance.