Preparation of Ag/SiO2 near-infrared absorbers using the combination of sputtering and spin-coating depositions

This study presents the design and fabrication of near-infrared (NIR) absorbers constructed in multilayer structures using Ag and SiO2 materials. The absorbers, consisting of Ag and SiO2 films, were fabricated using sputtering and spin-coating approaches, respectively. The fabricated absorbing devices were evaluated using ultraviolet-visible-NIR spectra. Results revealed that the structure of the Ag/SiO2/Ag films exhibited an NIR absorbing effect. The absorbing properties were substantially influenced by the fabrication parameters and the thickness of the multilayer films. Furthermore, the NIR absorbing performance improved significantly when the SiO2 layer was annealed at 300 °C before the deposition of the top Ag film. Additionally, the absorptance of the absorbers was affected by the thickness of the top Ag layer. The long-term stability of the multilayer absorber was tested and verified based on absorptance data analysis. The NIR absorbing performance can be further improved using the optimal device design of the film thickness and by fabricating additional Ag/SiO2 layers.